As part of my road-trip round Brazil, I visited Inmetro – the Brazilian standards lab. Located around 50 km north of Rio de Janeiro, Inmetro certainly has the feeling of being well away from the hustle and bustle of one of Brazil’s major cities.
The first thing that you notice when you enter Inmetro’s vast campus is that the buildings have a unique architecture (see above). The bunker-like structures are built in such a way that they are protected from the Sun, which can deliver 40 °C temperatures in summer. (Thankfully, I am here in autumn, but the temperature is still a warm 30 °C.)
Inmetro’s campus was built about 40 years ago with the help of the PTB – the German standards lab. The buildings were also specially designed so that the labs are vibrationally separate from the offices. So, any wild jumping around at your desk won’t affect the sensitive measurements in the lab.
While on my trip, I have visited a number of institutes that focus on materials research. But I also had the chance to talk a bit of policy when visiting FAPEMIG – the main state funder for research in Minas Gerais, which is the second most populous state in Brazil.
It’s the nightmare scenario for any PhD student: losing all those research results that you carefully squirreled away for when you finally sit down to write your thesis. That’s just what happened to biologist Billy Hinchen, who lost four years’ worth of 3D time-lapse videos of developing crustacean embryos when his laptop and back-up drives were stolen. Find out what happened next in “What would happen if you lost all of your research data?” by Julia Giddings at the scientific software firm Digital Science. Hinchen also tells his tale of woe in the video above.
An artist’s illustration of how BOSS uses quasars to measure the distant universe. (Courtesy: Zosia Rostomian, Lawrence Berkeley National Laboratory; Andreu Font-Ribera, BOSS)
By Calla Cofield at the APS April Meeting in Savannah, Georgia
Scientists looking at data from the Baryon Oscillation Spectroscopic Survey (BOSS), the largest programme in the third Sloan Digital Sky Survey, have measured the expansion rate of the universe 10.8 billion years ago — a time prior to the onset of accelerated expansion caused by dark energy. The measurement is also the most precise measurement of a universal expansion rate ever made, with only 2% uncertainty. The results were announced at a press conference at the APS’s April meeting on Monday, at the same time that the results were posted on the arXiv preprint server.
The rate of universal expansion has changed over the course of the universe’s lifetime. It is believed to have gradually slowed down after the Big Bang, but mysteriously began accelerating again about 7 billion years ago. BOSS and other observatories have previously measured expansion rates going back 6 billion years.
I don’t know about you, but I look back rather nostalgically on the practical exams that I took as an 18 year old as part of my A-levels in physics and chemistry. At the time, I wasn’t looking forward to them at all – they lasted three hours each and there was always the very large possibility of completely mucking up your experiment and/or dropping all your samples on the floor.
Although I’ve forgotten everything about my physics practical exam, the chemistry practical still sticks out in my mind. I remember making some needle-like crystals that, through amazing good fortune, turned out really well – certainly far better than the watery mush I’d created in my mock exams. So when I walked over to the other side of the lab to measure the temperature at which the crystals melted, they did so over a really narrow range – and presumably at the “correct” temperature too.
This all-sky image, constructed from two Fermi datasets, shows how the gamma-ray sky appears at energies greater than 1 GeV. (Courtesy: NASA/DOE/Fermi/LAT Collaboration)
By Calla Cofield at the APS April Meeting in Savannah, Georgia
The American Physical Society (APS) April meeting has been taking place in Savannah, Georgia, for the past three days. On Saturday, Tracy Slatyer from MIT spoke to reporters about a paper that she and colleagues posted on arXiv in February, in which they suggest that a mysterious excess of gamma rays surrounding the galactic centre could be explained as dark-matter particle annihilation.
The researchers use what Slatyer calls a “simple” model of dark matter, in which the invisible substance is made up of weakly interacting massive particles (WIMPs) with a mass of about 35 GeV. The model predicts that WIMPs may collide with each other and annihilate, producing gamma rays and either b-quarks or some other mixture of quarks. The Fermi Gamma-ray Space Telescope surveys the entire observable sky for the presence of gamma rays. Fermi’s observation of the plane of the Milky Way revealed that our galaxy is bright with gamma rays, but Fermi has not been able to identify the sources of all those powerful photons. Gamma-ray excesses (more than can be explained by known sources) near the galactic centre have been identified in the Fermi data in the past – most notably at about 130 GeV.
The work presented by Slatyer and her colleagues identifies an excess of gamma rays between 1 and 3 GeV. The researchers say they can see a distinctly spherical, bubble-like collection of photons. Slatyer told reporters that based on the dark-matter model, this spherical shape is not a coincidence – the dark-matter annihilation theory does not hold for a more stretched-out, elongated cluster of gamma rays; nor would it hold if the bubble were not at the centre of the galaxy.
The joke’s on me: click on the image for a larger version where you can see the instruction for users
By Hamish Johnston
On Tuesday I was feeling particularly pleased with myself over the April Fool’s piece that I penned. It was about a fictitious microwave-oven ban organized by radio astronomers at the UK’s Jodrell Bank Observatory. But now it looks like I might have a bit of microwaved egg on my face because two of my colleagues visited Jodrell Bank this week and guess what? Astronomers there have built a Faraday cage around the microwave in their tearoom to stop it from interfering with their equipment. Louise Mayor took the above photos: click on the image to read the reminder to microwave users.
If you’re a busy researcher, you’ll know just how precious time can be. But for many physicists, there’s a growing pressure to communicate, collaborate and interact – often at the expense of having time in silence to sit and think.
It’s an issue tackled in the cover story of the April issue of Physics World magazine by Felicity Mellor from Imperial College London, who runs a project called “Silences of Science“. The cover of this month’s issue was specially commissioned by us from artist Dave Cutler.
As Mellor puts it, current research policy – in the UK at least – emphasizes silence’s opposite. “From assessing publications and rewarding collaborations, to requirements for public engagement, policy initiatives urge scientists to speak up,” she writes.
Yet there is a danger, Mellor warns, that in the midst of all this enforced interaction, an important precondition for creativity in physics could be lost. “With all these demands to talk, do scientists still have the chance to think?” she wonders.
An international group of astronomers is calling for people to stop using their microwave ovens for 24 hours next April to give scientists a better chance of finding gravitational waves.
The ubiquitous kitchen gadgets broadcast copious amounts of electromagnetic radiation at frequencies around 2.45 GHz – exactly that of the cosmic microwave background, which bears the signature of gravitational waves from the early universe.
The call for a one-day global microwave oven ban comes just a fortnight after scientists detected B-mode polarization from the early universe using the BICEP2 telescope at the South Pole.