Universal 'Now' at Time-Zero

[geordief]

Dimension - a measurable extent of a particular kind, such as length, breadth, depth, or height. (My bolding; it is only using volume as an example). It could also be force which has the dimensions of mass and acceleration.

Are there any ways measurements can be performed without using EM?

 

EM did not exist did it ,in the early stages.? So are there any measurements that can be performed under those conditions?

 

No measurements = no dimensions?

Edited August 21, 2016 by geordief

[StringJunky]

Are there any ways measurements can be performed without using EM?

 

EM did not exist did it ,in the early stages.? So are there any measurements that can be performed under those conditions?

 

No measurements = no dimensions?

I can't answer because I don't know.

[tar]

Mordred,

 

You might try one equation. I am half way sure I will not comprehend its meaning. I have talked myself into not believing that an immense and complicated universe can be symbolized in a couple of lines. I always have real trouble grasping where the analogies are strong and meaningful and where they are shaky or assumptions are made that I am unaware of the process that was gone through to get to the conclusion. Where terms were dropped, or approximations made. It generally seems odd to me that we talk about how the universe will look in 600 billion years, when we don't even know how our eyes will work by then.

 

Regards, TAR

[michel123456]

No other types of galaxies weren't generated afiak. It is an immensely huge dataset.

 

Funny I don't find expansion unimaginable. Of course I've spent years studying expansion. Quite frankly nothing is more natural than the development of those strands and expansion.

 

It follows the rules of an adiabatic and isentropic fluid and particle physics in exquisite detail.

 

If your intetsted in the math I can provide several key formulas to large scale structure formation later on.

I suppose that you have the image of a growing fluid that tears apart filaments of matter when expanding. Is that it?

Edited August 22, 2016 by michel123456

[Strange]

It generally seems odd to me that we talk about how the universe will look in 600 billion years, when we don't even know how our eyes will work by then.

 

 

This is an example of you getting distracted by irrelevant details. When people talk about how the universe looked in the past or will look in the future, the nature or existence of eyes at that time is irrelevant.

[disarray]

I think we have mentioned before the universe has likely always been around in some form/s.

 

That may have been mentioned, but I hardly think that this claim is part of any contemporary standard model of the universe.

 

But am curious....What might the form of the universe have been like pre-Big Bang....say, 100 billion years ago (if we can talk about time pre-Big Bang at all) . Or are we talking about some other model re the origins of the universe?

[tar]

Strange,

 

Well perhaps irrelevant to you, but central to me. How can you see without involving your eyes? The human, and all life, and all arrangements of matter are so, partially because of the environment they are in. Plants grow toward the Sun, because the Sun is there. If the universe is expanding, to where wavelengths of light are getting longer and longer, then those long wavelengths will be what is hitting items in 600 million years. If radio waves are the only waves coming in from the rest of the univer se, in 600 billion years, then a conscious being at that point will be conscious of that fact through either evolution or technology. If the waves are of very long duration and so little energy as to be not visible to a current day human, there is no reason to suggest that beings of that future epoch will not be long lived enough and sensitive enough, or smart enough to receive and store the signal. Perhaps our "eyes" will be like huge radio telescope receivers, and we will sense distant galaxies like we today sense the CMB.

 

Regards, TAR

[Strange]

 

That may have been mentioned, but I hardly think that this claim is part of any contemporary standard model of the universe.

 

 

There are various models that involve an infinitely old universe.

 

 

 

But am curious....What might the form of the universe have been like pre-Big Bang....say, 100 billion years ago (if we can talk about time pre-Big Bang at all) .

 

If we are talking about the classic big bang model then there is not before (the question literally has no meaning, like :what is north of the north pole).

 

Other answers depend on the nature of the model. It could be that the universe is cyclic, or the singularity is an infinite time in the past, or our universe is only one inflation among many, or ...

Well perhaps irrelevant to you, but central to me. How can you see without involving your eyes?

 

The word "look" in this context is purely metaphorical. We can talk about what the universe "looked like" 13.7 billion years ago even though it is impossible there was anyone to see it. What is meant is "what was [will be] the nature of the universe at that time".

