Confirmed! James Webb Space Telescope has bagged the oldest known galaxies

[billslugg]

"OK, in a laboratory we can gate a single photon and measure its energy with a photo detector, can't we?"

Yes, but the amount of energy we measure varies by how fast we are going relative to the photon. The photon is not changing, our relationship to it is changing.

A detector on a target will measure a large energy in the bullet that hits it.
A detector on the bullet measures no energy on the bullet, all the energy is in the target moving towards it.
Energy is not conserved when moving from one reference frame to another, it is only conserved within a particular frame.

 

[billslugg]

"I don’t understand this. If you look at the CMBR spectral distribution, it will be much, much less than it’s original 3000K distribution." Helio

Yes, that is true but the CMBR must fill a lot more volume now. It should work out to the same amount of energy.

 

[rod]

All I am saying is that light that is redshifted by expansion of space ends up occupying a larger volume of space, so the question about where the energy goes when expansion decreases the "energy" of "photons" is answered by it simply gets expanded to a lower density, but does not change total energy in the universe.

With regard to whether experiments on Earth can verify that space is actually expending here, I don't think it is measurable in dimensions so small. And, if the meter sticks on Earth are expanding at the same rate as space, then it would not be evident with simple measurements, anyway. So, hard to prove or disprove.

Okay, so far, I see nothing in this discussion that demonstrates what is said for the CMBR verified by lab experiments or the cosmological redshift explanations. Given the lab experiments, what lab experiments verify that:

1. 4D space is actually expanding like H0 requires? Remember, using c.g.s. units, that converts to ~ 10^-18 cm/s/cm. Do lab experiments verify that 4D space is actually expanding like this in nature?
2. What lab measurements and tests verify that as 4D space expands, the photon will redshift like what is said to explain the origin of the CMBR, or the cosmological redshift explanation used?

Unclear Engineer stated, "With regard to whether experiments on Earth can verify that space is actually expending here, I don't think it is measurable in dimensions so small."

If this is true, that means the explanation for the origin of the CMBR and postulated redshift of about 1100, has never been verified by experimental science that photons will redshift like this or 4D space expands by such a large volume from what would be initially, a very small volume of space. If this is true, I would think science should point this out clearly to the public when presenting the BB cosmology.

 

[Helio]

Yes, that is true but the CMBR must fill a lot more volume now. It should work out to the same amount of energy.

I think not. The energy (power) is the integral of the distribution. If one increases temperature, the entire distribution moves up in watts per sq. meter per unit nm. So the microwave portion moves up as well. The peak also blueshifts.

 

[billslugg]

Here is an answer from Astronomy Stack Exchange. According to this guy, the total energy in CMBR scales inversely to the scale factor.

"The energy density in the radiation field scales like a^−4, and the volume scales like a^3. Since the total energy is the density times the volume, the total energy scales like a^−1. Note that a is called the "scale factor" and a=1/1+z."

 

[Turtle]

Do we possibly have two different effects going on here?

Doppler shift of light we understand, emitters and detectors moving in relation to each other. Moving away red shifts and moving toward blue shifts.

But space is also expanding and this is seen through very large distances and the rate of expansion is increasing.

They both have an effect on the light but are they different?

 

[billslugg]

As best I understand it, yes there are two effects, proper motion and the expansion of space. Both lead to redshifts. I believe the end effects are identical.

 

[Helio]

Here is an answer from Astronomy Stack Exchange. According to this guy, the total energy in CMBR scales inversely to the scale factor.

"The energy density in the radiation field scales like a^−4, and the volume scales like a^3. Since the total energy is the density times the volume, the total energy scales like a^−1. Note that a is called the "scale factor" and a=1/1+z."

That’s interesting. It looks to me that energy density decreases faster than volume increases. So, if we double the radius, we will have 8x the volume, but the energy density drops to 1/16th. Is this right?

 

[billslugg]

Yes, I am thinking this is related to Stefan-Boltzman Law whereby the energy emitted by an object increases by the fourth power of temperature.
As temperature decreases linearly, energy density decreases by the fourth power.
As distance increases to the first power, volume increases by the third power.
Net effect is that energy density decreases faster than volume increases.
Yes, double the radius, you get 8x the volume and 1/16x the energy density.

