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?

[swansont]

2 hours ago, tmdarkmatter said:

So are scientists having in mind these "pedestrian speeds" when calculating the redshift of Andromeda or not?

Since the blue shift of Andromeda can be directly measured, this question makes little sense.

See e.g.

http://www.astrosurf.com/buil/redshift/demo.htm

I’m sure papers have been published with other measurements 

 

If you want to know about significant digits, all you have to do is ask.

[tmdarkmatter]

17 hours ago, swansont said:

Since the blue shift of Andromeda can be directly measured, this question makes little sense.

So can be measure the blue shift of Andromeda from an extragalactic point in space, not beeing on the Milky Way carousel?

17 hours ago, Bufofrog said:

Andromeda's tangential or sideways velocity with respect to the Milky Way

This means the movement of Andromeda on its own axis, not our movement around the center of the milky way (?)

Andromeda has its own tangential movement, so we should see one half of Andromeda more redshifted than the other half.

By the way, this red- or blueshift should even be much more intense in the center of the galaxies, where the movements are much faster.

If the center of the Andromeda galaxy moves at a speed of 2000 km/s and our position is not in a 90 degree angle to the surface of the galactic disk, we should be able to observe this movement, especially with Andromeda, where we are definitely not in an angle of 90 degree (just check a picture of Andromeda).

Now if you say that there is no detectable blueshift/redshift because of this movement, than the universe is also not expanding, because the cause of redshift would not be the movement of galaxies/light sources.

Edited November 18, 2023 by tmdarkmatter

[Bufofrog]

2 hours ago, tmdarkmatter said:

This means the movement of Andromeda on its own axis, not our movement around the center of the milky way (?)

No, the sentence was about sideways motion of Andromeda relative to the milky way.

2 hours ago, tmdarkmatter said:

Andromeda has its own tangential movement, so we should see one half of Andromeda more redshifted than the other half.

OK.

2 hours ago, tmdarkmatter said:

By the way, this red- or blueshift should even be much more intense in the center of the galaxies, where the movements are much faster.

Not as much as you might think.  The outer edges of galaxies rotate almost as fast as the center.

2 hours ago, tmdarkmatter said:

If the center of the Andromeda galaxy moves at a speed of 2000 km/s and our position is not in a 90 degree angle to the surface of the galactic disk, we should be able to observe this movement, especially with Andromeda, where we are definitely not in an angle of 90 degree (just check a picture of Andromeda).

OK.

2 hours ago, tmdarkmatter said:

Now if you say that there is no detectable blueshift/redshift because of this movement, than the universe is also not expanding, because the cause of redshift would not be the movement of galaxies/light sources.

I didn't say there wasn't a detectable blue/red shift that I recall.

[Markus Hanke]

4 hours ago, tmdarkmatter said:

the cause of redshift would not be the movement of galaxies/light sources

The cause of redshift is an increase in distances between objects that are not gravitationally bound to each other; it’s not motion in the classical sense, but what’s called apparent motion. This is different from the claim that the objects somehow accelerate to greater and greater (superluminal!) speeds - that’s evidently not what happens.

To be more precise, metric expansion means that the outcome of distance measurements on the same set of points depends on when the measurements are performed - as you age into the future, the measured distance between any two points will increase, unless they are gravitationally bound. Thus, all points will appear to recede from all other points - which, again, is different from all points moving radially outwards from a common center. 

[swansont]

5 hours ago, tmdarkmatter said:

So can be measure the blue shift of Andromeda from an extragalactic point in space, not beeing on the Milky Way carousel?

Since we do not have the ability to place a sensor outside of our galaxy, no. But we can solve for it, since we know what our motion is and have measured the relative velocity of Andromeda.

[tmdarkmatter]

2 hours ago, Markus Hanke said:

apparent motion.

This is interesting. How would you define the difference between two points separating from each other because of their movements and two points separating from each other because of expansion? What exactly would be the difference? According to maths, there would be no difference at all, because it is just some Δx/t. Maths does not care where the Δx comes from.

4 hours ago, Bufofrog said:

I didn't say there wasn't a detectable blue/red shift that I recall.

What I want to say is that before speculating with the movements of the furthest galaxies and expansion of the universe, we should first try to figure out what kind of redshift or blueshift we can find in those objects surrounding us, so we can define what the effects of different movements on redshift should be, before we can confirm if galaxies are indeed moving away from us or if their redshift has another cause (like gravity). Creating special rules for galaxies that are "not gravitationally bound" would only lead to false theories. By the way, how should a galaxy not be gravitationally bound if the force of gravity is infinite?

[swansont]

2 hours ago, tmdarkmatter said:

By the way, how should a galaxy not be gravitationally bound if the force of gravity is infinite?

The force of gravity is not infinite.

The range of gravity is infinite, but the force drops off as 1/r^2

[Bufofrog]

2 hours ago, tmdarkmatter said:

What I want to say is that before speculating with the movements of the furthest galaxies and expansion of the universe, we should first try to figure out what kind of redshift or blueshift we can find in those objects surrounding us, so we can define what the effects of different movements on redshift should be, before we can confirm if galaxies are indeed moving away from us or if their redshift has another cause (like gravity).

We have.  

2 hours ago, tmdarkmatter said:

Creating special rules for galaxies that are "not gravitationally bound" would only lead to false theories.

That is not a 'special rule' that is part of the theory.

 

[Markus Hanke]

12 hours ago, tmdarkmatter said:

How would you define the difference between two points separating from each other because of their movements and two points separating from each other because of expansion?

Local relative motion in a static background would be limited to subluminal speeds in accordance with the usual laws of kinematic, so for redshift we’d find z<1 always, whereas with metric expansion there is no such limit. 

