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Alubadi21

What was before the BB?

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По последним открытиям и наблюдениям можно заключить,что Большой Взрыв не был виновником происхождения Вселенной,а был всего лишь промежуточным этапом?

 

[By recent discoveries and observations, one can conclude that the Big Bang was not the originator of the origin of the universe, but was just an intermediate stage?]

By recent discoveries and observations, one can conclude that the Big Bang was not the originator of the origin of the universe, but was just an intermediate stage?

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The Big Bang is our best explanation for the early moments of the universe NOT the beginning; this is not a recent change due to discoveries but has always been the case - however, pop-science has often described the Big Bang as the origin which it was never intended to be. We just do not have the physics to probe earlier - we are a long way from doing this theoretically and perhaps even further experimentally

 

Большой взрыв - наше лучшее объяснение ранних моментов вселенной НЕ начало; Это не недавнее изменение из-за открытий, но всегда было так - однако поп-наука часто описывала Большой взрыв как происхождение, которого он никогда не предназначался. У нас просто нет физики, чтобы исследовать ее раньше - мы далеко от того, чтобы делать это теоретически и, возможно, даже дальше экспериментально

Извинения за плохой перевод

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The fabric of the future universe must have already been

contained in the singularity so it must have had some existence before the BB. Can we ask: " Where was the singularity; how it came into being ; how long had it existed before the BB?"

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The fabric of the future universe must have already been

contained in the singularity so it must have had some existence before the BB. Can we ask: " Where was the singularity; how it came into being ; how long had it existed before the BB?"

The idea of the singularity is an artifact of taking General Relativity too far. What it means is that it's explanatory power has failed. Scientists are looking to quantum physics to describe events at the Big Bang and before but it's still a work in progress. Hopefully, they'll have a quantum gravity theory at some point.

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The Big Bang is our best explanation for the early moments of the universe NOT the beginning; this is not a recent change due to discoveries but has always been the case - however, pop-science has often described the Big Bang as the origin which it was never intended to be. We just do not have the physics to probe earlier - we are a long way from doing this theoretically and perhaps even further experimentally

 

Большой взрыв - наше лучшее объяснение ранних моментов вселенной НЕ начало; Это не недавнее изменение из-за открытий, но всегда было так - однако поп-наука часто описывала Большой взрыв как происхождение, которого он никогда не предназначался. У нас просто нет физики, чтобы исследовать ее раньше - мы далеко от того, чтобы делать это теоретически и, возможно, даже дальше экспериментально

 

Извинения за плохой перевод

So the Big Bang was not the origin? What would be he theory to describe the moments just before the Big Bag? Are there scientific hypotheses in place?

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If there was a singularity, would that mean that the total existing mass of the present universe had already existed in expanded form before it was " squeezed " into this singularity?

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A 'singularity' can be described as where/when events share one or more co-ordinates, and can also be achieved by a co-ordinate transformation.

Simpy done by taking an x-y Cartesian grid and rotating the y co-ordinate by 90 deg. Is this what is known as a co-ordinate singularity ?

 

Similarly, as we back up the film towards the big Bang event, if we get to small enough features such that geometry in no longer valid, then there cannot be such a thing as time anymore. and before, after and duration ceases to have meaning.

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If there was a singularity, would that mean that the total existing mass of the present universe had already existed in expanded form before it was " squeezed " into this singularity?

 

 

It would mean that all the mass (finite or infinite) of the universe was in zero volume and there was no "before".

 

For these, and the reasons given above, no one seriously believes a singularity represents physical reality.

So the Big Bang was not the origin? What would be he theory to describe the moments just before the Big Bag? Are there scientific hypotheses in place?

 

There are various (currently untestable) ideas for the early universe. For example, a "big bounce" (the universe formed from the collapse of an earlier universe), "eternal inflation" (new universes are constantly being created) and some recent attempts to combine quantum theory with GR suggest that the universe is infinitely old.

 

We will probably need a proper theory of quantum gravity before we can answer such questions.

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It would mean that all the mass (finite or infinite) of the universe was in zero volume and there was no "before".

 

For these, and the reasons given above, no one seriously believes a singularity represents physical reality.

