By Louise Mayor, Grenoble
(Left) Suited and booted and (right) Cherenkov radiation from an old reactor core
When I awoke last Thursday morning I didn’t expect that by the end of the day I’d have seen a nuclear reactor. And I don’t just mean looking at a big concrete building from the outside – I saw stuff glowing and had to wear a funny-looking suit and booties.
I was visiting the Institut Laue-Langevin (ILL) in Grenoble, France, where atoms are split not to generate electricity but to use the neutrons in experiments. In fact, that’s the whole purpose of the ILL reactor, known as a “neutron source”.
But why neutrons? Being electrically neutral, neutrons can penetrate deep into matter, right to the nuclei of atoms. Charged particles, in contrast, get scattered by atomic electrons. Neutrons can be thought of as a particle or wave, and with a wavelength on the order of Angstroms like those produced at the ILL, they interact with crystal structures to form a diffraction pattern as described by Bragg’s law. This pattern can be used to find out the positions of atoms in a sample, as well as how they move.
One application of neutron scattering I heard about was to look inside a turbine blade that’s been subjected to a projectile frozen chicken – the experimental version of a real-life, unlucky stray pigeon or seagull. Neutrons have been used to probe inside the turbine blade without having to interfere with it further by cutting it apart.
(Left) Neutron goings-on and (right) leaving via the air lock
Upon leaving the reactor hall I went back out through an air lock; there is a lower pressure inside the building so that if there is some leak, gas goes in and not out. Not quite the end of it, I then had to put my hands in a hole each and watch a progress bar slowly fill the screen ahead before I got the reassuring confirmation: “NOT CONTAMINATED”.
Another way to generate neutrons is “spallation”, where protons are accelerated towards a heavy metal target and knock neutrons off atomic nuclei. This method will be used in the European Spallation Source (ESS), which Sweden and Denmark won the bid last year to co-host in Lund, Sweden. To find out more, you can watch this video where the ESS is introduced by none other than Sir Patrick Stewart.
By Louise Mayor
We were delighted to hear that Mark Williamson won “Best Space Submission” in the Aerospace Journalist of the Year Awards 2010, for an article published in Physics World last March.
His victorious piece, Up close and personal, is about how planetary astronomy has developed from a science of entirely remote observation to one of immersive experimentation.
I caught up with Mark to find out his reaction to winning, and his thoughts on writing for Physics World in particular. Also – perhaps with selfish motives – I found out his tips for successful science writing.
Mark said that he was pleased to win the award, and explained that each of the categories is judged by other writers: “So it’s a sort of peer review,” he said.
I asked Mark whether writing for Physics World requires a different approach to some of the other publications he contributes to, such as Engineering & Technology and Space Times. But as he explained, “Physics World has a very different readership from the other magazines I write for, but I have exactly the same attitude to writing as for any other audience.
“It’s clear that a majority of the readership has a professional interest in physics, so you have to find a reason for them to read your article on space technology. You have to make it relevant, or at least interesting, to them.
“On the other hand, many physics graduates and readers of Physics World never work in physics, which is why a few years ago there was a drive to make the magazine more relevant to this audience too. Apart from that, physicists are not only interested in physics…are they?”
By Louise Mayor
A visit to the Louvre before heading off to Paris Diderot University for the conference
This week I was in Paris at the Eleventh International Symposium on the Frontiers of Fundamental Physics.
It was an intimate affair with only 145 participants, 20 of whom were invited speakers from the forefront of such research areas as dark energy, dark matter, supersymmetry and the LHC.
I was the only member of press, and several high-profile physicists were kind enough to explain their research fields to me over a coffee and mini pain au chocolat.
On Wednesday, I learned about inflationary models of the universe over lunch with Paul Steinhardt, Albert Einstein Professor of Science at Princeton University and co-author of the popular science book Endless Universe: Beyond the Big Bang. I was soon brought up to speed with the basics: inflation is the idea that shortly after the Big Bang the universe underwent rapid expansion over a very short space of time.
As an experimental physicist, I was interested to hear Steinhardt comment about how the roles of theory and experiment in cosmology have reversed: while cosmology used to be theory driven, technology has evolved to such a degree that, just using data from the last 10 years, we can test all the theories conceived over the course of human history to this point, and eliminate nearly all of them. “There are only two survivors capable of describing the current data in full detail – the inflationary model and the cyclic theory,” explained Steinhardt.
He also noted that it’s important to think of cosmology as a very new experimental science – all we really know comes from less than a century of measurements. For example, we only discovered the existence of galaxies and the expansion of the universe in the early 1920s.
Steinhardt also remarked that the rate at which we’re acquiring data about cosmology has now outpaced that of particle physics. (See my schoolgirl representation of this, right.)
There’s a phrase floating around that people use to describe this burgeoning area of physics: “precision cosmology”. I asked Steinhardt what he thinks of it. He said that he doesn’t use the phrase himself, because it implies that we have settled on the underlying theory and we’re down to measuring the detailed values of the underlying parameters. However, there is a real chance that the underlying theory is incorrect. “We might be precise – but precisely wrong,” he stressed.
