So last week marked another great discovery which, if confirmed, will likely be a contender for the next Nobel prize. It was of course the discovery of primordial gravitational waves in CMB, which was also concrete evidence for the theory of inflation. These and other news are discussed below. In order to receive these news straight to your email, register for our email newsletter.
On 17 March, astronomer John Kovac of the Harvard-Smithsonian Center for Astrophysics presented long-awaited evidence of gravitational waves — ripples in the fabric of space — that originated from the Big Bang during a period of dramatic expansion known as inflation. The discovery was important in two ways — it presented concrete evidence for the theory of inflation and gravitational waves, predicted by Einstein’s general theory of relativity. Even though scientists responsible for the discovery are confident that it is correct, additional measurements to confirm it will be needed. Despite this, however, due to the importance of the discovery, it has already been named as the leading contender for the upcoming Nobel prize.
The consequences of the big discovery has already been covered by some recently published papers. In particular, the results ruled out a class of models that attempted to explain both inflation and dark matter based on a hypothetical elementary particle called the axion. “The BICEP2 data would eliminate about 90% of inflationary models,” said Andrei Linde when commenting on the discovery.
Measuring masses is not as easy as it might often seem, especially when it comes to regions of space. The best you can do is consult a geometric formula. Three recent mathematical proofs recently took aim at refining one of the most useful of these formulas: Stephen Hawking’s definition of a region’s mass in a spacetime. “The problem of defining the mass inside a given region of a spacetime is fundamental to understanding general relativity, which is the current reigning theory of the large-scale structure of the universe,” said Hubert Bray, professor of mathematics and physics at Duke University.
One of the simplest formulas for calculating masses is a formula by Stephen Hawking. And recently, a team of three mathematicians and physicists published a paper refining Hawking’s formula and showing its advantages over other methods of calculating masses. To find out more use the link above.
The idea of changing constants in physics has been floating around for a while, and one of the constants that could be easily used to test these claims is the gravitational constant G. If G has been decreasing over time, for example, this would mean that the Earth’s distance to the Sun was slightly larger in the past, meaning that we would experience longer seasons now compared to at much earlier points in the Earth’s history. Physicists at Swinburne University of Technology in Melbourne, however, tested the theory in a bit more sophisticated way — they analyzed light given off by 580 supernova explosions in the nearby and far Universe and have shown that the strength of gravity has not changed.