Kelly Oakes
is a freelance science writer and science communication student based in London. She writes a blog for Scientific American and news for BBC Focus magazine, amongst other things. She also edits the science pages of Felix, Imperial College's weekly student newspaper.
Biography- Writing
- Other projects
- Basic Space
- Twitter
- Felix Science
- Contact
-
Biography
- EMPLOYMENT & EXPERIENCE
- Freelance writer. See Writing
- Editorial intern, BBC Future (Jan 2012)
- Blogger, Basic Space at Scientific American (2011-present)
- Science Editor, Felix - weekly student newspaper of Imperial College (2010-present)
- Observing Assistant, Royal Observatory, Greenwich (2010-present)
AWARDS & RECOGNITION- Shortlisted for Wellcome Trust Science Writing Prize 2011, in association with the Guardian and the Observer
- Physics Prize (2011) and shortlisted (2010) for the Royal College of Science Union Science Challenge Essay Competition
- Several Basic Space blog posts chosen as Editor's selections at ResearchBlogging.org
EDUCATION- MSc Science Communication, Imperial College London (2011-2012)
- MSci Physics (2:1), Imperial College London (2007-2011)
Full CV available on request. Email kelly.oakes@me.com.
-
Writing
- Space weather: Cloudy, with a chance of solar flares – BBC Future, April 2012
- Stormy crossing (PDF, p15) - Imperial magazine, March 2012
- ABSW director heads EU of science journalism associations, EUSJA - ABSW, March 2012
- Stars that go out with a bang - Scientific American (Print), March 2012
- Tiger stripes and ice volcanoes – Wellcome Trust blog, January 2012
- Helping journalists track retractions: one year of Retraction Watch - ABSW, August 2011
- What not-so-habitable exoplanets can tell us about Earth's origin - Scientific American (Guest Blog), December 2010
As well as the above I write monthly news for BBC Focus magazine and regular posts at my blog, Basic Space, for Scientific American.
-
Other projects
- Edible CERNThe Large Hadron Collider explained using sweets. Made as part of a practical project during my MSc.A timeline following the faster-than-light neutrino story from the first result to now, and beyond... an ongoing project.A Punch and Judy show charting how the scientific method has been perceived, fought over and changed through the ages. Group project for my MSc.
-
Posts
- May 18, 12
Point a camera at a particular patch of sky for more than 50 hours and what do you get? This image of Centaurus A, a galaxy 12 million light years away:
Well, for “camera” read (after taking a deep breath) “Wide Field Imager of the MPG/ESO 2.2-metre telescope at the European Southern Observatory’s La Silla Observatory in Chile”. But don’t let that put you off. You can also make out the galaxy with a pair of binoculars – in the night sky you’ll find it in the southern constellation Centaurus.
If you fancy a closer look, and a bit more history, keep on scrolling.
Zooming in on the strange galaxy Centaurus A from ESO Observatory on Vimeo.
Centaurus A, also known as NGC 5128, is a massive peculiar galaxy hiding a supermassive black hole at its heart. (Peculiar is an actual classification, not just an adjective.) A couple of things make it different from a run-of-the-mill galaxy. One is the dark band across its centre. That dark bands is made up of a lot of gas, dust and young stars. Bands like this are typically found in spiral galaxies. This one, however, is warped, making it look patchy and suggesting something funny has gone on in the galaxy’s past.
But that’s not all. If you take a look at the mass of bright stars in the picture, they look a lot like an elliptical galaxy. So which is it?
The answer could well be both. Astronomers believe that Centaurus A is the remnant of a collision on an intergalactic scale. In 2004, the Spitzer telescope revealed that it Centaurus A started off as an elliptical galaxy. This elliptical galaxy happened across a spiral galaxy around 200 million years ago. The result is what you can see above. Once it began devouring the spiral galaxy, Centaurus A twisted the spiral into a parellelogram shape – this was the clue, found by Spitzer, that led astronomers to the their conclusions about the galaxy’s gruesome history.
Centaurus A is one of the most prominent radio galaxies in the sky, and harbours a black hole with a mass around 100 million times that of the Sun. The galactic feeding frenzy it undertook is thought to provide the fuel for the strong radio activity that surrounds that black hole. View Centaurus A through a radio telescope and it looks a little different to the image above: you can see two jets shooting out from its black hole. Those jets are made of high energy streams of matter in which the electrons have been stripped away from their atoms – a plasma, in other words.
If you look closely at the image above, you can see reddish filaments that roughly line up with the black hole’s jets. Those filaments are stellar nurseries full of young stars. You can see them a bit better in the video below.
Panning over a deep view at the strange galaxy Centaurus A from ESO Observatory on Vimeo.
For the biggest version of the image available, head over to ESO where you’ll find a zoomable one which is pretty spectacular.
- May 13, 12
Cosmic dust close to Orion's belt. Credit: ESO/APEX (MPIfR/ESO/OSO)/T. Stanke et al./Igor Chekalin/Digitized Sky Survey 2
I took a couple of weeks off blogging while I had my exams at the start of the month. This is what I missed.
ESA has approved a billion-euro mission to Jupiter’s icy moons, called Juice (Jupiter Icy Moons Explorer). The spacecraft will (hopefully) launch in 2022 and reach Jupiter eight years later in 2030. When it gets there it will first fly by Europa a couple of times before moving out to higher latitudes to look down on the poles and magnetic field of Jupiter, before slowing down to study the subsurface ocean and geology of Ganymede. The BBC has a nice round up of the announcement with a few of interviews, including one with Imperial’s own Michele Dougherty.
Also at the BBC, Jonathan Amos dons clean room gear to go and have a look at the Mid-Infrared Instrument (Miri) for the James Webb Space Telescope, before it gets shipped to NASA.
The origin of a type of stellar explosion known as a type 1a supernova (that has been catching my eye for a while now) has been cleared up a little, or muddied further, depending on which way you look at it. Apparently, both explanations that have been put forward to explain the impressive death of certain stars could be right. I might write a longer post about this, if I get the time.
NASA’s Dawn spacecraft revealed that asteroid Vesta is a survivor of the formation of planets in the early solar system, and plenty more to boot.
Kepler finds an invisible exoplanet. Or rather, researchers detected it based on its interactions with other planets, they didn’t “see” it directy. Also, check out the last author’s affiliation on the paper that announced the result.
A beautiful time lapse of Iceland and its midnight sun that just won the Grand Prize in the X Prize Foundation’s video contest “Why Do You Explore?”. And a beautiful picture of some cosmic dust.
Finally, a little self promotion: With some fellow masters students, I’m co-running a radio show on Imperial’s student radio station. I was there on Wednesday talking about the not-so-supermoon you might have seen the other weekend. You can listen to past episodes here or listen live every Wednesday from 12-1 London time. Check it out if you like science and/or people messing up on live radio!
Did anything else notable happen while I wasn’t looking?
- Apr 28, 12
The big story this week was the launch of Planetary Resources, an asteroid mining company backed by the likes of James Cameron, Larry Page and Eric Schmidt. You can watch the full webcast of the press conference on YouTube. Paul Raeburn at the Knight Science Journalism Tracker has a good round up of the coverage and points out how little scepticism there has been, saying “…there is nothing especially romantic about carving up asteroids to feed an unsustainable demand for metals and minerals.” I must admit, as cool as asteroid mining sounds, similar thoughts did cross my mind too. As if predicting doubters, Forbes stepped in to speak to the company’s President Chris Lewicki and tell us how the company is already making money.
Oh, and while we’re on the topic of asteroids: The only thing that can stop this asteroid is your liberal arts degree.
“In a knitted spacesuit and tight-fitting helmet, Camilla the rubber chicken floated to the edge of space in a modified lunchbox as the sun unleashed the most intense radiation storm since 2003.” Need I say more?
If you want to know more about the big dark matter news from last week, read this blog post.
Another blow to astrophysics, as cosmic rays are not doing what we’d like them to. (For more detail, see this article.)
NASA released an supercut of footage of Earth from space, complete with dramatic music.
Scientists want to send a boat to Titan: “It’s a boat, essentially. You’d have been locked up… if you’d suggested that before.”
If this is what astronauts get to do all day, I want to be one even more now.
Prototype space shuttle Enterprise was flown over New York on Friday morning. I couldn’t see it from here in London, obviously, but those at the Scientific American offices got a good view. Though not as good as this one…
Here at Basic Space, I shared stories of snowballs around Saturn and meteorites from Mars. And over at BBC Future, I have a feature up about space weather forecasting: Cloudy, with a chance of solar flares. (If you’re reading from the UK, you might prefer this link.)
I’m afraid that’s it from me. Does anyone who hasn’t been in revision-induced hiding have any important/interesting/cool space links? Share them in the comments.
- Apr 26, 12
Computer generated image of Mars at daybreak. Credit: NASA/JPL-Caltech
A glowing fireball descended through the sky over North Africa last July, accompanied by two sonic booms. Observers saw the fireball turn from yellow to green, then split into two parts before one fell to the ground in a valley and the other crashed into a mountain. And then… nothing, for a while.
The rocks that created the fireball had fallen in the desert near the Morocco-Algeria border, in a sparsely inhabited area. They had come from somewhere even more remote, but it took a while for anyone to realise their significance.
By the time Tony Irving, Affiliate Professor at the University of Washington, Seattle heard about the rocks they had been on the ground for several months. “It was probably around October that people who found stones brought them into the towns where there might be someone who would know what they were,” said Irving. Once the rocks were brought in from the desert, people began to connect them to the fireball and piece together what had happened.
By November word got out to the more experienced meteorite dealers in Morocco. One of them sent a sample of the rock to Irving. He analysed it and found that it had come from Mars. “We confirmed it pretty easily,” he said.
Irving and his colleagues kept the discovery quiet for a while. “We did most of our work sort of in secret in a way, talking only to a few colleagues,” he said.
In January this year the meteorite was officially certified as Martian and named Tissint, after a village close to its landing site, by an international meteoritics committee.
Despite the seemingly slow start, Tissint is an impressive discovery. Most Martian meteorites are not seeing falling through the sky, making it almost impossible to know how long they have been lying on the ground before they are discovered. Tissint is only the fifth Martian meteorite in history that people saw fall, and the first in nearly 50 years.
In total, over 12kg of Tissint has been found. It joins sixty other Martian rocks that now reside on Earth.
Tissint was probably ejected from Mars when an asteroid struck the planet, sending rocks from around the impact site hurtling into space. It stayed in space as debris for many years, before being picked up by Earth’s gravity and sent hurtling towards our planet’s surface.
Being able to say for sure that Tissint and the other meteorites came from Mars required some help from the Viking spacecraft, which touched down on the red planet in 1976. Viking measured the proportion of different gases in the Martian atmosphere. When a suspected Martian meteorite was found in 1979, scientists analysed the composition of bubbles of gas trapped within glass veins in the rock. They found that the gas in the bubbles was in the exact same proportions as Viking had measured on the planet itself. Little pockets of Martian atmosphere had travelled across the solar system, trapped inside the rock, and ended up in a lab here on Earth. It was the crucial piece of evidence needed to confirm the rock’s origin.
Not all of the meteorites from Mars have these bubbles of Martian atmosphere trapped inside them. Some fulfil other criteria, such as containing particular minerals. But if the atmospheric link had never been found, it would have been difficult to conclusively say that any of the rocks had come from Mars.
Tissint has plenty of glass pockets, formed when it underwent shock as it was ejected from Mars. No bubbles of gas from the meteorite have been analysed yet, but Irving doesn’t doubt that a match will be found once they are.
For scientists working on Tissint, the next step will be to find out how old it is. Preliminary results show that Tissint was ejected from Mars 1.1 million years ago. This links it to some other Martian meteorites that have been found on Earth, adding weight to the view that the sixty or so Martian rocks we have do not come from sixty different places on Mars. “It’s probably more like seven or eight places that have ejected groups of rock that land randomly [on Earth],” says Irving.
But for now, and until we send a sample return mission to the planet itself, Tissint and the other Martian meteorites are the only rocks we can use to piece together a picture of the red planet. “These are the only samples of rock from Mars that we have, and there are only sixty or so of them,” says Irving. “We need to put the whole forensic puzzle together as best we can.”
- Apr 24, 12
Six images of the mini-jets taken by Cassini between 2005 and 2008. Credit: NASA/JPL-Caltech/SSI/QMUL
Objects half a mile in diameter have been spotted punching through Saturn’s outermost ring, the F ring, and leaving glittering trails as they drag icy particles behind them. Scientists are calling these trails mini-jets.
