Is the universe at least 136 billion years old, is the universe not expanding at all, did the universe begin its expansion when Hubble measured its redshift for the first time or was light twice as fast 13.5 billion years ago than it is today?

[Phi for All]

21 minutes ago, tmdarkmatter said:

But I prefer to be stupid and say: "No, I have no idea." Because that would mean that I still have the opportunity to learn.

The opportunity to learn from who?

[tmdarkmatter]

8 minutes ago, Phi for All said:

The opportunity to learn from who?

I define it as "the environment"

[Bufofrog]

35 minutes ago, tmdarkmatter said:

I define it as "the environment

You would learn alot more if you listen to people who have an education in physics.

[tmdarkmatter]

1 minute ago, Bufofrog said:

You would learn alot more if you listen to people who have an education in physics.

But what if they cannot answer basic questions?

[Bufofrog]

6 minutes ago, tmdarkmatter said:

But what if they cannot answer basic questions?

You have been given answers to your basic questions.  Pull your metaphorical fingers out of your ears and listen to the answers!

[tmdarkmatter]

1 minute ago, Bufofrog said:

You have been given answers to your basic questions

Not really, but thank you anyway

[Bufofrog]

13 minutes ago, tmdarkmatter said:

but thank you anyway

You're welcome.

[Phi for All]

2 hours ago, tmdarkmatter said:

I define it as "the environment"

If "the environment" has only one person in it, it's limited to the knowledge of that one person. Be careful you aren't making assumptions based on a single person's knowledge. That's not how science works.

[swansont]

1 hour ago, tmdarkmatter said:

Not really, but thank you anyway

Not liking (or understanding) the answers is not the same as not being given the answers.

[tmdarkmatter]

3 hours ago, swansont said:

Not liking (or understanding) the answers is not the same as not being given the answers.

What kind of answers should I expect for the questions "Where does dark energy come from?" or "Is it possible that the redshift of the furthest galaxies is not related to expansion?"

[zapatos]

1 hour ago, tmdarkmatter said:

What kind of answers should I expect for the questions "Where does dark energy come from?" or "Is it possible that the redshift of the furthest galaxies is not related to expansion?"

Answers based on science.

[tmdarkmatter]

On 11/21/2023 at 2:20 AM, zapatos said:

Answers based on science.

And what are these answers?

[swansont]

On 11/20/2023 at 6:59 PM, tmdarkmatter said:

What kind of answers should I expect for the questions "Where does dark energy come from?" or "Is it possible that the redshift of the furthest galaxies is not related to expansion?"

The first is more of a philosophy question (metaphysics), but dark energy appears to be a property of spacetime.

Any kind of “is it possible” question has to be addressed in terms of what mainstream science says. If you have a different model, you need evidence to support it. With mainstream science there’s always the  possibility of some better model, but of what value is an alternative model if there’s no evidence to support it?

So “is it possible” doesn’t add much to the discussion. Does it violate any known laws? If no, then it’s possible. But if you don’t have the alternative theory in place, so what? Gravity could be due to invisible fairies, but since there’s no testable model for that, we don’t waste time entertaining the notion.

[tmdarkmatter]

Ok, in that case there is no proof of a big bang, dark energy, dark matter, expansion of the universe. There is not even a clear proof that all of these galaxies we see are actually anywhere close to what we see. The light can also be bent to such an extent that the light of our own milky way is coming back from billions of different angles to us, simulating faraway galaxies. So we should stop speculating until we can travel to these galaxies. Don´t forget that we do not see stars, we only see some light and this light is bent, deviated, manipulated in a sense we still don´t know. If 7 minutes of sun gravity can bend the light by 1.75 arc-sec, I am wondering by how much the light should be bent when travelling through the universe.

[iNow]

Proof is for math. You’re right, there is no proof in science. Just evidence. Lots and lots of evidence, and a willingness to update our models when the old ones prove to be faulty. 

[swansont]

57 minutes ago, tmdarkmatter said:

Ok, in that case there is no proof of a big bang, dark energy, dark matter, expansion of the universe. There is not even a clear proof that all of these galaxies we see are actually anywhere close to what we see. The light can also be bent to such an extent that the light of our own milky way is coming back from billions of different angles to us, simulating faraway galaxies. So we should stop speculating until we can travel to these galaxies. Don´t forget that we do not see stars, we only see some light and this light is bent, deviated, manipulated in a sense we still don´t know. If 7 minutes of sun gravity can bend the light by 1.75 arc-sec, I am wondering by how much the light should be bent when travelling through the universe.

