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What happened before the Big Bang?

An artist's interpretation of the Big Bang
An artist's interpretation of the Big Bang
(Image: © © Scott Wiessinger (USRA): Lead Producer Aaron E. Lepsch (ADNET): Technical Support Krystofer Kim (USRA): Lead Animator)

In the beginning, there was an infinitely dense, tiny ball of matter. Then, it all went bang, giving rise to the atoms, molecules, stars and galaxies we see today.

Or at least, that's what we've been told by physicists for the past several decades. 

But new theoretical physics research has recently revealed a possible window into the very early universe, showing that it may not be "very early" after all. Instead it may be just the latest iteration of a bang-bounce cycle that has been going on for … well, at least once, and possibly forever. 

Of course, before physicists decide to toss out the Big Bang in favor of a bang-bounce cycle, these theoretical predictions will need to survive an onslaught of observation tests.

Bouncing cosmologies

Scientists have a really good picture of the very early universe, something we know and love as the Big Bang theory. In this model, a long time ago the universe was far smaller, far hotter and far denser than it is today. In that early inferno 13.8 billion years ago, all the elements that make us what we are were formed in the span of about a dozen minutes.

Even earlier, this thinking goes, at some point our entire universe — all the stars, all the galaxies, all the everything — was the size of a peach and had a temperature of over a quadrillion degrees.

Amazingly, this fantastical story holds up to all current observations. Astronomers have done everything from observing the leftover electromagnetic radiation from the young universe to measuring the abundance of the lightest elements and found that they all line up with what the Big Bang predicts. As far as we can tell, this is an accurate portrait of our early universe.

But as good as it is, we know that the Big Bang picture is not complete — there's a puzzle piece missing, and that piece is the earliest moments of the universe itself.

That's a pretty big piece.

Related: From Big Bang to present: Snapshots of our universe through time

The conflagration

The problem is that the physics that we use to understand the early universe (a wonderfully complicated mishmash of general relativity and high-energy particle physics) can take us only so far before breaking down. As we try to push deeper and deeper into the first moments of our cosmos, the math gets harder and harder to solve, all the way to the point where it just … quits.

The main sign that we have terrain yet to be explored is the presence of a "singularity," or a point of infinite density, at the beginning of the Big Bang. Taken at face value, this tells us that at one point, the universe was crammed into an infinitely tiny, infinitely dense point. This is obviously absurd, and what it really tells us is that we need new physics to solve this problem — our current toolkit just isn't good enough.

Related: 8 ways you can see Einstein's theory of relativity in real life

To save the day we need some new physics, something that is capable of handling gravity and the other forces, combined, at ultrahigh energies. And that's exactly what string theory claims to be: a model of physics that is capable of handling gravity and the other forces, combined, at ultrahigh energies. Which means that string theory claims it can explain the earliest moments of the universe.

One of the earliest string theory notions is the "ekpyrotic" universe, which comes from the Greek word for "conflagration," or fire. In this scenario, what we know as the Big Bang was sparked by something else happening before it — the Big Bang was not a beginning, but one part of a larger process.

Extending the ekpyrotic concept has led to a theory, again motivated by string theory, called cyclic cosmology. I suppose that, technically, the idea of the universe continually repeating itself is thousands of years old and predates physics, but string theory gave the idea firm mathematical grounding. The cyclic universe goes about exactly as you might imagine, continually bouncing between big bangs and big crunches, potentially for eternity back in time and for eternity into the future.

Before the beginning

As cool as this sounds, early versions of the cyclic model had difficulty matching observations — which is a major deal when you're trying to do science and not just telling stories around the campfire. 

The main hurdle was agreeing with our observations of the cosmic microwave background, the fossil light leftover from when the universe was only 380,000 years old. While we can't see directly past that wall of light, if you start theoretically tinkering with the physics of the infant cosmos, you affect that afterglow light pattern.

And so, it seemed that a cyclic universe was a neat but incorrect idea.

But the ekpyrotic torch has been kept lit over the years, and a paper published in January to the arXiv database has explored the wrinkles in the mathematics and uncovered some previously missed opportunities. The physicists, Robert Brandenberger and Ziwei Wang of McGill University in Canada, found that in the moment of the "bounce," when our universe shrinks to an incredibly small point and returns to a Big Bang state, it's possible to line everything up to get the proper observationally tested result.

In other words, the complicated (and, admittedly, poorly understood) physics of this critical epoch may indeed allow for a radically revised view of our time and place in the cosmos.

But to fully test this model, we'll have to wait for a new generation of cosmology experiments, so let's wait to break out the ekpyrotic champagne.

Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute, host of Ask a Spaceman and Space Radio, and author of Your Place in the Universe.

Originally published on Live Science.

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  • PaulWolf
    Admin said:
    The Big Bounce theory was once thought impossible. But two physicists have just resurrected it.

