Age of Universe - Is time the same today as at the beginning

[BlameTheEx]

Freethinker

 

Graphite does indeed make a good black body. However it is a SOLID form of carbon. I specified gasses. Vaporised carbon emits only on spectral lines the same way as any other element, and that is the form you will find it in on the surface of the stars under discussion.

 

Still, I am amused. Once you recognise that a fair bit of this starlight does indeed consist of spectral lines that are red shifted, how do you explain what makes the rest of the light so different that it is not?

 

You wanted evidence. Hm. Scientific papers tend to assume a clear understanding of redshift rather than explain what should be learned in school. Best I can give you is primers on the topic:

 

http://astron.berkeley.edu/~mwhite/darkmatter/dopplershift.html

http://www.arachnoid.com/sky/redshift.html

But I suppose they could have got it wrong, so how about NASA?:

http://imagine.gsfc.nasa.gov/YBA/M31-velocity/Doppler-shift-2.html

 

Please note that while there is some reference to spectral lines, the formula and explanation makes clear that ALL photons will be shifted. A black body may emit photons at many different wavelengths, but each photon emitted has a wavelength, and that wavelength can, and will be shifted by the doppler effect.

 

Oh, I see you are still trying to twist my words. Sorry and all that, but as anybody can see them in their original context, I ain't going to bother to correct you here. I know your being ether stupid or obnoxious in this, and so will anybody else. Frankly I am now leaning towards the obnoxious explanation. Stupidity of that degree seems unnatural.

[Freethinker]

Originally posted by: BlameTheEx

Oh, I see you are still trying to twist my words.

???

 

I see! By QUOTING THEM VERBATUM and then providing FACTS showing they are WRONG, I am TWISTING your words!

 

You have no clue do you?

 

Let's look at the REAL discourse.

Originally posted by: Freethinker

Now let's put some reality into the discussion.

Originally posted by: BlameTheExThose atoms can only emit photons by changes in the orbits of their electrons.

"orbits of their electrons"? Perhaps if you catch up on the last 100 years of scientific knowledge you would understand the topic.

Originally posted by: BlameTheExElectrons only orbit at fixed positions

LOL!

 

So you have found a way to disprove QM and the Uncertainty Principle? We all want tickets to your Nobel Prize Award dinner!

In review. YOU SPECIFICALLY ASSERTED

Originally posted by: BlameTheExThose atoms can only emit photons by changes in the orbits of their electrons.

That is plain and simply WRONG! There is nothing needed to twist your words. YOU WERE WRONG! and I proved it!

Originally posted by: BlameTheExElectrons only orbit at fixed positions

NO TWIST! direct quote! and YOU WERE WRONG!

Sorry and all that, but as anybody can see them in their original context,

You want to BlameTheME for ErrorByTheYou! This is NOT a matter of CONTEXT. The assertions are WRONG no matter what the context is!

I know your being ether stupid or obnoxious in this, and so will anybody else. Frankly I am now leaning towards the obnoxious explanation. Stupidity of that degree seems unnatural.

I see. *I* am being "stupid or obnoxious"? Providing FACTUAL INFORMATION is suddenly being STUPID? Correcting BLATANT ERRORS is being OBNOXIOUS?

 

If there is ANY twisting, it is obvious that it is YOU that is trying to twist things!

I ain't going to bother to correct you here.

What with MORE ERRORS?

 

You won't "bother to correct (me) here" because I am already CORRECT!

Originally posted by: BlameTheExElectrons only orbit at fixed positions

Ya OK, correct ME here!

[Freethinker]

Boy I don't know where to start! It is easy to see who's argument is falling apart by the attempt to change the context. This started as a discussion involving ANY photon from ANY source

08/23/2004 02:15 AM

Originally posted by: BlameTheEx Light from distant galaxies is, in effect, red shifted because it was emitted in the past.

After I challenged him by asking for PROOF, it slowely morphed into:

Originally posted by: BlameTheEx

Freethinker

 

Graphite does indeed make a good black body. However it is a SOLID form of carbon. I specified gasses.

???

 

OK, along the way BlameEveryoneElse, seeing he was WRONG, tried to slowly change his claim. But the ORIGINAL CONTEXT had NOTHING to do with

Originally posted by: BlameTheEx I specified gasses.

But the attempt to TWIST HIS OWN WORDS was slow.

 

08/23/2004 02:15 AM

Originally posted by: BlameTheExLight from distant galaxies is, in effect, red shifted because it was emitted in the past.

Was then diverted by

08/26/2004 12:34 AM

Originally posted by: BlameTheEx Oh dear. You ignored the word "apparently".

The LATEST TWIST did not appear until EIGHT DAYS LATER!

08/31/2004 01:29 AM

Originally posted by: BlameTheEx The surface of most stars (most in terms of light output. I can't answer for stars with little or no light output) is composed of very hot gas.

