Evidence spotted for universe's early growth spurt
By MALCOLM RITTER
AP Science Writer
NEW YORK (AP) -- Researchers say they have spotted evidence that a split-second after the Big Bang, the newly formed universe ballooned out at a pace so astonishing that it left behind ripples in the fabric of the cosmos.
If confirmed, experts said, the discovery would be a major advance in the understanding of the early universe. Although many scientists already believed that an initial, extremely rapid growth spurt happened, they have long sought the type of evidence cited in the new study.
The results reported Monday emerged after researchers peered into the faint light that remains from the Big Bang of nearly 14 billion years ago.
The discovery "gives us a window on the universe at the very beginning," when it was far less than one-trillionth of a second old, said theoretical physicist Lawrence Krauss of Arizona State University, who was not involved in the work.
"It's just amazing," Krauss said. "You can see back to the beginning of time."
Marc Kamionkowski, a theoretical physicist at Johns Hopkins University who did not participate in the research, said the finding is "not just a home run. It's a grand slam."
He and other experts said the results must be confirmed by other observations, a standard caveat in science.
Right after the Big Bang, the universe was a hot soup of particles. It took about 380,000 years to cool enough that the particles could form atoms, then stars and galaxies. Billions of years later, planets formed from gas and dust that were orbiting stars. The universe has continued to spread out.
Krauss said he thinks the new results could rank among the greatest breakthroughs in astrophysics over the last 25 years, such as the Nobel prize-winning discovery that the universe's expansion is accelerating.
Monday's findings were announced by a collaboration that included researchers from the Harvard-Smithsonian Center for Astrophysics, the University of Minnesota, Stanford University, the California Institute of Technology and NASA's Jet Propulsion Laboratory. The team plans to submit its conclusions to a scientific journal this week, said its leader, John Kovac of Harvard.
Astronomers scanned about 2 percent of the sky for three years with a telescope at the South Pole, where the air is exceptionally dry.
They were looking for a specific pattern in light waves within the faint microwave glow left over from the Big Bang. The pattern has long been considered evidence of rapid growth, known as inflation. Kovac called it "the smoking-gun signature of inflation."
The reported detection suggests that "inflation has sent us a telegram," Kamionkowski said.
The researchers say the light-wave pattern was caused by gravitational waves, which are ripples in space and time. If verified, the new work would be the first detection of such waves from the birth of the universe, which have been called the first tremors of the Big Bang.
Krauss cautioned that the light-wave pattern might not be a sign of inflation, although he stressed that it's "extremely likely" that it is. The pattern is "our best hope" for a direct test of whether the rapid growth spurt happened, he said.
Alan Guth of the Massachusetts Institute of Technology, a creator of the idea of inflation, said the findings already suggest that some ideas about the rapid expansion of the universe can be ruled out.
It had not been clear whether the light-wave pattern would be detectable even if inflation really happened, he said, but luckily "nature is cooperating with us, laying out its cards in a way that we can see them."
Scientists say they have extraordinary new evidence to support a Big Bang Theory for the origin of the Universe.
Researchers believe they have found the signal left in the sky by the super-rapid expansion of space that must have occurred just fractions of a second after everything came into being.
It takes the form of a distinctive twist in the oldest light detectable with telescopes.
The work will be scrutinised carefully, but already there is talk of a Nobel.
"This is spectacular," commented Prof Marc Kamionkowski, from Johns Hopkins University.
"I've seen the research; the arguments are persuasive, and the scientists involved are among the most careful and conservative people I know," he told BBC News.
The breakthrough was announced by an American team working on a project known as BICEP2.
This has been using a telescope at the South Pole to make detailed observations of a small patch of sky.
The aim has been to try to find a residual marker for "inflation" - the idea that the cosmos experienced an exponential growth spurt in its first trillionth, of a trillionth of a trillionth of a second.
Theory holds that this would have taken the infant Universe from something unimaginably small to something about the size of a marble. Space has continued to expand for the nearly 14 billion years since.
Inflation was first proposed in the early 1980s to explain some aspects of Big Bang Theory that appeared to not quite add up, such as why deep space looks broadly the same on all sides of the sky. The contention was that a very rapid expansion early on could have smoothed out any unevenness.
