Who said the Universe had a beginning?

[Airbrush]

How does the universe happen with "no beginning?"  We don't know ABOUT the beginning, but because it exists, and it's expanding, it looks like it popped out, somehow, less than 14 billion years ago.

Edited August 16, 2019 by Airbrush

[Strange]

50 minutes ago, Airbrush said:

How does the universe happen with "no beginning?"  We don't know ABOUT the beginning, but because it exists, and it's expanding, it looks like it popped out, somehow, less than 14 billion years ago.

It could be infinitely old. It could be the result of a "big bounce" (the collapse of an earlier universe). There are many other speculative ideas (eternal inflation, ekpyrosis, etc).

[Ghideon]

1 hour ago, Airbrush said:

How does the universe happen with "no beginning?"  We don't know ABOUT the beginning, but because it exists, and it's expanding, it looks like it popped out, somehow, less than 14 billion years ago.

Interesting, I’ll try to comment! Since our models fail to describe, and observations can not observe, the very earliest time, are we sure that time existed in the same sense as we define and observe it today? I mean, do we even know if ”beginning” makes sense?

Edited August 16, 2019 by Ghideon
Grammar

[Mordred]

Well it never makes sense to ever think of time not existing. Time is a property of rate of change but is also a property of duration. It's common to try to equate it to its own entity but that wouldn't be accurate.

 

[Ghideon]

22 minutes ago, Mordred said:

Time is a property of rate of change

I think I get your point, I'll try to formulate a comment as part of my learning* about this: We have observations supporting models today that are limited; they do not reach all the way back to or beyond time=0. (But they get pretty close). Any model anyone may come up with, that extents beyond what we know today, must contain some changes and rate of change. A model with no measure of duration or rate of change will not make sense. It does not matter much what kind of model someone will present, what that is that is changing or how thins are changing. We still need a degree of freedom (dimension) for rate of change in any such model.
Interpretations of models are also not really important at that point, important is that we can't do a model without a dimension describing rate of change or durations (AKA time).

 

46 minutes ago, Mordred said:

Well it never makes sense to ever think of time not existing. 

So: It never makes sense to ever create a model of the universe where time is not existing. Correct?

 

 

*) Your skill in these matters are far greater than mine; I've better try. 

[Mordred]

The only way you can apply zero time is to literally complete non existence. That is the only possible way not have change or duration of a state regardless of size. Obviously it makes no sense to describe time to something that doesn't exist.

Edited August 16, 2019 by Mordred

[QuantumT]

This is speculation and metaphysics. Something we will never know for sure. Any answer is unfalsifiable.

To me, the universe seems virtual. It fits all the data, but again, it's unfalsifiable.

[beecee]

On 8/17/2019 at 1:26 AM, Airbrush said:

Scientists don't know the big bang started?   That's interesting.   How can any event happen and not begin?  How can the big bang happen, if it never began?

The BB is a theory of how our "observable" universe evolved from a hotter, denser state, to the conditions we see today. 

http://www.astro.ucla.edu/~wright/infpoint.html

"The Universe was not concentrated into a point at the time of the Big Bang. But the observable Universe was concentrated into a point. The distinction between the whole Universe and the part of it that we can see is important" 

more at link.....

Edited August 17, 2019 by beecee

[Gater]

On ‎8‎/‎11‎/‎2019 at 11:45 AM, Mordred said:

Belief isn't science. As mentioned you need to show a scientific reason not based on belief that the universe is infinite and that it has always been here. Current observational data shows that our Observable universe is finite to the limit of our observation. However we know there is more beyond that. It also shows that the Observable portion had a beginning when you extrapolate expansion back into the past. 

As far as the entire universe we have no way of knowing if it's finite or infinite. So what evidence can you present other than belief for an infinite universe over a finite universe? 

The Universe is infinite - its always been here here - and yet you get banned in this room for writing the truth.

[iNow]

5 minutes ago, Gater said:

The Universe is infinite - its always been here here - and yet you get banned in this room for writing the truth.

More precisely, for asserting your speculations as absolute and without any supporting evidence whatsoever. 

