Concise description of the Big Bang Theory (or ΛCDM models), possible? or not?

DeiRenDopa

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Is it possible to write a concise description of the Big Bang Theory? Of the general class of ΛCDM cosmological models (leaving the values of the parameters, including uncertainties, to a separate table)?

Can this be done without the need for lots of links?

Why am I asking this? Because a recent thread requested something similar, and what was provided was ~2000 words, and 11 references.

Can you describe the Big Bang Theory concisely?

Moving to a more technical level, can you describe the general class of ΛCDM cosmological models, concisely?

Starting presumption: your audience is familiar with standard, textbook, physics, to an appropriate level (popsci for 'the Big Bang Theory', last year of an undergrad science degree for ΛCDM cosmological models).
 
DeiRenDopa said:
Is it possible to write a concise description of the Big Bang Theory? Of the general class of ΛCDM cosmological models (leaving the values of the parameters, including uncertainties, to a separate table)?

Can this be done without the need for lots of links?

Why am I asking this? Because a recent thread requested something similar, and what was provided was ~2000 words, and 11 references.

Can you describe the Big Bang Theory concisely?

Moving to a more technical level, can you describe the general class of ΛCDM cosmological models, concisely?

Starting presumption: your audience is familiar with standard, textbook, physics, to an appropriate level (popsci for 'the Big Bang Theory', last year of an undergrad science degree for ΛCDM cosmological models).
Click to expand...


I'll be interested to hear this. And my post that you quoted above was definately not a request to explain the entire scope of plasma cosmology, it was a responce to Sols post on Olbers' paradox allegedly proving the universe is finite, and I gave my opinion on whether the universe is finite or infinite by writing a brief comparison to the fundamental difference in approach of Plasma Cosmology and the Big Bang.
 
Zeuzzz said:
I'll be interested to hear this. And my post that you quoted above was definately not a request to explain the entire scope of plasma cosmology, it was a responce to Sols post on Olbers' paradox allegedly proving the universe is finite, and I gave my opinion on whether the universe is finite or infinite by writing a brief comparison to the fundamental difference in approach of Plasma Cosmology and the Big Bang.
Click to expand...
Indeed.

Here is how you prefaced your reference to that post, in direct response to the request "[post] a concise description of Plasma Cosmology":
This post I just wrote may act as a good starting point
Click to expand...
 
DeiRenDopa said:
Is it possible to write a concise description of the Big Bang Theory? Of the general class of ΛCDM cosmological models (leaving the values of the parameters, including uncertainties, to a separate table)?

Can this be done without the need for lots of links?

Why am I asking this? Because a recent thread requested something similar, and what was provided was ~2000 words, and 11 references.

Can you describe the Big Bang Theory concisely?

Moving to a more technical level, can you describe the general class of ΛCDM cosmological models, concisely?

Starting presumption: your audience is familiar with standard, textbook, physics, to an appropriate level (popsci for 'the Big Bang Theory', last year of an undergrad science degree for ΛCDM cosmological models).
Click to expand...

I think that it could be done without lots of links.

I would imagine a brief overview could be a single post, with another post of parameters, and another of references.

I have seen some technical papers that contain pretty good overviews.
 
I'll take a stab at it...

About a dozen billion years ago, the entire visible universe was the size of a peach, and had a temperature of several million degrees. In this era, all the hydrogen (and some helium and lithium) were formed. The universe expanded and cooled. As it expanded, tiny fluctuations in the vacuum expanded to become the seeds of structure. When it became cool enough for atoms to form, light that was created then sailed on through, not really interacting with matter until some of it hit our detectors. This is the Cosmic Microwave Background, and carries the signal of those first little bumps and wiggles that grew up into clusters of galaxies. The first bits of matter to form into structures were some form of particles that don't interact with light, called dark matter. Normal matter followed right behind. First small structures formed: galaxy-sized clumps or smaller. They coalesced into ever-larger objects. Right now, the largest structures, superclusters, are still forming. About five billion years ago the expansion of the universe started accelerating. This is caused by some unknown entity, called dark energy.
 
That, at least, is my "elevator ride" description of cosmology. As for the different classes of LCDM. Well, we don't know a priori how much of the universe is made up of dark matter, normal matter, radiation, and dark energy. There's also a few other free parameters. Depending on the values of these, you get slightly different universes. However, the general structure of the theory (big bang expansion, cold dark matter, and late-time acceleration) describes the universe very well.
 
This could be a fun thread.

