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I don't think space is expanding.

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Mike Helland

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Cosmology seems to be getting a lot of press these days. And not really good press.

Just search for cosmology and news, and you'll see things like "crisis" and "new physics".

The gist is the best new measurements of the expansion of space disagree. Either 74 or 64.7.

Here's my take.

Imagine you're jogging down the road and every block you pass you look at your watch, and every block takes 2 minutes.

Then one day you run farther than normal, as you go, you notice that it takes 2:03 to run a block, then 2:10, then 2:29.

Clearly, the blocks far away from your house seem to be growing!

What makes them grow? Dark forces!

Obviously, that's not the case, you're just slowing down. Blocks aren't expanding. You're just not running as fast as when you started.

But imagine it's 1930, and relativity is really new and really cool. And galaxies are also really new and really cool.

And we're not talking about a jogger, we're talking about light.

Light travels to infinity forever at c. Relativity says so.

Or..... maybe it doesn't. At least, not for infinity it doesn't.

The speed of a wave of frequency x wavelength.

Redshift is an observed drop in frequency.

Take literally.... redshift would lead to a drop in frequency

I make a hypothesis based on this:

v_photon = c - H * D

It's basically Hubble's Law, but moved to the speed of a photon, instead of the speed of a galaxy.

I also found that this version of Hubble's law is slightly different than the standard model, in that it predicts less expansion at the extreme end of the observable range, which is what we see with the Hubble tension.
 
That's called a "tired-light" hypothesis, and they've been around since the redshift was first observed. When I was young there was still a considerable amount of discussion about them, though they had already fallen pretty far out of favor.

Tired-light theories don't match observations well. Redshift caused by relative motion reduces the surface brightness of a distant body more than redshift caused by light slowing down alone. (The first dims the energy of each photon and also slows down the apparent rate of photons being emitted due to time dilation; tired light would have only the first effect.) Brightness measurements are more consistent with relative motion.

Other observations such as the duration of supernova events are also consistent with increasing time dilation with increasing distance (that is, expansion) and not with distance alone.

ETA: There's also the little matter of the cosmic microwave background. That could be very tired light, maybe, but tired light from what? It couldn't be from a big bang, if there's been no expansion.
 
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Myriad said:
ETA: There's also the little matter of the cosmic microwave background. That could be very tired light, maybe, but tired light from what? It couldn't be from a big bang, if there's been no expansion.
Click to expand...

The CMB is a real puzzle for anyone wanting some alternative cosmology. It’s actually quite hard for most people to understand why it’s so remarkable. The absolutely perfect blackbody shape of the CMB spectrum is something we can’t even produce artificially.
 
Myriad said:
That's called a "tired-light" hypothesis, and they've been around since the redshift was first observed. When I was young there was still a considerable amount of discussion about them, though they had already fallen pretty far out of favor.
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Yeah, this is a novel version of tired light with varying speed of light mixed in.

Tired-light theories don't match observations well. Redshift caused by relative motion reduces the surface brightness of a distant body more than redshift caused by light slowing down alone. (The first dims the energy of each photon and also slows down the apparent rate of photons being emitted due to time dilation; tired light would have only the first effect.) Brightness measurements are more consistent with relative motion.
Click to expand...

This seems pretty relevant, but doesn't seem to be all that well followed up in science.

According to the wikipedia on Tolman Surface Brightness test:

"The exponent found is not 4 as expected in the simplest expanding model, but 2.6 or 3.4, depending on the frequency band."

What's up with that?


Other observations such as the duration of supernova events are also consistent with increasing time dilation with increasing distance (that is, expansion) and not with distance alone.
Click to expand...

I'm certainly familiar with that one too.

If you look up "Supernovae Light Curves: An Argument for a New Distance Modulus" by Jerry Jensen, he says those supernovae are bigger because of a "Malquist type II" bias.

Not much follow up on that one either.