And all he has done is to provide more WRONG information. Remember the original assertion was about

Originally posted by: BlameTheEx Light from distant galaxies

which we were LATER told

Originally posted by: BlameTheEx Starlight, and thus light from galaxies is ALL spectral lines...In short a free atom emits light only at specific frequencies. The atom emits only at its characteristic spectral lines. Simple molecules, in a gas, have more options for electron orbit change, but they too emit only within fixed spectral lines.

But this is WRONG. Stars DO NOT "emit only within fixed spectral lines" , and if memory serves, we have one close by. What does NASA say about this?

 

"Our Sun emits light at all the different wavelengths in electromagnetic spectrum"

http://imagers.gsfc.nasa.gov/ems/uv.html

 

And firther what about the light from Galaxies, do they also "emit only within fixed spectral lines"?

 

"Galaxies normally emit light of every wavelength, from the long radio and microwave end over the IR, visual and UV light to the short, high-enregy X- and gamma rays. Interstellar matter is coolest and therefore best visible in radio and IR, while supernova remnants are most conspicuous in the high-energy part of the electromagnetic spectrum."

http://www.crystalinks.com/galaxies.html

 

No matter how you slice it, claiming that Stars, Galaxies, ... "emit only within fixed spectral lines" is WRONG!

 

And twisting your claims all over the palce as you go does not change the FACT that you are WRONG!

[Freethinker]

But let's get down to the original assertion, it's error and the 180 turnaround attempted to cover this blatant error. We started originally with a simple (though WRONG) assertion

 

08/23/2004 02:15 AM

Originally posted by: BlameTheEx

Light from distant galaxies is, in effect, red shifted because it was emitted in the past.

Note, there is not a single mention of doppler. In fact this explanation was offered IN PLACE OF Doppler.

 

After being shown over and over that he IS WRONG, he wants to pretend he never said it!

 

09/01/2004 11:26 PM

Originally posted by: BlameTheEx

Please note that while there is some reference to spectral lines, the formula and explanation makes clear that ALL photons will be shifted. A black body may emit photons at many different wavelengths, but each photon emitted has a wavelength, and that wavelength can, and will be shifted by the doppler effect.

Hey, had you said this in the first place you would have been CORRECT and not had to spend so much of our time trying to twist your story around.

Stupidity of that degree seems unnatural.

Not for everyone obviously.

[BlameTheEx]

Sigh

[Bo]

I lost complete track of this discussion, so my reply may not be relevant, but reading the last few posts the following came to my mind (for references, see standard texts on cosmology)

 

- Every photon is red shifted. The obvious effect is when observer and emmiter have a relative velocity not equal to zero, but even if the rel. vel. is zero there is a red shift, due to the expension of space itself. (hubble's law)

- a spectral line is just a 'hole' in the photon spectrum. By Fermi's principle this can be seen as a normal photon and obey's the same laws as a normal photon.

- The expension of space is not a constant in time (IOW Hubble's constant is not a constant)

- The standard definition is a "time-length" is a constant troughtout the history of the universe, and space has a time-dependent scaling factor. BlameTheEx proposed a time-dependent time scale. apart from the fact that this makes the mathematics much more difficult, i think that this is impossible. A possibility is a space dependent time-length, but in principle this is the same is the normal convention.

- Electrons are of course not in fixed places or (in the classical sense) orbits, but the convention to talk about 'fixed orbits', 'falling down' etc is widely used (and imho a lot more practical then talking about "Probability distributions corresponding to the n-th eigenvalue of the nuclear potential" ) (strange/wrong names occur everywhere in physics; a black hole is not a hole, a string is a D-dimensional manifold, Hubble's constant is not constant, etc).

- A perfect black body doesn't exist (the most perfect BBR observed is the cosmoic microwave background); By their specific composition some elements (like carbon) represent the BBR quite good; QM permits it from being perfect.

- I like to attend any noble prize dinner

 

Bo

[Freethinker]

Originally posted by: Bo

I lost complete track of this discussion, so my reply may not be relevant, but reading the last few posts the following came to my mind (for references, see standard texts on cosmology)

Thanks for jumping in Bo. Hadn;t heard from you for a while. Always good to get more voices in. Esp those that have some factual background.

- Every photon is red shifted. The obvious effect is when observer and emmiter have a relative velocity not equal to zero, but even if the rel. vel. is zero there is a red shift, due to the expension of space itself. (hubble's law)

I agree with most of what you post (since most of it agrees with what I post anyway lol) But I have to debate this one.

 

"Red Shift" is a relative phenomenon. It indicates that a marker, at it's place of OBSERVATIONN is in a spot lower in frequency than the same marker would be expected to be based on OTHER references. That one photon's marker is shifted COMPARED TO another photon's.

