Where is the center of the universe?

[Admin]

The universe is undeniably vast, and from our perspective, it may seem like Earth is in the middle of everything. But is there a center of the cosmos, and if so, where is it? If the Big Bang started the universe, then where did it all come from, and where is it going?

Where is the center of the universe? : Read more

 

[Catastrophe]

Or, to put it more succinctly, the entire Universe is beyond our capacity to observe, being limited by the speed of light, which places every observer at the centre of their own observable universe. Furthermore, such observable universes may vary according to means of assisted observation, such as telescopes.

Questions regarding the past and future of the Universe are limited by contingent constraints.

Cat

 

[Helio]

Articles are meant to be somewhat easy on the general reader, but Hubble tends to get caught in the current of favoritism more than he should, IMO.

“In the 1920s, astronomer Edwin Hubble made two amazing back-to-back discoveries: Early in the decade, he found that "island universes," now known as galaxies, sit very far away from us; later that decade, he discovered that, on average, all galaxies are receding away from us.”

Yes: Oct. 4, 1923. This was the famous plate image of M31 (Andromeda). Hubble had discovered the first "Cepheid" variable star. He found others and by 1926, IIRC, had over a dozen of what he felt were fairly accurate distance measurements to other “extragalactic nebulae”, as he called them.

But “No”: He didn't "discover" recessional velocities for spiral nebulae. [He, mainly Humason (co-astronomer), produced great works for redshifts, along with Hubble's great work on distances.]

Almost a decade earlier, Slipher (1914) received a standing ovation from the AAS for his discovery of redshift velocities. He held that their great speeds presented these spiral nebulae as “island universes”, as he published several years later. [This term seems to have come from Shapley who referred to globular clusters as “island universes”, partly to counter the cosmic model of Bohlin (1909) who placed globulars in the center of the universe; MW stars in a ring much farther out.]

One of the strange twists of fate seems to be found in Hubble's Cepheid calculations. His 900,000 lyrs. distance for Andromeda was due to his, or anyone's, lack of knowledge for the Pop II Cepheids (i.e. W. Virginis) variables, which are roughly 4x dimmer and far less massive.

But Leavitt's work was of the Cepheids (Pop I), and Hubble seems to have been finding these same Cepheids, so how did he stumble with such a low distance estimate for M31?

One source mentions that he favored Shapley's detailed work in finding "Cepheids" in globular clusters. So, IMO, with his use of the world's greatest telescope at Mt. Wilson, Shapley likely had better P-L data superior to Leavitt, perhaps. But these, proved later by Baade, were the Pop II (W. Virginis) dimmer variables. Hence Hubble thought he was observing distant Cepheids (per Shapley's data) when he was really seeing the brighter Pop I. This would make for an erroneous closer distance calculation for Andromeda. It also produced too fast of a "Hubble Constant", which he seems to have shrunk a little to about 500 kps/Mpc from his initial estimate. [Lemaitre's, first ever expansion constant, was something like 650 kps/Mpc.]

Any comments on this, because this isn't something often mentioned anywhere that I've noticed? There must be something I'm missing in these calculations.

 

[Homer10]

OK, let me ask a slightly different question.
At some point in the past there was a large explosion, and the Universe as we know it, is created, and expands to a very large size very quickly, and continues to expand today. At the moment of this big bang, it happened somewhere. Let's call this the origin (x=0, y=0, z=0). The Universe expands for 13.8 (more or less) Billion years. We are now at some new location as referenced to the origin point. If we look back in the direction from where we came from, can we determine how far we have traveled from the origin? If we look back in the direction from where we came from, what would we see? Notice I didn't ask for a center. I'm looking for a distance traveled from an origin point.

 

[Helio]

OK, let me ask a slightly different question.
At some point in the past there was a large explosion, and the Universe as we know it, is created, and expands to a very large size very quickly, and continues to expand today. At the moment of this big bang, it happened somewhere. Let's call this the origin (x=0, y=0, z=0). The Universe expands for 13.8 (more or less) Billion years. We are now at some new location as referenced to the origin point. If we look back in the direction from where we came from, can we determine how far we have traveled from the origin? If we look back in the direction from where we came from, what would we see? Notice I didn't ask for a center. I'm looking for a distance traveled from an origin point.

This is a very common assumption. But BBT has the universe itself (space) expanding. A balloon will expand such that all the marks, if any, on it remain proportionally the same distance ratio with one another.

Thus, we are essentially in the same location we were after, say, the first trillionth of a second, but space has expanded so much that our close neighbors aren't close any more. [Motions through space, of course, alters this somewhat.]