[Strange]

24 minutes ago, Gater said:

The Universe is infinite - its always been here here - and yet you get banned in this room for writing the truth.

You don't know if that is true.

And you haven't been banned. No one gets banned for "writing the truth". We don't have a rule against that, for some reason.

So 0 out of 2.

[Airbrush]

On 8/16/2019 at 9:29 AM, Strange said:

It could be infinitely old. It could be the result of a "big bounce" (the collapse of an earlier universe). There are many other speculative ideas (eternal inflation, ekpyrosis, etc).

The universe could be infinitely old, but our big bang (or bounce) happened about 13.8 billion years ago.

[zapatos]

59 minutes ago, Airbrush said:

The universe could be infinitely old, but our big bang (or bounce) happened about 13.8 billion years ago.

Not really. The BB was not an event that started and ended 13.8 billion years ago.

[Strange]

4 hours ago, Airbrush said:

The universe could be infinitely old, but our big bang (or bounce) happened about 13.8 billion years ago.

Apart from the fact that the big bang is still ongoing, I don’t think anyone is disputing that 

[Airbrush]

10 hours ago, zapatos said:

Not really. The BB was not an event that started and ended 13.8 billion years ago.

Sorry I never intended to suggest that when I said the BB "happened."  I thought the BB only started 13.8 billion years ago.  Our bang had a beginning, even if it was only one of many "bounces."  Our BB or bounce is NOT infinitely old.

Edited August 19, 2019 by Airbrush

[StringJunky]

On 8/16/2019 at 8:47 PM, Mordred said:

The only way you can apply zero time is to literally complete non existence. That is the only possible way not have change or duration of a state regardless of size. Obviously it makes no sense to describe time to something that doesn't exist.

In a pre-BB scenario does time have to move forward? Can it not move in any direction it likes? If there is no space/distance between things and the universe is completely homogenous in substance would time need to exist as we know it because there would be nothing to relate it to; time being relative? 

Edited August 19, 2019 by StringJunky

[dimreepr]

7 minutes ago, StringJunky said:

In a pre-BB scenario does time have to move forward? Can it not move in any direction it likes?

Is there a reason pre-BB is any different to now?

 

[swansont]

19 hours ago, Gater said:

The Universe is infinite - its always been here here - and yet you get banned in this room for writing the truth.

!

Moderator Note

What we have a problem with is people who make bald assertions. What gets you into trouble is if you are unable or unwilling to back up a claim, and keep making the assertion.

You can choose to follow the rules, or not. But let's be clear: it's your choice.

 

[StringJunky]

4 minutes ago, dimreepr said:

Is there a reason pre-BB is any different to now?

 

In relativity, the clock, as we know it, starts with it.

[dimreepr]

17 minutes ago, StringJunky said:

In relativity, the clock, as we know it, starts with it.

What makes you think the clock has anything to do with time? 

[Strange]

1 hour ago, Airbrush said:

Our BB or bounce is NOT infinitely old.

Well, I have seen at least one model where it is.

https://arxiv.org/pdf/1411.0753.pdf

This spawned some truly terrible news stories, typically with headlines like "the Big Bang never happened". But this one seems reasonably sane: https://www.livescience.com/49958-theory-no-big-bang.html

[Airbrush]

19 minutes ago, Strange said:

Well, I have seen at least one model where it is.

https://arxiv.org/pdf/1411.0753.pdf

This is a model of a big bang that had no beginning?  The scientific language and math intimidate me.   It is above my level of understanding, so could you summarize it for us please?

Edited August 19, 2019 by Airbrush

[StringJunky]

16 minutes ago, dimreepr said:

What makes you think the clock has anything to do with time? 

A clock measures time by definition. We are in a science section, so let's not wander off on a whimsy.

[dimreepr]

5 minutes ago, StringJunky said:

A clock measures time by definition. We are in a science section, so let's not wander off on a whimsy.

So lets start with a definition.

Edited August 19, 2019 by dimreepr

[zapatos]

29 minutes ago, dimreepr said:

So lets start with a definition.

"a mechanical or electrical device for measuring time, indicating hours, minutes, and sometimes seconds, typically by hands on a round dial or by displayed figures."