How do you explain the science behind a rainbow to a child?
By Tushna Commissariat
It never rains but it pours, they say, and 1964 experienced quite a downpour of amazing “physics firsts” as the first papers about quarks, the Higgs mechanism and the EPR paradox or Belle’s inequality were all published. Also, Arno Penzias and Robert Woodrow Wilson made their first measurement of the cosmic microwave background on 20 May 1964, detecting the whisper of the Big Bang. To celebrate 50 years since these world-changing discoveries were made, the Harvard-Smithsonian Centre for Astrophysics has produced a webcast (you can watch the video on their YouTube page in a week’s time) featuring leading cosmologists Alan Guth, Robert Woodrow Wilson, Robert Kirshner and Avi Loeb. You can read more about it in this fascinating article by David Kaiser on the Huffington Post website, as he take a deeper look at the eventful year of 1964.
Could sterile neutrinos constitute dark matter? (Courtesy: Bubul et al./ arXiv:1402.2301)
By Tushna Commissariat
It is always interesting to us at Physics World when a particular topic suddenly attracts the attentions of the physics community, especially when it’s a rather hotly debated subject. The past couple of days, for example, have seen a lot of talk about “sterile neutrinos”, based on two papers – published in quick succession on the arXiv preprint server – that suggest the tentative detection of these hypothetical paricles.
Both papers are based on an unidentified emission line seen in the X-ray spectrum of some galaxy clusters obtained by the European Space Agency’s XMM-Newton observatory. Intriguingly, sterile neutrinos are also considered to be possible dark-matter candidates, meaning that – if discovered – they would be the first fundamental particles to lie beyond the bounds of the Standard Model of particle physics.
The first 45 minutes of Amy Smithson’s talk here at the 2014 AAAS meeting were interesting but not especially controversial. Smithson, a senior fellow at the Center for Nonproliferation Studies in Washington, DC, began by speaking about her role in combating the spread of nuclear, chemical and biological weapons over the past two decades, and how this made her persona non grata for both conservative Republicans and the Clinton White House during the 1990s. After drawing parallels between Iraq in the late 1980s and Syria today, she outlined some of the tactics that “bad guys” like Saddam Hussein and Bashar al-Assad have used to circumvent international weapons treaties and delay their enforcement.
At that point, Smithson changed tack. Warning that she was about to become “the skunk at the party”, Smithson turned her fire on the scientific community. Policy-makers, she observed, can’t make weapons of mass destruction on their own. For that, they need scientists, and over the past 60 years, “hundreds of thousands of scientists” have obliged by working on nuclear, chemical or biological weapons.
If you’re fed up with floods in England, sick of snow in the US or mystified by mild temperatures in Scandinavia, blame it on Santa Claus. That’s the message coming from atmospheric scientist Jennifer Francis, whose “Santa’s revenge” hypothesis suggests that the weather weirdness that we’re currently seeing at middle latitudes could be linked to recent warming in the Arctic.
Francis’ theory begins with the polar jet stream, the high-altitude “river of air” that flows over parts of the northern hemisphere. This jet stream owes its existence to the temperature differential between the Arctic region and middle latitudes: because warm air expands, that temperature differential produces a “hill” of air with (for example) England at the top and Greenland at the bottom. The Earth’s rotation means that air doesn’t flow straight down this hill; instead, it curves around, producing the west–east flow seen in animations like the one in this video from the NASA Goddard Science Visualization Studio.
The light from natural gas flares burning in North Dakota’s Bakken oil field can be seen from space. (Courtesy: NASA Earth Observatory)
By Margaret Harris in Chicago
The environmental risks of shale-gas production are real, but the things people worry about most aren’t necessarily the ones that cause the most damage. That was the message of this morning’s AAAS symposium on “Hydraulic Fracturing: Science, Technology, Myths and Challenges”, which featured talks on the social implications of hydraulic fracturing as well as the risks of water and air contamination.