 

[Rangerer]

I remember an article referencing a galaxy not far from ours that was formed only a few hundred million years after the Big Bang. Doesn't that imply that we are very close to the center of the universe?

 

[Unclear Engineer]

The analogy of an expanding balloon's surface is not a good fit with the statement that there is nothing outside our universe. It implies that there is another dimension not modeled in our concept of our universe.

And, the insistence that expansion observed now can be extrapolated backward to everything being at a single point is not very imaginative, especially considering all of the imaginative ideas that have gone into trying to explain how that could have worked in the time-going-forward direction to get to what we can see now.

The BBT says we don't understand 95% of the matter and energy needed to fit the model to the observations. That is a lot that these theorists agree we do not understand. It occurs to me that there could be plenty of ways to not understand that the universe did not originate from a single point, but is instead going through some sort of dynamic process that does not require an origin at a single point for everything in the universe.

The idea that the universe is flat, as far as we can tell, would seem to imply an infinite universe. Perhaps somebody can tell us what the minimum radius of the universe would have to be in order for us to see it as "flat" in our currently available data.

 

[Atlan0001]

The universes emerge from every deep, therefore "at-a-distance," relatively dense-hot (Chaos Theory level "smooth) state (T=1), Planck point of universe(s). An infinity of points . . . and, yet, just one Horizon (P (BB)) of them all (Chaos Theory's level "smooth" state)!

Since it is our internally deepest state points [and/or] Horizon, and is superposition Horizon everywhere and deepest state points in everything everywhere, therein is the "Planck constant (unity ('1'))" emergent universe (Ever was! Ever is! Ever will be)!

 

[Gibsense]

OK, let me ask a slightly different question.
At some point in the past there was a large explosion, and the Universe as we know it, is created, and expands to a very large size very quickly, and continues to expand today. At the moment of this big bang, it happened somewhere. Let's call this the origin (x=0, y=0, z=0). The Universe expands for 13.8 (more or less) Billion years. We are now at some new location as referenced to the origin point. If we look back in the direction from where we came from, can we determine how far we have traveled from the origin? If we look back in the direction from where we came from, what would we see? Notice I didn't ask for a center. I'm looking for a distance traveled from an origin point.

I don't seem able to get this point across to most. The Distance travelled (your question) is time. People need to get their heads around the fact that time and distance units are interchangeable. A light year IS a year and a year IS a light year. This is not a debatable point in current science.
The elephant in the room is time. Time. Where do you see a definition of time rather than some vague assertion about arrows? Or clocks.
Given the above, it is clear that the "centre" does not exist anywhere in the here-and-now universe. It has been left behind in the past. The current model is dead and buried (by data from James Webb) and people cling to the idea of flat Euclidian space simply because it is easy to understand and 'consensus'
Our perception of reality in everyday life is untrue. Grabbing facts and shuffling until coherent mathematics makes sense and describes reality with numbers (spacetime) is a correct result. Minkowski (Einstine's teacher) did a good job of a description of relativity. Alive now he would point out that a better understanding of time (as a spatially additional dimension that does not change relativity mathematics) and we could all move forward to new ideas.
Ha ha. Sorry about the rant but I get so frustrated. It is obvious.
Easy to understand:

Think of a balloon being inflated. This is an analogy that has been used for decades. We live on the surface. (this is the universe description by dropping a dimension to 'make things clear'). Our 3D environment is the surface and nowhere else in this description.
The balloon was just a blob before inflation - The Big Bange event.
Inflate the balloon and you get an expanding universe. The Universe is the surface only. The origin is back in time (a distance away) at the centre of the balloon. Conceivably, if you consider the Big Bang as a piece of material-type substance that has been teased out to the skin of the balloon then you could describe the universe centre as 'everywhere'.
This is ok of course but it disguises the reality of a geometric centre that does not exist in the universe 'now'. By doing this 'everywhere' we avoid having to decide what time actually is and our limited perception of it!

 

[Gibsense]

Furthermore, such observable universes may vary according to means of assisted observation, such as telescopes.

Questions regarding the past and future of the Universe are limited by contingent constraints.

Cat

I don't get this. Whether or not you have lost your glasses or your telescope makes not one jot of difference to the distance to the event horizon of an "observable universe".
AH! I guess I have just cottoned onto your sense of humour! lol

 

[Gibsense]

The universes emerge from every deep, therefore "at-a-distance," relatively dense-hot (Chaos Theory level "smooth) state (T=1), Planck point of universe(s). An infinity of points . . . and, yet, just one Horizon (P (BB)) of them all (Chaos Theory's level "smooth" state)!

