Humbled by Hubble

[beil]

If the farthest objects show the greatest expansion velocities-- Their signal, image must be the oldest, having travelled the longest. -- so:
why do we not recognize that outward velocities were greatest just after the so called . "Big Bang" The Start, The beginning of spacetime? ?

 

[James R]

We can only see back to around 380,000 years after the big bang. The first galaxies we can see formed about 400 million years after the big bang.

The rate of expansion of the universe appears to be speeding up over time. It's important to distinguish between the velocities of objects in space from the velocities due to the expansion of space.

Also, bear in mind that the big bang happened everywhere in the universe at once, not at a single point somewhere in an existing space.

 

[beil]

yeah, of course, if you are here, you must have been in some way have been with us in the Big Beginning.. everywhere.
Then there was the event termed " inflation" at super c. .
How do our observations distinguish between the velocities, accelerations due to individual movement and that of the spacetime framework?
My question was, if the oldest, (closest to the beginning) objects show the greatest outward velocities, Does that not imply that the escape velocities were greater then than now? or at halftime?
Perhaps the more learned audience that shuns the fringe and reads the real science forums, could chime in, if the theme is moved.

 

[geordief]

The rate of expansion of the universe appears to be speeding up over time. It's important to distinguish between the velocities of objects in space from the velocities due to the expansion of space.

Would it be a valid point of view (or maybe just just the commonly accepted view among physicists) that this "space" in the "expansion if space" is not a physical thing like we might normally think of space as being but just the measured distances between objects in space(outside of gravitational influence) ?

Not a "thing" but a measurement and part of a model?

eah, of course, if you are here, you must have been in some way have been with us in the Big Beginning.. everywhere.

I don't think it is necessarily the case that there was any "Ɓig Beginning".I think observations(?) only go back to the Big Bang .

I don't know myself if any ideas exist of what may have been going on before then,or if any of them posit a "beginning".

My question was, if the oldest, (closest to the beginning) objects show the greatest outward velocities

Where is "outward" from?

 

[Pinball1970]

yeah, of course, if you are here, you must have been in some way have been with us in the Big Beginning.. everywhere.
Then there was the event termed " inflation" at super c. .
How do our observations distinguish between the velocities, accelerations due to individual movement and that of the spacetime framework?
My question was, if the oldest, (closest to the beginning) objects show the greatest outward velocities, Does that not imply that the escape velocities were greater then than now? or at halftime?
Perhaps the more learned audience that shuns the fringe and reads the real science forums, could chime in, if the theme is moved.

Why is this in pseudoscience? Hubble and the expansion of the universe is fine in science.

Anyway Hubble's law states the further away a galaxy is the faster it is moving away from us and this has been measured by ground and space telescopes.

The universe expansion rate is an active area of research. In 1998 Saul Perlmutter and his team published a study that claimed the universe expansion is accelerating, a more recent study claim that it is slowing down.

 

[beil]

Would it be a valid point of view (or maybe just just the commonly accepted view among physicists) that this "space" in the "expansion if space" is not a physical thing like we might normally think of space as being but just the measured distances between objects in space(outside of gravitational influence) ?

Not a "thing" but a measurement and part of a model?



I don't think it is necessarily the case that there was any "Ɓig Beginning".I think observations(?) only go back to the Big Bang .

I don't know myself if any ideas exist of what may have been going on before then,or if any of them posit a "beginning".


Where is "outward" from?

About the general idea, may I refer you to the ALMA thread in Alternative Theories post # 1 147 ?

Any look, is also a lookback in time. We only see the past. " Far" means not only "Old" but alo EARLIER. By that line of reasoning,
Hubble actually works in reverse, it is the earlier universe that was expanding fastest
The vigour of youth.

 

[Pinball1970]

the earlier universe that was expanding fastest

No according to some cosmologists after inflation the expansion slowed then sped up about 6 billion years ago.

 

[beil]

Why is this in pseudoscience? Hubble and the expansion of the universe is fine in science.