Steinhardt explained that while we do know a few things reasonably precisely, such as the matter density, there are still deep questions about the underlying theory – both the inflationary and cyclic models are better described as “scenarios” with some details, but many parts that are sketchy and questionable. “For example, the more we have learned about the inflationary theory over the last 30 years, the more we have to question whether it really makes the predictions that it is credited to make,” he said.
Steinhardt went on to describe the inflationary model of the universe and its problems to me in more detail, and while I followed it to some extent, if you want to hear a good explanation then I would direct you to his book!
by Louise Mayor
Earlier this month, I and some of my colleagues – Kate Gardner, Margaret Harris and Dens Milne – braved the back streets of Bristol on a very important mission: to bring the readers of Physics World magazine a slightly-more-innovative-than-usual image on the front cover.
We were looking for something a bit different for the May issue of Physics World. This month we are marking the 50th anniversary of the laser by bringing readers top features from a host of eminent laser scientists, as well as a snazzy laser timeline. We needed a front cover that would do it justice.
Our brain wave was “laser-writing”. It would involve the four of us congregating in a darkened room, photographing a blank wall using a camera set to have a long exposure. We would write our chosen phrase on the wall using a red laser pen and capture this on camera. The relevancy would be immense – an image made of pure laser light, just the thing to introduce our laser special issue. Great idea, right?
Full of anticipation, after a drawn-out meal at the local curry house while we waited for darkness, we embarked on our mission. In a dark room we set up our digital SLR camera on a tripod. We used an exposure of tens of seconds to capture each individual alphanumeric character that we needed; these could then be later combined into words. And hey presto! … Hey presto? … Peering at the camera’s digital display, we realised that the effect was not as good as we’d hoped. The laser dot was so small in comparison to the size of the characters that the result appeared spindly.
But fret we did not, as we had back-up. We also tried using a torch (see I ♥ LASER image, top), and an array of bluish-white LEDs. The LEDs became the tool of choice that would eventually make the front cover with the “The laser at 50″ image shown right. Note that the issue itself is available as a free pdf download.
We also tried to go a bit more arty, and took to the dimly lit streets. Our best outdoor shot is shown above; the venue was a fenced-up disused garage. If you are interested in trying this sort of thing yourself, take a look at this great guide to light-graffiti.
We hope that you enjoy our efforts!
Einstein with his dog friend Hannah. Credit: Charlie Cantrell
By Louise Mayor
Meet Einstein, the world’s smallest horse. He is a pinto stallion, born last week weighing just 2.7 kg, and only 35 cm tall.
I got in touch with Einstein’s owners, Charlie Cantrell and Dr Rachel Wagner from New Hampshire, US, to ask what inspired the naming of this cute little fella.
They replied to say that they named him Einstein because they felt it would be a reminder of two things. The first was “that one has to be intelligent when purchasing a miniature horse [as] they require a massive amount of specialized care.” The second was that “Einstein believed in compassion for all living creatures. He was an advocate of humane treatment of animals.”
“Oh yes, and we thought the name was befitting of him because he had such a huge head for such a little foal,” they added.
So it turns out that Einstein the foal is aptly named! Indeed, supporting the owner’s comments is this animal-friendly quote from Einstein: “Our task must be to free ourselves – by widening our circle of compassion to embrace all living creatures and the whole of nature and its beauty.”
Update: Here is the latest image from the European Space Agency’s Envisat satellite, taken yesterday afternoon. A plume of brownish-grey ash from the Eyjafjallajökull volcano can be seen leaving Iceland in a roughly south-easterly direction.
(Edited 20 April 2010 – the original story follows below.)
New satellite image of ash spewing from Iceland’s volcano.
(Image acquired 19 April 2010, 1:45 PM) Credit: ESA
Volcanic ash cloud as viewed from space.
(Image acquired 15 April 2010, 12:25 PM) Credit: ESA
By Louise Mayor
This image, taken yesterday, shows the extent of the volcanic ash that has been spewing out of Iceland’s Eyjafjallajökull volcano since Wednesday. The ash, which contains tiny particles of rock and glass, can be seen as a grey streak in the upper half of the image, being swept by winds high in the atmosphere towards the rest of western Europe.
In the bottom-right of the image you can just about make out the Republic of Ireland, and the UK where all but a few individually permitted flights have been grounded for a second day running as a result of the ash cloud.
The picture was acquired by the Medium Resolution Imaging Spectrometer (MERIS) on board the European Space Agency’s Envisat satellite. Launched in 2002, the satellite’s primary purpose is to image the colour of the Earth’s oceans using 15 spectral bands over the 390–1040 nm range. These images reveal characteristics of water such as its concentration of chlorophyll, which can then be used to understand the role of our oceans in the carbon cycle.
Taken from an official here. It is refreshing to hear, as well, that half of the engineers who operate the Large Hadron Collider are women anyway.
On the same web page you can also watch video interviews, including one featuring graduate student, Laura Jeanty, who works at the ATLAS detector. Jeanty explains why she is supporting International Women’s Day and why she thinks that more women are needed in the particle physics community.