The First Three Minutes - Steven Weinberg

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The discussion centers on Steven Weinberg's book "The First Three Minutes," which describes the early conditions of the universe following the Big Bang. Participants express concern over Weinberg's use of language, particularly the term "explosion," which may mislead readers about the nature of cosmic expansion. There is a request for reliable scientific sources that corroborate the data presented in the book, with suggestions to search academic platforms like arXiv. Some participants highlight that while Weinberg is an authority, his explanations may contain outdated or misleading concepts due to the evolving understanding of cosmology. Overall, the conversation emphasizes the need for clarity and accuracy in popular scientific literature.
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Has anyone studied the book "The First Three Minutes" written by Steven Weinberg? In this book the author stated the early universe conditions as: "At about one hundredth second after the big bang, the temperature of the universe was about a hundred thousand million degrees Centigrade. As the explosion continued, the temperature dropped, reaching thirty thousand million Centigrade after about one-tenth of a second, ten thousand million after about one second and three thousand million degrees after about fourteen seconds".

Can anyone tell me about a scientific book or paper where these data are written in a reliable format?
 
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Since Weinberg is an authority on this, why not poke around on the internet to see if you can find papers by HIM?
 
yes! Thanks for the idea... but if you know where to look... tell me
 
Try arxiv.
 
phinds said:
Since Weinberg is an authority on this, why not poke around on the internet to see if you can find papers by HIM?

He's an authority on this ? The OP's quote of the book says;

As the explosion continued ..

Yet we hear constantly that it was no explosion.
 
alt said:
He's an authority on this ? The OP's quote of the book says;

I suspect there may have been sarcasm in Phinds's post.
 
No sarcasm. Weinberg IS an authority on this. Unfortunately even good serious physicists such as he is DO use really sloppy language in their popular books.
 
Guys... thanks a lot... but can you provide me some papers where I can find these exact data?
 
s_sayed said:
Guys... thanks a lot... but can you provide me some papers where I can find these exact data?

reread post #4
 
  • #10
Thanks. Can you give me specific links? It will save a lot of my time.. moreover this is not my field...
 
  • #11
s_sayed said:
Thanks. Can you give me specific links? It will save a lot of my time.. moreover this is not my field...

You may get lucky and someone here will know of something, or even less likely someone may be willing to do your research FOR you, but generally, folks here are expected to do their own work where they can, and you can do a search as easily as anyone else.
 
  • #13
phinds said:
No sarcasm. Weinberg IS an authority on this. Unfortunately even good serious physicists such as he is DO use really sloppy language in their popular books.

Thanks. Sloppy language can be a problem ..
 
  • #14
@Borek: Thank you for the link to arxiv! That is great fun.
 
  • #15
I happened to read bits of this book last night.

I think it's more critical than sloppy language. I've only ready Chapt 2, Expansion of the Universe, but there are several issues.

He states several times that the recession velocity of very distant galaxies must be corrected to avoid going above speed of light. We know that's wrong, distant galaxies can and do recede from us at speed greater than c. That's the whole point of the Hubble sphere. (I've since noted that this very book is listed in the references of the "Common misconceptions" paper by Davis & Lineweaver).

What really bugged me is the conclusion of the chapter. It goes something like that (re-translated from French to English so not the original text) :

« We don't think that this expansion is the effect of a particular repulsive cosmic force, but simply escape velocities acquired in a past explosion. These velocities decrease progressively under the influence of gravity (…) »

:frown:
 
  • #16
phinds said:
No sarcasm. Weinberg IS an authority on this. Unfortunately even good serious physicists such as he is DO use really sloppy language in their popular books.

Also, sometimes famous physicists will use language that in hindsight is considered non-optimal. One example of this is George Gamov's explanation of relativity as increasing mass, which has led to a lot of confusion and it's considered non-optimal today. The first edition was written in the late 1970's, and I think it's taken a while for people to get confused looks from people thinking about the big bang as an explosion to realize that it's not a good idea to call it an explosion.

The other thing is that google has it's limitations. For one thing google doesn't classify things by level of difficulty, and it's difficult to get something that is between at the popular science level and things that are intended for graduate students. Weinberg has written several excellent graduate level textbooks, but that may not be what the OP is looking for.
 
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  • #17
jobigoud said:
I happened to read bits of this book last night.

I think it's more critical than sloppy language. I've only ready Chapt 2, Expansion of the Universe, but there are several issues.

He states several times that the recession velocity of very distant galaxies must be corrected to avoid going above speed of light. We know that's wrong, distant galaxies can and do recede from us at speed greater than c. That's the whole point of the Hubble sphere. (I've since noted that this very book is listed in the references of the "Common misconceptions" paper by Davis & Lineweaver).

What really bugged me is the conclusion of the chapter. It goes something like that (re-translated from French to English so not the original text) :

« We don't think that this expansion is the effect of a particular repulsive cosmic force, but simply escape velocities acquired in a past explosion. These velocities decrease progressively under the influence of gravity (…) »

:frown:

The original edition of this book was written in 1977. No, wait. Actually, it was PUBLISHED in 1977, so written even earlier. The accelerated expansion of the universe was not known at that time. Even the 2nd edition was published in 1993 and the accelerated expansion was STILL not known.