    What happened before the Big Bang? : Read more

    What could be worse than the second coming of the big bang? The theory will be endlessly resurrected, like an episode of the Twilight Zone, as long as there's an overpowering psychological need to validate the Genesis story and prove that the universe was created. To its adherents, the big bang theory proves the existence of God. But the evidence shows that the observable universe is in a steady-state and is not expanding.

    The first problem is that the red shifts of galaxies, measured by Hubble, and more recently of supernovas, are all isotropic. This would only be consistent with the big bang theory if the big bang occurred at the position of the observer. Otherwise, one could determine the location of the starting point of the big bang from the relative motion of the galaxies. Galaxies on the opposite side would be moving away from us, while galaxies on the same side would be moving in the same direction as us. It has never been possible to determine the location of "ground zero," though, because the observed red shifts are isotropic. It doesn't make sense that they could be caused by the Doppler effect. Whatever is causing them, they tend to disprove, not prove, the big bang theory. Only recently have creationists stopped claiming that the red shifts are caused by the Doppler effect. This was the main evidence cited by them, until the red shifts were shown to be isotropic.

    Now, they argue an abstraction of the big bang theory, that "space itself" is expanding uniformly like the surface of a balloon. There was, in fact, no great explosion, or ground zero where the big bang occurred. This abstract version was disproven by the Michaelson-Morley experiment, and is the same as arguing the medieval concept of the aether. "Space itself" cannot expand, because there is nothing there to expand. Electromagnetic waves don't interact with empty space, which doesn't act as a medium for light the way water does for ocean waves. The Michaelson-Morley experiment was one of the most important in the history of physics, and can't be ignored. It has been repeated and validated all across the EM spectrum.

    Moreover, Einstein's theory of special relativity means that the frame of reference is relative between the observer and observed. It would be hard to reconcile with the concept of an aether; ie., an "expanding universe" or universal frame of reference. This is a hidden flaw in any theory of an expanding universe, which implies a universal frame of reference that exists independently of the observer. To say nothing of how odd it is to choose a frame of reference that is changing over time. According to relativity, no frame of reference is preferred over any other.

    The other data used to argue the big bang theory, the presence of a nearly isotropic background of microwave radiation, suffers from the same problem. One wonders why the microwaves aren't all heading away from ground zero, the starting point for the big bang. Our own galaxy is racing away from ground zero at lightspeed - isn't this the basic idea of the big bang theory? The fact that the CMB is more or less isotropic tends to disprove that it originated in a big bang, just as the red shift data does.

    There is also something called the matter-antimatter asymmetry problem. (CERN) In the laboratory, matter and antimatter particles are always produced in pairs. If they come into contact, they annihilate each other, leaving only energy. The observed universe is made almost entirely of matter. If all matter was created from energy in a big bang, by what mechanism was it created, that did not result in the creation of an equal amount of antimatter? There is no explanation, and no known mechanism.

    That's because the big bang theory is a creationist myth. It has already been disproven a dozen different ways. Yet nothing will convince the zealots whose religious beliefs are always in need of support.
    Reply
  • Mark W. Miller
    PaulWolf said:
    What could be worse than the second coming of the big bang? The theory will be endlessly resurrected, like ...<many words removed>

    So, in short, no one has a clue...ok then,


    “Sentience Orders,
    Nothing else does,
    Therefore the Universe
    Is Ordered By
    An Agency of Mind;
    The Secret to the Universe
    Is not a Secret -
    And We are Legion."
    -Stanza I, The Next Testament.

    Origin studies are a mugs game, its all about the order.
    Reply
  • JohnP
    Admin said:
    The Big Bounce theory was once thought impossible. But two physicists have just resurrected it.

    What happened before the Big Bang? : Read more
    Well, is our current situation the beginning of the end or the end of the beginning? I don't mean to be flippant but I think it is a serious question as to what is going on with our universe.
    Reply
  • mati
    Admin said:
    The Big Bounce theory was once thought impossible. But two physicists have just resurrected it.

    What happened before the Big Bang? : Read more
    i am an ordinary person without high science twisted mind.....and to me the universe is endless and eternal--no beginning,no end....it s in human mortal nature to seek for the beginning and end and also a human nature is not comprehending the nature of eternity,endlessness,infinity....but i have always pondered abut impossible....and have understood the infinity of reality---and at the cost of my mental health--i am considered now a schizophrenic--and i am under pressure for what i have understood and experienced....
    Reply
  • rod
    The space.com reports does point out near the end:

    "In other words, the complicated (and, admittedly, poorly understood) physics of this critical epoch may indeed allow for a radically revised view of our time and place in the cosmos. But to fully test this model, we'll have to wait for a new generation of cosmology experiments, so let's wait to break out the ekpyrotic champagne."

