Dark energy could be getting weaker, suggesting the universe will end in a 'Big Crunch

[Admin]

The first year of Dark Energy Spectroscopic Instrument (DESI) data seems to show that dark energy is weakening over time, possibly the biggest cosmological discovery for 25 years.

Dark energy could be getting weaker, suggesting the universe will end in a 'Big Crunch : Read more

 

[LordElfa]

This could, if true, point to a constantly repeating big bang/big crunch cycle of universal renewal.

 

[G.nosticO.mniD.eity]

The law of Conservation of Mass Matter and Energy states that that mass, matter and energy are neither increased nor decreased...and Star Trek states: Ya' canna' change the laws of physics.

 

[Unclear Engineer]

The BBT just makes up new physics to over-ride the effects of the existing laws.

 

[billslugg]

You need to over-ride your post and correct "effects" to "defects".

 

[Unclear Engineer]

So, is it a "defect" in Relativity Theory to believe that all comoving observers in the universe would observe the same velocity for light at all times, including all the way back to the Big Bang? If you believe that is not a defect, then you have a problem explaining homogeneity in the very early universe. Or, just maybe the BBT has the "defect", not GRT.

"Inflation" is simply a way to override the General Relativity Theory result that a glob of matter representing the whole universe squeezed into a sub-atomic volume would not be able to expand against its own gravity. Inflation isn't explained. And it isn't constrained. It just is assumed to do whatever is needed to make the BBT work. And it is assumed to not do anything else that would make the BBT not work. Even if the something else seems like a logical extension of the something that is needed.

So, I stick by my original wording of my post.

 

[billslugg]

C is constant. Why don't you go measure it and show us the data saying it's not? Otherwise I'm going with the entire scientific community for the last 100 years versus an anonymous source.

Inflation overrode gravity due to its energy. The Schwartzchild radius is for matter absent energy pushing it outward.

 

[Unclear Engineer]

Bill, I have measured he speed of light, myself.

And I am not the one who is saying that the apparent speed of light must be different for (conceptual) observers in the very early universe - that is the result of the BBT saying that the light must have traveled across the whole early universe fast enough to keep it uniform in its parameters. That is the "horizon problem". But, we can't have it both ways. I am just pointing out the inconsistency between the 2 theories.

And, as far as we can tell, the Schwarzchild radius is applicable with the energies of all known forces. Nothing gets out, no matter what its charge level, kinetic energy, temperature, pressure, etc.

Yet, "inflation" is supposed to somehow have more energy than gravity. It would be able to explode our current black holes. So, why doesn't it? What happened that it expanded the very early universe, with far more mass in far less space than any of the black holes we now find, but it has no effect on our current black holes?

I'll add some thoughts about potential answers to that last point. "Inflation" is supposed to have expanded "space" and taken matter with the space as it expanded. That is to be consistent with General Relativity Theory not allowing matter to go through space at the speed of light (or faster). So, what would this look like from outside the expanding universe? Some people insist that is a forbidden question because their definition of "universe" says there is not any "outside". But, in fact, the frame of reference used by BBT theorists for the "very early universe" essentially assumes the view from outside, not inside. So, how would it have looked from inside? An astronomer's reference is relative to the inside of the universe.

Is it plausible that the view from inside a black hole (that we are outside of) looks to those inside like an expanding universe? I have read that is the case, but have not seen any general agreement on that. It would require a situation where the inside appears to be larger than the outside, at least from the frame of reference of those of us outside if we go inside. Sort of a "tardis" effect for those who are "Dr. Who" fans.

The whole BBT requires some real mind-bending mental gymnastics if you try to understand it in a comprehensive manner. It annoys me to keep reading pronouncements of weird and wonderful supposed "facts" by BBT proponents when they just blow off questions about how their beliefs are possible, or even internally self-consistent.

They may turn out to be right, but, for now at least, they are not convincing at the "bartender" level we discussed in the other thread.

And, yes, a physicist can tend bar.

 

[billslugg]

What did you get for the speed of light?

Inflation and a variable speed of light are two competing theories. I happen to go with inflation.

There is no "outside" to the universe.