I'm not trying to ignore these findings, but it's also true that the standard model is running sideways with plenty of observations, and that's after the patchwork of inflation and dark energy and matter they're got going on.

ETA: There's also the little matter of the cosmic microwave background. That could be very tired light, maybe, but tired light from what? It couldn't be from a big bang, if there's been no expansion.
Click to expand...

It could just be light from a universe that stretches out trillions of light years, well beyond Hubble's limit.

The CMB also shows us a cold spot to the south, which runs counter to current standard models, but not an indefinite universe.
 
If the CMB is just light coming in at the edges of its physical limits (Hubble Length), then of course it wouldn't reflect any light.

Alternative cosmologies can deal with the anomalies in the CMB, like the cold spot and the slightly cooler northern hemisphere, better than the standard model.
 
Mike Helland said:
It could just be light from a universe that stretches out trillions of light years, well beyond Hubble's limit.
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No, it could not. There are no other significant sources of light in the universe which present a perfect blackbody spectrum.

Mike Helland said:
If the CMB is just light coming in at the edges of its physical limits (Hubble Length), then of course it wouldn't reflect any light.
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You seem confused about what a blackbody spectrum actually is. No shame in that, it's actually not a simple thing. Thermodynamics is not an easy subject*, and even seemingly simple concepts like temperature are much more complex and strange than they initially seem. But your theory can't turn ordinary stars into blackbody emitters.

Alternative cosmologies can deal with the anomalies in the CMB, like the cold spot and the slightly cooler northern hemisphere, better than the standard model.
Click to expand...

No, they cannot handle it better. None of them can handle the perfect blackbody spectrum, and that's a much more significant fact than the extremely minor variations of temperature within that perfect spectrum. They may have adjustable parameters that can be tuned to produce variations, but none of that matters if the basic shape isn't even close.

As I said:

Ziggurat said:
The CMB is a real puzzle for anyone wanting some alternative cosmology. It’s actually quite hard for most people to understand why it’s so remarkable. The absolutely perfect blackbody shape of the CMB spectrum is something we can’t even produce artificially.
Click to expand...

*Trivia: one of the best introductions to any textbook comes from a thermodynamics textbook, and reads as follows.
States of Matter said:
Ludwig Boltzmann, who spent much of his life studying statistical mechanics, died in 1906, by his own hand. Paul Ehrenfest, carrying on the work, died similarly in 1933. Now it is our turn to study statistical mechanics.

Perhaps it will be wise to approach the subject cautiously.
Click to expand...
 
If the CMB is just the temperature of space, it's not a body at all.

Therefore it reflects nothing. Perfect black body.
 
Mike Helland said:
If the CMB is just the temperature of space, it's not a body at all.

Therefore it reflects nothing. Perfect black body.
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No. Space itself is not a black body. A black body isn’t defined by what it doesn’t reflect, but by what it absorbs, and space absorbs nothing.

I don’t mean to sound insulting, but it’s clear you don’t understand thermodynamics. Again, no shame in that, most people don’t. But because you don’t, you should approach the subject with a bit more humility.
 
RecoveringYuppy said:
Not a terribly helpful comment. Plenty of accurate and knowledgeable sources refer to the CMB as the temperature of space.
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Also, the temperature of space was predicted by Arthur Eddington to be 3K before the Big Bang theory was even a thing.

This prediction is more accurate than the predictions based on the CMB.
 
abaddon said:
Space doesn't have a temperature.
Click to expand...

To expand on what RY said, you can define a temperature for space on the basis of electromagnetic radiation within it. The space inside a sealed container will then come to thermal equilibrium with that container. The problem with what Mike said isn't assigning a temperature to space, but describing it as a black body. A black body is not defined by its reflectivity, but by its absorptivity.

This may seem at first glance to be an irrelevant distinction, since in many cases, light must either be absorbed or reflected, so that absorptivity and reflectivity can have a 1-to-1 correspondence. But the difference is crucial, because that correspondence doesn't always hold. There is in fact a third option: transmission, as happens in transparent materials. So glass, for example, can transmit light, and thus neither reflect nor absorb it. Thus, our choice of absorption or reflection for defining a black body is not a mere technicality, but is crucially important.