 

There are various (currently untestable) ideas for the early universe. For example, a "big bounce" (the universe formed from the collapse of an earlier universe), "eternal inflation" (new universes are constantly being created) and some recent attempts to combine quantum theory with GR suggest that the universe is infinitely old.

 

We will probably need a proper theory of quantum gravity before we can answer such questions.

These hypotheses are interesting. So do scientists believe in an infinite Universe over a finite existence?

Doesn't this matter then reduce down to subjective and personal belief then?

This quantum gravity thingummy, isn't that Prof. Penrose's theory?

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These hypotheses are interesting. So do scientists believe in an infinite Universe over a finite existence?

 

 

Some probably may a finite universe, some may prefer an infinite one. But that has nothing to do with science.

 

 

 

This quantum gravity thingummy, isn't that Prof. Penrose's theory?

 

He may have done some work on it. But it is a huge area of research, with many people developing new ideas. Most famously, there is string theory, but also loop quantum gravity, causal dynamical triangulation, and several others.

https://en.wikipedia.org/wiki/Quantum_gravity

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Is it then, that the expansion of the Universe is the the only clue we have to any kind of beginning? May i also ask this layman's question: if everything is in a state of acceleration, does this mean that the total mass of the Universe is continually increasing and so the strength of gravitational attraction is also increasing proportionately enough to slow down the acceleration or, conversely, speed up the expansion?

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Is it then, that the expansion of the Universe is the the only clue we have to any kind of beginning?

 

 

Only if naively extrapolated. There is no real evidence for a "beginning".

 

 

 

May i also ask this layman's question: if everything is in a state of acceleration, does this mean that the total mass of the Universe is continually increasing and so the strength of gravitational attraction is also increasing proportionately enough to slow down the acceleration or, conversely, speed up the expansion?

 

Tricky question.

 

Firstly, relativistic mass is a (potentially misleading) concept from special relativity. It only applies locally, when things are in motion relative to one another with no significant gravity. It doesn't really apply in cases where GR has to be used (like cosmology). That also means that relativistic mass (which is just a way of accounting for the total energy of the system) doesn't contribute to gravity (at least, not in any easy to calculate way).

 

And things aren't really being accelerated by expansion - there is no force acting on them. They just naturally tend to get further apart in the absence of any force (which is why gravitational force, for example, holds galaxies and galaxy clusters together).

 

Whether the expansion of the the universe slows down or speeds up is dependent on the total mass-energy density of the universe. The accelerating expansion can be explained by the presence of a constant amount of energy per unit volume. As the volume has increased, this energy has come to exceed the effects of gravity that was previously slowing expansion.

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All the big bang tells us is about THIS locality of infinity.

This is the science section, not speculations

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The topic is a speculation. "What was before the BB?" That is meaningless in science.

 

Everything we know about the universe comes from our observations within the observable universe. That is science. Beyond the observable is what, a wall with a sign that says "Edge of Universe"? More likely it continues. We only know about what goes on within the observable universe and we can infer that beyond the observable is much the same, but for how far? When you get out to a distance of a google light years the rules of the game may be different.

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I'm sorry that, as a relative newcomer,( in every sense), i only have questions, not answers; so may i ask if the expansion of the Universe is isotropic? If so, must it not have had a central location from which it evolved, even before the theoretical Big Bang , and therefore a circumference in which everything observable or unobservable is included and homogeneous ,no matter how much this circumference expands?

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The expansion is isotropic. And it is centered on us! The reason for that is because everything is moving away from everything else, and so wherever you are it will look as if everything is moving away from you isotropically. There is then a circumference of the observable universe (all the stuff that we can see because there has been enough time for its light to reach us). But the whole universe beyond that may be infinite or it maybe finite (but probably with no edge or boundary).

 

The place where the bag bang "happened" is, well, everywhere. Perhaps the easiest way to understand that is to think of time running backwards. The positions of our galaxy, and another galaxy a billion light years to the left, and another galaxy 10 billion light years to the right will eventually all end up adjacent to one another and then all in the same place. So everywhere is that "central location".

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The expansion is isotropic. And it is centered on us! The reason for that is because everything is moving away from everything else, and so wherever you are it will look as if everything is moving away from you isotropically. There is then a circumference of the observable universe (all the stuff that we can see because there has been enough time for its light to reach us). But the whole universe beyond that may be infinite or it maybe finite (but probably with no edge or boundary).

