Which probability do you assign to the big bang having actually occurred? After all, we are extrapolating from a single point in time and only in the visible part of the universe in which we see things flying apart. Perhaps the movement is much more complex than that (e.g. a pulsing motion).
A pulsing motion of what sort, and how tightly do you draw a line around ‘big bang’? We can see by direct observation that things have been continually getting further apart for the past 13-odd billion years or so, and the earliest thing we can see is consistent with there not being a whole lot of structure before then.
Even if the behavior in the very beginning is different than we usually expect, that seems like a big bang to me.
What I have in mind is that it’s just a local turbulence in a much larger structure, for example. It seems that we have very little data about a huge structure, so fitting any model to it at this point might give us a fairly large margin of error (especially since we extrapolate from a theory that we know that is incomplete).
It’s better to think about the Big Bang as an admission of failure: using our best stitching of the two best theories that we have about the universe, and extrapolating back the data at hand as further as we can, we arrive to a point where our description breaks down (the singularity). Will a better theory cast a brighter light on this point in space-time? I assign a 99.9% probability that it will. I think that only the most zealot between relativists bite the bullet that inside a black hole there’s actually a point where the gravitational field reaches an infinite value. And given that the more time passes the more paradoxes we discover about black holes, I’d say that quantum gravity will revolutionize our understanding of singularities.
So my probability to Big Bang actually happening is 0.1%
That there was a finite time in the past in which all matter was squeezed tight and hot enough to undergo primordial nuclear reactions, and that the universe has expanded since, is pretty dang incontrovertible at this point. The nature of that event is still up for debate. Examining the fine details of light of different ages continues to reveal things, like the expansion appearing to initially slow followed by accelerating which is currently best explained by a dark energy model which is also favored for reasons relating to physical models of space I am unprepared to examine.
Couldn’t it still be just a local region that was temporarily squeezed as a result of an event on a much larger scale than the visible universe (sort of like a turbulence in a liquid like substance)?
Which probability do you assign to the big bang having actually occurred? After all, we are extrapolating from a single point in time and only in the visible part of the universe in which we see things flying apart. Perhaps the movement is much more complex than that (e.g. a pulsing motion).
A pulsing motion of what sort, and how tightly do you draw a line around ‘big bang’? We can see by direct observation that things have been continually getting further apart for the past 13-odd billion years or so, and the earliest thing we can see is consistent with there not being a whole lot of structure before then.
Even if the behavior in the very beginning is different than we usually expect, that seems like a big bang to me.
What I have in mind is that it’s just a local turbulence in a much larger structure, for example. It seems that we have very little data about a huge structure, so fitting any model to it at this point might give us a fairly large margin of error (especially since we extrapolate from a theory that we know that is incomplete).
What are your thoughts on this finding: http://www.caltech.edu/news/farthest-galaxy-detected-47761
It’s better to think about the Big Bang as an admission of failure: using our best stitching of the two best theories that we have about the universe, and extrapolating back the data at hand as further as we can, we arrive to a point where our description breaks down (the singularity).
Will a better theory cast a brighter light on this point in space-time? I assign a 99.9% probability that it will.
I think that only the most zealot between relativists bite the bullet that inside a black hole there’s actually a point where the gravitational field reaches an infinite value. And given that the more time passes the more paradoxes we discover about black holes, I’d say that quantum gravity will revolutionize our understanding of singularities. So my probability to Big Bang actually happening is 0.1%
That there was a finite time in the past in which all matter was squeezed tight and hot enough to undergo primordial nuclear reactions, and that the universe has expanded since, is pretty dang incontrovertible at this point. The nature of that event is still up for debate. Examining the fine details of light of different ages continues to reveal things, like the expansion appearing to initially slow followed by accelerating which is currently best explained by a dark energy model which is also favored for reasons relating to physical models of space I am unprepared to examine.
Couldn’t it still be just a local region that was temporarily squeezed as a result of an event on a much larger scale than the visible universe (sort of like a turbulence in a liquid like substance)?
It absolutely could be. But we’ve seen no evidence that distinguishes such a scenario from the big bang theory, and so we prefer it by Occam’s razor.
There’s a similar scenario for explaining Big Bang in string theory: the ekpyrotic universe.