The scientists were actually looking at Prometheus, one of Saturn’s small moons, when they saw the first of the trails. They went back to look for more and, after combing through all 20,000 of the seven years’ worth of Cassini images, found around 500 of them.
Prometheus is no stranger to disrupting the F ring. It creates channels and ripples in the ring, and the snowballs themselves too. But scientists didn’t know what happened to the snowballs after they were created. These images show that some of them survive and go on to push through the F ring on their own.
“These little guys are the missing link,” says Carl Murray, a Cassini imaging team member based at Queen Mary, University of London, who narrates a video explaining the finding. If you are interested in how Cassini scientists study images of Saturn and the F ring, watch the video right until the end.
- Apr 21, 12
If I lived elsewhere in the multiverse, this is the news and cool space stuff I’d have been covering this week. Unfortunately, in this universe I didn’t have the time.
Last weekend, Cassini dipped down close to Enceladus to “taste” the jets that erupt from its surface. For some background on Enceladus, see my entry for the Wellcome Trust Science Writing Prize 2011. (For any budding science writers out there, the prize is running again this year – but it closes on Wednesday, so be quick!).
Some of the pictures Cassini took were released just one day after they reached Earth.
While we were all fawning over the new Cassini pictures, a huge solar flare was erupting from the surface of the sun. Luckily, it wasn’t directed at us.
Back on Earth, space shuttle Discovery left the Kennedy Space Center and made its way to the Smithsonian’s National Air and Space Museum. From APOD:
Discovery retires as NASA’s most traveled shuttle orbiter, covering more than 148 million miles in 39 missions that included the delivery of the Hubble Space Telescope to orbit. Operational from 1984 through 2011, Discovery spent a total of one year in space.
Want to know more about how a space shuttle travels around on Earth? Check out this video at NASA. And at Bad Astronomy, Phil Plait shared his mixed emotions about the shuttle.
Astronomy Picture of the Day “might need funding help” and is asking for advice on its forum.
Hubble turns twenty-two soon, and this gorgeous image was released for its anniversary. And here’s a different view of the same star forming region. Happy Birthday Hubble!
If you only ever watch one time lapse video of the northern lights, make it this one by Ole C Salomonsen. For more time lapse goodness have a look at Earth as seen from the International Space Station.
The Atlantic have an interview with Alberto Conti, Innovation Scientist for the James Webb Space Telescope and ex-Archive Scientist at the Space Telescope Science Institute, about how data changes the way astronomy is done.
If those Cassini images from the recent fly-by aren’t enough for you, check out this video by Sander van der Berg compiled using footage from NASA’s Cassini and Voyager missions. Even if you think you’ve already had your fill of beautiful space pictures for this week, still watch it. Trust me.
While we’re on the topic of out-of-this-world images, Matthew Francis has a thoughtful post that asks “Are Astronomical Images All Faked?” In keeping with Daily Mail tradition of posing questions-to-which-the-answer-is-no in headlines, he doesn’t think they are.
A new space company, backed by a host of important people has announced that it’s launching on Tuesday and will “create a new industry and a new definition of ‘natural resources’.” Sounds like asteroid mining, says Christopher Mims.
And last but by no means least, it looks like there isn’t any dark matter around the solar system. It’s a puzzling result that is not compatible with how we think about dark matter now, but not everyone is convinced by the conclusions of the paper yet. Stay tuned on that one.
That’s all I’ve got for this week. Is there anything you think I missed? Feel free to add it in the comments.
- Apr 17, 12
Two thousand comets a day collide around nearby star Fomalhaut creating a continually replenished dust belt in the outskirts of the star’s system, according to a new paper recently published in the journal Astronomy & Astrophysics.
Fomalhaut and its dusty disk, as seen by Herschel. Credit: ESA/Herschel/PACS/Bram Acke, KU Leuven, Belgium
Fomalhaut is a young star. It is twice as massive as the sun and sits 25 light years away from us. In the 1980s, astronomers discovered that it was surrounded by large amounts of dust. The Herschel Space Observatory has now produced the best ever far-infrared images of the star system and given a team of astronomers lead by Bram Acke at the University of Leuven in Belgium chance to take a fresh look at the system.
Most intriguing is a narrow belt of dust and debris in the outer edges of the Fomalhaut system, that is a bit like the solar system’s own Kuiper belt. Fomalhaut’s belt is 140 times further from the star than the Earth is from the sun. The dust particles that fill it have temperatures between -170C and -230C.
In our solar system, the Kuiper belt includes Pluto and two other dwarf planets but mostly consists of smaller icy objects left over from the formation of the solar system. Belts like this tend to exist in planetary systems at locations where, for one reason or another, no planets formed. Fomalhaut’s belt is much younger than the Kuiper belt, though. And it is more active too. The Fomalhaut system resembles our solar system in its most active phase, says Acke.
Fomalhaut system as seen by Hubble's High Resolution Camera (HRC) of the Advanced Camera for Surveys (ACS) in 2008. Credit: NASA, ESA and P. Kalas (University of California, Berkeley, USA)
The belt is off-centre with respect to its star, hinting at one or more planets close by interacting with it via gravity. The narrowness of the belt, confirmed by the new Herschel observations, also points to planets nearby that keep the dust and debris in place and stopping it spreading out.
But that’s not the most interesting thing about Fomalhaut. Neither is the existence of a dusty disk around the star – they are probably as common as planets (which are very common indeed). “What makes Fomalhaut special is the presence of large amounts of very small dust,” says Acke.
Dust in Fomalhaut’s narrow belt absorbs light as if it were made of tiny particles, micrometers across, according to the new Herschel observations of the dust grains’ “glow”. But previous Hubble observations saw the dust belt reflect light as if it were made of much larger grains.
To resolve this, Acke and his colleagues suggest that the grains that fill Fomalhaut’s belt are “fluffy”. That is, they are small, as Herschel shows, but clump together loosely and reflect light as if they were bigger.
A fluffy dust particle from our own solar system, formed by a cometary collision. Credit: NASA
But there was another problem: small grains like those in Fomalhaut’s belt should get blown out of the system by strong winds from the star. Larger grains have enough gravitational staying power to resist getting blown away, but smaller ones do not. That there are still small grains in the belt suggests that they are being constantly replenished somehow.
The “fluffy” nature of the particles pointed to comets as the source of the dust, says Acke. So, along with his colleagues, he calculated how many comets would need to be destroyed to keep the belt full of tiny dust particles. “From the amount of small particles, we deduced that 2000 [1km-sized] comets are reduced to dust each day,” he says.
- Apr 03, 12
Artists illustration (left) of the inner layers of Cassiopeia A's predecessor star, just before it exploded. Chandra image (right) of the Cassiopeia A supernova remnant today. Iron is shown in blue, other elements are sulphur (green) and magnesium (red). Credit: NASA/CXC/M.Weiss; X-ray: NASA/CXC/GSFC/U.Hwang & J.Laming
Astronomers have taken a fresh look at an old supernova and found that it was turned inside out during its explosion. Iron, which forms during the stars death, is usually in the centre of the supernova remnant. But in Cassiopeia A they found it on the outside instead.
This analysis has also shed some light on a phenomenon called ‘neutron star kick’, in which the neutron star formed in a supernova recoils during the explosion.
Cassiopeia A (or Cas A for short) is the result of a core-collapse supernova, a type of stellar explosion that only really massive stars go through. It is located about 11 thousand light years from Earth and exploded 330 years ago, making it the second youngest supernova remnant in our galaxy.
Stars run on hydrogen. When they have used it up, something has to give. The star’s core begins to collapse, heating up as it goes. This increase in temperature means that the star can start to fuse helium instead. All main sequence stars (like our sun) will eventually reach this ‘red giant’ stage.
But what happens next depends on how big they are. Really massive stars, over eight times the mass of the sun, begin to fuse heavier elements. They burn their way through carbon, oxygen, neon and silicon, the core collapsing more each time and outer layers cooling and expanding. Eventually, a core of iron is left. Fusing iron uses up more energy than it makes, so fusion stops.
Now there is no outward pressure from the fusion, gravity takes over and the star collapses. In about a second, the core of the star collapses down from something roughly Earth-sized to a neutron star (about 15km across) or a black hole (theoretically, 0km across). The subatomic particles that made up the core are crushed together. Protons and electrons turn into neutrons and neutrinos.
These neutrinos rush outwards, pushing infalling layers of the star back out into space. This neutrino ‘bounce’ gives the infalling layers, now a shock front moving outwards, enough energy to fuse even heavier elements. Gold, silver, platinum, and even uranium, form in supernovae.
The neutrinos that formed during the star’s collapse reach the Earth before we see any light – they get a head start while the shock is still battling through the outer layers of the dying star. Light is emitted as a result of expanding shock wave crashing into gas and dust on its way out of the supernova. By studying this light, astronomers can identify elements present in the supernova remnant.
Cas A, at somewhere between 15 and 25 times the mass of the sun before it exploded, followed this path. But something strange happened.
The iron that formed during its death was ejected out from the centre of the supernova remnant, according to a new paper by Una Hwang and J Martin Laming, of the Goddard Space Flight Centre, Maryland, and the Naval Research Laboratory, Washington, respectively, published in the The Astrophysical Journal.
Hwang and Laming studied X-ray data from Cas A collected by NASA’s Chandra X-ray Observatory. They looked at how various elements were distributed across the supernova remnant. All of the iron they saw was well outside the central region of the remnant. “It is surprising that we see basically all the iron that we expected, but it is on the outside, with apparently nothing in the centre,” said Laming.
We are seeing Cas A 330 years after it exploded. Normally, we wouldn’t be able to see the inner ejecta – the bits of the exploded star – so early on in the remnant’s evolution. But thanks to a companion star that ‘stole’ some of its material, the remnant’s predecessor lost a lot of mass. This means that we can have a look inside Cas A a lot earlier than we otherwise would have been able to.
“[The mass loss] allows the shocks that light up the ejecta in X-rays to have made it nearly entirely through the star in just over 300 years, so that much of the ejecta can be observed,” said Hwang. “Even though Cas A is actually the second youngest supernova remnant in our galaxy, it’s virtually the only core-collapse supernova remnant that shows significant emission from iron ejecta.”
This stroke of luck meant that Hwang and Laming could investigate another phenomenon associated with core collapse supernovae: neutron star kick.
It has long been known that neutron stars, left behind after supernovae explode, recoil from the centre of the explosion. This is called the neutron star kick. Hwang and Laming think that this kick is generated by instabilities in the core of the supernova. If momentum is conserved (and it should be if the neutron star kick comes about this way) then the ejecta would move in the opposite direction to the neutron star – and that’s exactly what they saw with Cas A. The ejecta, as a whole, moved in the opposite direction to the neutron star. But they didn’t see the iron moving in the opposite direction, which they would have expected, too.
But this analysis is only the first attempt at a detailed, comprehensive view of Cas A’s X-ray emitting ejecta. Hopefully it will not be the last. “Believe it or not, these data can probably support at least a 4 times more detailed study, but it takes a lot of man and computer power,” said Hwang. “We hope that some theorists who are working on simulations of core-collapse explosions will take notice and realize that there are data out there that can begin to test their theories.”
NuSTAR, the first high energy X-ray observatory, is due to launch later this year. It should be able to provide better data with which astronomers can investigate how Cas A came to be and how its neutron star came to be kicked.
In particular, it will help pin down the location of titanium-44 in the supernova remnant. This radioactive nucleus is produced in the same process that makes pure iron, so should get distributed in the same way that the iron does. Laming says that hints from the current data suggest that it is not located with the iron on the outskirts of the remnant, but is in fact in the centre. But, he cautioned, that data is noisy and inconclusive. NuSTAR will be able to image the titanium-44 and hopefully provide more definitive answers.
“If it turned out to be true, it would be a major surprise,” said Laming.
Titanium-44 in the centre of the remnant could say something about the presence of ‘invisible’ (that is, unshocked) iron that might also exist in the centre, or it could give clues about the details of the explosion or the nature of the neutron star, said Hwang.
Reference
Una Hwang, & J. Martin Laming (2011). A Chandra X-ray Survey of Ejecta in the Cassiopeia A Supernova Remnant ApJ arXiv: 1111.7316v1
- Mar 29, 12
To say a picture is worth a thousand words would be selling this one rather short.
