Raymond Tallis: Time Travel and Other Myths about Time

The simple explanation of the CMB is that it comes from intergalactic dust, the more complicated explanation (preferred by physicists) is that it is light from the Big Bang stretched out over 14 billion years of expansion.

David

1. Interstellar dust is not almost perfectly distributed and uniformly heated up across the universe to provide a feasible alternative theory for the CMB radiation.
2. Spectrography provides alternative confirmation of redhifting

End of story.

1. Interstellar dust is not almost perfectly distributed and uniformly heated up across the universe to provide a feasible alternative theory for the CMB radiation.
2. Spectrography provides alternative confirmation of redhifting

End of story.

Yes, but I deliberately said intergalactic dust - because there are huge volumes of space with no source of radiation nearby - any dust in such regions will only radiate BB radiation.

The other thing is that this signal would have arisen from a vast volume of space as the signal passed though 14 Billion light years (say). That could do an awful lot of averaging.

The CMB was discovered in 1964, and Fred Hoyle died in 2001, so it would be interesting to see why he did not accept the conventional model.

Regarding redshifting, it is worth considering another famous astronomer - Halton Arp. He fell out of favour for collecting evidence that many quasars seemed to be associated with much closer galaxies.

This of course makes no sense if the red shifts indicate the distance of these objects. His point was (he died in 2012) that there are other reasons why objects have large redshifts. This was opposed by the astronomical community (who tried to take away his telescope time!).

David

Yes, but I deliberately said intergalactic dust - because there are huge volumes of space with no source of radiation nearby - any dust in such regions will only radiate BB radiation.

The other thing is that this signal would have arisen from a vast volume of space as the signal passed though 14 Billion light years (say). That could do an awful lot of averaging.

The CMB was discovered in 1964, and Fred Hoyle died in 2001, so it would be interesting to see why he did not accept the conventional model.

Regarding redshifting, it is worth considering another famous astronomer - Halton Arp. He fell out of favour for collecting evidence that many quasars seemed to be associated with much closer galaxies.

This of course makes no sense if the red shifts indicate the distance of these objects. His point was (he died in 2012) that there are other reasons why objects have large redshifts. This was opposed by the astronomical community (who tried to take away his telescope time!).

David

1) The intensity of the CMB is nearly uniform in all directions, with very slight variations. This uniformity suggests that the source of this radiation was in a state of high isotropy and homogeneity. Creating such uniformity in a static universe would require a mechanism that evenly distributes energy across vast distances.

2) According to thermodynamics, an object that emits radiation loses energy and cools down over time. For the CMB to be the result of emission from intergalactic dust, as proposed in the static universe scenario, there would need to be a mechanism for this dust to have been uniformly heated to the same temperature initially (but I guess there is no 'initial' in your cosmology) and then cooled uniformly, which is not straightforwardly explained by basic physics principles.

3) Gravity would play a significant role in preventing the formation of the perfectly uniform intergalactic "blanket" of dust you propose must exists out there (and leave it in a steady state forever) But if you don’t want to believe in gravity either then this is a moot point.

Perhaps it's best to leave our debate here. While it's been an engaging discussion, I'm mindful that it might not hold broad interest for other visitors to this forum. Feel free to have the last word on the matter.

2) According to thermodynamics, an object that emits radiation loses energy and cools down over time. For the CMB to be the result of emission from intergalactic dust, as proposed in the static universe scenario, there would need to be a mechanism for this dust to have been uniformly heated to the same temperature initially (but I guess there is no 'initial' in your cosmology) and then cooled uniformly, which is not straightforwardly explained by basic physics principles.

Don't forget that it would seem Fred Hoyle must have dismissed the CMB argument for the Big Bang, because it was discovered in 1964 and Fred Hoyle died in 2001.

But surely we are talking about an equilibrium state - one in which grains of dust absorb and radiate BB-radiation at 2.3 K indefinitely

3) Gravity would play a significant role in preventing the formation of the perfectly uniform intergalactic "blanket" of dust you propose must exists out there (and leave it in a steady state forever) But if you don’t want to believe in gravity either then this is a moot point.

How can I not believe in gravity while I am sitting in a chair

If large clouds of dust can exist within galaxies, when they are much closer to stars that might pull them in, then I don't see why it is unreasonable to postulate such clouds outside the galaxies where the forces would be a lot weaker. The important difference is that such clouds would get very little illumination, and so would be harder to detect. Their only signal would be BB radiation!