Hydraulic fracturing, or “fracking”, involves drilling a well and filling it with a high-pressure mixture of water and other chemicals. These high pressures cause nearby rock formations to fracture, releasing trapped oil and gas. According to the first speaker, energy consultant David Alleman, fracking and horizontal drilling have “revolutionized the energy picture in the US”: a few years ago, the country imported 60% of the oil it consumed, but today the figure is just 30%.
If you like piña coladas and quantum mechanics, then we hope you are currently on the two-week “Bright Horizons 19” Southeast Asia cruise, as on board is physicist and writer Sean Carroll. He will be giving multiple lectures over the next 15 days on everything from the Higgs boson to dark matter and other fundamentals of quantum mechanics. Also floating along with Carroll are other lecturers who will cover topics from natural history to genetics to military strategy. If, like us, you are stuck at home, you can take a look at Carroll’s slides on his blog, maybe have a cocktail while you are at it.
It’s ice cold outside (–16 °C the last time I checked), but Chicago is still a hot ticket for scientists this week as the capital of the American Midwest prepares to host the 2014 meeting of the American Association for the Advancement of Science (AAAS).
As usual, there are plenty of fascinating talks planned for the meeting, which runs from today through Monday. Looking through the schedule just now, I’m pretty sure I could fill all five days with seminars on scientific entrepreneurship, policy and communication – although if I did, I’d miss out on some great physics topics such as dark-matter detection, quantum cryptography and next-generation materials for batteries. Which would be a shame.
I’ll be posting regular updates throughout the conference here on the physicsworld.com blog, and I’ll also be live-tweeting a few of the talks (only the really interesting ones, I promise) as @DrMLHarris on Twitter. So check back soon for more on the 2014 AAAS meeting.
Is the Euler identity the most beautiful equation of them all?
By James Dacey
If you have ever talked with your arty friends about the sense of “beauty” you feel from maths, you may well have been greeted with a sympathetic smile. Perhaps even with jeers of derision. Well, next time you find yourself in that position you will have some scientific evidence to back up what you are saying. A group of researchers in the UK has demonstrated that getting your noggin around an equation can trigger the same part of the brain as staring at the Mona Lisa or listening to The White Album.
In an experiment described in Frontiers in Human Neuroscience, 15 mathematicians were presented with a series of 60 equations and asked to rate them for their beauty on a scale of –5 (ugly), through to +5 (beautiful). The same subjects were then hooked up to a functional magnetic resonance imaging (fMRI) machine and asked to view the same list of equations. It turned out that when mathematicians viewed the equations they had previously rated as beautiful, it triggered activity in a part of the emotional brain associated with the experience of visual and musical beauty.*
Materials research is enjoying a new golden age. The hit parade of supermaterials that has been discovered in the relatively recent past is extensive. It includes the likes of high-temperature superconductors, quantum dots, bucky-balls, nanotubes, aerogels, silver nanowires and graphene. Meanwhile, new approaches to the commercialization of materials – such as the recent Materials Genome Initiative in the US – are improving the processes by which new materials are transferred from the science lab to practical applications in the real world.
In conjuction with these new discoveries, materials scientists have also made dramatic improvements to the tools they have available for studying and manufacturing materials. Here, the list of advances is seemingly endless. Researchers can now simulate, image and analyse materials with far more accuracy than ever before. Developments in production methods – such as the advent of 3D printing – are also enabling researchers to scale up their new materials with greater ease.
There’s definitely an educational vibe to this week’s picks from the Red Folder, which begins with Tanner Higgin’s selection of “Five apps that test your physics skills“. Writing on Mind/Shift, a website based in California and dedicated to learning, Higgin highlights Crayon Physics Deluxe, which allows users to draw physical objects and then let gravity and other physical effects take over. Also featured is Amazing Alex, which allows users to combine more than 30 different household objects to create fantastical Heath Robinson/Rube Goldberg contraptions.