Full image containing (at least) a billion stars. Click for a bigger version, see text for the really big version, or scroll down for zoomed in view. Credit: Mike Read (WFAU), UKIDSS/GPS and VVV
This edge-on image of the Milky Way contains at least a billion stars. The full version is available here. But be warned: it’s 39,300 by 3,750 pixels. My laptop was not at all happy when I tried to download it, and your machine may feel similarly.
The truth is that no computer screen could ever really do it justice. But here we go anyway…
A zoomed in version of the full picture, looking at a star forming region. Click for a bigger version. Credit: Mike Read (WFAU), UKIDSS/GPS and VVV
The above picture, zoomed in even more on the star forming region. There are still over ten thousand stars in this picture. Click for a bigger version. Credit: Mike Read (WFAU), UKIDSS/GPS and VVV
Scientists made the image by combining infrared images from two sky surveys done by the UK Infrared Telescope in Hawaii and ESO’s VISTA in Chile. By looking at infrared light, scientist are able to cut through much of the dust in the Milky Way that would otherwise obscure light coming from the centre of the galaxy.
After collection, the data was processed and archived by teams at the universities of Edinburgh and Cambridge in the UK. It is now available to researchers around the world who want to have a go at analysing it.
“Having data processed, archived and published by dedicated teams leaves other scientists free to concentrate on using the data and is a very cost-effective way to do astronomy,” said Nick Cross from the University of Edinburgh, in a press release for the picture.
The project is called the VISTA Data Flow System and is funded by the Science and Technology Facilities Council. It aims to make use of the vast amount of data the telescope is capable of recording – up to 1.4 TB per night for 10 years. The idea is that the data will be stored in an archive that is “more than a simple repository of data.” Scientists should be able to mine this archive for discoveries in years to come.
This one should keep them busy for a while.
- Mar 19, 12
"Do you think the missing 60ns got lost down there?" Credit: ICARUS
It looks like the faster-than-light neutrino saga – or should that now be slower-than-light or the-same-speed-as-light? – may nearly be over. On Friday, CERN updated their statement on the initial OPERA result with some new results from ICARUS, another experiment at the Gran Sasso laboratory in Italy.
Here are the important bits of the statement:
The ICARUS measurement, using last year’s short pulsed beam from CERN, indicates that the neutrinos do not exceed the speed of light on their journey between the two laboratories.
[...]
The ICARUS experiment has independent timing from OPERA and measured seven neutrinos in the beam from CERN last year. These all arrived in a time consistent with the speed of light.The ICARUS experiment has also uploaded a paper to arXiv.org, if you want more detail on how they conducted the experiment. (Or if you like your sentences oddly worded, like this: “The result is compatible with the simultaneous arrival of all events with equal speed, the one of light.”)
So, that’s that. Or is it?
In the updated statement, CERN Research Director Sergio Bertolucci stresses the importance of rigour in scientific experiments. Bertolucci says:
The Gran Sasso experiments, BOREXINO, ICARUS, LVD and OPERA will be making new measurements with pulsed beams from CERN in May to give us the final verdict. In addition, cross-checks are underway at Gran Sasso to compare the timings of cosmic ray particles between the two experiments, OPERA and LVD.
The more measurements we have, the more sure we can be of the result. But the evidence is starting to suggest that the initial OPERA result was wrong.
Bertolucci goes on to say:
Whatever the result, the OPERA experiment has behaved with perfect scientific integrity in opening their measurement to broad scrutiny, and inviting independent measurements. This is how science works.
[Emphasis mine.]
A commenter on this blog has said that the whole faster-than-light neutrino saga (as I’m quite enjoying calling it) is a “failure of communication rather than physics.” But I don’t think it is necessarily a failure of anything.
As many people have pointed out, OPERA behaved exactly as they should have done. There was no way they could have sat on the result until they had checked it further. It would have leaked eventually, and them keeping quiet wouldn’t have helped speculation or science. More, independent measurements are always good. Openness, in theory, is always good.
When they announced their result, they did so in the best possible way. In a statement the collaboration said:
Given the potential far-reaching consequences of such a result, independent measurements are needed before the effect can either be refuted or firmly established.
Once the result was announced, there was no way the media could have not reported on it. If it was true, it would have changed physics forever.The general tone of articles about the initial result suggested that most news outlets were sceptical of the result. In a good way. It was more “Oh look, some physicists might have proved Einstein wrong, weird huh?” than “OH MY GOD RUN FOR THE HILLS CAUSALITY IS NO MORE!”.
Ok, the whole “dodgy wiring” update was too good not to poke a little fun at. But it was harmless. I don’t think anyone who commented on it sounding a little silly was suggesting that the scientists had been stupid to make that mistake. I certainly was not suggesting that.
In a way, to put the result down to an experimental error as mundane as dodgy wiring is rather comforting. It reminds us that science is done by scientists who are human too, and fallible just like everyone else. (Except their mistakes almost accidentally bring down Einstein’s theory of relativity, rather than resulting in a broken hairdryer.)
In fact I’m inclined to think that the faster-than-light neutrino saga has been rather good for the relationship between science and the rest of us. Or, at least, it has the potential to be good. Perhaps now we can stop pretending that science is this big impersonal entity that moves along in increments the exact size of a scientific paper. Perhaps we can realise that science and scientists can make mistakes, but that’s ok.
If the story of the faster-than-light neutrinos is a failure of anything, it’s the way we think about science. Sergio Bertolucci was right when he said “this is how science works.” We just need to get used to it.
- Mar 08, 12
Today is International Women’s Day. To celebrate, here’s a post showcasing just a couple of the many really amazing discoveries made by women in astronomy.
*
Annie Maunder was born in Ireland in 1868. She won a scholarship to go to Cambridge, where she studied mathematics. She was top in her year, but did not receive a BA – they were only awarded to men at the time.
After her degree she began work as a ‘computer’ at the Royal Observatory, Greenwich. This was low paid, menial work. Luckily for Annie, she became assistant to Edward Walter Maunder, who was in charge to the Photographic and Spectroscopic Department at the Observatory. They collaborated in tracking sunspots – dark spots on the sun created by intense magnetic activity – and eventually married.
Annie resigned her post at the Observatory but carried on working with her husband. Together, they showed that there was a connection between the number of sunspots on the sun and the Earth’s climate. The Maunder minimum, an extended period of time during which there was an unusually low number of sunspots, is named after the two of them.
Above is modern version of the butterfly diagram published by Edward Maunder and based on work done with his wife, Annie. The diagram shows that sunspot location varies over the sun’s 11 year cycle. And it looks a bit like a line of butterflies – hence the name.
For more about the butterfly diagram and sunspot cycles, head over to NASA.
*
Caroline Herschel was the first woman to discover a comet – and went on to find eight in total. Though she is best known for her comets, she also discovered several deep-sky objects, including the Sculptor Galaxy.
Caroline was born in 1750 in Hanover, Germany. From the age of 22 she lived with her brother, William, in England. After discovering Uranus, William became an astronomer to the Royal Family, and Caroline his assistant. King George III granted Caroline a £50 salary for her work, making her the first woman to earn a living from astronomy.
The Sculptor Galaxy. Credit: ESO/J. Emerson/VISTA.
Caroline discovered the Sculptor Galaxy, or NGC 253, in 1783. It lies about 13 million light years from Earth and is undergoing a huge burst of star formation. It’s a dusty galaxy – only when looking at it in infrared can we see the true extent of the intense star formation within. This image, taken by the European Southern Observatory’s VISTA telescope reveals the galaxy’s spiral arms and bright core.
Caroline also independently discovered Messier 110, a satellite of the Andromeda Galaxy.
*
Today, of course, there are many more women working in astronomy. The barriers to entry are not the same as they were in Caroline Herschel’s or Annie Maunder’s days. But we’ve still got a long way to go before there are equal numbers of men and women working in science, engineering and technology. (According to the UKRC, for example, women make up only 15.5% of SET professionals in the UK.)
To find out more about International Women’s Day see the website or search for #womensday on twitter.
- Feb 29, 12
Artist's impression of a galaxy that is releasing material via two particle jets (red/orange) as well as via ultra-fast outflows (grey/blue), both powered by a black hole. Credit: ESA/AOES Medialab
Something unusual has been spotted lurking around several galaxies’ central black holes. Astronomers think it may be limiting the growth of the black holes – and stars elsewhere in the galaxies, too.
Astronomers studying nearby galaxies have found a new type of outflow called an ultra-fast outflow, or UFO. An international team of astronomers led by Francesco Tombesi from the University of Maryland and NASA’s Goddard Space Flight Centre in Maryland, US, carried out the work. They published their findings in Monthly Notices of the Royal Astronomical Society yesterday.
Astronomers have known for years that the more massive the black hole lying at the centre of a galaxy, the more stars they could expect to find in that galaxy’s ‘bulge’ – a large, roughly spherical region packed with stars.
But they thought it was a little odd that the two were linked. A black hole – though often portrayed as an all-consuming cosmic vacuum cleaner – only really affects the space close to it and on the whole has little impact on the galaxy in which it resides.
Black holes are surrounded by a million degree X-ray emitting disk of gas. This gas is sucked into the black hole and powers it. Some of the disk material, however, escapes and is redirected outwards as a jet of energetic particles.
These jets do not explain the link between black holes and bulges, though. So astronomers went looking for a new kind of black hole outflow that was somewhere between these particle jets, which travel at half the speed of light, and known outflows that travel much slower.
Now, Francesco Tombesi and his colleagues have found that new type of outflow. It is called “ultra-fast” because it is faster than already-known outflows, but slower than jets. UFOs could explain the link between black hole and bulge size. They contain more mass and have a wider opening angle than jets do, so should interact more with the stuff between stars in the galaxy.
Tombesi’s team surveyed 42 nearby galaxies that were known to host black holes using ESA’s XMM-Newton X-ray Observatory.
In 40% of galaxies they looked at, Tombesi and his team saw that there must be a cloud of material in between Earth and the black holes. These clouds were changing the properties of the X-rays coming from the black holes’ disks. The team worked out that the clouds of material must be between 0.001 and 0.1 light years away from the black hole. In astronomical terms, that is extremely close.
Tombesi’s team has previously published two papers showing that the clouds they saw were a new kind of outflow. The paper published yesterday helps to hone in on the properties of UFOs.
Because of their proximity to the black hole, UFOs get exposed to a vast amount of radiation. This means the particles they are made of have their electrons stripped from their atoms in a process known as ionisation, leaving the UFOs consisting of highly ionised plasma.
UFOs take material from around the black hole, around one solar mass per year, and eject it at speeds of up to 100,000 kilometres per second. That mass could have otherwise fallen into the black hole, or been used in star formation in the galaxy’s bulge. By removing this matter from the centre of the galaxy the UFOs stunt both the growth of the black hole and the growth of stars in the bulge.
Tombesi and his team have one more paper is in the works. It will compare UFOs with a slower outflow known as a warm absorber that they believe has a different origin. After that, they will have to wait until the launch of the Astro-H X-ray telescope, scheduled for 2014, to get a better picture of how the UFOs affect their black hole’s galaxy.
Reference
Tombesi, F., Cappi, M., Reeves, J., & Braito, V. (2012). Evidence for ultrafast outflows in radio-quiet AGNs – III. Location and energetics Monthly Notices of the Royal Astronomical Society: Letters DOI: 10.1111/j.1745-3933.2012.01221.x
- Feb 22, 12
The detector at the Gran Sasso end of the OPERA experiment. Credit: OPERA
The faster-than-light neutrinos seen by the OPERA particle physics experiment last year may have just been explained. By a loose cable. I wish I was joking.
To back up a little, the OPERA collaboration based at the Gran Sasso laboratory underneath the mountain of the same name in Italy published a paper to pre-print server arxiv.org last September saying that they had seen neutrinos, a type of sub-atomic particle, travel faster than the speed of light. They recorded neutrinos, which had travelled from CERN, Geneva, through the Earth to Gran Sasso, Italy, arriving at the laboratory 60 nanoseconds earlier than they would had they travelled at the speed of light.
Since then, scientists around the world have been collectively scratching their heads and publishing papers that tended to fall into one of two categories: suggesting an error with the experiment (such as the clocks at the two laboratories not being synchronised properly), or suggesting an addition to the current theory of particle interactions that could explain the strange result (for example, a new dimension that the neutrinos could have skipped through to make their journey shorter – so they would have never actually travelled faster than light at any point).
But I don’t think anyone expected it to be something as simple as this.
