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Shocked Physicist Learns His Big Bang Theory Is True [Video]

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Andrei Linde Hears BICEP2 Results

Andrei Linde and Renata Kallosh get a surprise visit from Chao-Lin Kuo, co-leader of the BICEP2 experiment, to share his results. Credit: Stanford University

Few people were as thrilled with the big physics news today as physicist Andrei Linde. One of the main authors of inflation theory—the idea that the universe expanded incredibly rapidly just after it was born in the big bang—Linde has reason to be excited. Physicists announced this morning that they have discovered imprints of gravitational waves in the cosmic microwave background light pervading the sky—a finding that many are calling “direct evidence” of inflation theory.

Chao-Lin Kuo, an assistant professor of physics at Stanford University and a co-leader of the Background Imaging of Cosmic Extragalactic Polarization 2 (BICEP2) team behind the finding, knocked on Linde’s door to deliver the news personally. Kuo tells an accompanying cameraperson, “He has no idea that I’m coming.”

Linde and his wife Renata Kallosh, both professors of physics at Stanford, look flummoxed when they answer the door. “I have a surprise for you,” Kuo says. “It’s 5 sigma, at .2.” Linde and Kallosh are taken aback; she comes forward to hug Kuo as Linde says, “What?” The ensuing reactions of both as they process the news are completely endearing—all the more so because Kuo’s arcane pronouncement could elicit such joy only from the few people in the world who would immediately know what he meant.

5 sigma” refers to the statistical significance of BICEP2’s discovery. Kuo was telling Linde and Kallosh that his experiment had seen a very strong signal. “Sigma” denotes standard deviations, and a discovery with a statistical significance of 5 sigma has only about a one-in-3.5-million chance of being a fluke.

The second part of Kuo’s message, “.2,” refers to the value BICEP2 had measured for a parameter called r, which indicates the ratio of the fluctuations in the CMB caused by gravitational waves to the fluctuations caused by perturbations in the density of matter. Previous experiments such as the European Planck satellite had suggested r might have a value of less than 0.11, so the measurement of 0.20 is noteworthy.

The idea of inflation first came from physicist Alan Guth in 1980. Linde was one of the early theorists who helped refine the theory and has proposed versions of inflation in which our universe is one of many inflationary universes in a vast multiverse.

The findings announced today validate many of Linde’s ideas and make a pretty solid case for inflation being the true history of our universe. As Linde says, “Let’s just hope that it is not a trick.”

Clara Moskowitz About the Author: Clara Moskowitz is Scientific American's associate editor covering space and physics. Follow on Twitter @ClaraMoskowitz.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. tuned 4:25 pm 03/17/2014


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  2. 2. steve161 9:23 am 03/18/2014

    The expression on Linde’s face is priceless and deeply moving.

    I wish the writer had said, not that the observation indicates that inflation is ‘true’, but that it failed to contradict it. That in itself is a very big deal. Our confidence in the inflationary model has increased significantly in the last few years. Guth, Linde and others may congratulate themselves on a breathtaking intellectual achievement.

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  3. 3. momofickthis 1:01 pm 03/18/2014

    The BICEP2 results do not confirm cosmic inflation. A
    particular graph in the scientific paper shows that the
    results predicted from cosmic inflation
    do not match the observations of this study. It’s entirely possible that 100% of the
    BICEP2 observations can be explained by non-inflationary
    factors such as gravitational lensing. The BICEP2 study
    relied on some old software called LensPix, and the site
    for that software says “there are almost certainly bugs”
    in the software.

    See my blog post “BICEP2 Study Does Not Confirm Cosmic Inflation”

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  4. 4. David Cummings 5:48 pm 03/18/2014

    Some people are calling this Day 1. It’s certainly the greatest detection event since the first detection of the echo of the big bang, back in 1965. I am very excited about this. I’ve been a fan of Alan Guth and Andrei Linde for decades.

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  5. 5. JshC77 8:24 pm 03/20/2014

    I call bull crap to this entire article and will give many reasons why the big bang theory is nothing more then just hog wash.

    First We have already encountered the horizon problem in conjunction with the discussion of the cosmic microwave background: when we look at the microwave background radiation coming from widely separated parts of the sky, it can be shown that these regions are too separated to have been able to have ever communicated with each other even with signals travelling at light velocity. Thus, how did they know to have almost exactly the same temperature? This general problem is called the horizon problem, because the inability to have received a signal from some distant source because of the finite speed of light is termed a horizon in cosmology. Thus, in the standard big bang theory we must simply assume the required level of uniformity.

    Second we have a major problem with flatness. The experimental evidence is that the present Universe has very low geometrical curvature in its spacetime (it is nearly flat). Theoretical arguments that are well established but too complex to go into here suggest that this is a very unlikely result of the evolution of the Universe from the big bang, unless the initial curvature is confined to an incredibly narrow range of possibilities. While this is not impossible, it does not seem very natural.

    The third problem is with monopoles. The only plausible theory in elementary particle physics for how nuclei in the present universe were created in the big bang requires the use of what are called Grand Unified Theories (GUTs). In these theories, at very high temperatures such as those found in the instants after the Universe was created the strong, weak, and electromagnetic forces were (contrary to the situation today) indistinguishable from each other. We say that they were unified into a single force. In addition there is as yet no certain evidence for the validity of such theories, there is strong theoretical reason to believe that they will eventually turn out to be essentially correct. Our current understanding of elementary particle physics indicates that such theories should produce very massive particles called magnetic monopoles, and that there should be many such monopoles in the Universe today. However, no one has ever found such a particle. So the final problem is: where are the monopoles?

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  6. 6. m12345 12:29 am 03/21/2014

    At JshC77

    Look at it this way in one of the 3.5 million other universes you are right…


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