Anyway Hubble's law states the further away a galaxy is the faster it is moving away from us and this has been measured by ground and space telescopes.

The universe expansion rate is an active area of research. In 1998 Saul Perlmutter and his team published a study that claimed the universe expansion is accelerating, a more recent study claim that it is slowing down.

I put this in "pseudo" out of habit. you are right any dealings with real data should be dignified by valid "science" classification , like the " Jupiter Vo and Vr cancel " thread imho.
I highlighted your "is" because we do not know it's current state. --It was_going so fast in the past
I am with Perlmutter, In " Alma" I posited that the universe is expanding into Timespace, Energytime. Absorbing more energy as we grow. Feeding the acceleration.

 

[beil]

No according to some cosmologists after inflation the expansion slowed then sped up about 6 billion years ago.

Glad we live in more stable times, at least as the cosmos goes.

 

[Pinball1970]

Timespace, Energytime

Not a thing

 

[Pinball1970]

Glad we live in more stable times, at least as the cosmos goes.

We don't know, the universe could be slowing down. Enjoy your life.

 

[Roosters for ever]

We don't know, the universe could be slowing down. Enjoy your life.

That probably would be the case with the universe/spacetime expansion being slowed by the incessant pull of gravity. But then we discovered "Dark Energy" which works against gravity, as a repulsive force.

 

[Roosters for ever]

We don't know, the universe could be slowing down. Enjoy your life.

That probably would be the case with the universe/spacetime expansion being slowed by the incessant pull of gravity. But then we discovered "Dark Energy" which works against gravity, as a repulsive force.

It seems that the previously held notion that universal/spacetime expansion is speeding up is now debatable.

https://www.smithsonianmag.com/smart-news/the-universes-expansion-may-be-slowing-down-not-speeding-up-new-research-suggests-180987660/

The Universe’s Expansion May Be Slowing Down, Not Speeding Up, New Research Suggests​

A new study challenges a long-held idea that the universe’s expansion is accelerating.​

Scientists have long held that the universe is expanding at an ever-increasing rate, driven by a mysterious but measurable force known as dark energy. Now, a new study might upend that idea, suggesting the universe’s expansion is actually slowing down—and that dark energy is diminishing, rather than stable..

These findings could have major implications for how we see the cosmos and understand its future. The work relies on observations from the Dark Energy Spectroscopic Instrument (DESI), which is using telescopic images to create a massive 3D map of the universe. Other recent results from the instrument have also implied that dark energy may not be a constant after all—and that it might be weakening.
more at link....

 

[James R]

geodief:

Would it be a valid point of view (or maybe just just the commonly accepted view among physicists) that this "space" in the "expansion if space" is not a physical thing like we might normally think of space as being but just the measured distances between objects in space(outside of gravitational influence) ?

Short answer: Yes.

The point is that the space between things (i.e. measured distances) tends to increase over time, even in the absence of apparent forces that would cause things to move apart. To put it another way, most forces are interactions between two objects. So, for example, the Moon orbits the Earth because the Earth and Moon interact with one another gravitationally. But the 'force' that pushes two widely-separated galaxies apart does not seem to be related to the properties of the galaxies. It seems that this "anti-gravity" force is just a property of space itself. It is often given the label "dark energy", but as far as I am aware, nobody knows what causes it yet.

I don't think it is necessarily the case that there was any "Ɓig Beginning".I think observations(?) only go back to the Big Bang .

As I said above, we can only observe things from about 380,000 years after the big bang. Before that, light was not able to freely travel through space, basically because space was too full of stuff to let the photons through. Once the density decreased sufficiently, light could travel uninterrupted across vast distances.

Nobody knows whether the big bang was the "beginning" of everything there is. We have no way of looking back to see if there was anything before the big bang (if there was a "before"), so we can't rule out that possibility.

 

[James R]

Then there was the event termed " inflation" at super c.