And the only way to define a black body in a way that makes sense, from a thermodynamics point of view, is on the basis of absorption, NOT reflection, because it is absorption, not reflection or any converse of reflection, which must be balanced with emission in order for thermal equilibrium to be possible. So perfectly transparent things are, like perfectly reflective things, the opposite of black bodies. They have zero emissivity. And space is the most perfectly transparent thing that can exist.

Long story short: space itself cannot be the source of the CMB, even if we use it to define the temperature of space.
 
Mike Helland said:
We know what it absorbs based on what it reflects.
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No. You forgot transmission. See my previous post. Space neither absorbs nor reflects, because it transmits. And since it absorbs nothing, it emits nothing.
 
Mike Helland said:
Also, the temperature of space was predicted by Arthur Eddington to be 3K before the Big Bang theory was even a thing.

This prediction is more accurate than the predictions based on the CMB.
Click to expand...

Wrong again. Eddington's prediction may have gotten the temperature roughly correct, but he got the spectrum completely wrong. He thought it would be the spectrum of starlight, which is peaked in the visible, NOT the microwave. That's about as far off as possible.

And as I said before, the critical feature of the CMB is not its temperature, but the shape of the spectrum. The temperature changes as the universe expands, so it is not constant in time. But the shape is. It remains a perfect blackbody shape in perpetuity. The Big Bang theory predicts that shape. You need additional inputs (such as the age of the universe and how fast it's expanding) in order to get the temperature, and those things are not easy to measure, so getting that wrong in the beginning is no big deal. But the shape, well, the shape is everything. BBT got it right from the very beginning. Eddington got it wrong.

I told you the shape was the key, but you still don't actually understand.
 
Ziggurat said:
So glass, for example, can transmit light, and thus neither reflect nor absorb it.
Click to expand...

At the quantum level, glass is absorbing and emitting photons.

If galaxies keep going, at some point, their light will dim below the ambient temperature of space.

We see that as the CMB. It isn't a body in itself.
 
Ziggurat said:
The temperature changes as the universe expands, so it is not constant in time.
Click to expand...

According to the big bang theory. According to my theory, the CMB was the same temperature billions of years ago and billions of years from now.

But the shape is. It remains a perfect blackbody shape in perpetuity.
Click to expand...

Ok, well, what specific feature of that shape can only the CMB explain?
 
Mike Helland said:
At the quantum level, glass is absorbing and emitting photons.
Click to expand...

That's one way to interpret the process, but it doesn't matter. The point remains: black body emissivity is proportional to absorptivity, NOT to 1-reflectivity. And space has zero absorptivity, and therefore zero emissivity.

If galaxies keep going, at some point, their light will dim below the ambient temperature of space.

We see that as the CMB. It isn't a body in itself.
Click to expand...

No. Galaxies do not emit perfect blackbody spectra. They have characteristic absorption and emission lines, which make them very NOT like the CMB. You can't make the spectra match even if you red shift it.
 
Mike Helland said:
Ok, well, what specific feature of that shape can only the CMB explain?
Click to expand...

The fact that it's a perfect blackbody shape. Stars don't do that. Nebula don't do that. Interstellar gas doesn't do that. Dust doesn't do that. Planets don't do that. All other sources in space have significant deviations from blackbody spectra.

And as I said, Eddington got the spectrum completely wrong, not even close.
 
Ziggurat said:
The fact that it's a perfect blackbody shape. Stars don't do that. Nebula don't do that. Interstellar gas doesn't do that. Dust doesn't do that. Planets don't do that. All other sources in space have significant deviations from blackbody spectra.

And as I said, Eddington got the spectrum completely wrong, not even close.
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Ok, so, star light is headed our way, and it hits some dust, a couple photons get knocked in stray directions.

