Starlight and Time

[dad1]

Does science know what time, specifically time in the distant universe is? If you claim it does, then be prepared to support that claim.

If science does not know that time exists out there in a way we know it here, then one implication is that no distances are knowable to distant stars.

Why? Because distances depend on the uniform existence of time. If time (in this example 4 billion light years from earth) did not exist the same as time near earth, then what might take a billion years (of time as we know it here) for light to travel a certain distance in space might, for all we know, take minutes weeks or seconds of time as it exists out THERE!

So what methods does science have to measure time there? I am not aware of any. Movements observed at a great distance and observed from OUR time and space would not qualify. Such observations would only tell us how much time as seen here it would take if time were the same there.

How this relates to religion is that a six day creation thousands of years ago cannot be questioned using cosmology if it really did not take light that reaches us on earth and area a lot of time to get here.

[DrNoGods]

[Replying to dad1 in post #28]

No I would expect that all things once they enter this center of the universe zone here that they would then start to exist as they must here and therefore obey laws here. Operate in space and time here.

You missed the point. If we see a red shifted spectrum of the hydrogen balmer series, with relative line positions (wavelengths) and intensities exactly matching the spectrum of atomic hydrogen on Earth, and the photons came from a distant star (imaged by the telescope/spectrometer), then the hydrogen atoms at that star must be the same as the hydrogen atoms on Earth as far as electronic structure (electron orbital details, one proton for the nucleus, etc.).

But we can see spectra of many different atoms and molecules to know that they are also the same as the molecules that are present here on Earth. The oxygen we can see in the spectrum of a star is the same oxygen we have here on Earth, as shown by the characteristics of the spectrum. The implications go beyond this however. The mechanisms for how molecules absorb and emit light are very well understood (grab a spectroscopy book or book on quantum mechanics), and if light had different characteristics "out there" than it does here (speed of light, or some other difference that you haven't described), then we would not see identical absorption and emission spectra (or any spectra at all). But that isn't the case.

You're trying to argue that somehow time, or the characteristics of light, may be different elsewhere in the universe and then is magically the same as we see it here because we measure it here. But you don't seem to have thought through the implications of that on observations that we do make, or have any mechanism for how such a wild scenario could actually work. It is just a convenient way to wave off deep time and astronomical distances, just like the primordial material nonsense of AIG, without any responsibility to show it makes a sense or is a viable hypothesis. Anybody can make wild claims if they only have to support them with handwaving arguments.

[DrNoGods]

[Replying to Miles in post #30]

In their paper published in 1972 in the journal Science, Hafele and Keating reported that the airborne clocks were about 59 nanoseconds slower than a ground-based atomic clock when traveling east, and 273 nanoseconds faster than the ground-based version when traveling west. Their results supported Einstein's theory that time fluctuates throughout the universe.

Yes ... but relative to an observer that was not on either plane. To the occupants of the planes, time passed normally (ie. 1 ns was 1 ns, to them). We have to correct the GPS clocks for time dilation because the locations on Earth's surface are moving much slower than the satellites are.

The GPS satellite speeds (~14,000 km/hr) make them appear to a given Earth location to tick slower by about 7 us/day, while the altitude of ~20,000 km results in a reduced effect of Earth's gravity that is a much bigger effect and speeds the onboard clocks up by ~45 us/day. So the net result is that the onboard GPS clocks tick about 38 us/day faster than a fixed clock on Earth. As Einstein showed ... it is all relative (to the observers locations and their relative velocities/acceleration).

[dad1]

How would you distinguish ‘science not knowing’ from you simply not understanding science?

One way is to start a thread and watch those who pretend fail.

Then it is all a matter of belief.

This suggests that you don’t understand the principles of scientific thought.

On the contrary, if you did you would agree.

Science can't win in that arena.

Science isn’t in that arena.

It is belief based. We wait for you to show otherwise on the topic.

Well, that’s fine for them. But why then would they feel the need to ‘prove science wrong’?

All things that oppose and exalt themselves against truth should be dealt with. They do not need to prove anything. Science needs to evidence and support it's claims.

Why did you start this thread? If someone attempts to explain the science behind astronomic distances to you, it’s because they believe you may be interested in learning about the observed universe.

Why pretend it is I that need anything explained?

If you don’t want to know about or understand a scientific viewpoint, then this is the wrong sub-forum to debate in. It’s not obvious that you’re engaging in ‘good faith’ (ironically!).

If you can present the 'scientific viewpoint' on determining the exact nature of space and time in the far universe, why have you waited so long to do so? It seems you prefer to pretend there is one somehow somewhere, but you can't produce it.

