Direct Evidence of Big Bang’s Gravitational Waves!!
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As part of his General Theory of Relativity, Einstein predicted that acceleration of large masses would cause waves to ripple through space in a manner analogous to ripples on the surface of a pond. Indirect evidence abounds for gravitational waves, but almost a century after Einstein predicted it direct evidence remained elusive
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 Cosmic Microwave Background.
Only the gravitational waves moving through the Universe in its inflationary phase could have produced such a marker. It is a true "smoking gun".
At rare moments in scientific history, a new window on the universe opens up that changes everything.
Yesterday was quite possibly such a day.
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.
At a press conference on Monday 17th March 2014
morning at the Harvard-Smithsonian Center for Astrophysics, a team of scientists operating a sensitive microwave telescope at the South Pole announced the discovery of polarization distortions in the Cosmic Microwave Background Radiation, which is the observable afterglow of the Big Bang.
The distortions appear to be due to the presence of gravitational waves, which would date back to almost the beginning of time.
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 gravitation, 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.
If verified, the find will dispel any lingering doubts about Relativity Theory, transform our understanding of the universe's beginning and provide astrophysicists with a new tool to probe the universe. The importance of the detection is hard to overstate.
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."
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, and leaves non-inflationary versions completely on the outer.
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.
Other experiments will now race to try to replicate the findings. If they can, a Nobel Prize seems assured for this field of research.
(^^That's also partly quotes)
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Originally Posted by iflscience.com
How inflation works
Scientists use the word "inflation" to describe how the universe rapidly expanded after the Big Bang in a ripping-apart of space. The BICEP2 results are the "smoking gun for inflation," Marc Kamionkowski, professor of physics and astronomy, said at a news conference. Kamionkowski also was not involved in the project.
Imagine that you are making a raisin bun, said Stanford physicist Kent Irwin, who worked on sensors and readout systems used in the experiment. As the dough bakes and expands, the distance from any given raisin to another increases.
"Certainly everything in the universe that we see now, at one time before inflation, was smaller than an electron," Irwin said. "And then it expanded during inflation at faster than the speed of light."
You may have learned in physics class that light sets the universe's speed limit, but space-time is an exception; it can stretch faster than the speed of light, Irwin said.
Stanford University professor Andrei Linde, who helped develop the current inflation theory, said the new results are something he had hoped to see for 30 years.
"If this is true, this is a moment of understanding of nature of such a magnitude that it just overwhelms and let's just hope that it's not a trick," Linde said in a university video interview.
Another cool tidbit: Inflation can be used in theories that suggest the existence of multiple universes, Irwin said, although these results do not directly address such theories.