Today, Science is reporting that a fibre optic cable connecting a GPS receiver and an electronic card in a computer was loose. They go on:
After tightening the connection and then measuring the time it takes data to travel the length of the fibre, researchers found that the data arrive 60 nanoseconds earlier than assumed
This news (though still unconfirmed) rather casts a shadow over another recent explanation, involving something slightly less ridiculous.
In a paper published in journal Astronomy & Astrophysics, Claudio Germana of the Astronomical Observatory of Padova, Italy, suggests that there was a problem with the synchronisation of clocks at the two ends of the experiment. His calculations suggest that if the experiment had been run at a different time of year, the neutrinos would in fact have arrived 50 nanoseconds later than light.
I spoke to Carlo Contaldi, a physicist at Imperial College London, who last year published a paper on arxiv.org pointing out a possible problem with clock synchronisation, about the new paper. Though he thought the calculations and the large effect the calculations seemed to show were “interesting”, he had some reservations:
[Germana] does not seem to mention the latest measurements that were carried out by OPERA in November 2012. Those showed a consistent value for the neutrino’s time of flight as the previous results and it would be interesting to see how that time frame fits in with these corrections.
It’s an interesting hypothesis though – and one that is easily testable by running the experiment at a different time of year.
This paper is just the latest in a long string of attempts to explain the faster-than-light neutrinos. For more of the explanations that have been offered over the last few months, have a look at a timeline I made that follows the story right from the beginning until now.
.
All of these papers could have been for nothing, of course, if the new report of a loose cable is true. It would be a little disappointing if this turns out to be the case. I’m going to reserve judgement for now, at least until the “sources familiar with the experiment” become something a little more concrete.
I’ll be updating the above timeline as the story unfolds.
UPDATE: The Nature News Blog now has an official statement from OPERA, that says they have “identified two issues that could significantly affect the reported result” – you can read the full statement over there.
UPDATE 23rd Feb: The OPERA experiment has issued an official statement. Here it is in full:
The OPERA collaboration has informed its funding agencies and host laboratories that it has identified two possible effects that could have an influence on its neutrino timing measurement. These both require further tests with a short pulsed beam. If confirmed, one would increase the size of the measured effect, the other would diminish it. The first possible effect concerns an oscillator used to provide the time stamps for GPS synchronizations. It could have led to an overestimate of the neutrino’s time of flight. The second concerns the optical fibre connector that brings the external GPS signal to the OPERA master clock, which may not have been functioning correctly when the measurements were taken. If this is the case, it could have led to an underestimate of the time of flight of the neutrinos. The potential extent of these two effects is being studied by the OPERA collaboration. New measurements with short pulsed beams are scheduled for May.
So, there was a (possible) faulty cable that might have led to an underestimate of the time it took the neutrinos to reach Gran Sasso, which would led to an overestimate of their speed. But there was also another fault that might have led to an underestimate of the speed. Looks like we will have to wait for the new measurements in May to see just how much each of these faults contributed to the early arrival of the neutrinos and whether they can add up to the 60 nanoseconds to fully explain the result.
- Feb 17, 12
Judging by the many flares erupting from the sun at the moment, it is well on track to reach its next peak in activity early next year. As this peak approaches, we can expect many more huge bursts of energy that erupt from the sun and send lots of energetic particles, and sometimes magnetic fields, our way. These in turn will lead to more of the fantastic light displays, which you might have seen (or at least heard about) lately, creeping down from the North Pole towards the equator.
Aurora as seen from the International Space Station as it crossed over the southern Indian Ocean on September 17, 2011. Credit: NASA
These light shows are the visible sign that a geomagnetic storm is raging overhead. But there’s another phenomenon that happens alongside the northern lights that you won’t have noticed at all. Surrounding our planet, way up above the atmosphere, is a doughnut shaped ring of charged particles held in place by Earth’s magnetic field. In fact, there are two of them. They’re called the inner and outer Van Allen belts.
The Van Allen belts were found in 1958 and were the first major scientific discovery of the space age. During geomagnetic storms, electrons in the Van Allen belts have been known to vanish – only to return a few hours later. This strange phenomenon was first spotted in the 1960s, and has puzzled physicists ever since.
Surely, they thought, at the height of a geomagnetic storm in which many energetic particles from the sun hit Earth’s atmosphere, there would be more electrons in the Van Allen belts, not less?
A new paper published online at Nature Physics seems to have the answer: the electrons are swept away by particles from the sun.
Drew Turner, from the University of California, Los Angeles, and his colleagues (also at UCLA) used data from three different spacecraft for this research: THEMIS, GOES and POES spacecraft.
THEMIS stands for Time History of Events and Macroscale Interactions during Substorms (and is also the name of a Greek goddess, something that I’m guessing wasn’t entirely coincidental) and was a NASA mission that investigated what causes auroras to go from moving slowly across the sky to dancing rapidly within minutes. It consisted of five identical satellites that lined up over North America once every four days to witness auroras.
The original THEMIS mission ended in 2009. Now two of the satellites have been sent off to orbit the moon and only three remain close to Earth. Those three were teamed up with two GOES (Geostationary Operational Environment Satellite) and six POES (Polar Operational Environmental Satellite) spacecraft, both run by the National Oceanic and Atmospheric Administration (NOAA), with the POES also jointly run by European Organization for the Exploitation of Meteorological Satellites, to witness a small geomagnetic storm on 6th January last year.
THEMIS and GOES both orbit Earth near the equator, with POES taking on the polar regions at a lower altitude, and pass through the Van Allen belts several times a day.
A solar flare accompanied by a coronal mass ejection (CME) erupted from the sun on January 23rd 2012. Credit: NASA/SDO
There are several solar phenomena that can cause geomagnetic storms. Coronal mass ejections, or CMEs, are one that we hear about a lot, possibly because of the amazing images that NASA mission Solar Dynamics Observatory (SDO) has been talking of them lately. But what caused the storm on 6th January 2011 was something called a co-rotating interaction region (CIR). CIRs are created because there are two different streams of particles coming from the sun: fast and slow. The fast stream taking over the slow one causes turbulence at the boundary between the two and creates a CIR.
During the 6th January storm, several satellites in the outer Van Allen belt noticed a ‘dropout’ of electrons – they appeared to go missing, but reappeared again around six hours later.
Turner and his colleagues looked at the data from the THEMIS, GOES and POES satellites and found that, while some electrons at lower energies did appear to have been replaced by electrons coming in with the CIR that caused the storm, ones with higher energies were pushed out from the Van Allen belts and away from Earth.
Some physicists thought that the electrons might have fallen downwards out of the belts during geomagnetic storms, but this new research is clear evidence that they seem to be pushed up and away instead. It might seem like a small distinction, but information on how the Van Allen belts work is important if we are to properly protect satellites flying around in them.
An upcoming NASA mission, Radiation Belt Storm Probes (RBSP) should be able to help give a fuller answer to what happens to the Van Allen belts during these storms. It’s due to launch this August – just in time to witness the many solar storms that will come our way in the run up to the next solar maximum.
Reference
Turner, D., Shprits, Y., Hartinger, M., & Angelopoulos, V. (2012). Explaining sudden losses of outer radiation belt electrons during geomagnetic storms Nature Physics DOI: 10.1038/nphys2185
- Feb 01, 12
Eros as seen on 14th February 2001 by the NEAR spacecraft. Credit: NASA
Fed up of simply reading about space and want to do some real science? Well, here’s your chance: astronomers are asking anyone with a pair of binoculars or telescope to train them on a new object visible in the night sky.
The object is an asteroid called 433 Eros. At 20 miles wide it’s one of the largest near-Earth asteroids, but it only really gets close to use once every 1.76 years because of it’s highly elliptical orbit. Its about to get the closest to Earth that its been in over thirty years – but don’t worry, at 16.6 million miles away it won’t pose any threat.
In fact, it could prove useful. From now until this Friday, the Eros Parallax Project is asking anyone with the right equipment to snap photos of Eros at specific times depending on their location. If you’re quick, you might be able to jump on board and help. There’s more information about the project here.
Depending on where you are on Earth, you will see Eros in a slightly different place in the sky relative to the background stars. This phenomenon is known as parallax. You can see it if you hold a finger up at arms length, look at where it is relative to the background with one eye closed, then switch eyes and watch it shift in relation to whatever is behind it.
Astronomers will use all the data submitted to find the distance to Eros. They will then use this to get a better estimate of the size of the solar system.
- Jan 31, 12
Aurora borealis above Bear Lake in Alaska. Credit: U.S. Air Force photo by Senior Airman Joshua Strang
The Sun is hotting up, and we can see the results right here on Earth. Across the northern hemisphere, fantastic light displays have been visible of late, and the frequency of these events is set only to increase as the Sun heads toward a peak in its magnetic activity.
In light of this (no pun intended), I decided a post about what is going on during an aurora was in order.
What exactly is happening with the Sun at the moment?
A coronal mass ejection that occurred on 1st August 2010 and caused a spell of aurorae that summer. Credit: NASA/STEREO
The Sun goes through cycles, each lasting around 11 years. During this cycle, its magnetic field increases and then decreases again. The magnetic field of the Sun is the source of its ‘activity’ – a term which describes solar phenomena like sunspots, faculae and prominences. Activity can also come in the form of coronal mass ejections (CMEs). These are huge bubbles of material with diameters a few times that of the Sun that explode into space, releasing billions of tons of charged particles, or plasma.
A few of years ago the Sun’s activity was at an exceptionally low and long-lasting minimum, but since then it’s been increasing and we’re heading for a maximum early in 2013. This means lots more activity is on the horizon: near a solar minimum we get around one CME a week, near a maximum this increases to two or three per day.
What has this got to do with the northern lights?
The northern lights (aka aurora borealis) are an amazing display of green and sometimes red light seen near to the magnetic north pole, and they’re caused by CMEs. Their southern equivalent occurs near the south pole, and is known as aurora australis.
After a CME erupts from the Sun, it can interact with the solar wind and cause huge interplanetary shock waves that go on to reach the Earth. When particles from the solar wind get to Earth, they are channelled down our planet’s magnetic field lines and end up accelerating towards the magnetic north and south poles. These particles then interact with atoms and molecules in our atmosphere and excite them, causing them to release photons. It is these photons that make up the light we see in the sky during an aurora.
*
This BBC News article has a good illustration showing the solar wind’s interaction with the Earth’s magnetic field.
This post is a slightly modified version of one that appeared at my old blog in August 2010.
- Jan 14, 12
A composite image taken by Cassini on a fly by in 2005. This is roughly what Titan would look like to the human eye. Credit: NASA/JPL/Space Science Institute
Underneath Titan’s dense atmosphere lies something rather unusual, by terrestrial standards. Some features of the Saturnian moon, at first glance, might look similar to some features we have on Earth — it is the only other body in the solar system with lakes, and appears to have an active weather system. But instead of water, it’s methane that rains from the skies to fill Titan’s vast lakes, before it evaporates to form clouds that cover the surface. Curiously similar to the water cycle here on Earth, but at the same time rather alien.
The Cassini spacecraft has been able to take a closer look at this alien weather system and has seen that the distribution of lakes and clouds is not even across the surface of the moon. The lakes tend to cluster around the poles, in particular in the northern hemisphere. Clouds, meanwhile, prefer the south – that is the hemisphere that until recently was experiencing summer. A year on Titan is the equivalent of 30 years on Earth, so summer lasts a long time. Clouds stick around for about 25 out of these 30 years, but vanish for the remainder.
Some scientists at Caltech have come up with an explanation for this uneven distribution of clouds and lakes. They published their findings in Nature recently, and I wrote about their new model for Imperial’s student newspaper this week – head over to Felix Online to read all about it, if you wish.
I spoke to Dr Ingo Mueller-Wodarg, a planetary scientist in the Physics department at Imperial about the paper, and he explained why the new model is better than previous ones.
“What this study does is reproduce reasonably well, better than others before, the observations in terms of lake and cloud distribution. The significance of this is that we have gained a first understanding of what controls these features, namely a complex interplay of global wind transport, microphysical processes such as condensation and evaporation, cloud formation and radiative heating.
As far as I can tell this model has advanced on two fronts, namely being 3D rather than 2D and fully including the coupling between the atmosphere and surface in terms of methane transport and including surface reservoirs of methane. Many [previous] models are 2D, since calculation times otherwise become prohibitive due to the number of years that the models need to be run to assess seasonal trends (given that a Titan year is equivalent to 30 Earth years!). As far as I know, many models have significantly simplified the surface-atmosphere methane transport processes and hence got differing results. Importantly, many studies previously didn’t fully account for surface reservoirs of Methane and how these change over a year in response to the atmosphere.”