Furthermore, if there is only local motion in an otherwise static space, then some of these objects will recede from one another, whereas others approach each other, like molecules in a gas. We’d see a mix of both blue- and red-shift, unless you want to postulate that we are the Center of the universe, and everything moves radially away from us for some reason, which is not very plausible. But with metric expansion, it’s the space in between that “expands” (I don’t like this term, but it has become standard), so on the largest scales everything will appear to recede from everything else, and it will do so the same way no matter what direction you look at, and irrespective what’s in between here and there.

Also - if the rate of apparent recession isn’t constant (which is what seems to be the case), then, if you were to deal with local motion, you would have to have either some mechanism of acceleration, or some explanation as to why everything falls away from us. Overall you’d end up with a model that’s actually much more complicated and much less plausible than metric expansion.

Edited November 19, 2023 by Markus Hanke
z value typo

[tmdarkmatter]

On 11/19/2023 at 6:13 AM, Markus Hanke said:

Overall you’d end up with a model that’s actually much more complicated and much less plausible than metric expansion.

So we are using this model because "it is less complicated"? What about finding the truth? lol

On 11/19/2023 at 6:13 AM, Markus Hanke said:

so for redshift we’d find z<1 always, whereas with metric expansion there is no such limit.

Of course what is most important for us religious humans is having a universe with z>1 so there is always a mystery for us. How would you confirm the existence of z>1 if you never measured that in any of the billion galaxies? Why would you try to explain something that still does not exist? Why not try to explain some supernatural event?

On 11/19/2023 at 6:13 AM, Markus Hanke said:

it’s the space in between that “expands”

If space is "nothing", how can "nothing" "expand"? And you still did not answer what makes this movement special in order to distinguish it from the "moving away" movement. This is still ONLY an increase of the distance in a certain time in both versions.

Edited November 20, 2023 by tmdarkmatter

[tmdarkmatter]

Instead of some negative points I prefer some intelligent answers lol

And it´s funny to think that space expands just because.

Edited November 20, 2023 by tmdarkmatter

[Bufofrog]

10 minutes ago, tmdarkmatter said:

I prefer some intelligent answers lol

How ironic lol

[swansont]

Argument from incredulity is not a persuasive objection.

[tmdarkmatter]

If you prefer, just change it to -9999 and I won´t care.

1 minute ago, swansont said:

Argument from incredulity is not a persuasive objection.

If there can be no incredulity, there is no science, only fundamentalism. Real science also does not need to be persuasive, because numbers and facts should convince on their own.

[Bufofrog]

31 minutes ago, tmdarkmatter said:

Real science also does not need to be persuasive, because numbers and facts should convince on their own

The numbers and the facts are the persuasive part.

Edited November 20, 2023 by Bufofrog

[Phi for All]

21 minutes ago, tmdarkmatter said:

because numbers and facts should convince on their own.

You'd think, but you're showing us this isn't true.

[zapatos]

39 minutes ago, tmdarkmatter said:

If there can be no incredulity, there is no science, only fundamentalism.

Nice straw man. When you don't at least pretend to contemplate the responses you receive you paint yourself a troll.

[swansont]

42 minutes ago, tmdarkmatter said:

If you prefer, just change it to -9999 and I won´t care.

If there can be no incredulity, there is no science, only fundamentalism. Real science also does not need to be persuasive, because numbers and facts should convince on their own.

You can be as incredulous as you want. But your deficient level of understanding does not convince me that my understanding is incorrect. It does not validate your rejection of scientific results, or acceptance of flawed experiments 

The fix for argument from incredulity is for you to raise your level of knowledge and understanding.

And, as zapatos notes, equating the logical fallacy with some virtue is yet another logical fallacy.

[tmdarkmatter]

Why are we again turning away from the universe and its explanation?

Who cares who I am or if I believe or not. That does not modify reality.

Why should the universe expand?

[swansont]

43 minutes ago, tmdarkmatter said:

Why are we again turning away from the universe and its explanation?

Who cares who I am or if I believe or not. That does not modify reality.

It matters if you have an understanding of the science involved, even if you don’t accept it. It’s clear that you don’t; most of your OP is wrong. Subsequent discussion has shown even more misunderstanding 

43 minutes ago, tmdarkmatter said:

Why should the universe expand?

GR tells us a static universe is unstable. So it’s either contracting or expanding. The evidence says it’s expanding. 

[tmdarkmatter]

Why should there be dark energy?

Why would a static universe be unstable?

"By the way, for those who are not familiar with human science, GR means that silly theory that space-time is bent." "Oh, that one with the balls and the hole?" "Yeah, they still have not discovered yet how gravity works."

Edited November 20, 2023 by tmdarkmatter

[swansont]

2 minutes ago, tmdarkmatter said:

Why should there be dark energy?

Poorly formulated question. “should” implies a preferred result or intent.

Accelerated expansion implies dark energy.

2 minutes ago, tmdarkmatter said:

Why would a static universe be unstable?

Do you know what an unstable equilibrium is?

[tmdarkmatter]

15 minutes ago, swansont said:

Do you know what an unstable equilibrium is?

There is no real evidence of its existance, there is only the redshift effect humanity is still not understanding and the background light that is confusing them. Radiation that is deviated from its original course should always lose part of its energy, and light coming from galaxies far away were deviated thousands of times for millions or billions of years. There is no "straight" light.

Edited November 20, 2023 by tmdarkmatter

[swansont]

2 minutes ago, tmdarkmatter said:

There is no real evidence of its existance, there is only the redshift effect humanity is still not understanding and the background light that is confusing them. Radiation that is deviated from its original course should always lose part of its energy.

That doesn’t answer my question.

[tmdarkmatter]

Oh, I forgot that I must somehow show you that I am smart. 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. Something I am not seeing very often in current human science. Please do not get offended. I just want people to relax a little.