Post by DaleI have heard many times that omni-directional expansion is evidence of
a singularity making a big bang
That puts the cart before the horse.
It is a consequence of the big bang, and is explained by it.
Post by Dalewouldn't that mean there would be a central point, and direction
surrounding the point for the expansion?
Not necessarily. We are part of that "central point" which has itself
expanded.
Post by Dalethis leads me to think spacetime is a continuum, as opposed to being a
cycle of bangs/crunches or a finite bang then crunch
It depends what you mean by those words.
The problem is that at we don't have the language to describe a lot of
scientific concepts so much of it is analogy and metaphor. Those who
understand the field understand the metaphors, but those who don't,
don't.
And the physicists use some extremely esoteric mathematics to describe
it, rather than imprecise, everyday words.
A prime example is DNA, which is sometimes called "the genetic code"
even though it isn't a code, just a long, complex molecule that spins
off other complex molecules. It is precisely defined as DNA, one of a
family of nucleic acids and the biologists, geneticists etc don't call
it "the genetic code" among themselves - it is only called that as an
analogy, when trying to describe it to laymen in their language.
With cosmology, you have to understand that the universe is considered
to have a zero sum over its lifetime.
Physics (at the quantum level) knows about causeless events including
the spontaneous appearance of fundamental particles, with the
necessary energy being "borrowed" and "pain back" at the end of their
life.
This is one of the many possibilities for the origin of the universe,
and it breaks no known physical laws.
So straightaway, any potential problem with mass/energy conservation
vanishes. Just as it does with the other scientific speculations which
treat it as a zero sum.
Post by Dalestill would leave room for a multi-verse, if the multi-verse has a
cardinality of spacetime greater than the universe's
It depends what you mean by multiverse, and what properties you think
it might have.
A cut'n'paste from a post I made last year on a similar topic. The
stuff with no ">" marks, with two or with four is mine...
Post by DaleAll evidence points to the contrary. Time is of our
universe. It exists within and because of our universe.
Step outside our universe and there is no such thing as
time.
Time is simply how we measure the sequence of events from our frame
of reference.
Post by DaleWhat evidence is that? You have yet to provide any evidence
that your god exists let alone where its digs are.
Time is simply how we measure the order of events.
_We_.
Post by DaleUnless everything is simultaneous then some events happened
before others, - so there is time.
Even "outside the universe".
Some well respected scientists propose that time did not exist
at or before the Big Bang. It came very soon after.
From our frame of reference.
Because our spacetime expanded from the big bang.
Time is how we measure the sequence of events, and the universe as
we know it started from the big bang. So in our frame of reference
there was no "before the big bang".
But if you're going to talk about what, if anything, caused the big
bang or happened "before" it, you have to do it from a different
time frame - even if it is only theoretical.
The same problem occurs with describing what it happened "in" -
because unless there is something wrong with the concept and
understanding of spacetime, space as we know it didn't exist before
the big bang either.
Post by DaleBut if the big bang occurred "in" something or somewhere, there
is a different concept of time for that somewhere.
Because it is from a different frame of reference.
Post by DaleUnfortunately the language doesn't have the words for this
different kind of time. But you can qualify everyday words to
show they mean time from a theoretically different time frame.
...but you can't assume you know anything about that theoretical time
frame...
Post by DaleCall it something like meta-time, in which there was a
meta-before the big bang which happened meta-somewhere.
"It's time, Jim, but not as we know it".
If you go to far with this stuff you tend to get into Dunne's
"infinite regress", because for a dimension to be time-like implies
a succession of states in a defined order, and that tend to imply
yet another time dimension so that you can envisage moving
through time.
That's not the point, which is that we don't even have the language
to discuss it - whatever "it" turns out to be.
And when you come up with it you avoid introducing confusion like
"extra time dimensions" when you really mean "time as perceived in
different frames of reference".
You don't even need to know anything about meta-time, meta-before,
meta-where, etc. Just that they are from a different and theoretical
frame of reference.
And no, it's not like the theist "outside time" and "outside the
universe" because it doesn't claim any unjustified knowledge.
It's just an attempt to come up with meaningful language with which
this can be discussed.
We are inside the event horizon of the big bang, and can't see beyond
it to what if anything is beyond it or meta-before it.
There are a lot of different scenarios which are at present just
thought exercises, and nobody insists that any of them are right.
But in most of them the universe has a zero sum over its life, ie it
all adds up to nothing. Which gets over infinite regression problems,
whatever may or may not have happened meta-before the big bang.
And the scientific speculations break no known laws of physics.
All I'm doing, is trying to overcome language limitations that
introduce confusion and unconscious equivocation due to looking at
things from inside the universe and theorising whatever is beyond the
event horizon of the big bang.
Whichever scenario turns out to be correct, it could be any of them,
or even one we haven't made yet because there are facts we haven't yet
discovered.
An example, using the meta-prefix to avoid ambiguity. Not that I
"believe" this one...
The universe could be infinitely old, with what we live in being just
the latest incarnation, perhaps preceded by a big crunch. In which
case the big crunch would have been meta-before the big bang because
in our frame of reference, time started there. But from the different
time frame of the "whatever the big-bang occurred in", it was
"before".
And it doesn't matter what the "whatever" actually is. It is a
meta-somewhere that could be the n-dimensional space of string
theory, it could be absolute nothingness, or it could be anything
else.
A bit like the X in an equation. You don't need to know whether it is
apples, pizzas or leprechauns - it is a useful abstraction.