A long long time ago, like, a really really long time ago, everything was all in one place, and there wasn't anything else but everything in one place, which was really small, and really hot, except there wasn't any heat yet, or gravity, so there really wasn't anything, if you were around to see it, you couldn't.

Don't ask where it came from, it just was there. Somewhere, except there wasn't any space or time, so we can't say where it was, so just imagine everything was a tiny little ball of, something, and it was there for some time, if time had been invented yet, which it wasn't, so it was there for eternity, until it blew up, in a really big bang.

Then everything, which was a moment before, a tiny little ball, turned into the entire Universe. At first it was a lot of energy, but then it turned into matter, which turned into everything we know today, except for waves of light and other electromagnetic energy, which are still going, but anyhow, time was created, and so we can say now, this happened billions of years ago, and we know this because everything we see, except for some things, are all flying away from each other, except at some point dark energy just showed up, along with dark matter, both of which are causing everything to speed up, instead of slowing down, which is what you might expect, with gravity and everything, but it is not, so dark energy is causing everything to just keep expanding, and we know this because we can see it.

Well, we can't see it, which is why it is called dark, but it has to be there because there isn't enough mass, even with dark matter added in, to slow down the expansion of everything, which means it will just keep getting bigger and bigger, and never collapse back into a little ball again.

If it wasn't for dark energy, everything would slow down and start heading back towards everything becoming a little ball of really hot stuff again. Except for all that energy going away at the speed of light, which won't come back, no matter how much gravity there is, because light isn't effected by gravity, but space/time is, and if space time is distorted enough by a really really lot of gravity, even light will curve so it can't go flying off like it wants to.

OK that wasn't really concise, and probably some people won't even agree with parts of it.

So post your own version then.
 
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OK maybe I should try and be more serious. Because this origin of the Universe is serious business.

All real scientists agree that the universe began some 12 to 20 billion years ago, which means there is an 8 billion year difference, but since that is only about a half, or a third of the total age of the universe, depending on who you agree with, it isn't important. This theory is known as the Big Bang because Fred Hoyle, in 1950, used the term to mock those who wanted to use a Creation myth to explain how the Universe came to be. In a sweet move, his detractors embraced the term, which really annoyed Hoyle. You might think the Big Bang means there was a big explosion, but it wasn't really an "explosion" , what really happened is space itself exploded.

"Before" the Big Bang, the universe was really really small and very very hot. Hotter than hot, like, really really really hot. Smart scientist believe that all forms of matter and energy, as well as space and time itself, were formed at the moment this dense hot "something" exploded. So because there was no time before the Bang, within the context of known physics, we don't have to answer any questions about what happened "before" the explosion.

Most scientist say we don't really know anything about what happened between the Big Bang and 10^-43 seconds later. But we think Space was certainly expanding, really fast, and this expansion of space formed a highly energetic soup of particles and antiparticles. Not matter, but something that could turn into matter later. Like plasma.

From 10^-43 to 10^-35 seconds after the Big Bang, everything is a bit confusing. Gravity existed, but electromagnetism and the nuclear forces were all one. Moving on, we jump to the next event, which we know a lot more about.

Like anything that expands, the Universe got cooler. At 10^-35 seconds, the temperature was around 10^27 degrees K, give or take a few million degrees, so the universe underwent a phase transition, and the strong nuclear force split off from the other forces. As if things weren't bad enough, this released an enormous amount of energy.

Suddenly, the universe grew by a factor of 10^50 in 10^-33 seconds!
(Hey, I know that is hard to believe, but it is a fact baby. Get used to it)

Then things slowed down and got even cooler. Suddenly, matter appeared, stuff like photons, quarks, neutrinos, and electrons, and then, like magic, protons and neutrons! All this in less than one second!
A billion years later, this matter turned into the first stars and galaxies.

Now, which is either 11 or 19 billion years after that, the Universe is 5 times bigger, still expanding, and still ringing with the "sound" of the original explosion, which is called background radiation. At some point Dark Energy appeared, and is messing with the slowing of the expansion.
 
DeiRenDopa
Is it possible to write a concise description of the Big Bang Theory? Of the general class of ΛCDM cosmological models (leaving the values of the parameters, including uncertainties, to a separate table)?
Click to expand...

The uncertainties can be answered? I thought uncertainties were random...


BTW: When the universe started... were there any dimensions? Or they didn't exist until the expansion began?
 
robinson said:
OK maybe I should try and be more serious. Because this origin of the Universe is serious business.

