More than one "Big Bang"?

[LuckyGurovich]

Is there any data to ascertain that stars or galaxies far away from us are a result of "our" Big Bang?
A unique Big Bang?
Universe (infinite and eternal) and Cosmos (derived from our BigBang) as a subset of the Universe
LuckyGurovich

 

[billslugg]

Yes, no matter what direction we look, at a given distance galaxies are receding at a certain rate. The Hubble Constant is the same no matter where we look. There was one Big Bang and it happened everywhere at once. Tracing the motion of distant galaxies backwards leads to just one point of origin.

 

[Catastrophe]

billslugg

"The Hubble Constant is the same no matter where we look."

That is news to me. I will really greatly appreciate it, if you will kindly refer me to this new agreed result.
I am not trying to be funny. Even if you simply refer to greater equanimity, I will welcome more unification in methods and conclusions.

Cat

https://imgur.com/a/VD72OMp

View: https://imgur.com/a/VD72OMp

 

[billslugg]

This is not a "new result", the Hubble Constant has always been the same no matter which direction we look, to within a few percent. There is some anisotropy but that is due to our movement through space. There is also disagreement as to what the exact number is, mostly because of difficulty in determining distances. Here is a discussion:

Cosmology Tutorial - Part 2 (ucla.edu)

 

[LuckyGurovich]

Very interesting Tutorial from UCLA. It seems to answer my question related to all celestial bodies are a result of an unique Big Bang; however the possibity of a unique pre BigBang infinite and eternal Universe still can be postulated

 

[Catastrophe]

billslugg,
Thank you for your reply. I am sorry if I misunderstood what you posted:
"The Hubble Constant is the same no matter where we look."
I now understand that you are making certain assumptions.
"This is only approximately true"
I see no point in elaborating further. EOS.

Cat

 

[billslugg]

You asked a question and I gave you the answer. Now you don't like the answer. So why did you ask the question?

 

[Catastrophe]

On the contrary, your answer could not have been more helpful, and I extend to you my sincere thanks.

Are you aware of Korzybski (esp. General Semantics)?. One of my interests is to apply his edicts, such as "The map is not the territory" to statements, and to question the assumptions involved.

If you wish, I will walk through my thought processes?

Cat

 

[billslugg]

Yes, it is OK to question assumptions, they need to be listed clearly.

 

[Catastrophe]

OK, it went like this:

1. I am aware of the wide spread of results for the "Hubble InConstant", such as shown on #3.
2. I am also aware of the fact that these results are slowly being refined. Vide:
"Whatever dark energy is, explanations for it have less wiggle room following a Hubble Space Telescope observation that has refined the measurement of the universe's present expansion rate to a precision where the error is smaller than five percent. The new value for the expansion rate, known as the Hubble constant, or H0 (after Edwin Hubble who first measured the expansion of the universe nearly a century ago), is 74.2 kilometers per second per megaparsec (error margin of +/- 3.6). The results agree closely with an earlier measurement gleaned from Hubble of 72 +/- 8 km/sec/megaparsec, but are now more than twice as precise." My bold.
Source:NASA - Refined Hubble Constant Narrows Possible Explanations for Dark Energy
3. I saw your post #2, which contains: "Yes, no matter what direction we look, . . . . . . The Hubble Constant is the same no matter where we look"
I questioned whether this might reflect improved accuracy in the HC, and therefore asked you
"That is news to me. I will really greatly appreciate it, if you will kindly refer me to this new agreed result." I added: "I am not trying to be funny. Even if you simply refer to greater equanimity, I will welcome more unification in methods and conclusions." because I didn't want to confuse the possibilities of "a perfect result" with a less dramatic, but still important, improvement in accuracy. I mentioned unification in methods and conclusions since there have been two cases requiring different methodology and giving different results. I was therefore particularly interested in the possibility of unification in method/results which might have been obtained.
4. You clarified the issue by adding "to within a few percent". You will appreciate that this is very different from a bald "The Hubble Constant is the same no matter where we look."
5. I pointed out politely in my post #6
"Thank you for your reply. I am sorry if I misunderstood what you posted:
"The Hubble Constant is the same no matter where we look."
I now understand that you are making certain assumptions.
"This is only approximately true"
I see no point in elaborating further. EOS.
"Since we had established limits of accuracy, and I felt that nothing new had been introduced, and that there was no point to extending the discussion, I suggested that we had ended useful discussion of the subject. I am sorry if you interpreted this as being in any way harsh, but I was slightly sorry that what purported the possibility of new unification and accuracy in Hubble Constant data had turned out disappointing. If this upset you, then I apologise. At my age (83), I take my motto seriously "There never was a good war, or a bad peace."
I am a scientist, published by Marcel Dekker (Surfactant Science Series) as editor and author, and author of dozens of published articles and scientific training materials, and this may have resulted in my being a little "picky" in interpreting printed statements.

Catastrophe

 

[Harry Costas]

Very long notes.
Can you get to the point.