 

[rod]

My post #28 remains unanswered in all of this Doppler shift (as Turtle in #31 mentions) is confirmed by experimental physics (an object moving towards you or away from you can show the doppler shift). The cosmological redshift caused by 4D space expanding is not. The explanation for the origin of the CMBR is based upon the cosmological answer, not Doppler. This should be clearly pointed out to the public when promoting Big Bang answers to the origin of the universe. Doppler redshift has experimental verification, cosmological redshift does not. There is an enormous extrapolation for the redshift of the CMBR as 4D space expands immensely that has no experimental verification to show is true in nature like the Doppler redshift. We also have the need for 4D space to expand faster than c velocity in BB cosmology, something I have yet to see Einstein taught and accepted. Someone else did that math it seems. Attempting to verify that 4D space expands between the Earth and Moon and photons redshift IAW with this 4D space expansion is not verified. Thus, the foundation for the Big Bang model (CMBR redshift) rests upon physics that lack direct experimental verification to show is true in nature like the Doppler redshift. I think if this is correct, BB advocates need to tell the public that very clearly.

 

[rod]

Do we possibly have two different effects going on here?

Doppler shift of light we understand, emitters and detectors moving in relation to each other. Moving away red shifts and moving toward blue shifts.

But space is also expanding and this is seen through very large distances and the rate of expansion is increasing.

They both have an effect on the light but are they different?

Turtle asked, "They both have an effect on the light but are they different?"

Yes, Doppler redshift has an object like a star moving away from you (or towards you), but not and never faster than c velocity and is not caused by 4D space expanding. Concerning redshift caused by 4D space expansion, the cosmological redshift features 4D space expanding much faster than c velocity, that is required to explain redshifts in cosmology that are 1.4 or larger like this article discussed concerning JWST seeing a 13.2 redshift. This should always be made clear to the public, including which redshift explanation has experimental physics testing and verification, and which redshift explanation does not.

 

[rod]

Here is a July 2022 report on the cosmological redshift and possible experimental verification (not done yet).

Experiment with a laser and a mirror to accurately measure the Hubble constant, https://ui.adsabs.harvard.edu/abs/2022MPLA...3750148Y/abstract

"We propose a new method for calculating the redshift in galaxies, according to which the amount of redshift in the spectrum of each galaxy consists of two parts: about 2/3 of the redshift is due to the speed of the galaxy moving away from us, and about 1/3 is due to the fact that photons moving in the expanding Universe acquire an additional (non-Doppler) redshift. The additional reddening of photons in the spectrum of the galaxy is due to photons coming to us from the past, when the gravitational potential of the universe was lower, and consequently, the frequencies of atomic spectra were also lower than at present. A scheme of a laboratory experiment is proposed that will allow direct measurement of a non-Doppler (additional) part of the cosmological redshift and demonstrate the very fact of the expansion of the universe in real time in about 15 min. The experiment also makes it possible to measure the expansion rate of the universe and its current gravitational potential. These results will help to significantly refine modern ideas about the age of the universe, and about the amount of dark energy and dark matter in it."

The cosmological redshift used to explain the origin of the CMBR in the BB model - presently is not experimentally verified.

 

[Unclear Engineer]

First, what "cosmologist think" and what we actually know are not completely identical.

Second, light has been described as having a dual identity as a wave and a particle, because sometimes it displays behavior like one but not the other, and other times is does the exact opposite. We call that behavior "paradoxical" and have adapted our thinking to whichever effect we actually detect.

So, when we are trying to answer a question like the OP, where "light" is considered to be a single photon with a specific energy, and then ask what happens when the space occupied by that photon is stretched, we should not be at all surprised if we get different answers when we treat the photon as a wave and a particle.

What we really don't understand is (1) what light is, and (2) how space "stretching" (if it really does that) would affect whatever light is.

Theorists try to think of photons only as waves in a "field" that permeates all of space. Engineers tend to think of fields as the maps of the effects created by the particles. It is a question of which is the primary entity and which is the effect of that entity.

So, when space "stretches", what happens to the fields and particles? Do they stretch, too, and if so, how? You can't just assume that we know that answer and then use that assumption to prove that energy is conserved or not conserved when space stretches.

What we really need is an experiment that demonstrates that space is actually stretching and also allows us to observe the effects of stretching on things like the behavior of photons, electrons, baryons, etc.

Regarding the thought experiment where we "gate" a single photon that originated in light emitted by a star billions of years ago, the real question comes down to how do we affect the outcome by the experimental setup. Given that we can "gate" individual photons in a diffraction experiment and get 2 different outcomes (different patterns of light effects on a target surface), depending on the experimental setup, we really can't predict what the effects of the hypothesized experiment should show without arbitrarily picking our expectations of whether all of the light emitted by the distant star is just independent particles (photons) or interdependent "waves".

Yes there are "true believers" of various theories. but I am an "agnostic" thinker who basically believes that "true believers" are simply being blind to what they don't understand.