All real scientists agree that the universe began some 12 to 20 billion years ago, which means there is an 8 billion year difference, but since that is only about a half, or a third of the total age of the universe, depending on who you agree with, it isn't important. This theory is known as the Big Bang because Fred Hoyle, in 1950, used the term to mock those who wanted to use a Creation myth to explain how the Universe came to be. In a sweet move, his detractors embraced the term, which really annoyed Hoyle. You might think the Big Bang means there was a big explosion, but it wasn't really an "explosion" , what really happened is space itself exploded.

"Before" the Big Bang, the universe was really really small and very very hot. Hotter than hot, like, really really really hot. Smart scientist believe that all forms of matter and energy, as well as space and time itself, were formed at the moment this dense hot "something" exploded. So because there was no time before the Bang, within the context of known physics, we don't have to answer any questions about what happened "before" the explosion.

Most scientist say we don't really know anything about what happened between the Big Bang and 10^-43 seconds later. But we think Space was certainly expanding, really fast, and this expansion of space formed a highly energetic soup of particles and antiparticles. Not matter, but something that could turn into matter later. Like plasma.

From 10^-43 to 10^-35 seconds after the Big Bang, everything is a bit confusing. Gravity existed, but electromagnetism and the nuclear forces were all one. Moving on, we jump to the next event, which we know a lot more about.

Like anything that expands, the Universe got cooler. At 10^-35 seconds, the temperature was around 10^27 degrees K, give or take a few million degrees, so the universe underwent a phase transition, and the strong nuclear force split off from the other forces. As if things weren't bad enough, this released an enormous amount of energy.

Suddenly, the universe grew by a factor of 10^50 in 10^-33 seconds!
(Hey, I know that is hard to believe, but it is a fact baby. Get used to it)

Then things slowed down and got even cooler. Suddenly, matter appeared, stuff like photons, quarks, neutrinos, and electrons, and then, like magic, protons and neutrons! All this in less than one second!
A billion years later, this matter turned into the first stars and galaxies.

Now, which is either 11 or 19 billion years after that, the Universe is 5 times bigger, still expanding, and still ringing with the "sound" of the original explosion, which is called background radiation. At some point Dark Energy appeared, and is messing with the slowing of the expansion.
Click to expand...

Why have you posted here? This could work into a great journal article. BB'ers would love it!
 
DeiRenDopa said:
Is it possible to write a concise description of the Big Bang Theory?
Click to expand...
I could, but it would include equations. It would take a bit of thought for which I don't have the time at the moment (this not being the area of physics I work in).

I'll be back Sunday if no one else has written a piece [that I think is better than what I would write].
 
I think it's important to note that matter is younger than energy. In the early universe, energy "condensed" into matter as space expanded. Sometimes, people have a hard time imagining how all the stuff in the universe could occupy such a small space, but it's easier when you realize that the "stuff" was energy, which can be compacted much more easily than matter.
 
TV's Frank said:
I'll take a stab at it...

About a dozen billion years ago, the entire visible universe was the size of a peach, and had a temperature of several million degrees. In this era, all the hydrogen (and some helium and lithium) were formed. The universe expanded and cooled. As it expanded, tiny fluctuations in the vacuum expanded to become the seeds of structure. When it became cool enough for atoms to form, light that was created then sailed on through, not really interacting with matter until some of it hit our detectors. This is the Cosmic Microwave Background, and carries the signal of those first little bumps and wiggles that grew up into clusters of galaxies. The first bits of matter to form into structures were some form of particles that don't interact with light, called dark matter. Normal matter followed right behind. First small structures formed: galaxy-sized clumps or smaller. They coalesced into ever-larger objects. Right now, the largest structures, superclusters, are still forming. About five billion years ago the expansion of the universe started accelerating. This is caused by some unknown entity, called dark energy.
Click to expand...

Yay for the universe!
 
It's in the opening credits of the TV show:

"Our whole universe was in a hot, dense state
Nearly 14 million years ago, expansion started -- wait --
The Earth began to cool
The autotrophes began to drool
Neanderthals invented tools
We built the Wall
We built the pyramids
Math, Science, History,
Unraveling the mystery,
It all started with the Big Bang."
 
This is just the big bang, not lambda or CDM:

We are at the exact center, and in all directions all the matter in the observable universe is streaming radially away from us with a speed proportional to its distance.* Because its speed is directly proportional to its distance, going back in time there must have been a single moment in the past when all that matter was concentrated at the center - the future location of the earth.* By measuring the constant of proportionality between speed and distance we can determine how long ago that was, and the answer is about 14 billion years.