Schwartzchild radius calculations at the time of the early universe do not allow for the formation a giant black hole. There is simply too much energy pushing outward. This is the reason we are here today.

 

[Unclear Engineer]

I measured the speed of light in 1966, and my result was not any different than expectation, within my error band for the measurement. As best I can remember 58 years ago, the result was 2.99something x 10^10 cm/sec.

You keep misunderstanding my point about the speed of light assumptions in the BBT. The BBT assumes BOTH that the speed of light to an "observer" in the very early universe was sufficient to quickly travel the entire diameter of that universe, AND that inflation occurred. That is what I am saying is inconsistent. You don't get to choose just one if you believe in the BBT. You basically have to believe that somehow, all of the universe expanded, except for a meter stick. That is why I am saying that the frame of reference for the BBT in the very early universe is an "outside" frame, similar to what a particle physicist has for an experiment with a relativistic particle accelerator like CERN. The BBT essentially switches frames of reference between that and the frame astronomers now have, somewhere around the CMBR age.

There is also the problem that the two parts of the BBT that are built around these 2 different frames of reference are built around two different and, so far, incompatible theories of physics. The very early universe in the BBT is built around the Standard Model for Quantum Theory, while the current state of the universe in the BBT is built around General Relativity Theory of gravity. The transition point in the time line is where we are currently having problems with both observations and theory. Not a surprise.

Your statement that "Schwartzchild [sic] radius calculations at the time of the early universe do not allow for the formation a giant black hole." are based on the assumptions that go into the calculations, not measurements. And, the statement that there was just too much energy does not have a basis other than speculation that there is some sort of energy that we do not currently understand, which the BBT assumes caused "inflation". All of the types of energy that we do understand are insufficient to expand such dense matter against its own gravity.

You really did not address what I said about that assumption not still being applied to the black holes in the currently observable universe. If there really is something that can expand space sufficiently to get matter and energy from a density that produces a black hole to a lower density that does not produce a black hole, why was that operating in the early universe but not operating today in volumes of space with essentially the same matter and energy conditions? It seems impossible for the universe to have transitioned from all matter and energy being in a volume smaller than an atom to its much more diffuse state astronomers observe today, without it having passed through the set of conditions we currently postulate for the inside of observed black holes. So, why didn't "inflation" stop expanding the universe when it got to those conditions? Or, why doesn't it expand the black holes that are in our universe, now?

Looks really inconsistent to me. I want to listen to you explain it to the bartender.

 

[billslugg]

Here is what I understand about inflation:
- We see a certain smoothness of CMBR
- We know from Heisenberg what the magnitude of the early quantum fluctuations was
- The two are not compatible. The fluctuations should have created a lumpier CMBR
- A possible solution is simply to make the starting point much, much smaller than we thought
- This puts the pesky quantum fluctuations originating in a universe that is so tiny it can communicate all the way across with light and it evens out as the universe expands during inflation.

Here is what I understand about why the universe did not immediately form a Black Hole:
- The early universe was extremely dense and extremely hot.
- This is a battle between the EM force pushing out and gravity pulling in.
- The EM force is 10^34 times stronger than gravity and easily wins the contest
- In our current state of affairs, the EM force is diluted by expansion so much it can't do anything now
- On the other hand, matter can overcome this expansion by coalescing in to stars, planets, etc.
- Regular matter coalesces, EM waves do not.
- There is nothing ruling out a pure EM Black Hole, they are looking for them now.

 

[Unclear Engineer]

This puts the pesky quantum fluctuations originating in a universe that is so tiny it can communicate all the way across with light and it evens out as the universe expands during inflation.

So, what does that assumption say about the apparent speed of light in the early universe? For an observer inside the universe? The observer would have to "see" that the universe is tiny, so that light goes across it in a short time. But, that observer then stays "uninflated" as the universe inflates, so that, later in the life of the universe, the observer is measuring a larger universe and light cannot get across it at all, because its "edges" are going apart faster than light can catch up. In effect, such an non-inflating observer is looking at the inflating universe from the "outside". Otherwise, the observer would be a tiny thing with a tiny "meter stick" that makes the universe still look huge, and, if light only went 3 x 10^8 of those tiny meters per second, it would not get across the tiny universe in a short period. So, if the tiny observer in the very early universe still sees the speed of light as 3 x 10^8 m/s, there is still a "horizon problem" with explaining the size of the fluctuations in the CMBR to make it fit the BBT.