 

Also, much of what we "see" in the universe involves infra-red, ultraviolet, gamma rays, radio waves, neutrinos, gravitational waves, and many other things we can't see with our eyes. We can talk about what the universe "looks like" in any of those forms.

 

The word "look" is not intended to be taken literally.

 

It is a METAPHOR.

[tar]

or perhaps a being from that time could search the archives for a picture from the Hubble

[disarray]

 

There are various models that involve an infinitely old universe.

 

 

Hard to trace back causality infinitely. Um...sounds like a case for detective Zeno.

[StringJunky]

 

That may have been mentioned, but I hardly think that this claim is part of any contemporary standard model of the universe.

I don't think you'll find many scientists that think it just 'popped' into existence. Consider this: if the whole universe turns out be infinite in extent then it couldn't have done that in a finite amount of time; it had to have always been around.

 

"In the beginning there was nothing, which exploded" - Terry Pratchett. Faintly ridiculous, don't you think? Unless there's an extant creator.

Edited August 22, 2016 by StringJunky

[tar]

Strange,

 

But you are bias as a human to our 5 senses. All our equipment accentuates and refines the abilities we already have developed. Our sight brought us in contact with the EM spectrum and we enhanced that sense though magnifying glass and radio telescope. We can develop senses that "see" magnetic fields, and will probably extend our senses to include the sensing of arrangements that are implicit through aligning various senses and figuring out there is an arrangement out there, like gravity fields.

 

StringJunky is limiting the ability of the early hot/dense universe to exchange information, to after photons flew. He is taking "looks like" very literally and limiting it to electromagnetic waves, which is somewhat human sense biased. If looks like is a metaphor, then it should be extended to information that can be gleaned, or shared or felt by any means, not limited to the eye or its enhancements.

 

Regards, TAR

[StringJunky]

StringJunky is limiting the ability of the early hot/dense universe to exchange information, to after photons flew. He is taking "looks like" very literally and limiting it to electromagnetic waves, which is somewhat human sense biased. If looks like is a metaphor, then it should be extended to information that can be gleaned, or shared or felt by any means, not limited to the eye or its enhancements.

You're the one using his senses, commonsense and anthropomorphic terms like 'gleaned', 'shared' and 'felt'; I'm not. I'm talking in abstractions.

Edited August 22, 2016 by StringJunky

[disarray]

I don't think you'll find many scientists that think it just 'popped' into existence. Consider this: if the whole universe turns out be infinite in extent then it couldn't have done that in a finite amount of time; it had to have always been around.

 

"In the beginning there was nothing, which exploded" - Terry Pratchett. Faintly ridiculous, don't you think? Unless there's an extant creator.

 

Well I think that the majority accept the Big Bang model. Sure research is being done with regards to the Higgs Boson field, etc., but I don't think anyone is really speculating that there was anything before the Big Bang. Of course, one does not necessarily hear the phrase "popping out ex nihilo" in this regard, but I don't think that there are widespread claims that the universe must have existed in some form before the Big Bang. If so, I am certainly willing to look at quotes you might provide.

 

Of course, there is the multiverse theory based on math speculation....but again, whatever might exist as a backdrop to the universes that arise out of them is an unknown, and certainly, even if we had some inkling about what such a backdrop might be, there is no reason we should think that it resembles the universe as we know it to such an extent that we could reasonably claim that the universe was always existed, perhaps back into infinity (which is also just metaphysical speculation).

 

I presume that you know far more than me about physics, but I think that you are "winging it" here for some reason.

Edited August 22, 2016 by disarray

[tar]

Strange,

 

We are also bias to our time scale and size scale. We are not immediately concerned with the drift of the continents, nor conscious of sound waves with wavelengths as long as an AU. Nor do we "feel" the iinformation that causes Brownian motion. "Inform" is a biased word that is anthropomorphic at its base. How do we get the form, that is out there, in?

 

Regards, TAR

[Strange]

Well I think that the majority accept the Big Bang model.