Perhaps it's best to leave our debate here. While it's been an engaging discussion, I'm mindful that it might not hold broad interest for other visitors to this forum. Feel free to have the last word on the matter.

OK, but note that Fred Hoyle had a different concept of the universe:

https://en.wikipedia.org/wiki/Fred_Hoyle

My main point is that modern physics and astronomy seem to jump to conclusions too quickly when other perfectly good alternatives exist.

David

I think it's likely they have now harnessed the ability to slow time down - within some positive geometric shape/volume they create (could be tiny), which gets displaced within spacetime. It might give them some way of moving things (or joining together other places in time), that were there (before), to here (now). It's a peculiar notion that you might be able to join a past place and time, to a present place and time, by retarding time. I'd expect they might be able to figure our a way of using it as a type of shield.

Perhaps it's best to leave our debate here. While it's been an engaging discussion, I'm mindful that it might not hold broad interest for other visitors to this forum. Feel free to have the last word on the matter.

I have been silent while I tried to crystallise my objection to the CMB requiring any special explanation above and beyond Plank's law.

Suppose that before the whole issue of the BB had been invented, someone had designed an experiment to determine the 'temperature of the universe'. I am not completely sure if the concept makes sense, but surely if you took a hot black body in deep space, it would cool until it reached the temperature of the universe. At that point the body would absorb as much thermal energy as it would emit. I think this would be a valid question with or without dust - maybe I introduced the issue of dust by mistake.

If that is a valid way to reason, then the CMB does not require any additional explanation beyond Plank's law - so it can't be used as evidence for the BB or anything else.

David

I have been silent while I tried to crystallise my objection to the CMB requiring any special explanation above and beyond Plank's law.

Suppose that before the whole issue of the BB had been invented, someone had designed an experiment to determine the 'temperature of the universe'. I am not completely sure if the concept makes sense, but surely if you took a hot black body in deep space, it would cool until it reached the temperature of the universe. At that point the body would absorb as much thermal energy as it would emit. I think this would be a valid question with or without dust - maybe I introduced the issue of dust by mistake.

If that is a valid way to reason, then the CMB does not require any additional explanation beyond Plank's law - so it can't be used as evidence for the BB or anything else.

David

I'm not sure I understand this as an alternative explanation for the CMB but it's certainly true that the body will cool until it reaches equilibrium
at some very low temperature. This was one reason it took months to commision the JWST. It had to cool to something like 25K (don't remember the exact temperature) and they basically just had to wait for that to happen. Any higher temperature would pollute the infrared images. But you still need a body to emit the BB to apply Planck's law. If not dust then something else.

In the meantime I looked up Hoyle. He was an interesting character (meant in a positive way).

I'm not sure I understand this as an alternative explanation for the CMB but it's certainly true that the body will cool until it reaches equilibrium
at some very low temperature. This was one reason it took months to commision the JWST. It had to cool to something like 25K (don't remember the exact temperature) and they basically just had to wait for that to happen. Any higher temperature would pollute the infrared images. But you still need a body to emit the BB to apply Planck's law. If not dust then something else.

Well do you need the dust?

I suspect that even empty space has a temperature represented by the electromagnetic energy it contains. It is a rather subtle point, but if all space is filled at least by zero-point energy, why should it not contain additional energy corresponding to some temperature?

David

Well do you need the dust?

I suspect that even empty space has a temperature represented by the electromagnetic energy it contains. It is a rather subtle point, but if all space is filled at least by zero-point energy, why should it not contain additional energy corresponding to some temperature?

David

This might be true. However, if so, it wouldn't be blackbody radiation. Additionally, vacuum energy is unlikely to emit the characteristic spectrum of electromagnetic frequencies associated with blackbody radiation.

This might be true. However, if so, it wouldn't be blackbody radiation. Additionally, vacuum energy is unlikely to emit the characteristic spectrum of electromagnetic frequencies associated with blackbody radiation.

Agreed - space is filled with blackbody radiation! The ZPE is there too according to QFT (which I only know vaguely) but there doesn't seem to be any way to do anything with it.

Anyway, my point is that this radiation is to be expected anyway - it doesn't need a BB to 'explain' it.

David