"We received an important message from the first fractions of a second of the universe after the Big Bang"

This is what Prof. Mark Kamionkowski, a theoretical physicist from Johns Hopkins University, who proposed conducting the experiment at the South Pole, said in an interview with the Hidan website. Prof. Kamionkowski was a guest at the Hebrew University and delivered the lecture named after Arnold Rosenblum at the Rakeh Institute of Physics at the Hebrew University.

"The discovery of the pattern in the cosmic background radiation, and therefore the proof of inflation is the most important discovery in cosmology, but it created new questions about what preceded inflation and how it was conducted in all its stages." Says Prof. Mark Kamionkowski, a theoretical physicist from Johns Hopkins University, who suggested conducting the experiment at the South Pole in an interview with the Hidan website. Prof. Kamionkowski was hosted by Prof. Zvi Piren at the Rakeh Institute of Physics at the Hebrew University and delivered the Arnold Rosenblum lecture to the Institute's researchers. A lecture that of course dealt with the important discovery of the discovery of gravitational waves in the cosmic background radiation.

As I recall, at a press conference in which Prof. Kamionkowski also participated on March 17, astronomers from the Harvard-Smithsonian Center for Astrophysics in Massachusetts, from the California Institute of Technology (CALTECH) and from NASA's Jet Propulsion Laboratory in California announced that, according to their calculations, they had discovered evidence of the existence of gravitational waves - ripples in the fabric of space-time. This is the first direct evidence that the universe underwent a brief but massive rapid expansion immediately after the Big Bang.

The result was obtained by scanning a section of the sky while looking for tiny changes in the pattern of the cosmic background radiation, the echo of the Big Bang that can be seen today in every direction in the sky in the microwave field, at a temperature of three degrees Kelvin. Back in the late 2010s, Prof. Kamionkowski proposed to place a telescope at the South Pole, to examine the cosmic background radiation, a discovery that was eventually made with consecutive observations over three years 2012-XNUMX by the team that announced the findings about two weeks ago.

"The discovery of cosmic inflation is surprising and tells us things we didn't know before. This is by far the biggest discovery since the cosmic constant (and the fact that the universe is expanding rapidly) in 1998. In my opinion, over time it will be revealed that this is an even more important discovery. In any case, both discoveries were unexpected and through them we learned new details about the universe and how it behaves.

If we interpreted the signals correctly, this is a greeting from the universe when it was a trillion-trillionth of a trillionth of a second after the big bang. We know this is only the tip of the iceberg. The list of things we don't know will always be longer than the list of things we already know and it's exciting to discover something new every time.

The current inflation model generically predicted the existence of gravitational waves, but we did not know how strong the signals we would see, once we discovered the signs and we know their strength it will be easier to focus the search and answer other important questions such as how the inflation of the universe developed step by step, and in particular what It preceded it, because inflation has the property of erasing all the information that existed before its occurrence.

What caused inflation?

"That's a good question. As I mentioned, the observations made as part of the research give us reason to believe that there was inflation. There are many theories that try to explain why it happened. We still don't know what the correct inflationary theory is, but the range of possibilities has narrowed and through further research and measurements we will know why it happened."

Why was it actually necessary to move to the South Pole, is it because there are continuous nights for half a year, doesn't that make the research more expensive?

"The cost of a telescope at the South Pole is not that great. It is difficult to estimate its exact cost acceleration because the National Science Foundation (NSF) already operates the station at the South Pole for other purposes, so there was already an infrastructure for such an experiment. The cost of the telescope and the experiment itself is not that great, compared to cosmological studies. Indeed, the team members went down there in our winter - which is summer in the southern hemisphere, and they leave in the Antarctic winter, except for a researcher on duty who operates the systems in winter, the observation work itself was carried out remotely. Since these are radio waves, day or night does not matter, except for the hours when the sun is directly above you and in the observations conducted over three years. In addition, this is an area free of disturbances."

"Their data spans from 2010-2012. They also used data from a previous study carried out (with less advanced equipment) in 2006-9 and collaborated with another study whose results were also included in the calculation."

They discovered a pattern in the polarization of the cosmic background radiation known as BMODE, which is proof of the existence of gravitational waves. However, they observed a very small part of the sky, less than 1% of the surface of the sky. We can try to measure the pattern in larger areas of the sky. From what we understand so far there is some code in this pattern and so far we have only read a small piece of the message. The next step will be to map a larger area of ​​the sky. As mentioned, this was enough to obtain proof that inflation occurred, but further measurements will reveal to us how it developed over time, and the mechanism that preceded it. There are different types of physics in areas where the conditions were completely different from those where we experience the four forces of nature today. Measuring these patterns over a larger portion of the sky may provide evidence of how this happened."

Does inflation have an effect on the way galaxies are formed?
Prof. Kamionkowski: "The answer is not much. The current discovery has not changed the knowledge we have regarding the question of how galaxies were formed, but it does raise a question regarding the effect of expansion on the distribution of galaxies in the universe. We may be able to answer a simple question through a comprehensive galaxy survey.”

What do you think about multiverse theories?
"The multiverse solution is one of the theoretical explanations for the question of why inflation was created. One of the problems with inflation is that it erases almost any sign of what came before. The new discovery does not tell us what preceded inflation, but I hope that future experiments will give us answers on the matter. However, the multiverse idea is an immature theoretical idea. The theorists refer to him all the issues for which we do not have an answer. I hope that the new measurements will find answers to questions that are still open, whether they prove this theory or another. I don't know yet what they will be. It's good because surprises are the best thing about science. Surprises by definition cannot be predicted.”

Do you believe the results, or is there still room for doubt?
"Yes, these are results with incredible consequences. If the claim is true, it is exceptional from any other claim in science, it requires exceptional proof, as the late Carl Sagan said more than once. The next thing, as with any scientific discovery, is that other groups will make the same measurements, and that their friends will re-examine all the assumptions, and then we can determine with greater certainty whether what they see is indeed garlic. The current team raised the issue. They did a good job and scrutinized the results. They examined every alternative explanation and rejected several of them. Results on such a scale should be checked again, and I believe that in a year or two we will have additional information that will allow us to prove this."

Prof. Avi Leib from Harvard University and you stated that this is a discovery on the scale of a Nobel Prize, is this something close to the Higgs boson for which Higgs and Engler won the Nobel about six months ago?

"This is an even more important discovery than the Higgs. By the time the Higgs was discovered the theory was already established, many of the alternatives had been eliminated and it was just a question of building a complex device that could provide the result. In the current case, as I mentioned, we also discovered things we didn't know, and therefore it's a more exciting theory."