Tag archives: cosmology
BICEP2’s findings trigger new kind of ‘inflation’
By Tushna Commissariat
Scientists and laypeople the world over were intrigued by the announcement made by the BICEP2 collaboration earlier last month, when it claimed to have detected the primordial “B-mode polarization” of the cosmic microwave signal (CMB). Many researchers have hailed it as the first evidence for cosmic inflation – the extremely rapid expansion that cosmologists believe our universe underwent a mere 10–35 s after the Big Bang.
Indeed, after a quick search of the arXiv preprint server, I found nearly 172 papers based on the BICEP2 data that have been written since the team’s announcement on 17 March. Some 200 individual citations to the original BICEP2 paper can also be found on the server.
3D printing food, ‘Top 10’ lists, teenage nuclear physicists and more
By Tushna Commissariat
Over the past few years, 3D printing has captured the imagination and interest of scientists and the public alike. Now, a €3 million EU-funded project known as “PERFORMANCE – PERsonalised FOod using Rapid MAnufacturing for the Nutrition of elderly ConsumErs” is adapting 3D printing technology to food in order to create easily digestible sustenance that is not only nutritious but also looks and tastes like the real thing. The proposed printer would work like its conventional inkjet counterpart – except the cartridges would be filled with liquefied food instead of ink! While that may not sound like the most appetising way of eating your five-a-day, it might come as a relief for those who suffer from a condition known as “dysphagia” that makes swallowing food difficult. You can read more about the proposed scheme on the EU’s Horizon magazine website and take a look at the video above.
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BOSS uses 164,000 quasars to map expanding universe
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 (by rippstein). BOSS and other observatories have previously measured expansion rates going back 6 billion years.
BICEP2 surprise visit, a bizarre rant, credible science fiction and more
By Hamish Johnston
The big story this week is that astronomers working on the BICEP2 telescope may have spotted the first direct evidence for cosmic inflation. This is very good news for the physicist Andrei Linde, who along with Alan Guth and others did much of the early work on inflation. In the above YouTube video Linde, who is certainly in the running for a Nobel prize, receives a surprise visit from BICEP2 team member Chao-Lin Kuo. Kuo is the first to tell Linde and his wife, the physicist Renata Kallosh, the news that the theory that Linde developed more than 30 years earlier had finally been backed up by direct observational evidence. Not surprisingly, champagne glasses are clinking!
Here at physicsworld.com we have tried to tell both sides of the story: the thrill of seeing the first hints of cosmic inflation, tempered with calls for caution that more data are needed before inflation is victorious over other theories describing the early universe.
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Golden-anniversary physics, flaming challenges, smart lists and more
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 Bell’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.
Are ‘sterile neutrinos’ dark-matter particles after all?
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.
Condensed-matter cosmology and spin wires
By Hamish Johnston at the 2013 CAP Congress in Montreal
Yesterday morning I was back at the University of Montreal for more physics at the Canadian Association of Physicists Congress. I started off the morning with a bit of quantum cosmology and quantum gravity with a distinct hint of condensed-matter physics.
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Old-school cosmological calculations
By Tushna Commissariat
The next time you need to quickly convert the redshift of some distant cosmic object to parsecs or kilometres, and find that your laptop and phone have both run out of charge (the horror!), the “Paper-and-pencil cosmological calculator” might be just the thing for you. More of a chart than a “calculator”, the new table – that is based on the ΛCDM cosmological model of the universe – has been drawn up by Sergey Pilipenko from the Lebedev Physical Institute in Moscow. And here’s the best bit – all the parameters that Pilipenko has plugged into his table are from the latest Planck results unveiled last month.
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