They never reach us. They go somewhere else completely.

What happens to all those stray photons?
 
Mike Helland said:
Ok, so, star light is headed our way, and it hits some dust, a couple photons get knocked in stray directions.

They never reach us. They go somewhere else completely.

What happens to all those stray photons?
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It doesn't matter where they go. They cannot reproduce the CMB. Interstellar dust isn't black.
 
Mike Helland, I'd like to go back to your starting premise and ask a few questions, if you don't mind:

"I don't think space is expanding."

Say you're right. Space isn't expanding. What would would you say is the biggest change implied by this?
 
Mike Helland said:
Given that we observe a static background noise in the universe, it would seem those are the stray photons.
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Of course there are stray photons. So what? We know that gas and dust is out there, and that it scatters star light. That's not the issue. Those stray photons aren't responsible for the CMB. The issue is what can account for the CMB. dust cannot. Stars cannot. I don't think you appreciate how unlikely it is to find anything in nature that is truly black.

Your theory, as far as I can understand it, cannot produce the CMB. Eddington certainly couldn't. The BBT can.
 
Ziggurat said:
I don't think you appreciate how unlikely it is to find anything in nature that is truly black.
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Let's define the observable region as including any place light keep reach us.

Just beyond that, the Hubble Limit, light cannot reach us.

Seems like that would be pretty black, eh?
 
Mike Helland said:
Let's define the observable region as including any place light keep reach us.

Just beyond that, the Hubble Limit, light cannot reach us.

Seems like that would be pretty black, eh?
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No. No, it wouldn't, not from a thermodynamics perspective. And if you're talking about what's beyond where light can reach us, then obviously a blackbody spectrum cannot reach us from there, so this argument is rather self-defeating.
 
theprestige said:
Mike Helland, I'd like to go back to your starting premise and ask a few questions, if you don't mind:

"I don't think space is expanding."

Say you're right. Space isn't expanding. What would would you say is the biggest change implied by this?
Click to expand...

If space is expanding, it started as a small point 14 billion years ago, and it about 96 billion light years across today.

We used to think that stars were 20 billion years old, mind you.

If space is not expanding, as Edwin Hubble explains, "the observable region is an insignificant sample of a universe that stretches indefinitely in time and space."

The difference is a tiny little, young universe, and one that goes way WAY beyond what light can physically show us.
 
Ziggurat said:
No. No, it wouldn't, not from a thermodynamics perspective. And if you're talking about what's beyond where light can reach us, then obviously a blackbody spectrum cannot reach us from there, so this argument is rather self-defeating.
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First you say "No", then you say "Yes, obvously."

It's not a self-defeating argument. I think the word you're looking for is self-sealing, aka, tautological.

I misread.

I guess there is something to the black body thing I'm missing, because it seems obvious to me that when there is no body, it'll appear black.
 
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Mike Helland said:
If space is expanding, it started as a small point 14 billion years ago, and it about 96 billion light years across today.

We used to think that stars were 20 billion years old, mind you.

If space is not expanding, as Edwin Hubble explains, "the observable region is an insignificant sample of a universe that stretches indefinitely in time and space."

The difference is a tiny little, young universe, and one that goes way WAY beyond what light can physically show us.
Click to expand...

That's the biggest change implied by this, that you can think of? Stuff exists that we can never see or prove anyway?

Let me clarify: What is the biggest change to us here on Earth and the things we observe and work with, if space isn't expanding?
 
theprestige said:
Mike Helland, I'd like to go back to your starting premise and ask a few questions, if you don't mind:

"I don't think space is expanding."

Say you're right. Space isn't expanding. What would would you say is the biggest change implied by this?
Click to expand...
We are in the exact center of the universe?
 
Samson said:
We are in the exact center of the universe?
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That's not implied by my theory.

The universe is indefinitely large, like 10^100 bigger than you can think times another trillion.

We're at the center of our observable part, but beyond that, there's nothing to indicate the universe's size from our vantage point.
 
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