 

The place where the big bang "happened" is, well, everywhere. Perhaps the easiest way to understand that is to think of time running backwards. The positions of our galaxy, and another galaxy a billion light years to the left, and another galaxy 10 billion light years to the right will eventually all end up adjacent to one another and then all in the same place. So everywhere is that "central location".

I see: everything is moving away from the same centre, into an empty Universe that was already there before any expansion of matter. Can we answer Alubadi21's question, then, by saying that what was there before the Big Bang was the Universe?

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I see: everything is moving away from the same centre, into an empty Universe that was already there before any expansion of matter.

 

 

Ah, no. This is a very important point. It is the universe itself that expanded, not the matter in it. The universe has always been completely full of matter. That matter has cooled and got less dense as the universe expands.

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Ah, no. This is a very important point. It is the universe itself that expanded, not the matter in it. The universe has always been completely full of matter. That matter has cooled and got less dense as the universe expands.

Of course - how silly of me:if it was the matter that was continually expanding, as opposed to just naturally growing, perhaps we would all be the size of planets and getting bigger and bigger! Please forgive my lack of knowledge of these things; my questions are not those that a qualified scientist might ask, but i do love science and find this fascinating - bewildering too.

So then, if the Universe is governed by the laws of Nature/Science, would it be permissible, in scientific circles, to speak of Universal seasons - the Big Bang being Spring and , as things got cooler, a Universal Winter would eventually and unavoidably follow,leading to such cooling and loss of density that enough momentum would be lost to cause expansion to slow to a halt, perhaps even leading to a contraction back to a new Spring( a sort of Big Collision ) and so ad infinitum? ( As an analogy, ancient philosophers thought of the Universe as breathing in and out over colossal periods of time). Or perhaps so much density would be lost that the Universe/Matter would simply dissipate and we would be back to the "before "? Are these valid, or even sensible questions?

Edited by goldglow

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These are valid, and sensible, questions!

 

 

 

So then, if the Universe is governed by the laws of Nature/Science, would it be permissible, in scientific circles. to speak of Universal seasons - the Big Bang being Spring and , as things got cooler, a Universal Winter would eventually and unavoidably follow,leading to such cooling and loss of density that enough momentum would be lost to cause expansion to slow to a halt, perhaps even leading to a contraction back to a new Spring( a sort of Big Collision ) and so ad infinitum?

 

 

That was the expected scenario until recently: https://en.wikipedia.org/wiki/Big_Bounce

 

However, the discovery that expansion is accelerating suggests that won't happen. On the other hand, we don't really know enough about "dark energy" to be sure.

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These are valid, and sensible, questions!

 

 

 

 

 

That was the expected scenario until recently: https://en.wikipedia.org/wiki/Big_Bounce

 

However, the discovery that expansion is accelerating suggests that won't happen. On the other hand, we don't really know enough about "dark energy" to be sure.

Thanks. Checked out the web-link: so many wonderful, erudite theories and educated speculation! So much food for thought! I'm left with only one more question now: among all these complex (to me )studies, are there any facts at all that can be written in stone,or is everything a " best guess " - albeit backed up by painstaking, knowledgeable scholarship?

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Thanks. Checked out the web-link: so many wonderful, erudite theories and educated speculation! So much food for thought! I'm left with only one more question now: among all these complex (to me )studies, are there any facts at all that can be written in stone,or is everything a " best guess " - albeit backed up by painstaking, knowledgeable scholarship?

 

 

There is never anything written in stone in science. But these are our best theories (not guesses) based on the available evidence.

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Thanks. Checked out the web-link: so many wonderful, erudite theories and educated speculation! So much food for thought! I'm left with only one more question now: among all these complex (to me )studies, are there any facts at all that can be written in stone,or is everything a " best guess " - albeit backed up by painstaking, knowledgeable scholarship?

What history tells us is that theories eventually become incomplete with new discoveries, so new ones are needed to extend their explanation. Old theories aren't wrong as such, it's just that their domain of validity is found to be limited; they are still useful within their domain e.g. you can still use Newtonian gravity to land on the Moon. Nothing can be written in stone, in terms of any particular theory's explanatory completeness..

Edited by StringJunky

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