 

 

Indeed. However, the big bang model describes the evolution of the universe from a hot dense state. It doesn't go back to any notional time zero, nor does it say anything about the creation of the universe.

[StringJunky]

I presume that you know far more than me about physics, but I think that you are "winging it" here for some reason.

We've been 'winging it' for most of this thread.

 

If the mods think this thread is too weighty in speculations then I think it should be put in that forum.

Edited August 22, 2016 by StringJunky

[Strange]

Of course, one does not necessarily hear the phrase "popping out ex nihilo" in this regard, but I don't think that there are widespread claims that the universe must have existed in some form before the Big Bang.

 

 

"Before" (in the current model) is a meaningless word.

 

And, while the idea of an infinitely old universe is currently hypothetical, it is solidly based in science and is not "metaphysical speculation".

[disarray]

 

 

"Before" (in the current model) is a meaningless word. Well, yes, that was my point. My main query was whether you were trying to have your cake and eat it too; that is, agree with the current model, and claim that the universe was infinitely old as well.

 

And, while the idea of an infinitely old universe is currently hypothetical, it is solidly based in science and is not "metaphysical speculation".

 

But again, care to give me a few links that I might chew on, as I am not aware of the math, apart, as I mentioned, talk of a multiverse...but again, that theory would hardly be evidence for our universe being infinitely old.

 

[StringJunky]

 

 

 

"Before" (in the current model) is a meaningless word. Well, yes, that was my point. My main query was whether you were trying to have your cake and eat it too; that is, agree with the current model, and claim that the universe was infinitely old as well.

 

He can have his cake and eat it. GR says nothing about what initiated the BB phase; it only models to that point.

 

[Strange]

 

 

 

"Before" (in the current model) is a meaningless word. Well, yes, that was my point. My main query was whether you were trying to have your cake and eat it too; that is, agree with the current model, and claim that the universe was infinitely old as well.

 

And, while the idea of an infinitely old universe is currently hypothetical, it is solidly based in science and is not "metaphysical speculation".

 

But again, care to give me a few links that I might chew on, as I am not aware of the math, apart, as I mentioned, talk of a multiverse...but again, that theory would hardly be evidence for our universe being infinitely old.

 

 

 

Here is a recent example: http://phys.org/news/2015-02-big-quantum-equation-universe.html

(This has prompted some of the worst examples of science reporting ever.)

[disarray]

He can have his cake and eat it. GR says nothing about what initiated the BB phase; it only models to that point.

 

But don't follow. You are just agreeing that GR says nothing in support of an infinitely old universe...so the notion is, again, just metaphysical speculation.

[Strange]

But don't follow. You are just agreeing that GR says nothing in support of an infinitely old universe...so the notion is, again, just metaphysical speculation.

 

That isn't what he said. And that isn't what GR says. All (modern) models of an infinitely old universe are based on GR.

[disarray]

 

 

 

Here is a recent example: http://phys.org/news/2015-02-big-quantum-equation-universe.html

(This has prompted some of the worst examples of science reporting ever.)

Dont see anything about an infinitely old universe. I do see that there is a theory that it might be possible that "the universe starts to shrink until it collapses in on itself and becomes an infinitely dense point again," and perhaps, one might assume, the cycle continues.

 

However, there is no particular evidence to show that this might be the case. Indeed, the consensus seems to be that the universe is continuing to expand and will continue to do so (perhaps at increasing rates), and, given entropy, everything will disintegrate in due time, i.e., trillions of years.

Of course, if the universe is expanding, one can surmise that it can reverse itself. Hawkings entertained this notion for a while before abandoning it, and even thought time might run backwards, with people, for example, unlighting their cigarettes.

 

So, again, as far as I am concerned, there is no real evidence that it cycles, and such speculation is no less metaphysical than Nietzsche's concept of the Eternal Recurrence.

[StringJunky]

But don't follow. You are just agreeing that GR says nothing in support of an infinitely old universe...so the notion is, again, just metaphysical speculation.

The universe has a density that suggests it is flat, which means that it is likely to be infinite in extent. What is the probability of a starting universe expanding with infinite speed to create an infinite expanse in a finite amount of time?