I didn’t mention proof. As iNow has accentuated, I said evidence, and also models, mainstream physics has plenty of evidence to support existing models. What have you got?

Light is bent according to known conditions in GR, i.e. by close proximity to sources of gravity. So saying “we don’t know” is not true. Do you have evidence of light being bent under other conditions, or sources of gravity in interstellar space?

 

(and 7 min of sun gravity? what is that?)

[MigL]

Let me give it  shot ...

I apologize for not reading the previous 6 pages but I'm recuperating from eye surgery ( Ahmed valve installed for Glaucoma control ) and gave up after the lengthy title.

A variable light speed to explain numerous 'problems' with modern Astrophysics, such as the horizon problem,, expansion and red-shift was first proposed by R Dicke, in the 50s.
The biggest drawback is that there are simpler solutions that don't 'break' Physics like a variable speed of light would.
Variable c ( with time, energy, distance, etc. ) would eliminate two very important 'pillars' of modern Physics, Lorentz invariance and CPT symmetry, and all Physics would come crashing down.

This is still really hard to type, even with 150% screen magnification, so I'll let PBS explain in more detail

 

[tmdarkmatter]

11 hours ago, swansont said:

Light is bent according to known conditions in GR, i.e. by close proximity to sources of gravity. So saying “we don’t know” is not true. Do you have evidence of light being bent under other conditions, or sources of gravity in interstellar space?

I think it is interesting that we can clearly observe and measure the famous Einstein rings, but currently we consider that the remaining light passing by galaxies, if not beeing part of an Einstein ring, just travels totally straight, and that´s a big mistake. If gravity has an infinite range, our entire image of the universe is completely distorted. Even our own sun is distorting the image of the universe before it reaches us. When it was discovered that the sun bends light, they were happy because they could give Einstein a Nobel prize, but they did not further investigate what this bending would actually mean to us. What I mean with "If 7 minutes of sun gravity can bend the light by 1.75 arc-sec" it´s just an example of what we should expect to happen when light passes by a galaxy. The deviation does not only depend on the force gravity exerts on it, but also on the time of exposure. I know that GR would just say that space-time is bent to make it easier, but a Jet also has to spend more fuel the longer it travels around earth. I think when we observe Einstein rings, we are just observing the most distorted light surrounded by other distorted light where we do not really know the position of its sources, so the entire image is distorted, not only the rings. So we are considering the light right next to the Einstein ring as travelling straight and compare the Einstein ring with that (normal, not distorted) light to calculate the mass of the object involved, when the light next to the ring is also distorted. Therefore, the mass can be different too.

 

 

6 hours ago, MigL said:

I apologize for not reading the previous 6 pages but I'm recuperating from eye surgery

Don´t worry, you are not "forced" to do anything here. But I hope everything went well with your surgery and thank you for the video. I will watch it today when I have more time.

11 hours ago, iNow said:

Lots and lots of evidence, and a willingness to update our models when the old ones prove to be faulty. 

A great evidence that would make me shut up would be images of galaxies becoming smaller and smaller due to expansion, but we would have to wait for millions of years.

Edited November 24, 2023 by tmdarkmatter

[Bufofrog]

3 hours ago, tmdarkmatter said:

I think it is interesting that we can clearly observe and measure the famous Einstein rings, but currently we consider that the remaining light passing by galaxies, if not beeing part of an Einstein ring, just travels totally straight, and that´s a big mistake.

But nobody who has any knowledge about physics thinks that, so there is no big mistake.

 

3 hours ago, tmdarkmatter said:

If gravity has an infinite range, our entire image of the universe is completely distorted. Even our own sun is distorting the image of the universe before it reaches us.

The range can be assumed to be infinite but the force of gravity decreases by 1/r^2.

3 hours ago, tmdarkmatter said:

When it was discovered that the sun bends light, they were happy because they could give Einstein a Nobel prize, but they did not further investigate what this bending would actually mean to us.

That's not a very good conspiracy theory since Einstein did not get a Nobel for relativity.