    Here are some thoughts from Alan Guth in 2014 on the early BB modeling events. "We agree with Ijjas, Steinhardt, and Loeb that important questions remain. A well-tested theory of physics at the Planck scale remains elusive, as does a full understanding of the primordial singularity and of the conditions that preceded the final phase of inflation within our observable universe.", nflationary paradigm after Planck 2013
    Reply
  • Parkie
    I'd heard that the rate of expansion of the universe is increasing (dark energy). So that must reverse for the big bounce to happen. There must come a time when the dark energy starts to disappear out of our universe and the expansion rate must slow to a level such that the expansion will reverse and collapse will happen. Have I got that right?
    Reply
  • rod
    FYI. In July 1948, QM and GR resulted in a totally different equation of state to explain the expanding universe compared to the inflation/multiverse models of today.

    “Nineteen years after Edwin Hubble’s discovery that the galaxies seem to be running away from one another at fabulously high speeds, the picture presented by the expanding universe theory—which assumes that in its original state all matter was squeezed together in one solid mass of extremely high density and temperature—gives us the right conditions for building up all the known elements in the periodic system. According to calculations, the formation of elements must have started five minutes after the maximum compression of the universe. It was fully accomplished, in all essentials, about 10 minutes later.” —Scientific American, July 1948

    It is good to remember the history of cosmology and answers shown over the years to explain our origins :)
    Reply
  • harp
    Being a person of common sense rather than mathematics, I always thought; where does all that "everything" go when it enters a black hole?
    My thoughts are that it returns via string theory to another single point and when everything has left this "universe" the big bang repeats itself again in another plain. Thus another big bang repeats its self. My common sense of string theory.
    Reply
  • Wal726
    In the meantime, let's not wait to open the champagne. I'm out of bourbon.
    Reply
  • David N
    PaulWolf said:
    What could be worse than the second coming of the big bang? The theory will be endlessly resurrected, like an episode of the Twilight Zone, as long as there's an overpowering psychological need to validate the Genesis story and prove that the universe was created. To its adherents, the big bang theory proves the existence of God. But the evidence shows that the observable universe is in a steady-state and is not expanding.

    The first problem is that the red shifts of galaxies, measured by Hubble, and more recently of supernovas, are all isotropic. This would only be consistent with the big bang theory if the big bang occurred at the position of the observer. Otherwise, one could determine the location of the starting point of the big bang from the relative motion of the galaxies. Galaxies on the opposite side would be moving away from us, while galaxies on the same side would be moving in the same direction as us. It has never been possible to determine the location of "ground zero," though, because the observed red shifts are isotropic. It doesn't make sense that they could be caused by the Doppler effect. Whatever is causing them, they tend to disprove, not prove, the big bang theory. Only recently have creationists stopped claiming that the red shifts are caused by the Doppler effect. This was the main evidence cited by them, until the red shifts were shown to be isotropic.

    Now, they argue an abstraction of the big bang theory, that "space itself" is expanding uniformly like the surface of a balloon. There was, in fact, no great explosion, or ground zero where the big bang occurred. This abstract version was disproven by the Michaelson-Morley experiment, and is the same as arguing the medieval concept of the aether. "Space itself" cannot expand, because there is nothing there to expand. Electromagnetic waves don't interact with empty space, which doesn't act as a medium for light the way water does for ocean waves. The Michaelson-Morley experiment was one of the most important in the history of physics, and can't be ignored. It has been repeated and validated all across the EM spectrum.

    Moreover, Einstein's theory of special relativity means that the frame of reference is relative between the observer and observed. It would be hard to reconcile with the concept of an aether; ie., an "expanding universe" or universal frame of reference. This is a hidden flaw in any theory of an expanding universe, which implies a universal frame of reference that exists independently of the observer. To say nothing of how odd it is to choose a frame of reference that is changing over time. According to relativity, no frame of reference is preferred over any other.

    The other data used to argue the big bang theory, the presence of a nearly isotropic background of microwave radiation, suffers from the same problem. One wonders why the microwaves aren't all heading away from ground zero, the starting point for the big bang. Our own galaxy is racing away from ground zero at lightspeed - isn't this the basic idea of the big bang theory? The fact that the CMB is more or less isotropic tends to disprove that it originated in a big bang, just as the red shift data does.

    There is also something called the matter-antimatter asymmetry problem. (CERN) In the laboratory, matter and antimatter particles are always produced in pairs. If they come into contact, they annihilate each other, leaving only energy. The observed universe is made almost entirely of matter. If all matter was created from energy in a big bang, by what mechanism was it created, that did not result in the creation of an equal amount of antimatter? There is no explanation, and no known mechanism.

    That's because the big bang theory is a creationist myth. It has already been disproven a dozen different ways. Yet nothing will convince the zealots whose religious beliefs are always in need of support.
    I have a passing amateur interest in cosmology but what I've read (in Deep Space by G Schilling 2014) confirms above comments. The universe was not a tiny point at the "big bang" the universe was probably infinite then as it probably is now, it was just very densely packed together.

    (Again as an amateur:) if the universe goes on forever in space it is not hard to imagine it also goes on infinitely in time and the big-bang was not the beginning at all, there was no beginning.
    Reply