That happened long before there were any stars or galaxies or what we might call regular matter (atoms, molecules, etc.)

How do our observations distinguish between the velocities, accelerations due to individual movement and that of the spacetime framework?

Well, at the large scale of galaxies and stars and things, the only force that really exerts an influence between those things is gravity. Galaxies contain stars that interact with one another to bind the galaxy together gravitationally. But on an extragalactic scale, what we see instead is that galaxies are moving away from one another, apparently at increasing speeds.

So, really it's mostly a matter of the scale you're talking about.

My question was, if the oldest, (closest to the beginning) objects show the greatest outward velocities...

As I said, the big bang happened everywhere. The universe has no centre. Galaxies aren't expanding outwards from a central point somewhere in the universe. Instead, all galaxies are moving away from every other galaxy (unless they are part of a galaxy cluster bound together essentially by the local gravity of the component galaxies).

If I understand things correctly, I would assume that the newest galaxies show the greatest relative velocities - or, rather, the speeds of all galaxies now are higher than they were in the past - since the universe as a whole seems to be expanding faster than it did earlier in its history.

Does that not imply that the escape velocities were greater then than now? or at halftime?

Escape velocities from what?

 

[geordief]

Nobody knows whether the big bang was the "beginning" of everything there is. We have no way of looking back to see if there was anything before the big bang (if there was a "before"), so we can't rule out that possibility.

Do we have any theories as to what may have been going on in the period between 10^-43 seconds after the Big Bang and 38,000 years after the BB?

Is that period fairly well understood even if it cannot be observed directly?

Might gravitational waves offer a way of observing that time period at some future time?

 

[beil]

That probably would be the case with the universe/spacetime expansion being slowed by the incessant pull of gravity. But then we discovered "Dark Energy" which works against gravity, as a repulsive force.

An alternative theory is, that Energy is u8ncreatedable. has always existed, is still there in the pre-universe realm, aka timespace Energytime and is absorbed as our home universe expands.

 

[beil]

That happened long before there were any stars or galaxies or what we might call regular matter (atoms, molecules, etc.)

Well, at the large scale of galaxies and stars and things, the only force that really exerts an influence between those things is gravity. Galaxies contain stars that interact with one another to bind the galaxy together gravitationally. But on an extragalactic scale, what we see instead is that galaxies are moving away from one another, apparently at increasing speeds.

So, really it's mostly a matter of the scale you're talking about.

As I said, the big bang happened everywhere. The universe has no centre. Galaxies aren't expanding outwards from a central point somewhere in the universe. Instead, all galaxies are moving away from every other galaxy (unless they are part of a galaxy cluster bound together essentially by the local gravity of the component galaxies).

If I understand things correctly, I would assume that the newest galaxies show the greatest relative velocities - or, rather, the speeds of all galaxies now are higher than they were in the past - since the universe as a whole seems to be expanding faster than it did earlier in its history.

Escape velocities from what?

Big Bang happened everywhere? That requires the existence of a "space" to exist in. lets call that timespace accommodating a common point of time., origin. -- Unless you believe in a infinite universe ( and no possible others)
Even observed internal expansion might have an outer limit, (raisins in raising cake.) ( exploding "stars " at a fireworks).
My query here was very simple . the observational equivalent of time and distance. Anything Seen as " Far away" means also older. or Younger after the beginning. so,
Hubble showed
far away was faster. Younger was faster.

 

[James R]

beil:

Big Bang happened everywhere? That requires the existence of a "space" to exist in...

The big bang was the beginning of space as we know it. Space came into existence at the big bang and it has been expanding ever since. That's the theory.

... lets call that timespace accommodating a common point of time., origin.

The usual term is "spacetime", if you want to talk about time and space as a whole. But okay.

-- Unless you believe in a infinite universe ( and no possible others)...

Here's where things get tricky. How do you want to define "universe"?

One way is just to define the universe as our current iteration of spacetime - the one we can observe and measure.