The Caltech team’s model has enabled them to make predictions about what the weather will be like on Titan in the next few years – to see if their model is right, all we will have to do is stay tuned (and make sure Cassini is making the observations needed to check their predictions!).
Refererence
Schneider, T., Graves, S., Schaller, E., & Brown, M. (2012). Polar methane accumulation and rainstorms on Titan from simulations of the methane cycle Nature, 481 (7379), 58-61 DOI: 10.1038/nature10666
- Jan 11, 12
Size of the Sun now compared to how big it will expand to as a red giant. Credit: Wikipedia User:Mysid, User:Mrsanitazier.
Astronomers have found that the core of a red giant, the type of star that our Sun will eventually become, spins ten times as fast as its surface. And it happens because of a phenomenon we can see here on Earth, too.
You have probably seen a figure skater perform a so-called ‘scratch spin’, where she starts out with arms and free leg extended, before pulling them in – and spinning faster as a result. This happens because of a property known as angular momentum, a measure of how much an object is spinning. More specifically, it happens because the angular momentum of an object – in this case the figure skater – must stay the same before and after the manoeuvre. But angular momentum is not a property confined to figure skaters, people in general, or even things on Earth. Every spinning object in the universe has angular momentum, and each must obey the same physical law as the figure skater. In fact right at this very moment, across the universe, stars are performing scratch spins of their own.
Stars like our Sun run on hydrogen. When a star runs out of hydrogen, it is forced to burn other fuels. This switch triggers a change in the star. The core of the star collapses as the outer region expands and cools, creating a type of star known as a red giant.
We know that the angular momentum of the star must be conserved, so we also know that the core of the star that collapses must be spinning faster than the surface of the red giant. So far, though, our understanding of exactly how a star’s angular momentum changes as the star evolves is not especially good.
This is partly because we cannot directly observe how fast the core of a star is spinning. Now, though, an international collaboration of astronomers led by Paul Beck at the Institute of Astronomy at Leuven University in Belgium have found a way to measure the rotation of the core by probing the star’s interior using techniques from astroseismology. Astroseismology is a bit like the normal seismology that we use to study earthquakes, but instead of looking at waves traveling through Earth it looks at waves traveling through stars — starquakes. Their research was published in the latest issue of Nature, but is also available on arXiv.
Beck and his colleagues looked at small, regular variations in the light coming from several red giants observed by the Kepler spacecraft. Kepler’s main job is searching for planets outside of our solar system, so it is well suited to detecting extremely small changes in the brightness of stars, as this is a major way to spot that a star has a planet orbiting it.
The variations in light are caused by different waves traveling to different depths inside the star. Once Beck and his colleages had collected nearly two years worth of data on these variations, they compared what they had with theoretical predictions, and found that the core of the stars must be rotating at least ten times as fast as the surface.
This study advances astronomers’ knowledge of how the angular momentum of parts of a star change as it evolves, but there are still many questions left unanswered. The next step will be to study a larger sample of red giants at different stages in their lifetimes to learn more about how these stars change as they grow old, and what fate is in store for our Sun.
Reference
Beck, P., Montalban, J., Kallinger, T., De Ridder, J., Aerts, C., García, R., Hekker, S., Dupret, M., Mosser, B., Eggenberger, P., Stello, D., Elsworth, Y., Frandsen, S., Carrier, F., Hillen, M., Gruberbauer, M., Christensen-Dalsgaard, J., Miglio, A., Valentini, M., Bedding, T., Kjeldsen, H., Girouard, F., Hall, J., & Ibrahim, K. (2011). Fast core rotation in red-giant stars as revealed by gravity-dominated mixed modes Nature, 481 (7379), 55-57 DOI: 10.1038/nature10612
- Jan 09, 12
A false color image of Cassiopeia A using observations from both the Hubble and Spitzer telescopes, and Chandra X-ray Observatory. Credit: NASA/JPL-Caltech
They may come from completely different fields of study, but brain scans and supernovae have more in common than you would think.
In a new TED talk, Michelle Borkin explains how software developed for use in a hospital was able to help astronomers study the structure of supernovae.
An astronomer colleague of Borkin’s at the Harvard-Smithsonian Center for Astrophysics had eight years worth of data from the supernova remnant Cassiopeia A. She wanted to use the data to understand the remnant’s structure so she could work out how the star exploded. But there was a problem: she had no good way to look at the data. Luckily, Borkin did, and suggested that the astronomer try using 3D slicer software, originally developed in a hospital in Boston for looking at brain scans. It worked beautifully.
It is not just data analysis in these two fields that uses the same tools. The way data is collected from brain scans and radio telescopes is similar too. Even images in the fields of medicine and astronomy are alike: a confocal microscopy image of a human cornea looks much like a radio telescope image of star forming region NGC1333, despite the difference in scale.
This collaboration between astronomy and medicine is not the only example of an interdisciplinary connection in science – a lot of interesting science is now happening at the interface between two or more fields of study. Scientists working in all areas are looking outside their own lab in search of new ideas and methods, and more could benefit from joining them.
Video credit: TED
More about the Astronomical Medicine Project.
- Dec 31, 11
2011 has been a busy year for particle physicists. They’ve found a new particle, closed in on the elusive Higgs boson, and witnessed some neutrinos acting pretty strangely, amongst other things. I’m talking, of course, about the faster than light neutrinos detected by the Opera experiment in Italy. They dominated the science headlines for a few days at the end of September and have been popping up every now and then since as scientists try to grapple with the idea that Einstein’s theory of special relativity may not be as watertight as they would like to think.
In order to make sense of the finding, I collected together lots of the coverage and papers concerning the result and had a go with interactive timeline making tool dipity.com. Have a look at the timeline below. You can zoom in on particular weeks and days, to see the detail of who published what and when, or you can zoom out for a broader overview of how the story unfolded. This is very much a work in progress and I plan to add to it as and when new events occur. If there’s something I haven’t included that you think should be on there please let me know in the comments.
If you need a refresher on how Opera experiment found this result, have a watch of the video by Minute Physics below, which provides a nice and simple explanation.
All that remains for me to say is happy new year to those already in 2012, and I’ll see the rest of you on the other side.
- Dec 30, 11
Supernova 2011fe in the Pinwheel Galaxy. Credit: Thunderf00t
When a star becomes a white dwarf — an old, extremely dense star that would have once been similar to our own Sun — the eventful part of its life is over. It releases what heat and light it has left over billions of years, slowly cooling until it no longer shines.
Usually. Some white dwarfs, however, are not content with this ending.
If a white dwarf exists in a two star system with a companion it can avert its fate and go out with a bang, not a whimper. It does this by causing a particular type of stellar explosion called a type 1a supernova. A type 1a supernova starts when the white dwarf drags material from its companion onto itself. It grows and grows until it cannot get any bigger. At this point it implodes, then rebounds and explodes in a supernova bright enough to outshine whole galaxies.
The companion star from which the white dwarf steals matter is instrumental in this dramatic event. Its identity, however, has long been a mystery.
Despite their origins being somewhat muddy, type 1a supernovae have given us a lot over the past year. Saul Perlmutter, Brian Schmidt and Adam Riess, along with their respective research groups, used them to discover the accelerating expansion of the universe — caused by the mysterious force we call dark energy — that won them the 2011 Nobel prize in physics.
Now, a type 1a supernova spotted in August this year has allowed astronomers to narrow down the range of possible companions that give white dwarfs the mass boost they need to explode.
At one minute to four in the morning on 24th August 2011, an alert was sent out to astronomers working on the Palomar Transient Factory (PTF). Their telescope had spotted an extremely bright object in the Pinwheel galaxy that hadn’t been there before — a new supernova, now known as supernova 2011fe. At that time it was, relatively speaking, quite faint, but over time it brightened. You may have seen it yourself: ten days after it was first seen it became bright enough to see through a pair of good binoculars.
The Palomar Transient Factory had noticed the star just 11 hours after it exploded, winning them the record for the earliest ever detection of a type 1a supernova, and were quick enough to get a glimpse of the light coming from it just 16 hours after explosion using an instrument on the robotic Liverpool Telescope in the Canary Islands. Since then, other telescopes have looked over their observations of that night to see if they saw it too.
Three possible scenarios before a type 1a supernova explosion. Li's group rule out scenario (a) in which the second star is a red giant, but cannot rule out (b) or (c). Credit: Nature / (a) ESO; (b) STSCI, NASA; (c) NASA/T. Strohmayer (GSFC)/D. Berry (Chandra X-Ray Observ.)
Watching a supernova as soon as possible after it starts is key to discovering what happened to make it explode in the first place. Theoretical models say the companion star to an exploding white dwarf can be only one of three types: a red giant, a main sequence star like the Sun, or another white dwarf. Astronomers are keen to narrow this down further.
In Nature earlier this month a team from California published two papers analysing observations of supernova 2011fe in the hope of finding clues that will enable them to do this. One paper, led by Peter Nugent from the Lawrence Berkeley National Laboratory found that the companion star was probably a main sequence star. Nugent’s paper also confirms that the star that exploded was a white dwarf.
The other paper, led by Weidong Li of the University of California, Berkeley, rules out a red giant companion.
Li used observations from the Keck telescope on the summit of Mauna Kea in Hawaii to pinpoint the precise location of the supernova, then analysed images taken by the Hubble Space Telescope from before the supernova explosion to look for clues about the pair of stars from which it was born. In the space where supernova 2011fe was later detected, they saw nothing. This did not mean they had made a mistake — just that the system preceding the supernova was not bright enough to be detected. This information was enough for them to rule out a red giant as the companion because, at one hundred times as luminous as the Sun, it would have been bright enough to show up. They could not, however, rule out other types of stars.
Supernova 2011fe is the first type 1a supernova to be discovered for many years and, because instrumentation has moved on considerably in that time, will become the most studied supernovae in history. These two papers are just the beginning.
*
More on supernovae
References
Li W, Bloom JS, Podsiadlowski P, Miller AA, Cenko SB, Jha SW, Sullivan M, Howell DA, Nugent PE, Butler NR, Ofek EO, Kasliwal MM, Richards JW, Stockton A, Shih HY, Bildsten L, Shara MM, Bibby J, Filippenko AV, Ganeshalingam M, Silverman JM, Kulkarni SR, Law NM, Poznanski D, Quimby RM, McCully C, Patel B, Maguire K, & Shen KJ (2011). Exclusion of a luminous red giant as a companion star to the progenitor of supernova SN 2011fe. Nature, 480 (7377), 348-50 PMID: 22170681
Nugent PE, Sullivan M, Cenko SB, Thomas RC, Kasen D, Howell DA, Bersier D, Bloom JS, Kulkarni SR, Kandrashoff MT, Filippenko AV, Silverman JM, Marcy GW, Howard AW, Isaacson HT, Maguire K, Suzuki N, Tarlton JE, Pan YC, Bildsten L, Fulton BJ, Parrent JT, Sand D, Podsiadlowski P, Bianco FB, Dilday B, Graham ML, Lyman J, James P, Kasliwal MM, Law NM, Quimby RM, Hook IM, Walker ES, Mazzali P, Pian E, Ofek EO, Gal-Yam A, & Poznanski D (2011). Supernova SN 2011fe from an exploding carbon-oxygen white dwarf star. Nature, 480 (7377), 344-7 PMID: 22170680
- Dec 24, 11
Artist's impression of one possible scenario — the supernova model — for the creation of the Christmas gamma-ray burst. Credit: NASA/Swift/Aurore Simonnet, Sonoma State Univ.
How did the Christmas gamma-ray burst explode? No, it’s not a geeky Christmas cracker joke, it’s a real question scientists have been trying to answer since Christmas day last year, when a gamma-ray burst called GRB 101225A first lit up the sky. The Christmas burst, as its come to be known, exhibted some rather unusual characteristics.
Gamma-ray bursts are short-lived flashes of gamma rays, made up of light that is more energetic than x-rays. Most are thought to be the result of massive stellar explosions in distant galaxies. Bursts can be over in milliseconds or last for several minutes, but no longer than that. After they finish they leave behind a longer-lived afterglow that can survive into weeks and months. While they last, they are the brightest objects in the known universe.
The Christmas burst was unusual. It went on for at least half an hour, but its afterglow faded much faster than was expected and displayed some features that are incompatible with current models. When it was first observed, astronomers were unable to work out how far away it was from Earth.