*General relativity and the curvature of spacetime allow that statement to hold true for every point.
 
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Shower from the Clocktower

Wangler said:
Why have you posted here? This could work into a great journal article. BB'ers would love it!
Click to expand...

Does BB'ers mean Big Bangers? They have a journal?

I post here because, well, hmm .... give me a minute.































Damn. You know, that is a really hard question. Couldn't you ask about why some people differ on the estimates of how old the Universe is? That would be an easier question you know.
 
sol invictus said:
This is just the big bang, not lambda or CDM:

We are at the exact center, and in all directions all the matter in the observable universe is streaming radially away from us with a speed proportional to its distance.* Because its speed is directly proportional to its distance, going back in time there must have been a single moment in the past when all that matter was concentrated at the center - the future location of the earth.* By measuring the constant of proportionality between speed and distance we can determine how long ago that was, and the answer is about 14 billion years.

*General relativity and the curvature of spacetime allow that statement to hold true for every point.
Click to expand...

Sol,

This one is good, very straightforward and easy to understand.
 
The current, observed state of the universe can be successfully modelled assuming everything we can see today was once a hot, dense ball of {what goes here? I need to work on this}. The way the universe evolved from that hot, dense ball can be described using textbook particle physics {insert waystation here}, textbook nuclear physics {until the temperature/density dropped below X/X}, textbook atomic physics {extra phrase needed? or not?}, and above all by the General Theory of Relativity (GR). Just these four sets of theories, together with a small number of 'initial condition' parameter values, are sufficient to accurately account for the observed (large scale) structure of the universe, its composition, and apparent large scale motion of the galaxies.

---------------------------------------------
Needs some editing, and it's a WIP, but not a bad start, methinks.
 
Wangler said:
Sol,

This one is good, very straightforward and easy to understand.
Click to expand...

Sol's explanation highlights the main failing in critics of the big bang. They mainly want to complain about things the big bang does not claim to explain.
 
The Big Bang Theory (aka Fairy Story?)

Once upon a time (before there was time) all of everything (the universe) was virtually nothing (“infinitely small” - whatever that means). It couldn’t be totally, actually nothing because that would mean something came from nothing, and that‘s not good science (would require an act of magic, aka creation). The infinitely small universe (“singularity”) apparently existed before time existed (no time means no change). In other words, the singularity was in an inert state that didn‘t change. However . . . SUDDENLY! - this infinitely small, all of everything, inert singularity that didn’t change, CHANGED! How can this be? The singularity couldn’t be changed by something externally when all of everything is internal. And a thing that doesn’t change internally can’t change internally. The “scientific” answer seems to be “we don’t know”. The change resulted (among other things) in the singularity universally expanding (not exploding) and it continues to do so today (only space expands, not matter). Is space a "thing" that can expand? However . . . If the singularity then, and the universe now, both represent all of everything, how can a size be attributed to either? What’s the “other thing” that it’s being measured against? How can a thing be measured against itself? If it had a measurable size, surely it follows that it had edges (internal if not external), and it still must have those edges (where are the edges?). Why is infinitely small any more likely than infinitely large? Perhaps an infinitely large singularity could expand in to itself, what does and infinitely small singularity expand in to?

The BBT seems to me to be slap-happy science that apparently accepts stuff that would otherwise be classed as woo.

And they all lived slap-happily ever after? ;)
 
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ynot said:
The Big Bang Theory (aka Fairy Story?)

Once upon a time (before there was time) all of everything (the universe) was virtually nothing (“infinitely small” - whatever that means). It couldn’t be totally, actually nothing because that would mean something came from nothing, and that‘s not good science (would require an act of magic, aka creation). The infinitely small universe (“singularity”) apparently existed before time existed (no time means no change). In other words, the singularity was in an inert state that didn‘t change. However . . . SUDDENLY! - this infinitely small, all of everything, inert singularity that didn’t change, CHANGED! How can this be? The singularity couldn’t be changed by something externally when all of everything is internal. And a thing that doesn’t change internally can’t change internally. The “scientific” answer seems to be “we don’t know”. The change resulted (among other things) in the singularity universally expanding (not exploding) and it continues to do so today (only space expands, not matter). Is space a "thing" that can expand? However . . . If the singularity then, and the universe now, both represent all of everything, how can a size be attributed to either? What’s the “other thing” that it’s being measured against? How can a thing be measured against itself? If it had a measurable size, surely it follows that it had edges (internal if not external), and it still must have those edges (where are the edges?). Why is infinitely small any more likely than infinitely large? Perhaps an infinitely large singularity could expand in to itself, what does and infinitely small singularity expand in to?