 

[Harry Costas]

It’s funny that the Hubble constant allows for expansion of the universe from all surrounds.
This is not a correct statement.
Clustering of galaxies and stars and super clusters indicates that expansion of the universe maybe questionable.

 

[Catastrophe]

Very long notes.
Can you get to the point.

I am sure that the person who replied 'yes' to my question "If you wish, I will walk through my thought processes?" is fully able to appreciate my reply.

Nevertheless, if you would like a shorter answer, I suggest you do as I do, and ignore posts which one considers disproportionately long, or any which one considers as apparent spam, appearing as unconnected lists with no apparent purpose.

Cat

 

[LuckyGurovich]

Jeez, fellows: I never intended to create such an upheaval with my question. I just wanted to comment on the idea that the Cosmos (created by the Big Bang event) is expanding at an ever-increasing speed into the Universe, which may be infinite. Thus, maybe there was before (or at this very moment or will be, sometime in the eternal future) other events like our Big Bang, in a different realm of the Universe, creating a different Cosmos.

 

[Catastrophe]

LuckyGurovich,

No problem. Just a little friendly banter. Just shows it is alive here.

Cat

 

[Catastrophe]

Jeez, fellows: I never intended to create such an upheaval with my question. I just wanted to comment on the idea that the Cosmos (created by the Big Bang event) is expanding at an ever-increasing speed into the Universe, which may be infinite. Thus, maybe there was before (or at this very moment or will be, sometime in the eternal future) other events like our Big Bang, in a different realm of the Universe, creating a different Cosmos.

Welcome to the forum. Is that information helpful?

Cat

 

[billslugg]

Cat
Thank you for your detailed reply. All is well, no hard feelings here.
Bill

 

[Helio]

The current S&T issue addresses the Hubble Tension. It gives results for the Hubble-Lemaitre expansion rate using a number of clever methods. The odd thing is that though they are close to one another, there is a distinct difference of < 10%. Things like tweaking the scattering by dust, etc., has brought them closer together but the fact that they aren't able to tweak them to match makes for more interesting cosmology.

This is not that unusual in science, of course. When they tried to measure the distance to the Sun using a Venus transit, they noticed an error in their clock rate. After some study and relocations, it was determined that the mass of the Earth below them was different, thus the rate becomes different.

But that was tweaking and the H-L constant difference is more challenging.

The H-L expansion rate, fwiw, is true no matter what direction one looks, so the difference has little to do with where one is studying the expansion rate. I doubt anyone thinks otherwise, but it might be helpful for newcomers.

 

[Catastrophe]

Helio, if we (and everywhere else) were (to be) the centre of 'all', as we are supposed to be, then it would be expected that the CMB should be uniform. It isn't.

All these little nigglings.

Cat

 

[billslugg]

The CMB is non uniform for several reasons. One is we are moving through the universe so we see the CMB blue shifted ahead of us and red shifted behind. Also there are variations in the CMB due to quantum fluctuations in the original Big Bang fireball. Neither of these reasons negates the fact that the universe expanded everywhere at once thus every spot is considered to be at its center.

 

[Catastrophe]

I am no expert on the CMB, but I do find this on #124 really very interesting.

Ask Me Anything - Ask Dr. Joe - Now WEEKLY! | Page 5 | Space.com Forums

I look forward to seeing Dr Joe's reply.

Of course, I understand that we are, in a real sense, at the centre of 'an' observable universe (small u). As one moves around one's observable universe one loses those limits one is moving away from, but gains new limits in the direction moved into. Thus, one always has limits of similar age (hence CMB). Of course, I am not suggesting that we can physically move around to any significant extent - just indulging in a mind game.


Cat

 

[Helio]

The CMB is non uniform for several reasons. One is we are moving through the universe so we see the CMB blue shifted ahead of us and red shifted behind.

Yes, this is the CMB dipole that reveals we (our local group) is traveling at about 600 kps.

I don't think this is in the "bullet list", but should it be?

Also there are variations in the CMB due to quantum fluctuations in the original Big Bang fireball. Neither of these reasons negates the fact that the universe expanded everywhere at once thus every spot is considered to be at its center.

Indeed. Both the CMBR isotropy (smoothness) and anisotropy (tiny variations) are critical predictions coming from BBT. These are perhaps the most important bullets in that Big Bang Bullet thread.

By measuring the size of the tiny temperature variations on the CMBR map, scientists can determine a great deal about the early universe, testing some of the many Big Bang predictions. Those results have helped make the theory quite robust.

 

[Helio]

I am no expert on the CMB, but I do find this on #124 really very interesting.

Ask Me Anything - Ask Dr. Joe - Now WEEKLY! | Page 5 | Space.com Forums

I look forward to seeing Dr Joe's reply.

I think Dr. Joe will explain that the Pop III stars were massive and hot. If we assume a temperature of 20,000K, then its peak wavelength is 144nm. So if we use, roughly, z = 2.1, then the redshift would put the peak at about 300 nm, still in the UV band. But there are also strong emissions on either side of the peak wavelength in any Planck distribution.