Now, two groups of scientists have come up with explanations of why the Christmas burst exploded the way it did. Both put forward their explanations in the same issue of the journal Nature earlier this month. Each group’s hypothesis attempts to explain why the Christmas burst lasted for longer than most others and why its afterglow faded so fast. In doing so, they also provide an estimate of the burst’s distance — and each come up with different answers.
Sergio Campana, an astronomer at the Istituto Nazionale di Astrofisica in Italy, and his group think that the Christmas burst was created in an atypical way — by a comet falling onto an extremely dense star. On the other hand, Christina Thöne, from the Instituto de Astrofísica de Andalucía in Spain, and her group propose a more conventional creation, involving a supernovae born out of two stars.
Artist's impression of the scenario in which a small object like a comet falls onto a neutron star and triggers the burst. Credit: NASA/Swift/Aurore Simonnet, Sonoma State Univ.
In Campana’s hypothesis a “small” object — a comet or asteroid — is whizzing past a dense neutron star just a little too close. It gets pulled in by the gravity of the star, but before it reaches the star’s surface, the smaller object is overwhelmed by the force of the gravity and breaks up into fragments. This debris is thrown into orbit around the star and then falls back to form a disk. Eventually, the debris falls on to the star itself and explodes, releasing vast amounts of energy. If this version of events is true, the explosion must have happened in our own galaxy, no more than 10,000 light years away in the Perseus spiral arm.
Thöne’s explanation involves a burst that starts as as binary system — two stars, one an extremely dense neutron star and the other a supergiant helium star, orbiting each other. The neutron star sucks the mass off the helium star until both are surrounded by an envelope of gas. The two stars then merge into a black hole or magnetar, a dense star with a powerful magnetic field, creating a jet of intense energy that bursts through the gas envelope. In this scenario, the explosion happened over four and a half billion light years away.
Enrico Costa, independent of both groups, pointed out that though both groups’ suggestions are “plausible”, at least one must be wrong. Once the burst’s host has been found, one (or perhaps even both) of these models will be ruled out. For now, though, the jury is still out on how this unusual Christmas burst came to be, so perhaps we should keep an open mind about the origins of some of the brightest explosions in the universe.
*
Links
Astronomy Journal Club (#astrojc on twitter) dicussed this paper in their final meeting of the year. This is the review (and you can find the full meeting here).For some animations of the two possible scenarios, go here.
References
Thöne, C., de Ugarte Postigo, A., Fryer, C., Page, K., Gorosabel, J., Aloy, M., Perley, D., Kouveliotou, C., Janka, H., Mimica, P., Racusin, J., Krimm, H., Cummings, J., Oates, S., Holland, S., Siegel, M., De Pasquale, M., Sonbas, E., Im, M., Park, W., Kann, D., Guziy, S., García, L., Llorente, A., Bundy, K., Choi, C., Jeong, H., Korhonen, H., Kubànek, P., Lim, J., Moskvitin, A., Muñoz-Darias, T., Pak, S., & Parrish, I. (2011). The unusual γ-ray burst GRB 101225A from a helium star/neutron star merger at redshift 0.33 Nature, 480 (7375), 72-74 DOI: 10.1038/nature10611Campana, S., Lodato, G., D’Avanzo, P., Panagia, N., Rossi, E., Valle, M., Tagliaferri, G., Antonelli, L., Covino, S., Ghirlanda, G., Ghisellini, G., Melandri, A., Pian, E., Salvaterra, R., Cusumano, G., D’Elia, V., Fugazza, D., Palazzi, E., Sbarufatti, B., & D.Vergani, S. (2011). The unusual gamma-ray burst GRB 101225A explained as a minor body falling onto a neutron star Nature, 480 (7375), 69-71 DOI: 10.1038/nature10592
- Dec 12, 11
Tomorrow afternoon, in “the most eagerly awaited scientific presentation of the century to date”, particle physics laboratory Cern will update the world on its search for the Higgs boson, that elusive particle that is believed to give mass to fundamental particles.
The Higgs is the only particle predicted by the Standard Model of particle physics, currently the best theory we have to describe how particles interact, that we have not yet observed. Cern wants to change that.
Scientists working on Cern’s Large Hadron Collider (LHC) has been looking for the Higgs for quite a while now. I’m not quite sure how to break it to them, but I think I might know where it is…
Ok, ok. This is actually a stop motion animation that uses skittles (the sweet kind) to explain how the LHC works. It was made by a team of Imperial College Science Communication masters students, including myself, and the Higgs makes a blink-and-you’ll-miss-it appearance towards the end.
So whatever the announcement is tomorrow, remember that we found it first.
(For a slightly more serious post about the Higgs, go here to read why the Higgs matters)
Video credit: Peter Larkin, Harriet Jarlett, Heather Cruickshank, Sam Cavenagh, Kelly Oakes, Georgia Bladon, Antonio Torrisi, and Dharshani Weerasekera.
- Nov 30, 11
The Cygnus X star forming region contains several clusters of young, massive stars. In this image bright spots are where star formation is happening and ridges of dense gas mark the boundaries of cavities formed by the young massive stars. Credit: NASA/IPAC/MSX
Cygnus X is a star forming region in the constellation Cygnus in the night sky. It looks rather pretty in visible light, as shown at the beginning of the video below. But in radio, infrared and gamma ray wavelengths, Cygnus X really comes to life.
Recent Fermi Large Area Telescope (LAT) observations have shown that cavities created by massive stars within star forming clouds in the region are filled with gamma rays, created when the clouds are struck by cosmic rays.
Cygnus X is located 4,500 light years away from us. It has enough matter to make two million stars like our Sun, but contains stars that are much more massive than that.
Within Cygnus X are star clusters mainly made up of the hottest and brightest types of star — O and B type stars. These clusters, known as OB associations, are just five million years old — young, in stellar terms. O and B type stars are the most massive, which is why they’re so rare compared to other types of star. They “sculpt” the gas clouds in which they reside, emitting radiation and massive stellar winds that create cavities that surround the stars. In doing this the stars clear the area surrounding them of gas, making it much harder for more stars to form close by. They effectively climb up the ladder of star formation then kick it back down once they’ve got to the top.
Cygnus X was discovered in the 1950s as a source of radio waves. Now, Fermi LAT observations show a huge 160 light year across “cocoon” of cosmic rays exists in the region. The Fermi team said in a paper published in Science on November 25th that the cosmic rays “flood” the cavities carved out by massive stars in young star clusters.
Cosmic rays are beams of subatomic particles, usually protons, that travel through space at close to the speed of light — much like particles in a particle accelerator like the Large Hadron Collider.
When cosmic rays travel through space they get pushed about by magnetic fields which alter their path, making it difficult to see where the cosmic ray originated. When they meet the gas the lives between stars, they produce gamma rays. Gamma rays, unlike cosmic rays, are able to travel through whatever is in their way, arriving at Earth having followed a straight line path for their whole journey — so we can see where they originated.
The source of cosmic rays is a long standing problem in astrophysics. By tracing gamma rays, Fermi’s LAT can play a part in helping astronomers work out exactly where cosmic rays come from.
The newly discovered “cocoons” of cosmic rays are held together by magnetic fields created by the outflows from massive stars in the region. Shockwaves from the stars knot up the magnetic field so the cosmic rays become trapped.
Gamma Cygni, the remnant of a dying star — or supernova — exists within the Cygnus X region, making it a candidate for the cosmic ray source. But multiple shockwaves created by massive stars in the OB association is also considered as a possible source by the Fermi team.
This paper has shown that the life of a cosmic ray could be a lot more eventful than astronomers previously thought.
Reference
Ackermann, M., & et al (2011). A Cocoon of Freshly Accelerated Cosmic Rays Detected by Fermi in the Cygnus Superbubble Science, 334 (6059), 1103-1107 DOI: 10.1126/science.1210311
- Nov 27, 11
For those who can't read what it says on the trophy (i.e. everyone): "Royal College of Science Union, Science Challenge 2011, Imperial College Physics Prize, Kelly Oakes". Basically, I won a thing.
Every year the Royal College of Science Union at Imperial College runs an essay competition called the Science Challenge. There are usually four questions to answer and a number of prizes for the essays that answer them best.
I’ve been shortlisted before, but this year I finally won something — the Physics prize. Check out the photo to the left for a glimpse of my shiny trophy…
The essay question I answered was “Why should the average person care whether we discover the Higgs boson?” I took it as an opportunity to go off on one about why particle physics is important…
*
From afar it may seem entirely disconnected from the real world, but the Higgs boson is much more integral to life, the universe and, well, everything than you may think.
Have you ever contemplated why you weigh what you do? I am not alluding to the second doughnut you had the other morning, or the ill-advised chips on the way home from the pub, but rather the fundamental reason why the atoms that make up your body, and everything else in the world, have a certain mass. If you haven’t, you are not alone — until recently, scientists hadn’t thought much about it either.
Before the standard model of particle physics came along, the origin of mass was not even considered a problem; that an object had mass was simply assumed. But when scientists began probing objects at smaller and smaller scales, they discovered that it was not quite as simple as that: according to the standard model, fundamental particles should weigh nothing at all.The standard model describes the behaviour and interactions of all of the most fundamental particles we have seen — and one other particularly elusive one that, physicists hope, we will see in the near future. The model was developed throughout the 20th century and finalised when the existence of quarks, the particles that make up protons and neutrons, was confirmed in the 1970s. At the time many of the particles predicted by the standard model were yet to be seen. Over the years since then, physicists have ticked these particles off, one by one, like items on a shopping list. Now they are left with just one remaining unfound particle — the Higgs boson.
Peter Higgs, a theoretical physicist at the University of Edinburgh, came up with the idea of the Higgs field and its associated particle — the Higgs boson — in 1964. The field he proposed extends throughout the universe, and interacts with matter particles in such a way as to give them mass. After an interaction the field leaves behind a telltale sign — the Higgs boson. Finding a Higgs boson would prove that the Higgs field exists.
Two experiments that are part of the Large Hadron Collider (LHC) at CERN are searching for the Higgs boson. Thousands of people from all around the world — including physicists, engineers and even anthropologists — work at CERN. If a Higgs boson is discovered there, there will be more than a few celebratory glasses of champagne — and an inevitable Nobel prize for Peter Higgs.
Elegant though the mathematics is that describes the Higgs mechanism, there is a chance that it does not actually describe nature. In this case, we have to look to slightly less elegant sounding ‘Higgsless’ models to discover the origin of mass. Some Higgsless models use extra dimensions to fix problems that would remain without the Higgs, while others use different mathematical tools. In fact, some physicists are more excited about the prospect of not discovering the Higgs, as this would leave the door open for other solutions that go beyond the standard model, and solve more problems than just the origin of mass.
So there are a few people at least for whom the discovery — or not — of the Higgs would be a momentous occasion.But what about the rest of us? Well, there are many practical reasons to care about the search for the Higgs — if not that actual discovery. From conception through to the first collisions and beyond, particle accelerators spark many technological advancements that can be applied to fields as wide ranging as medicine, sustainable energy development and security. These advances would never have been made if we were not searching for as yet undiscovered particles like the Higgs.
However, one suspects that spin-off technologies and their economic benefits are not what the physicists at the LHC have in mind while running experiments and trawling data for signs of the Higgs boson. Peter Higgs told the Guardian why he was drawn to theoretical physics in the first place: “It’s about understanding! Understanding the world!” His enthusiasm is not abnormal in the physics community, even if it can sometimes be dampened by long hours spent staring at a computer screen analysing data. As humans we have a natural curiosity about the world around us, and we should not suppress that curiosity simply because the practical benefits of following it are not clear at the outset. Without such a curiosity the modern world as we known it would not exist.
Many people, including Peter Higgs himself, subscribe to the view that science for the sake of understanding the world around us is inherently valuable. If however, you need a more concrete reason to care about the Higgs, allow me to borrow some words from Carl Sagan: everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives on the pale blue dot we know as Earth — and none of it would have ever existed without the Higgs boson.
-
Tweets
- This is why bus > tube http://t.co/TdEFjmIN
- At the @SciCommForum #OADebate
- We're halfway through @Mission_Imposs now but still time to tune in! http://t.co/VVBkn28b
- I'm producing a radio show today – @Mission_Imposs – you can listen live here from 12-1pm http://t.co/fc0nTMmG
- I've been stubbornly ignoring the eclipse because it wasn't visible from here, but these photos are pretty good http://t.co/lux9zNBI
- Zoom in on an intergalactic collision http://t.co/4Bhvtg38 #SciAmBlogs
- Friday afternoon cute animal: cat eating a watermelon http://t.co/9wrJxYei (via @NaomiMc)
- You'd better be quick watching that video, because according to the ad that popped up during it "The End-Time Is Here"...