Hearing this makes me rather sad (more for any children you may have based in your username).

Cry me a river I guess. Sorry if you thought you had some right to train children in your belief set.

You’re using a computer on the internet and so have access to literally multiple lifetimes of knowledge. Yet your mindset appears antithetical to any that might seek to better understand the world we live in.

Been there done that, got the tee shirt. Now what is needed here is you to stop whining and moaning and saying nothing and address the topic and produce your support.

A rather sweeping statement! Perhaps you and your extended family have never needed any form of modern medicine, for instance?

Explain how modern medicine defines what time in the distant universe is?

[dad1]

You have no idea how far humans may be able to travel far into the future ..

Nor do you. We do know they have not gone far yet!

. we already have two spacecraft that have travelled past the heliopause (so they are in "deep space", technically).

As I mentioned, not even one light day away.

But we can observe photons from other stars and galaxies,

Yes, and we can watch tv also. All this we do here. Not there.

as well as see all kinds of physical structures millions and billions of light years away.

No. All time that you assign is belief based.

These photons, the telescopes that better capture them for magnification, and the dispersive spectrometers that show emission and absorption (by distant light passing through things between the light source and the telescope and spectrometers) are the "observers."

The telescope is here.

We also have several LIGO experiments now to measure gravity waves which are incredible instruments.

Meaningless if no star was the distance they thought it was.

You can't deny that light from the stars we can see is being emitted from that star, regardless of the distance it is away from Earth.

Why would I want to deny?

The question is how we know the distance to the stars, and there are multiple methods to estimate distance (eg. parallax, red shifts, Cepheids).

That question really is beside the point. All methods are faith based. Parallax requires time and space here for a baseline. For example, how far earth moves in the solar system space and time for 6 months. You cannot use that line and add lines to a star assuming all is equal.

[DrNoGods]

[Replying to Inquirer in post #21]

In science and mathematics one is free to assume anything so long as the assumptions or consequences arising from it, do not contradict observation, it really is as simple as that.

It seems to me that science isn't being taught very well these days if such basic tenets are really alien to so many people.

I see you've added a new sentence at the end after 6 edits of the post. What prompted you to add that though, as no one here has suggested that anyone isn't free to make assumptions. Was it just a way to sneak in yet another thinly-veiled insult (that someone wasn't taught science very well), or was there a point to be made on what is actually being discussed?

[dad1]

You missed the point. If we see a red shifted spectrum of the hydrogen balmer series, with relative line positions (wavelengths) and intensities exactly matching the spectrum of atomic hydrogen on Earth, and the photons came from a distant star (imaged by the telescope/spectrometer), then the hydrogen atoms at that star must be the same as the hydrogen atoms on Earth as far as electronic structure (electron orbital details, one proton for the nucleus, etc.).

So? Why would having hydrogen out there somewhere at some unknown distance matter?

But we can see spectra of many different atoms and molecules to know that they are also the same as the molecules that are present here on Earth.

Even if the spectra could not be affected by a changed space and time, why would it matter what elements are out there?

The oxygen we can see in the spectrum of a star is the same oxygen we have here on Earth, as shown by the characteristics of the spectrum. The implications go beyond this however. The mechanisms for how molecules absorb and emit light are very well understood (grab a spectroscopy book or book on quantum mechanics), and if light had different characteristics "out there" than it does here (speed of light, or some other difference that you haven't described), then we would not see identical absorption and emission spectra (or any spectra at all). But that isn't the case.

How does that even relate to time and what time is like out there? What characteristic that we can observe does time have? Why would light need to have 'different characteristics' out there? If light passed through space and time that was not the same as ours, what do you claim that would do to how light looks?

You're trying to argue that somehow time, or the characteristics of light, may be different elsewhere in the universe and then is magically the same as we see it here because we measure it here.

I never mentioned characteristics of light. You did. Explain what we would expect to see differently? By the way you only ever see the light here as you have been nowhere else!

[DrNoGods]

[Replying to dad1 in post #34]

Yes, and we can watch tv also. All this we do here. Not there.

The telescope is here.

What point are you trying to make with "here" vs. "there" comments? Do you have any justification ... any at all ... for claiming that physical constants, time, etc. are or might be different far away from our solar system or galaxy than they are here? Or is it just an idea you had that you think might discredit our present methods for determining the distance to distant stars and galaxies and cast doubt on their results? You don't seem to have any reasons for why you believe your idea should be taken seriously ... it seems to be just offered up with no justification whatsoever.