The BBT seems to me to be slap-happy science that apparently accepts stuff that would otherwise be class as woo.

And they all lived slap-happily ever after? ;)
Click to expand...

So what's ynot's preffered cosmology then?
 
Tubbythin said:
So what's ynot's preffered cosmology then?
Click to expand...
Do I have to have one? If I can’t provide a “better” answer, do I have to accept the one offered?

Accepting the challenge however - It seems to me that the mechanical properties of an expanding universe could be explained by universally shrinking matter instead of universally expanding space. Perhaps all matter was once an infinitely large singularity that universally shrunk/shrinks and formed/forms in to “clumps” separated by space. Ignoring the everyday motions inherent in the universe, the centers of the clumps would remain the same distance apart but the distance (space) between their outer surfaces would be constantly and uniformly increased (the surfaces would move apart). Perhaps there may be an understanding of gravity there? All human concepts of size have to be abandoned. Sure, it’s pretty wacky, but the BBT is no less wacky to me. Won’t hold my breath for a Nobel.
 
ynot said:
The Big Bang Theory (aka Fairy Story?)

Once upon a time (before there was time) all of everything (the universe) was virtually nothing (“infinitely small” - whatever that means). It couldn’t be totally, actually nothing because that would mean something came from nothing, and that‘s not good science (would require an act of magic, aka creation). The infinitely small universe (“singularity”) apparently existed before time existed (no time means no change). In other words, the singularity was in an inert state that didn‘t change. However . . . SUDDENLY! - this infinitely small, all of everything, inert singularity that didn’t change, CHANGED! How can this be? The singularity couldn’t be changed by something externally when all of everything is internal. And a thing that doesn’t change internally can’t change internally. The “scientific” answer seems to be “we don’t know”. The change resulted (among other things) in the singularity universally expanding (not exploding) and it continues to do so today (only space expands, not matter). Is space a "thing" that can expand? However . . . If the singularity then, and the universe now, both represent all of everything, how can a size be attributed to either? What’s the “other thing” that it’s being measured against? How can a thing be measured against itself? If it had a measurable size, surely it follows that it had edges (internal if not external), and it still must have those edges (where are the edges?). Why is infinitely small any more likely than infinitely large? Perhaps an infinitely large singularity could expand in to itself, what does and infinitely small singularity expand in to?

The BBT seems to me to be slap-happy science that apparently accepts stuff that would otherwise be classed as woo.

And they all lived slap-happily ever after? ;)
Click to expand...
Wow, just wow!! :jaw-dropp

I see that you're an old-hand here in the JREF forum's Science, Mathematics, Medicine, and Technology section ynot.

Sadly, it also seems all to clear that you either do not understand what you undoubtedly have read, or (much worse) cynically, deliberately, and with much malice aforethought misconstrue it (I doubt many other interpretations are fully consistent with the totality of your posting record).

For the record, this fairy tale (your post which I have quoted, and indeed it is a fairy tale) is a grotesque parody of the BBT, or any ΛCDM models.

Have you been completely asleep when it was explained to you, with considerable patience and much dumbing down, that no theory of the origin of the universe is possible until at least viable theory of quantum gravity (or, if you prefer, a quantum theory of gravity) is specified? What part of "GR and the SM are mutually incompatible in the Planck regime" do you not understand??

Do you even realise just you much of a borderline troll this post or yours make you? :eye-poppi
 
ynot said:
Do I have to have one? If I can’t provide a “better” answer, do I have to accept the one offered?

... snip ...
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Of course you don't! :mad:

However, the topic of this thread, in case your reading comprehension is not up the task, is Concise description of the Big Bang Theory (or ΛCDM models), possible? or not?

(I made it large, and bold, to help you read it).

Your contribution was, as I have said, a grotesque parody, bereft of life, a stiff, passed on, ... and if you hadn't nailed it to your perch, it'd be pushing up daisies!
 
ynot said:
Do I have to have one? If I can’t provide a “better” answer, do I have to accept the one offered?
Click to expand...
No. But it might be wise to not refer to a theory that better describes the observational evidence than you can manage a "fairy story" (with or without a question mark). Its the cosmological equivalent of you laughing at some kid in the playground because they only get £1 a week pocket money and then it being found out that you only get 10p.
 
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