- Want to know what it feels like to orbit Earth? (zero-G not included) http://t.co/fQrT5RsT
- Sometimes I see pictures, like this one from @APOD, and find it difficult to believe that the thing actually exists http://t.co/Qvq92zAT
- Lloyds bankers learn to be "hunter-gatherers in the corporate jungle". Amazing. http://t.co/HfsGtvJd via @RupertNeate
- This is so good. The Scientist, a silent film made by fellow sci comm students at #impcol http://t.co/0ZYKNFwI Well done @hjarlett et al!
- Under construction – ITER in LEGO at @sciam http://t.co/5mXByNgx
-
Posts
- May 24, 12
Researchers at Disney and Carnegie Mellon University have published new research which could make everyday objects and even the human body into a touchscreen. This could mean traditional interfaces would no longer be needed, as smartphones could be silenced by holding a finger to the lips, and the volume on mp3 players could be controlled with a tap of the hand. The technology, known as Touch and eacute;, uses Swept Frequency Capacitive Sensing, which is similar to the technology used in smartphone screens. Smartphones only detect electrical signals on one frequency, allowing them to know when they are being touched. Touch and eacute; takes this one step further by using a range of frequencies, so objects not only detect touch, but and lsquo;sense and rsquo; how they are being touched. Everyday objects can be equipped with the new technology by attaching only one electrode. and ldquo;It could immediately be used to create new and exciting ways for people to interact with ...
- May 24, 12
A study of the reproductive success of 6,000 Finnish people born between 1760-1849 suggests that the technological and social advances of the agricultural revolution did not put a stop to human evolution. and ldquo;It is a common misunderstanding that evolution took place a long time ago, and that to understand ourselves we must look back to the hunter-gatherer days of humans, and rdquo; says project leader Virpi Lummaa, of the Department of Animal and Plant Sciences at the University of Sheffield. But in a collaborative study, involving teams from Germany and Finland as well as the UK, Lummaa and colleagues looked at the life cycles of a large set of individuals using church records going back 250 years. They concluded that and ldquo;significant selection has been taking place in very recent populations, and likely still occurs. and rdquo; By tracking variables such as survival to adulthood, mate access, mating success, and fertility per mate, the researchers found that the ...
- May 24, 12
A new study has identified three key proteins in plants that may help the development of improved crops yielding higher qualities and quantities of oils. The scientists, of the Salk Institute for Biological Studies and Iowa State University, say that such plants could help to reduce the growing global demand for food and fuels, and negate the detrimental effect such demand may have on our environment and ecosystems. The research, headed by lead authors Joseph Noel and and nbsp;Eve Syrkin Wurtele, analysed genomic plant data and pinpointed the proteins responsible for regulating the metabolism of fatty acids in thale cress plants. These three proteins, dubbed FAP1, FAP2 and FAP3, control the molecular pathways responsible for plant oil production and bind fatty acids such as omega-3. and ldquo;This work has major implications for modulating the fatty acid profiles of plants, and rdquo; says lead author Joseph Noel. The researchers found that altering the expression of these proteins changed ...
- May 24, 12
Pesticides may be the bees knees when it comes to protecting crops, but researchers from the UK and France have shown that exposure to one common pesticide leads to a dramatic loss to the number of queen bees, and another pesticide affects foragers and rsquo; ability to find their way back to the hive. The new findings might go some way to explaining recent decline in bee numbers. Scientists at the University of Stirling and the Lancaster Environment Centre, both in the UK, exposed colonies of bumble bees to realistic levels of imidacloprid, and nbsp; a pesticide chemically related to nicotine, in the lab. They then placed the colonies into the field to forage on gardens, wildflowers and a variety of crops, and watched as the colonies that had been exposed to the pesticide suffered an 85% reduction in the number of new queens compared to colonies that were not exposed. The exposed bees also ...
- May 24, 12
Science and the law have clashed again this week, and it seems that the US is adamant in attempting to inhibit scientific advances yet again in the name of public safety. This time, it is the geneticists that are under pressure, as Californian senators are attempting to pass a bill that could hinder on-going research into genetic diseases. The bill, known as The Genetic Information Privacy Act, aims to introduce consent forms covering the explicit intended use of the genetic sample, which the person who is donating the material must then agree with. The bill also states that such genetic material must be destroyed after, and cannot be stored to be accessed at a later date. Supporters for the bill are keen to point out that it doesn and rsquo;t stop research, just adds a new bureaucratic component to protect personal information. With the National Human Genome Research Institute predicting that the cost of ...
- May 17, 12
Brad Amos, who contributed significantly to the development of the laser scanning confocal microscope while working at the Medical Research Council in Cambridge, has developed a new giant microscope, the and lsquo;Mesolens and rsquo;, that allows the imaging of an entire mouse embryo in subcellular detail. Amos hopes that his new Mesolens could make imaging in developmental biology much simpler because the lens and rsquo; huge field of view removes the need to stitch many small images together, reducing image acquisition times from a day to an hour. The confocal microscope, the current gold standard in biomedical imaging, is successful because it allows biologists to obtain an image from inside a thick specimen, a technique known as optical sectioning. It does this in two steps: the sample is illuminated with a small focused laser spot; this spot is then focused onto a tiny hole placed in front of a camera. In this way, only light that has ...
- May 17, 12
A Kenyan scientist and a Gambian clothes designer have joined forces to fashion a garment that has the power to repel mosquitoes and beat malaria. The one-piece multi-coloured bodysuit comes with an anti-mosquito mesh hood and a cape that contains mosquito repellent that has been bonded with the fabric and rsquo;s fibres at the molecular level. Because the repellent is embedded in the garment and rsquo;s fabric using nanotechnology it does not dissipate like regular skin-based insecticides, according to the scientist and clothes designer from Cornell University in New York. The and lsquo;binding technology and rsquo; even allows up to three times more insecticide to be embedded within the fabric compared to normal sleeping nets, which are only dipped in solution and usually need to be replaced or re-dipped every six months. Malaria, which is endemic in large parts of Africa, is a killer parasitic disease transmitted to humans through the bite of infected mosquitoes. It kills more than half a ...
- May 17, 12
A promising way to power vehicles and appliances in the future is through use of hydrogen fuel cells. These, however, require a source of hydrogen to work, and obtaining this hydrogen has typically been an expensive process. The most common method to obtain the gas and nbsp;is to split water into oxygen and hydrogen. This is an operation that requires a catalyst, and the catalyst must be such that it reduces the energy necessary for the reaction to occur as much as possible. The lower the energy that is required, the more efficient the system, because it means there is more energy left over to actually power your system. Hence, platinum catalysts are often used due to their excellent catalytic ability. A problem with platinum, however, is its ever-rising cost: something that has been seen with many rare metals as their availability becomes ever reduced. Hence, alternatives involving cheaper catalysts are needed, and researchers ...
- May 17, 12
The online publication of a controversial article outlining potentially damaging data about the influenza virus finally went ahead recently, after a significant delay. Nature, after careful deliberation, published the paper much to the dismay of several official bodies, after the case was brought to a hearing in April by the US Senate. With scientific research being increasingly hindered by outside influences, is it time to make an absolute decision over what exactly can be published once and for all? Or would this be detrimental to scientific advances? The paper, containing methodology and data covering artificial generation of a strain of H5N1 avian flu, that has the ability to transmit between mammals, was deemed initially unsuitable for publication unless highly censored by the US National Science Advisory Board for Biosecurity (NSABB) last November. However, such recommendation was only advisory; Nature still went ahead with the publication in full, entitled and ldquo;Experimental adaptation of ...
- May 17, 12
A recent study published in the journal Cell has identified a major genetic component of human brain development, with implications for research into autism and schizophrenia. Scientists at The Scripps Research Institute have found that the gene SRGAP2, the protein product of which is responsible for forming neuronal connections in neocortical development, has undergone two human-specific truncated duplications. One of the duplicates has been named SRGAP2C, and appeared in the genome about 2.4 million years ago, during the time in which human lineage separated from nonhuman primates (a related paper published in the same issue of Cell covers the recent evolution of SRGAP2). SRGAP2C interacts with the original SRGAP2 to inhibit its functions, delaying the maturation of dendritic spines on pyramidal neurons. Dendritic spines are crucial for integrating synaptic signals from other neurons. Far from having a negative effect on brain development, SRGAP2C ultimately results in a higher density of dendritic spines ...
- May 17, 12
The European Space Agency (ESA) is to lead a billion-euro mission to Jupiter and its icy moons. The Jupiter Icy Moons Explorer (JUICE) spacecraft is scheduled to launch in 2022, arriving in the Jupiter system in 2030. A five-tonne satellite will be sent out to Jupiter in order to make a series of close measurements of the giant planet and three of its moons: Ganymede, Callisto and Europa. The satellite, packed with instruments, will take eight years to reach Jupiter, spend another three years studying the system before crashing into the surface of Ganymede. UK researchers including Professor Michele Dougherty of Imperial College, lead scientist of the JUICE mission, played a central role in gaining approval for the mission. The JUICE concept was chosen over two other ideas, NGO, which would place three high-precision satellites in space to detect gravitational waves, and Athena, which would see the creation of the largest X-ray ...
- May 09, 12
Stars approaching a supermassive black hole are ripped apart by its huge tidal force. The black hole gobbles part of star and spits out some material in form of radiation. This fantastic phenomenon has been observed by a team of astrophysicists from US and UK through observations obtained from the telescope in Mount Haleakala, Hawaii, and the Chandra X-Ray Space Observatory. From a survey of thousands of galaxies, the scientists found that both the telescope and the Galaxy Evolution Explorer satellite had detected a luminous flare from the centre of a galaxy located at a distance of approximately 2 billion light-years from the Earth. The flare, dubbed PS1-10jh, is extremely intense and reveals an uncommon shape of the light-curve. and nbsp; The long duration of the phenomenon (a few months) was not typical of gamma ray bursts that fade away within a day and come from the explosion of massive stars or collisions ...
- May 09, 12
Researchers in New York have engineered a way to non-invasively trigger gene activation in live animals using nanoparticles and radio waves, a method that may, in the future, be used to remotely control genes in humans for medical purposes. Current methods of activating cells are unwieldy at best: direct stimulation using electrodes is invasive, potentially damaging and non-specific, whilst control of individual light-activated channels using different wavelengths of precisely-timed light pulses requires internally implanted light pipes. But, by abusing the properties of iron oxide nanoparticles (FeNPs) and temperature-sensitive ion channels, the researchers found a way to finely control certain genes non-invasively. Jeffery Friedman and colleagues of The Rockefeller University targeted FeNPs to a modified, temperature-sensitive cation channel, TRPV1 (otherwise known as the capsaicin receptor) by coating the nanoparticles with antibodies specific to a modified tag on the channel. Exposure to low- and mid-range radio wave frequencies heated up the targeted nanoparticles but ...
- May 09, 12
In March this year the British Science Association released a survey that indicated, at least to some degree, that the British public is slightly less concerned about the prospect of embracing genetically modified food. This comes in stark contrast to the hostility exhibited towards the technology a decade ago, when it was rejected in an outright fashion in the nationwide surveys dubbed GM Nation. This essentially halted the push for GM crops by Tony Blair and rsquo;s government and put research in this area on the backburner. But GM has now found its way back onto the radar; more flexible EU legislation regarding the technology combined with the survey results means that perhaps the public is once again in the mood for a conversation about the technology. All the interest groups, from anti-GM campaigners to researchers have been airing their arguments and framing the debate in a very public fashion over the ...
- May 09, 12
A well-known consequence of global warming is rising sea levels, caused by the melting of polar ice as the Earth heats up. Now, scientists have found evidence that sea level rise this century will fall short of the expected worse case scenario. A team at the University of Washington have found glacial flow in Greenland to differ from that of previous expectations. This latest research results in two main findings: that glaciers are moving a lot slower and that this movement is not likely to slow down. Glaciers are responsible for the transportation of ice and snow from landmasses into the sea. This, along with the direct melting of ice sheets when temperatures increase, results in rising sea levels. The glacial flows from Greenland and Antarctica alone contribute the most to rising sea levels. A staggering 250 billion tonnes of ice is pushed into the sea each year, resulting in an ...
