What Happened: Two Thoughts

By | July 2, 2007
3 Comments

Phil Plait at Bad Astronomy gives us the run-down on Martin Bojowald’s Big Bounce Theory of how our universe came into being:

What Bojowald’s work does, as I understand it (the paper as I write this is not out yet, so I am going by my limited knowledge of LQG and other theories like it) is simplify the math enough to be able to trace some properties of the Universe backwards, right down to T=0, which he calls the Big Bounce. The previous Universe collapsed down, and “bounced” outward again, forming our Universe. No doubt the physical aspects of this previous Universe were somewhat different; the quantum uncertainties at the moment of bounce would ensure that. It may have been much like ours, or it may have been quite alien. In his equations, it’s the volume of that previous Universe that cannot be determined. How big was it? It may literally be impossible to ever know.

In the traditional model, talking about anything happening “before” the Big Bang is meaningless. Time doesn’t really start until the the Bang occurs. Not that that stops people from talking about it anyway. I know that I, for one, tend to assume that if there are multiple universes, there must be some kind of larger time that could be observed in the relationships between them — if such relationships ever could be observed! The Big Bounce is intriguing, but if not quite weird enough for you, Plait also directs us to some information on Brane Theory:

For an eternity, our universe lay dormant—a frozen, featureless netherworld. Then, about 15 billion years ago, the cosmos got an abrupt wake-up call.

A parallel universe moving along a hidden dimension smacked into ours. The collision heated our universe, creating a sea of quarks, electrons, protons, photons, and other subatomic particles. It also imparted microscopic ripples, like ocean waves crashing on a shore.

These ripples generated tiny fluctuations in temperature and density, the seeds from which all cosmic architecture—from stars to gargantuan clusters of galaxies to galactic super clusters—ultimately arose.

So in this model, if that other universe had never slammed into us, our universe would never have been anything more than a sort of potential universe. Raising the question of how long (in that larger, inter-universal time) did we have to wait before coming into existence?

Just a little something to ponder as you start your week.

  • http://space.mit.edu/home/tegmark/multiverse.html MikeD

    waiting would be subjective. If there is no energy with which to run the next moment of your universal snapshot, then you’d have to wait exactly zero. There’s also no way to prove there isn’t an “eternity” of non-time between each moment of subjective reality. The fact that we’re all bound to the same clock means we share the same point of view. The fact that our model posits other discrete universes within the larger multiverse means there may be others just like us, but being completely independant makes them equally unable to do anything about us as we can do about them.

  • Phil Bowermaster

    MikeD –

    Good points. Within the context of the universe, we’re all tied to the same clock. But I’m suggesting a meta-clock which applies to the larger context that contains both our universe and the one that ran into it (and presumably a lot of other stuff.) In that context, the amount of “time” — for lack of a better term :-) — that our universe was dormant should be quantifiable.

  • http://www.mythusmageopines.com/wp mythusmage

    In other words, we owe our existence to a fender bender. I wonder what the deductible is on this sort of thing.