You clearly have little idea of what you are talking about.  Why don't you learn a little about a subject before dismissing it.

 

[swansont]

3 hours ago, tmdarkmatter said:

I think it is interesting that we can clearly observe and measure the famous Einstein rings, but currently we consider that the remaining light passing by galaxies, if not beeing part of an Einstein ring, just travels totally straight, and that´s a big mistake. If gravity has an infinite range, our entire image of the universe is completely distorted.

Infinite range, but drops off as 1/r^2. Meaning that light has to pass very close to a star to have measurable deflection. 

How many Einstein rings have we discovered, as compared to galaxies and stars? Why is there such a disparity?

 

3 hours ago, tmdarkmatter said:

 

Even our own sun is distorting the image of the universe before it reaches us. When it was discovered that the sun bends light, they were happy because they could give Einstein a Nobel prize, but they did not further investigate what this bending would actually mean to us. What I mean with "If 7 minutes of sun gravity can bend the light by 1.75 arc-sec" it´s just an example of what we should expect to happen when light passes by a galaxy.

Calculate what we should expect. This is just hand-waving, and shows only superficial understanding.

 

3 hours ago, tmdarkmatter said:

 

The deviation does not only depend on the force gravity exerts on it, but also on the time of exposure.

Why don’t we see deflection for light that isn’t passing very close to the sun? 

 

ETA:

18 minutes ago, swansont said:

Calculate what we should expect.

I won’t wait as I suspect the wait would be very long

The deflection formula can be easily found https://adsabs.harvard.edu/full/1929JRASC..23..208T#:~:text=For a light ray running,amounts to B %3D 1'.

The deflection varies with mass and inversely with distance of closest approach; we know the closest approach for light around the sun - it’s about 2 light seconds

The mass of the Milky Way is about 10^12 solar masses. The central bulge is about 5000 light years. or ~10^11 bigger than the sun closest approach. The ratio, which tells us the deflection, is 10x bigger than for the sun.

So in rough terms, light grazing the edge of the central bulge of a galaxy similar to ours will see ~17.5 arc seconds of deflection. We can’t see that, of course, because the galaxy would be too bright. And the deflection around the spiral, which is 10x bigger, would be 10x smaller. That’s for a source behind the galaxy, which is blocked by the galaxy.

For unblocked sources, there’s just empty space, which has no deflection.

 

[tmdarkmatter]

12 minutes ago, swansont said:

Why don’t we see deflection for light that isn’t passing very close to the sun? 

Did you check the images of the stars during the Eclipse that made Einstein famous? Not only the closest ones were displaced. Of course the further away from the sun, the lower is the displacement, according to the 1/r^2 equation, but this equation also never reaches an absolute zero. Only the stars that are completely opposite to the sun should maintain their original direction within the solarsystem, if not displaced by planets.

30 minutes ago, Bufofrog said:

That's not a very good conspiracy theory

I am not interested in conspiracy theories. I am interested in understanding the universe a little better.

[swansont]

3 minutes ago, tmdarkmatter said:

Did you check the images of the stars during the Eclipse that made Einstein famous? Not only the closest ones were displaced.

But they aren’t significantly further away. The deflection drops off as 1/r

[tmdarkmatter]

6 minutes ago, swansont said:

But they aren’t significantly further away. The deflection drops off as 1/r

of course you are right

[Bufofrog]

44 minutes ago, tmdarkmatter said:

I am not interested in conspiracy theories.

Then I would suggest that you should bring them up!

[tmdarkmatter]

1 hour ago, swansont said:

The mass of the Milky Way is about 10^12 solar masses. The central bulge is about 5000 light years. or ~10^11 bigger than the sun closest approach. The ratio, which tells us the deflection, is 10x bigger than for the sun.

It is interesting how simplified this approach is. Instead of light having to pass by individual stars to reach us, the light just needs to pass by a "central point" of the galaxy where you just sum up all the mass of the stars and position that mass on a single point. So when the light passes by stars very closely, according to your calculations these stars would have no mass at all, because you had already summed up their mass in the center of the galaxy. Imagine light having to pass by thousands of stars, each of them deviating by 1.75 arc-sec or even much less. I think this approach is too simple but maybe I am wrong.

Edited November 24, 2023 by tmdarkmatter