- May 09, 12
A mass sensor has been developed by a group of Spanish scientists, lead by Julien Chaste from the Catalan Institute of Nanotechnology, capable of weighing individual molecules, atoms, and even protons. Sensors of this type, known as nanomechanical mass sensors, have been developed before. However, previous developments only yielded a resolution of about 7000yg (yottagrams) for a microfabricated sensor, and around 200yg for a carbon nanotube based sensor. In this development, which is an improved version of the nanotube based sensor, the researchers achieved a resolution of 1.7yg, which allows weighing of individual protons. These sensors work by oscillating a resonator, either nanomechanical or carbon nanotube, at its characteristic frequency (the frequency at which resonance occurs, this is usually just below the natural frequency). A computer can measure this frequency. When atoms or molecules land on the resonator, the characteristic frequency of the resonator changes, and the computer can measure this change. ...
- Mar 15, 12
Scientists at Imperial College have discovered that efficiency savings of up to 80% in the production of biofuel can be made by lubricating the wood biomass. Biofuels are used widely in Brazil, where all light vehicles run on ethanol or a 25% ethanol in gasoline blend, and the USA where gasoline with 10% ethanol content is widely available. Wood chips from fast-growing trees such as pine are used to produce cellulosic ethanol as well as biodiesel. The first stage in this process, which often happens at the logging site, is the grinding of wood chips into even smaller particles to increase their surface area and thus their reaction and dissolution states. After this, the biomass is treated with ionic liquids as a solvent for the cellulose and lignin. The researchers, led by Dr. Agnieszka Brandt of the Department of Chemistry, studied the effects of treating the wood before the grinding process. They found ...
- Mar 15, 12
A powerful hallucinogenic drug once used by the CIA in torture experiments may help alcoholics stop drinking, according to new research. The research, funded by the Research Council of Norway and based on experiments conducted in the 1960s and 1970s, shows that the psychedelic drug LSD (Lysergic acid diethylamide) can have and ldquo;a significant beneficial effect on alcohol misuse. and rdquo; It fails to show how LSD works in alcoholics, but doctors who have seen the research say that LSD causes the human brain to function more and ldquo;chaotically and rdquo;, inspiring alcoholics to give up their dependency on booze. Robin Carhart-Harris, a psycho-pharmacologist at Imperial told Nature, and ldquo;Psychedelics probably work in addiction by making the brain function more chaotically for a period and ndash; a bit like shaking up a snow globe and ndash; weakening reinforced brain connections and dynamics. and rdquo; Once the dust settles, many people who take LSD say that their problems appear clearer and simpler, allowing them to ...
- Mar 15, 12
Honey bee scouts are at the forefront of bee exploration, seeking out new sources of food for the hungry hive and finding suitable nest sites for the colony when it outgrows its current home. These bees differ from their fellow foragers. They do not wait to be told where to go or what to do, but seek novelty, maybe even adventure. A new study, published in Science, has examined the brains of honey bee scouts and found that this novelty-seeking behaviour appears to be based on the same molecular pathways used in similar thrill-seeking human behaviour. Novelty-seeking behaviour in vertebrates involves catecholamine, glutamate and gamma-aminobutyric (GABA) signalling in the brain. The differences in thrill-seeking behaviour between individuals are often attributed to personality differences. So do insects like honey bees have personalities of their own, just as we humans do? The researchers, led by Gene Robinson and Zhengzheng Liang, compared the molecular underpinnings of ...
- Mar 15, 12
A decade after the completion of the human genome sequence, researchers have sequenced the genome of a female western lowland gorilla called Kamilah from San Diego zoo. This means we now have a fully sequenced, representative genome sequence from each of the four great ape groups: humans, chimps and bonobos, orangutans, and gorillas. Having the full set will enable scientists to better understand when each of these groups evolved and ndash; a current matter of debate. Humans are identical to our ape relatives in almost all of our DNA base-pairs. We differ by 1.37% from the chimp, 1.75% from the gorilla and 3.4% from the orang-utan. Molecular data suggests humans and their closest relatives, chimps, diverged about 4.5 million years ago while evidence from fossils suggests they diverged as far back as 7 million years ago. Having completed the sequencing of the great ape genomes, researchers at the Sanger Institute in Cambridge ...
- Mar 15, 12
Last week, just days before the anniversary of the Fukushima disaster, came evidence that radioactive plutonium has spread much further from the nuclear plant than previously thought. Scientists from the National Institute of Radiological Sciences in Japan, found traces of the potentially harmful substance over 20 kilometres away from the plant and ndash; thankfully though, they say this poses no health risk. The crisis, which left 27,000 people dead or missing and caused billions of dollars in damage, began on 11 March 2011. A magnitude 9.0 earthquake on the Pacific floor triggered a tsunami which impacted, and subsequently devastated, the northeast coastline of Japan. Moments after the initial quake, the three operating reactors at Fukushima Daiichi automatically shut down. However, 41 minutes later the tsunami burst through the plant and rsquo;s defences, flooding the reactors. Over the following days, emergency systems failed and the reactors melted down. Hydrogen gas was released, triggering explosions in ...
- Mar 08, 12
Scientists at the University of Oxford have developed a pair of protein fragments dubbed and lsquo;SpyTag and rsquo; and and lsquo;SpyCatcher and rsquo; that form an incredibly strong bond. Within minutes of being brought into contact the protein fragments form a covalent bond so strong that when put under pressure, the protein breaks away from the apparatus before the bond breaks. It is effectively a biomolecular superglue and ndash; except, due to its good specificity, without the possibility of accidentally sticking to the edge of the test tube or other unwanted molecules. The discovery was inspired by Streptococcus pyrogenes, which causes infections ranging in severity from sore throats to toxic shock syndrome. The bacterium uses the FbaB protein to bind to human cells before invading. The particular strength of this link is caused by the protein and rsquo;s shape. Rather than simply being made of a chain of covalently bonded amino acids held together by comparatively weak forces, FbaB forms ...
- Mar 08, 12
Most women will at some point in their lives encounter the ticking biological clock: the realisation that their fertile years are limited, and if they wish to start a family, they cannot wait much longer. This is because we have only the supply of oocytes or egg cells we are born with, and when they and rsquo;re gone, they and rsquo;re gone. At least that is the conventional view of how the female reproductive system works. But research published recently in Nature Medicine suggests that there may be more going on than we had previously realised. Several years ago a team of researchers, led by Jonathan Tilly at Harvard Medical School, studied the dynamics of ovarian follicles (which produce oocytes) in mice, by measuring the rate at which they mature and are released or simply die. and nbsp; They found that something did not add up. Given the measured rate of degeneration, there should have been few ...
- Mar 08, 12
Declining sea ice in the Arctic Ocean may be indirectly causing mercury fallout in the lower atmosphere, a NASA-led study suggests. The study reveals that the increasing replacement of multi-year ice by saltier seasonal ice is driving the increased release of salt ions such as bromine into the atmosphere, which then interacts with various atmospheric components such as pollutants and ozone. The team of researchers from the UK, USA, Canada and Germany combined data from NASA, European Space Agency and Canadian Space Agency satellites with field observations and an atmospheric model in order to observe bromine release and establish the atmospheric height at which the process occurs. Bromine occurs as dissolved ions in seawater, and becomes incorporated into sea ice upon freezing. Upon interaction with solar radiation at the boundary layer between the atmosphere and sea-ice surface, salt ions (such as bromine) are oxidised into reactive species and released into the troposphere. ...
- Mar 08, 12
In the 21st century, our minds are brimming with concepts from iPhones to genetic testing to superstring theory, that could not have been entertained by our human counterparts centuries or millennia ago. This is because our species has a unique capability for and ldquo;cumulative culture and rdquo;, a process through which knowledge accumulates over time and technology is advanced iteratively. On the other hand, we can reasonably assume that the ideas inside the minds of other animals today are not vastly different from those centuries ago. Therefore, a team of scientists from University of St Andrews are seeking to explain what is special about the human mind that allows us to gradually accumulate knowledge. A study reported this week in Science investigated the differences in the capacity for cumulative cultural learning among humans, our closest relatives, chimpanzees, and capuchin monkeys. There are various hypotheses regarding the cognitive capabilities, or social conditions, that are required ...
- Mar 08, 12
Drinking in space can be a messy affair. In the absence of gravity liquid floats, requiring all drinks to be sucked up from a pouch using a straw and ndash; a particularly odd sensation when having your hot coffee in the morning. But now, thanks to NASA astronaut Dr. Don Pettit, sipping from an open top cup is possible, even in the zero gravity. Dr. Pettit, a member of the International Space Station (ISS) crew, occupies his spare time in space by conducting fascinating experiments for school children via video and inventing useful gadgets. It was during the STS-126 mission to the ISS that he finally became fed up of feeling and ldquo;like an insect and rdquo; sucking up all his beverages and so, in 2008, he created the Zero-G Cup. To make the cup Pettit folded over plastic sheet and sealed it with yellow and ldquo;space-tape and rdquo; to form a teardrop shaped vessel with an acute angle ...
- Mar 01, 12
The once distinct lines between fact and science fiction are getting increasingly blurred almost on a daily basis. This month, it and rsquo;s biology taking the lead. The Wyss Institute, a department committed to Biologically Inspired Engineering at Harvard University, recently unveiled its first ever cellular robot. It could be little to no time before these miniature machines are flowing through your body as they look to be the big players in medicine for the future. Scientists in the US are currently developing these DNA nanorobots. They are based on the concept of and lsquo;DNA Origami, and rsquo; initially put forward by Paul Rothemund from Caltech in 2006. By manipulating DNA, the usual, regular double helix structure is split down the middle, and then, using the specific bonding of the base pairs, turned into complex 2D or 3D forms by twisting DNA over itself in various ways. At the Wyss institute, they have managed to build complex ...
- Mar 01, 12
The origin of life on Earth is one of the most compelling questions in science today. Recently, hydrothermal vents on the ocean floor have been cited as potential settings for this event. However, the Proceedings of the National Academy of Sciences has published a study led by Armen Mulkidjanian from the University of Osnabr and uuml;ck, Germany, arguing that the first life arose in pools of condensed vapour from geothermal vents on land. Nearly 4 billion years ago the and lsquo;late heavy bombardment and rsquo; saw Earth and rsquo;s surface pulverised by asteroids, leaving few rocks intact. This was bad luck for scientists, as the earliest life probably existed before then and ndash; so we will never discover its fossils. Consequently, scientists are trying to picture those organisms from the biological, not fossil, record: finding features that all living cells share, because they probably also occurred in our most ancient ancestors, or and lsquo;protocells and rsquo;. The Canadian biochemist Archibald Macallum pointed out ...
- Mar 01, 12
Every student faces the eternal dilemma: balancing work, having a social life and sleep. On average, we humans spend a third of our lives sleeping. So what is sleep and is it really that important? There are two main types of sleep. The first type is composed of four stages. Stage I is called light sleep, during which muscle activity slows down and you doze off. Brain activity is described by low-amplitude beta waves. Stage II, or true sleep, sees a slowdown of the breathing pattern and heart rate, as well as lower frequency, higher amplitude theta waves. Stage III, or deep sleep, is characterised by delta waves, which have a higher amplitude and lower frequency. During this period, your breathing and heart rate are at their lowest. During the final Stage IV, breathing becomes rhythmic and limited muscle activity takes place. The pattern then reverses. A complete cycle of this ...
- Mar 01, 12
I and rsquo;m sure I and rsquo;m not alone in my scepticism of the apparent healing properties of alcohol when suffering from a cold or general post-Saturday-night divine punishment. Yet the latest research conducted at Emory University, Atlanta, suggests that fruit flies genuinely use alcohol to combat infection and ndash; from parasitic wasps. As you may well have inferred from their imaginative name, fruit flies (Drosophila melanogaster) eat rotten fruit, or more accurately, the yeast that decays said fruit. As by-products of the decaying process, yeast produces carbon dioxide and ethanol, thus rendering the fruit slightly alcoholic. Subsequently, the fruit fly has evolved resistance to the harmful effects of alcohol (in the form of the enzyme alcohol dehydrogenase), an adaptation not exhibited by the parasitic wasps (Leptopilina boulardi and Leptopilina heterotoma) that deposit their eggs in its circulatory system. This disparity in ethanol resistance prompted Todd Schlenke and his colleagues to feed healthy and parasited fruit flies ...