Since it is our internally deepest state points [and/or] Horizon, and is superposition Horizon everywhere and deepest state points in everything everywhere, therein is the "Planck constant (unity ('1'))" emergent universe (Ever was! Ever is! Ever will be)!

Amen, the past still exists in the 5th dimension - along with an infinite number of others (you have been reading Hawking again) LOL.

 

[Gibsense]

Articles are meant to be somewhat easy on the general reader, but Hubble tends to get caught in the current of favoritism more than he should, IMO.

“In the 1920s, astronomer Edwin Hubble made two amazing back-to-back discoveries: Early in the decade, he found that "island universes," now known as galaxies, sit very far away from us; later that decade, he discovered that, on average, all galaxies are receding away from us.”

Yes: Oct. 4, 1923. This was the famous plate image of M31 (Andromeda). Hubble had discovered the first "Cepheid" variable star. He found others and by 1926, IIRC, had over a dozen of what he felt were fairly accurate distance measurements to other “extragalactic nebulae”, as he called them.

But “No”: He didn't "discover" recessional velocities for spiral nebulae. [He, mainly Humason (co-astronomer), produced great works for redshifts, along with Hubble's great work on distances.]

Almost a decade earlier, Slipher (1914) received a standing ovation from the AAS for his discovery of redshift velocities. He held that their great speeds presented these spiral nebulae as “island universes”, as he published several years later. [This term seems to have come from Shapley who referred to globular clusters as “island universes”, partly to counter the cosmic model of Bohlin (1909) who placed globulars in the center of the universe; MW stars in a ring much farther out.]

One of the strange twists of fate seems to be found in Hubble's Cepheid calculations. His 900,000 lyrs. distance for Andromeda was due to his, or anyone's, lack of knowledge for the Pop II Cepheids (i.e. W. Virginis) variables, which are roughly 4x dimmer and far less massive.

But Leavitt's work was of the Cepheids (Pop I), and Hubble seems to have been finding these same Cepheids, so how did he stumble with such a low distance estimate for M31?

One source mentions that he favored Shapley's detailed work in finding "Cepheids" in globular clusters. So, IMO, with his use of the world's greatest telescope at Mt. Wilson, Shapley likely had better P-L data superior to Leavitt, perhaps. But these, proved later by Baade, were the Pop II (W. Virginis) dimmer variables. Hence Hubble thought he was observing distant Cepheids (per Shapley's data) when he was really seeing the brighter Pop I. This would make for an erroneous closer distance calculation for Andromeda. It also produced too fast of a "Hubble Constant", which he seems to have shrunk a little to about 500 kps/Mpc from his initial estimate. [Lemaitre's, first ever expansion constant, was something like 650 kps/Mpc.]

Any comments on this, because this isn't something often mentioned anywhere that I've noticed? There must be something I'm missing in these calculations.

Maybe my post "Hubble Tension" would stimulate (?)

 

[Catastrophe]

Gibsense,

I don't get this. Whether or not you have lost your glasses or your telescope makes not one jot of difference to the distance to the event horizon of an "observable universe".
AH! I guess I have just cottoned onto your sense of humour! lol

Sorry. This is incorrect.

A telescope will collect more light from a dim object because it's area is so much larger than the pupil of yhe eye. Wiki gives:

The aperture (or more formally entrance pupil) of a telescope is larger than the human eye pupil, so collects more light, concentrating it at the exit pupil where the observer's own pupil is (usually) placed. The result is increased illuminance – stars are effectively brightened. At the same time, magnification darkens the background sky (i.e. reduces its luminance). Therefore stars normally invisible to the naked eye become visible in the telescope.

Cat

 

[Helio]

The analogy of an expanding balloon's surface is not a good fit with the statement that there is nothing outside our universe. It implies that there is another dimension not modeled in our concept of our universe.

The balloon analogy is perhaps the best way to help visualize one important element of BBT — expansion, in lieu of explosion. It is odd, nevertheless, since we often represent 3D objects with 2D drawings, but here we are taking a 3D object and restricting it to only the surface dimensions.

And, the insistence that expansion observed now can be extrapolated backward to everything being at a single point is not very imaginative, especially considering all of the imaginative ideas that have gone into trying to explain how that could have worked in the time-going-forward direction to get to what we can see now.

Right, it’s easy to look back in time. It was the discovery of the CMBR, as precisely predicted from BBT, that finally took BBT mainstream, though it was favored by most GR physicists before then. The remarkable success of GR only further adds support for BBT. But there’s more we don’t understand, so perhaps something will come along. If so it too will be required to explain all those observations stated in the Big Bang Bullets thread.