That question really is beside the point. All methods are faith based. Parallax requires time and space here for a baseline. For example, how far earth moves in the solar system space and time for 6 months. You cannot use that line and add lines to a star assuming all is equal.

More of the same. Where is your cutoff for what is "here" and what is "there"? Do you have one? Is alpha centauri at 4.37 light years away here or there? What about Neptune, or the Kuiper belt? If you don't think the stars we see in the night sky are tens, hundreds, thousands, millions and even billions of light years away, how far away are they? How big are they? Alpha centauri is about 22% larger in diameter than the sun ... how far away would it have to be to appear the size it does when we look at it from Earth? What would happen to temperatures on Earth if alpha centauri were not as far away as we think it is and was much closer? If you don't believe the 4.37 light year number, what do you think is the correct number, and why? Do you not believe that there even are stars millions of light years away from Earth, or just that we can't measure their distances so are clueless as to how far away they are, or how big they are?

[DrNoGods]

[Replying to dad1 in post #36]

So? Why would having hydrogen out there somewhere at some unknown distance matter?

Because we can observe it and see that it is identical to the hydrogen we have here on Earth (same for other atoms and molecules), which has implications given that the light we are measuring here in Earth either came from those distant H atoms, or was absorbed by them as light from a source "behind" them passed through.

Even if the spectra could not be affected by a changed space and time, why would it matter what elements are out there?

The important thing the spectra show is that the distant atoms and molecules are identical to the ones we have here on Earth, so they react chemically the same way, they absorb and emit light the same way, etc.

How does that even relate to time and what time is like out there? What characteristic that we can observe does time have? Why would light need to have 'different characteristics' out there? If light passed through space and time that was not the same as ours, what do you claim that would do to how light looks?

Light is an oscillating electric and magnetic field that propogates through space at a given velocity (the speed of light, c). The wavelength of the light is inversely proportional to the frequency of the light, and the product of wavelength (λ) and frequency (ν) equals the speed of light (λ * ν = c). Molecules absorb light mainly through electric dipole transitions (electric field of the light wave interacts with the electric dipole moment of the molecule). This is what creates the characteristic "fingerprint" absorption patterns in the (mainly) infrared used to identify different molecules because every molecule has its own specific "spectrum" in different wavelength regions.

The reason for going into this is because if light had a different speed in a vacuum "out there" than it does here on Earth, this would result in different absorption or emission spectra as it interacted with atoms and molecules along its path. The rates of absorption and emission are described using the Einstein A and B coefficients, for example:

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

https://nanohub.org/resources/25945/dow ... 52-L10.pdf

If you go through these equations you'll see "c" (speed of light) all over the place. If that were different it would impact the rates of absorption and emission and cause changes in the observed spectra (especially the relative intensities). This interaction between light and the molecules present near a distant star (or between a star and Earth) happens "out there", so if the spectrum were changed "there" you'd need some process to convert it back to what we see "here" when we measure it. What process could possibly do that? If the spectra were changed a million light years away because the speed of light was different, then we'd measure that change here ... not the identical spectrum we'd get here with no such change.

I never mentioned characteristics of light. You did. Explain what we would expect to see differently? By the way you only ever see the light here as you have been nowhere else!

See above. A change in the speed of light "out there" would have implications for things we measure here (via photons from "out there"), and we don't see any evidence of this happening.

[Diagoras]

How this relates to religion is that a six day creation thousands of years ago cannot be questioned using cosmology if it really did not take light that reaches us on earth and area a lot of time to get here.

<bolding mine>

For any observers of this thread, consider how we might try to establish the likelihood of that ‘if’ statement.

Believing the cosmological constant assumption is based on the fact that it has an implicit empirical basis, and makes future predictions which are testable in many different ways for independent observers (think GPS satellites and emission spectra as already stated upthread). Furthermore, this shows consistency with a large swathe of scientific evidence in unrelated fields such as radioactive decay, genetics, etc.

Believing that time and light behave so differently in other parts of the universe as to make the actual measured age of Earth only 6,000 years old, yet appear to make it look billions of years old would need an entirely new set of physical laws. And yet using the current laws have somehow got us to this point where GPS is a thing. If our assumptions about the universe really are that wrong, then we couldn’t be having this debate online in the first place.

[Diagoras]

[Replying to dad1 in post #33]

Science needs to evidence and support it's <sic> claims.

Plenty of posters here have put up such evidence, but you choose to ignore it. Saying “I see no evidence” is (as I’m sure you know), an argument from ignorance.