SO ... you are complaining about the guy not knowing stuff that NOBODY knew?
 
  • #18
phinds said:
SO ... you are complaining about the guy not knowing stuff that NOBODY knew?

That's not the problem. What will happen is that even with decelerating universes you will have galaxies eventually go past the Hubble horizon. v=Hr. You set v to c, and you'll get the radius at which galaxies are going away from you faster than light.

Now, I think he was referring to special relativistic corrections and talking about galaxies that we are observing now, but it's still potentially misleading.
 
  • #19
twofish-quant said:
That's not the problem. What will happen is that even with decelerating universes you will have galaxies eventually go past the Hubble horizon. v=Hr. You set v to c, and you'll get the radius at which galaxies are going away from you faster than light.

Now, I think he was referring to special relativistic corrections and talking about galaxies that we are observing now, but it's still potentially misleading.

Yes, clearly I didn't think it all the way through. Thanks for that correction. I was focusing on the age of the book more than the content being discussed ... big mistake.
 
  • #20
twofish-quant said:
That's not the problem. What will happen is that even with decelerating universes you will have galaxies eventually go past the Hubble horizon. v=Hr. You set v to c, and you'll get the radius at which galaxies are going away from you faster than light.

Now, I think he was referring to special relativistic corrections and talking about galaxies that we are observing now, but it's still potentially misleading.

The v = c sphere can reside inside the particle horizon, so we can see galaxies with v > c. That is the case in the most popular model, i.e., Einstein-deSitter.
 
  • #21
jobigoud said:
I happened to read bits of this book last night.

I think it's more critical than sloppy language. I've only ready Chapt 2, Expansion of the Universe, but there are several issues.

He states several times that the recession velocity of very distant galaxies must be corrected to avoid going above speed of light. We know that's wrong, distant galaxies can and do recede from us at speed greater than c. That's the whole point of the Hubble sphere. (I've since noted that this very book is listed in the references of the "Common misconceptions" paper by Davis & Lineweaver).

What really bugged me is the conclusion of the chapter. It goes something like that (re-translated from French to English so not the original text) :

« We don't think that this expansion is the effect of a particular repulsive cosmic force, but simply escape velocities acquired in a past explosion. These velocities decrease progressively under the influence of gravity (…) »

:frown:

However it was written unless there is a new edition, in 1977! When there was no data to indicate cosmic acceleration yet. And I think inflation was not yet in vogue.

Now if that disqualifies it as a strict information source I would suspect it should be longer lived than some others. Speaking from memory what was good about it was the solid and intuitive physics. An explanation of intuitively and physically why black body radiation is like it is, - instead of Rayleigh-Wien-Planck-this-formula-that-formula - helpful to any student. The explanation of how it comes about that the small nucleus (boron etc.) abundances are critically revealing of early-universe history even if his information must be out of date or limited. Again connecting with lasting parts of physics he emphasizes that after I think it is fifteen minutes from birth, known physical laws are adequate for all explanations. Maybe dark matter was not known then, maybe not much is known now - to know anything you have to use the known laws OK?
 
  • #22
epenguin said:
However it was written unless there is a new edition, in 1977! When there was no data to indicate cosmic acceleration yet. And I think inflation was not yet in vogue.

See post #17
 
  • #23
phinds said:
See post #17

OK. Independent discovery. :smile:
 
  • #24
Sorry if it looked like so, but I was definitely NOT referring to him not mentionning acceleration. (I have realized that acceleration of expansion has confused me before, and find it easier to first work out the concepts without it anyway.)

I was referring to the « velocities left over from a past explosion » which I think really invites the reader to think in terms of explosion in space, and « velocities gradually slowing down due to gravitation », probably my mistake, but again this invites me to think in term of an explosion, where you'd have some stuff exploding and then falling back to the ground due to gravity, except here it would be in all directions.

Even with linear expansion, (and even with decelerating expansion for that matter), isn't it better to describe expansion as some sort of cosmical stretching rather than a kind of inertial motion left over from an explosion ?
Maybe I was half asleep though :rolleyes:
 
  • #25
jobigoud said:
Sorry if it looked like so, but I was definitely NOT referring to him not mentionning acceleration. (I have realized that acceleration of expansion has confused me before, and find it easier to first work out the concepts without it anyway.)

I was referring to the « velocities left over from a past explosion » which I think really invites the reader to think in terms of explosion in space, and « velocities gradually slowing down due to gravitation », probably my mistake, but again this invites me to think in term of an explosion, where you'd have some stuff exploding and then falling back to the ground due to gravity, except here it would be in all directions.

Even with linear expansion, (and even with decelerating expansion for that matter), isn't it better to describe expansion as some sort of cosmical stretching rather than a kind of inertial motion left over from an explosion ?
Maybe I was half asleep though :rolleyes:

"Expansion" has several meanings/periods ... discussed here:

www.phinds.com/balloonanalogy
 
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