That is the frame of reference problem that I am trying to get across to you. An observer inside the inflating universe and the meter stick he is using for measurements, should be inflating with the universe, not maintaining a steady length as viewed from "outside". We have had this discussion in other threads. It is not even clear that an observer inside an inflating/expanding universe can measure the expansion with a (extremely precise) meter stick, if that meter stick is expanding at the same rate as the space around it. Yes, some people argue that only the space between galaxies expands, and matter stays the same size during expansion/inflation of space. But, that is an assumption with no basic proof available - it is just a convenient position to use to defend the BBT. It is hard to argue that space did not expand matter at all, because all matter was supposedly once all within a tiny volume compared to a sub-atomic particle. And, to me, it seems unlikely that space "inflation" could expand matter up to some point and then stop, given that the inflation is diluting the other forces by increasing the distances.

This whole "scale" of "inflation" seems to be applied inconsistently and without regard to anything other than making the BBT seem to "work".

There are similar issues with the rate of time passage. GRT says that time passes more slowly near matter. But, from the "inside" of an inflating universe, could an observer detect that the decreasing density of the universe was changing the rate of time passage - if it was doing so?

In another thread, I proposed an experiment to look at the amount of time dilation as a function of depth into a mass, such as the Earth. I think that experiment could be done, but it is tricky to avoid confounding variables for the measuring apparatus. But, it would tell us if time varies with the local acceleration rate or with the escape velocity from the mass (which are the same outside of the mass, itself). I think that would be a good thing to know as we try to figure out the evolution of our universe.

 

[billslugg]

It does not matter how dense the universe was, the speed of light is constant for all observers all the time.

A person inside the tiny universe does not sense that their clock is running slower due to the extreme density. At that point the universe is so tiny that light crosses it in a very short time. Any observer sees their own meter stick never changing its size since they too are getting bigger. It's a wash. Any speculation as to what an outside observer would see is not possible since there is no such thing as "outside the universe".

Time dilation in a gravitational field is a function of how far down the gravitational well you are. The farther down in the Earth you go, the more time dilation there is.

 

[George²]

I didn't even know that someone had actually proven that dark energy existed and measured its value. All this seems to me merely an exercise in the amusement of brains too lazy to do any real useful work.

 

[Unclear Engineer]

Bill, I understand that those are the teachings of the BBT believers, but I am questioning some of that on the bases of either no proof or inconsistency or both. Just telling me those are the "facts" is the problem, because they really are not established facts, they are only assumptions or results of assumptions. So, they are worthy of some critical thinking and discussion.

Trying again on the tiny observers in the tiny universe still measuring the same speed of light with their tiny meter sticks and their enormous seconds, what you seem to be saying is that they would somehow have measured their universe to be much smaller than we measure our universe today. But, if the meter stick has shrunk at the same scale factor as the universe, then how is that measurement going to change? Maybe because they use light to infer their universe's dimensions, rather than laying the tiny meter stick from one side to the other side. If the seconds are longer duration, doesn't that mean that fewer of them are required to get light across the universe? That might make some sense if it works out quantitatively. So, from inside the universe, things might appear to happen very rapidly due to the much longer "seconds", compared to the outside view that you don't seem to be able to conceptualize. Maybe you could think of it as an observer today looking backward in time and seeing extreme time dilation in the very early universe. But, it time dilation, don't physical processes actually slow down, not just human perceptions of them? It still looks to me like the BBT has some frame of reference shifting that is not accounted for. But, if the "looking back in time and seeing time dilation" works for you, then that might be conceptualized as "space" seeming to expand faster than the speed of light for those in the past. It is definitely a mind-bending exercise, trying to reconcile the view from the early universe to the view from now. Our poor understanding of time may have a lot to do with our problems conceptualizing what happened and how that affects our observations.