A different way to define the universe is to say it is everything that has ever existed or ever will exist. If we want to talk about the universe in that sense, then if you think it's not infinite you need to give me some reasons for why you think that. As for me, I'm agnostic on that question because, as far as I'm aware, we have no way to access anything beyond our current iteration of time and space.

In fact, even if you only want to talk about "the universe" in terms of the more limited definition, you'll still need to give me some reasons if you want to assert that universe is finite. I'm equally agnostic on that question, because I'm not aware of any data that definitively answers the question one way or the other.

Even observed internal expansion might have an outer limit, (raisins in raising cake.)

It might, but I'm not aware of any evidence that it does. Are you?

Also, I can't think of a good physical reason why we ought to think it does. Can you?

... ( exploding "stars " at a fireworks).

Even using the more limited of the two definitions of "universe" given above above, you're still talking about all the stuff we can ever see and measure. All the space. That stuff doesn't expand into something larger. By definition, it is everything there is. There can't be any extra space "outside" the universe we have defined.

The firework analogy doesn't work, because a firework explodes and the piece go off into the empty sky around the firework. But when our universe expands, it doesn't have pieces that got off into some external reality.

My query here was very simple . the observational equivalent of time and distance. Anything Seen as " Far away" means also older.

Light from things farther away was emitted from those things earlier, certainly.

so,
Hubble showed
far away was faster.

Yes. Hubble showed that distant galaxies are moving away from us faster than closer galaxies.

Assuming the universe as a whole is reasonably homogeneous on large scales, this also means that anybody in another galaxy would observe exactly the same thing we do: galaxies that are more distant from him would be moving away faster than ones closer to him.

Younger was faster.

No. If anything, younger was slower, for reasons I explained in a previous post.

 

[James R]

geordief:

Do we have any theories as to what may have been going on in the period between 10^-43 seconds after the Big Bang and 38,000 years after the BB?

Yes. Lots of them. In fact, I think most astrophysicists would say that is the most interesting time during the Big Bang.

The relevant theories are in the subfields of particle physics and quantum field theory.

For example, we have theories that postulate that the four fundamental forces of nature (gravity, the strong and weak nuclear forces and electromagnetism) were all indistinguishable in the very early universe. Then, at various times as the universe expanded and cooled, that symmetry was broken. First, gravity separated out from the other three forces. Next, the strong force separated out. Last of all, the weak force separated from the electromagnetic force.

Meanwhile, the matter content of the universe went through a bunch of major changes. It started off as a quark-gluon plasma, with lots of photons and electrons. Originally, there were almost - but not quite - equal amounts of matter and antimatter, but essentially all of the antimatter annihilated with matter, leaving only a little leftover matter. Then, as the universe continued to expand and cool, the quarks combined to form nucleons. Some nucleons combined to form the earliest atomic nuclei - mostly hydrogen with some helium and lithium and smaller amounts of a few other elements. Then there was a (relatively) long wait before things cooled down enough for electrons to combine with nuclei to form the first atoms. All this time, photons were bouncing around in the matter cloud, being continuously absorbed and re-emitted, until eventually the universe's mean density got low enough that some photons were able to travel freely without being absorbed. That's at the 380,000 year mark, approximately.

Is that period fairly well understood even if it cannot be observed directly?

Many aspects of the particle physics are well understood, because we can reproduce similar conditions to the early universe using particle accelerators such as the Large Hadron Collider, and watch the particles interacting.

We also have quantum field theories that have been rigorously tested. For instance, the theory of quantum electrodynamics, which describes the electromagnetic field, is perhaps the most precisely tested theory in all of science. We have also confirmed that the electromagnetic force and the weak force become indistinguishable at high temperatures, such that we can talk about "electroweak" theory.

Might gravitational waves offer a way of observing that time period at some future time?

Yes. Very probably, gravitational observatories will allow us to look further back in time than we are currently able to. But it's still early days for gravity wave telescopes.