 

[Helio]

Maybe my post "Hubble Tension" would stimulate (?)

The IAU officially changed the “Hubble constant” to the “Hubble-Lemaitre constant”.

Lemaitre’s theory (1927) included a changing expansion rate, so I don’t really get where the “tension” is.

 

[Atlan0001]

To Gibsense, or the artistic part of the Space.com staff, whichever:

Light Cones, Onions, and Time

I am still having problems with images, my bad I am sure, but I will keep trying. In the meantime here is a link to a diagram for the Nature of time in Euclidian space for debate. https://postimg.cc/MX900dWw]

forums.space.com

 

[T. Jefferson]

The universe is undeniably vast, and from our perspective, it may seem like Earth is in the middle of everything. But is there a center of the cosmos, and if so, where is it? If the Big Bang started the universe, then where did it all come from, and where is it going?

Where is the center of the universe? : Read more

The universe is not actually expanding nor is it contracting It is more or less convecting, roiling, boiling, and recycling itself endlessly. Some areas are moving from the fourth dimension into our three-dimensional reality while other areas are removing matter from our three-dimensional reality and depositing it into the fourth dimension.

 

[Catastrophe]

How come every single location in the Universe is at its centre?

Not that difficult if you accept the idea that the universe is analogous to (the surface of) a two dimensional sphere.

I put it this way because technically the surface is the sphere.
It is a two dimensional surface in three dimensional space.

Just think. Where is the surface of the Earth's surface?
Any point is equivalent to any other point. Each or none is the centre of the surface.

Do not be confused by the Earth, which is a ball, which has a surface.
The Earth has a centre, because it is solid.


Cat

 

[Catastrophe]

Reminder:

Wiki gives this:

Mathematicians consider a sphere to be a two-dimensional closed surface embedded in three-dimensional Euclidean space. They draw a distinction between a sphere and a ball, which is a three-dimensional manifold with boundary that includes the volume contained by the sphere.

Cat

 

[Catastrophe]

Experimental proof for the observable universe being a "zero-energy universe" is currently inconclusive. Gravitational energy from visible matter accounts for 26–37% of the observed total mass–energy density.[15] Therefore, to fit the concept of a "zero-energy universe" to the observed universe, other negative energy reservoirs besides gravity from baryonic matter are necessary. These reservoirs are frequently assumed to be dark matter.[16]

Zero-energy universe - Wikipedia

en.wikipedia.org

Cat


Can anyone explain how this affects matter and anti-matter not exactly cancelling out?
Just as a matter of interest.

 

[Gibsense]

The IAU officially changed the “Hubble constant” to the “Hubble-Lemaitre constant”.

Lemaitre’s theory (1927) included a changing expansion rate, so I don’t really get where the “tension” is.

'MOND' is a possibility that is still debated. But the principle it states - that variation by direction - is a real possibility. if I recall correctly, in my "Hubble Tension" I used relativity as a possible explanation but differently: Stars and galaxies have speed therefore their clocks will differ from Cmb clocks i.e. the time element (age of the universe) will differ when comparing 1a Supernova with the Cmb.
This has to be 'plugged into' my calculation involving a geometric distance to the 'Age of the Universe' As set out in my Hubble Tension post.
Hubble Tension is still an issue. MOND is one possibility.

 

[Gibsense]

Gibsense,



Sorry. This is incorrect.

A telescope will collect more light from a dim object because it's area is so much larger than the pupil of yhe eye. Wiki gives:

For the Navy.
For Astronomers there is the Horizon Problem.

I think the most common interpretation of Observable Universe would be the volume to the Event Horizon. Some might suggest a Hubble Sphere, others a Particle Horizon.

When used in a technical Cosmology sense the choice of telescope does not define the Observable Universe Limits, more likely would be the Past Light Cone limits for example at t=0

 

[Catastrophe]

Your post is mostly blank and is incomplete.

Can you edit this please?

Cat

 

[Gibsense]

Your post is mostly blank and is incomplete.

Can you edit this please?

Cat

Yes I have been working on that for some time. It seems the various kit on my desk decided to keep its finger on 'enter' . I think that's ok now.

 

[Catastrophe]

Gibsense, is there something very wrong with your system?

Universe | Definition & Facts | Britannica

The “observable universe” is the region of space that humans can actually or theoretically observe with the aid of technology. It can be thought of as a bubble with Earth at its centre.

This seems to confirm exactly what I posted.

Cat