Regarding the assertion that "Time dilation in a gravitational field is a function of how far down the gravitational well you are," we agree in the region above the surface of a mass, where the gravitational acceleration and the escape velocity vary together with altitude above the surface of a mass. What I am asking is how do we know what happens below the surface of the mass, where the gravitational acceleration decreases while the escape velocity still increases all the way to the center of mass. Because we are not seeing the behavior we expect from General Relativity Theory for the speeds of stars in galaxies, there is reason to question the predictions of GRT for locations inside of a mass. I am not aware of any actual experiment to determine what the time dilation is as a function of depth in the Earth (or anywhere else). So, that seems to me to be a logical test of the GRT prediction, and the result will have some value in figuring out why we have observations in astronomy that don't seem to fit the GRT predictions. So, just telling me what GRT predicts is not addressing my point. If you have some actual experiment to cite, that would be an appropriate response. But, the citation needs to be on the parameter in question, not just some general statement that "GRT has passed all of its tests to date", or some thing like that. if that GRT test has not been done, then the only excuse for not doing it would be that we do not have the capability to do it. But, I think it is a test that we could do.

 

[billslugg]

UE

In the early universe, an observer's clock runs just fine, the meter stick is of normal length, the universe in only an inch across. It is very hot and dense outside. There is no such thing as an outside observer to the universe, but if there was, clocks would run very slow.

Time dilation is a function of your position in a gravity well, it makes no difference if you are surrounded by rock.

Please try and be a bit more concise. And lose the put downs, that would be nice. Thank you.

 

[Unclear Engineer]

In the early universe, an observer's clock runs just fine, the meter stick is of normal length, the universe in only an inch across. There is no such thing as an outside observer.

Time dilation is a function of your position in a gravity well, it makes no difference if you are surrounded by rock.

Please try and be a bit more concise.

Bill, Usually, you are more willing to try to think about something complicated. But, apparently this is not one of those times. "Concisely" restating theoretical dogma is not the way forward in a scientific discussion - it just indicates a closed mind. I took the time to try to explain what is definitely a complicated and hard to understand problem about the early universe from a different perspective, as concisely as I could make it. If that is too much for you to bother with, then we are done with that, here. But, it surprises me that you cannot even deal with the pretty simple concept of testing a GRT prediction with a direct experiment. I would think you would be able to deal with that.

 

[billslugg]

You didn't lose the put downs. Go find someone else to bother. Goodbye.

 

[George²]

"Concisely" restating theoretical dogma is not the way forward in a scientific discussion

A lie, repeated 1000 times, include by influential people, begins to be perceived as truth by the crowd. The crowd is unable to easily find (and use) another thesis because the information space is flooded with lies. Separately, in the crowd there are rarely particularly highly educated and, above all, people with initiative and creativity. I.e. the so-called people with their own thoughts, not by rote learning and repeating as dogma the things that are presented to them in their accessible information space, in which
"have chosen" to "surf". Including (supposedly) the official and reliable sources of information. Because these are areas of knowledge that cannot be properly formulated with observations from within (in the universe). In fact, calling everything as far as the look with a name is enough for us, it presupposes some idea of extremity, of outlines. Our language itself is our enemy and hinders us, imposes limitations on us.

 

[Classical Motion]

Without a stationary point, a constant length, and a constant time......one can not measure, he can only dream.

 

[Atlan0001]

The Universe (U) isn't about to end in any gravitational "Big Crunch" because gravity doesn't work that way. Gravity is the force of open system, of accelerating expansion in opening the system . . . actually in keeping the system always open . . . via gravity's waves geometrically extending radially out from and crisscrossing every 0-point center-point of universe (u) grid! The 'wake' of gravity's waves extending out in accelerating expansion is strong force (for a force combine in fundamental gravitational strong force -- to include combine as non-Q (QM)-Verse, "classical matter physics" -- matching up with electromagnetism's and weak force's force combine in a fundamental "electroweak force").

It puts the increasing density (to an indeterminate infinity of "Big Crunch/Big Bang" density)), eternally present, always to the outside 'Horizon' (H) everywhere . . . never the inside horizons (h) anywhere.

The overall infinite set of forest is never going to crush its infinite constituency of trees, particularly when the superposition set of the forest is at once deep in every individual constituent tree.