Astrophysics: A telescope at the South Pole has made the biggest cosmological discovery so far this century

Astrophysics: A telescope at the South Pole has made the biggest cosmological discovery so far this century
Mar 22nd 2014 | From the print edition
ONE useful feature of a scientific theory is that it makes testable predictions. Such predictions, though, do not have to be testable straight away. Physics is replete with prophecies that could be confirmed or denied only decades later, once the technology to examine them had caught up. The Higgs boson, for example, was 50 years in the confirming.Now something similar is happening in cosmology. On March 17th the Harvard-Smithsonian Centre for Astrophysics, in Cambridge, Massachusetts, announced that a team led by John Kovac, of Harvard University, had spotted signs of gravitational waves—ripples in the fabric of space—that had formed when the universe was but a trillionth of a trillionth of a trillionth of a second old. In doing so, Dr Kovac and his colleagues have confirmed a 30-year-old idea called cosmic inflation, which proposes that shortly after it was born the universe underwent a sudden, enormous expansion.
For cosmologists, this is a big advance. The primordial gravitational waves Dr Kovac and his colleagues have found not only confirm inflation, they may also help physicists forge the long-sought link between quantum theory and relativity, two presently irreconcilable ways of explaining the universe.
Gravitational waves are a prediction of Einstein’s general theory of relativity, which is the modern theory of gravity. They have never been seen directly, though an indirect proof of their existence, based on studying a pair of collapsed stars, was rewarded with the 1993 Nobel prize in physics. Dr Kovac’s team have not changed this state of affairs. But they have inferred the waves’ presence from their effect on the cosmic microwave background radiation—a faint afterglow of the universe’s hot youth that now forms an electromagnetic mist which pervades the cosmos.
Dr Kovac used BICEP2, a telescope (pictured above) near the South Pole, to look for a subtle “curl” in this mist, which inflation theory suggests should be there. And, after months of staring into the Antarctic sky and more months of checking and rechecking the data, that curl has turned up.
The Big Bang theory
Inflation was conceived in the 1980s by theorists such as Alan Guth and Andrei Linde as a “beautiful fudge”, as Chris Lintott, an astrophysicist at the University of Oxford, puts it. It was attractive because it let cosmologists explain, or explain away, some inconvenient facts about the universe—chiefly, how boring it is.
Geometrically, the universe is flat (ie, parallel lines within it remain the same distance apart no matter how far they are projected). Since there are an infinite number of ways of being curved and only one of being flat, this needs explaining. Similarly, the distribution of matter in the universe, at least at the grandest scales, is strikingly homogenous when it might be expected to be random.
Inflation disposes of these difficulties. The more you inflate a balloon, to give a two-dimensional example, the less pronouncedly curved its surface gets. If you could inflate it to an infinite diameter, its surface actually would be flat. Similarly, any irregularities on the surface of a deflated balloon are quickly smoothed away by blowing it up. Since inflation expanded the size of the universe ten billion billion billion-fold, it had an effect that is, mathematically, almost indistinguishable from that of an infinite expansion.
This inflationary expansion would, theory predicts, have generated huge quantities of gravitational waves. And the data from BICEP2 suggest this is exactly what happened. The specifics of the traces Dr Kovac has seen should let physicists start working out which versions of inflation theory best match the data.
The most exciting part of BICEP2’s results, though, is not their confirmation of predictions past, but the crack they open in the doorway to the future. Inflation took the universe from a scale at which quantum mechanics (which is a theory of the very small) dominates proceedings to one at which relativity (a theory of the very large) does so. Studying the transition may bring the eight-decade search for a link between them to fruition.
There is general agreement that the way forward is to “quantise” gravity, and numerous mathematical treatments have attempted to do so. The gravitational waves detected by BICEP2, formed by inflation, a quantum-mechanical process, prove gravity can be quantised and thus provide a lens through which these treatments can be examined.
All in all, then, a big day for cosmology—assuming the results hold up. Although there have been quibbles, the consensus among those physicists to whom The Economist has spoken is that the data look solid and that Dr Kovac’s team have been diligent in their attempts to excise sources of error that might pollute them. As Andrew Jaffe, a cosmologist at Imperial College, London, puts it, “It’s hard to imagine that these results could be completely wrong, but it’s conceivable that some of the numbers might change a little once we start getting more data.”
Happily, such data should soon be forthcoming. BICEP2 itself is still churning them out.Planck, a now-defunct satellite that belonged to the European Space Agency, also studied the cosmic microwave background and its data are now being crunched. Other ground-based missions, too, are on the case.
If these efforts ended up unifying quantum mechanics and relativity, that really would be the discovery of the century. Whether such a unified theory would be, or would lead to, the much-sought “theory of everything” which physicists hope will describe reality without fear, favour or fudge is impossible to know. But it might.

About bambooinnovator
Kee Koon Boon (“KB”) is the co-founder and director of HERO Investment Management which provides specialized fund management and investment advisory services to the ARCHEA Asia HERO Innovators Fund (, the only Asian SMID-cap tech-focused fund in the industry. KB is an internationally featured investor rooted in the principles of value investing for over a decade as a fund manager and analyst in the Asian capital markets who started his career at a boutique hedge fund in Singapore where he was with the firm since 2002 and was also part of the core investment committee in significantly outperforming the index in the 10-year-plus-old flagship Asian fund. He was also the portfolio manager for Asia-Pacific equities at Korea’s largest mutual fund company. Prior to setting up the H.E.R.O. Innovators Fund, KB was the Chief Investment Officer & CEO of a Singapore Registered Fund Management Company (RFMC) where he is responsible for listed Asian equity investments. KB had taught accounting at the Singapore Management University (SMU) as a faculty member and also pioneered the 15-week course on Accounting Fraud in Asia as an official module at SMU. KB remains grateful and honored to be invited by Singapore’s financial regulator Monetary Authority of Singapore (MAS) to present to their top management team about implementing a world’s first fact-based forward-looking fraud detection framework to bring about benefits for the capital markets in Singapore and for the public and investment community. KB also served the community in sharing his insights in writing articles about value investing and corporate governance in the media that include Business Times, Straits Times, Jakarta Post, Manual of Ideas, Investopedia, TedXWallStreet. He had also presented in top investment, banking and finance conferences in America, Italy, Sydney, Cape Town, HK, China. He has trained CEOs, entrepreneurs, CFOs, management executives in business strategy & business model innovation in Singapore, HK and China.

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