But inflation came with a very specific prediction - that it would be associated with waves of gravitational energy, and that these ripples in the fabric of space would leave an indelible mark on the oldest light in the sky -the famous Cosmic Microwave Background.
The BICEP2 team says it has now identified that signal. Scientists call it B-mode polarisation. It is a characteristic twist in the directional properties of the CMB. Only the gravitational waves moving through the Universe in its inflationary phase could have produced such a marker. It is a true "smoking gun".
Speaking at the press conference to announce the results, Prof John Kovac of the Harvard-Smithsonian Center for Astrophysics, and a leader of the BICEP2 collaboration, said: "This is opening a window on what we believe to be a new regime of physics - the physics of what happened in the first unbelievably tiny fraction of a second in the Universe."
Completely astounded
The signal is reported to be quite a bit stronger than many scientists had dared hope. This simplifies matters, say experts. It means the more exotic models for how inflation worked are no longer tenable.
The results also constrain the energies involved - at 10,000 trillion gigaelectronvolts. This is consistent with ideas for what is termed Grand Unified Theory, the realm where particle physicists believe three of the four fundamental forces in nature can be tied together.
But by associating gravitational waves with an epoch when quantum effects were so dominant, scientists are improving their prospects of one day pulling the fourth force - gravity itself - into a Theory of Everything.
The sensational nature of the discovery means the BICEP2 data will be subjected to intense peer review.
It is possible for the interaction of CMB light with dust in our galaxy to produce a similar effect, but the BICEP2 group says it has carefully checked its data over the past three years to rule out such a possibility.
Other experiments will now race to try to replicate the findings. If they can, a Nobel Prize seems assured for this field of research.
Who this would go to is difficult to say, but leading figures on the BICEP2 project and the people who first formulated inflationary theory would be in the running.
One of those pioneers, Prof Alan Guth from the Massachusetts Institute of Technology, told the BBC: "I have been completely astounded. I never believed when we started that anybody would ever measure the non-uniformities of the CMB, let alone the polarisation, which is now what we are seeing.
"I think it is absolutely amazing that it can be measured and also absolutely amazing that it can agree so well with inflation and also the simplest models of inflation - nature did not have to be so kind and the theory didn't have to be right."
British scientist Dr Jo Dunkley, who has been searching through data from the European Planck space telescope for a B-mode signal, commented: "I can't tell you how exciting this is. Inflation sounds like a crazy idea, but everything that is important, everything we see today - the galaxies, the stars, the planets - was imprinted at that moment, in less than a trillionth of a second. If this is confirmed, it's huge."
by ADAM FRANK
A previous version of this post incorrectly referred to a decimal point with 35 zeros after it. The correct number of zeros is 34.
漂亮! |
34个0? ![]() ![]() 拜晴MM所赐, 帅 ![]() |
如果在其狭窄的光路某处附近有两个,或两个以上周期性出现的大质量星体,它们各自的引力波正好在所摄的光通道里发生干涉呢? 本贴由[salmonfish]最后编辑于:2014-3-18 0:6:53 |
当然啦,在南半球的南极上看到的,应该只是宇宙的一部分。 是不是在别的星空能再现,似乎不是最重要的,需要别的类似但原理不一样的仪器也能看到,就大功告成。网上的材料表明, 当然国际上、甚至于美国国内,都有多个竞争性的团队,也做这个,哈佛的这一队一年前就有了初步结果,也许 大约别的团队也快出结果了,所以不能再等、再推敲、再验证了 ![]() ![]() |
而这次测的引起B-mode的重力波,和你所说的由于大质量星体运动导致光线弯曲的那种重力波不同。后者 出现在较年轻的宇宙,前者是Big Bang的最初那个Bang的时候出现。观测上,前者是个比较小尺度的视角上看到, 而这次所见的有3°左右的视角,很大,和前者是不一样的特征。 ![]() |
BBC看来还不如俺半吊子来得专业 ![]() 这是重大失误,应该叫gravitational waves。 ![]() |
网络改变了生活,俺决定多用网络成语,不卖糕了, ![]() ![]() 拜晴MM所赐, 帅 ![]() |
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