 

You relate to "obvious effect" when one photon from a source with relative velocity that is not the SAME as that from presumably a locally fixed source (one with the same velocity as the observer). But it is ONLY an "obvious effect" when compared to a locally fixed source photon (or the historically observed marker from locally fixed photons).

 

If ALL photon's were red shiifted, they would all be the same and thus NOT red shifted.

 

- Electrons are of course not in fixed places or (in the classical sense) orbits, but the convention to talk about 'fixed orbits',

I understand the "convention". It was drilled into my brain during 4 years of electronics education. Valance rings, electron flow....

 

If we were discussing a light switch and how current flows when it is closed or doesn't when it is open, it could simplify the issues. But it is NOT a convention when discussing QM issues such as wave/ particle issues and Uncertainty. ]

strange/wrong names occur everywhere in physics;

Yes, this is a shortcoming of language, especially when trying to describe things that are outside of the words available and established. This does not excuse incorrect applications of terms when an agreed meaning is applied, such as a Black Hole. No it is NOT a hole. But a Candy Apple Red car is not covered in candy apples either.

 

I will be back next week to see what you think.

[Bo]

Red shift:

 

Red shift is of course always relative. so often what is meant by the red shift is (frequency emitted)/(frequency received). And sure, if every photon is redshifted by the same amount we wont see any redshift. My point was that apart from the standard redshift of relative velocities, photons are also redshifted by the expension of the universe. (if the expension was constant, this effect wouldn't take place, but this isn't the case). Of course one must realize that this effect only is significant over a veeeeeery long period of time.

 

Yes, this is a shortcoming of language, especially when trying to describe things that are outside of the words available and established. This does not excuse incorrect applications of terms when an agreed meaning is applied

 

yes that is of course true, but the use of the term 'fixed orbit' is quite well established. but 'fixed quantum numbers' or so would be better.

 

Bo

[BlameTheEx]

Bo

 

Thanks for the comments.

 

Regarding the idea of a time dependant time scale, I didn't propose it, but I suppose I can be said to have second it, as I offered what I figured was a plausible model that would allow it.

 

Best as I can figure it, it doesn't really make the maths more difficult. You can think of it as a way of explaining redshift and time dilation of distant objects for a steady state universe. That is one that isn't expanding and has no Big Bang. In fact the maths should be dead simple, in that the redshift/time dilation would be without any other consequences. Better, as I have no particular explanation for why time should vary, there is no reason to suppose that whatever relationship there proves to be between redshift and distance is wrong for it. From that point of view you could say there isn't any maths involved at all, as I haven't proposed a formula.

 

The problems with the theory are obvious. It doesn't explain much, and I can't think of any evidence to advance it over other theories. I have to confess I consider It unlikely myself.

 

Could you explain why you consider it impossible, or is this just a gut feeling? It would be nice to be able to eliminate it completely so we can concentrate on more likely options.

 

Regarding Carbon. Graphite is of course a good approximation of a black body. However graphite is only one form that carbon can take. You would not consider a diamond as a black body, and yet it is pure carbon too! There is at least one more form carbon can take, that of a gas. While I don't ever expect to see gaseous carbon on earth, the surface of a star is too hot for anything but gasses. Gasses never act like black bodies.

 

Regarding spectral lines, they can be holes. This depends on whether they are due to absorption (holes) or emission (peeks).

[BlameTheEx]

Check this out:

 

http://jersey.uoregon.edu/elements/Elements.html

 

This is a wonderful applet here that give the emission and absorption spectra for the entire periodic table. It is for the purpose of explaining spectra from stars, so presumably it shows spectra for elements in their gaseous form.

 

You can click on any of the elements and see a well defined spectra. No black bodies here! In particular check out carbon.

 

There is one peculiarity. Elements 85 and 87 apparently have no emissions in the visible light range at all!

[Bo]

Could you explain why you consider it impossible, or is this just a gut feeling? It would be nice to be able to eliminate it completely so we can concentrate on more likely options.

 

Well it was just a gut feeling

but here: http://pancake.uchicago.edu/~carroll/notes/seven.ps you can find the proof (page 1 to 6).

But this is very mathematical....

The main line of thought is the following:

Lets assume one mass in a completely empty universe. Then we assume that the influence of this mass on the structure of space-time (the metric) is spherical symmetric. (a logical assumption, since each direction in space is the same) (building our complete universe is just a matter of adding many such sollutions together)

The most general structure space time then can have is given by (eq) 7.13. in this most general metric the timelength has a time-dependent scaling factor (given by the function alpha(t,r); where t is time).

in the next part the Einstein equation is solved for this metric; then it is showed that we can always take alpha(t,r)=alpha® (so no time dependence). So the time-dependent timescale is ruled out.

 

Bo

[BlameTheEx]

Bo.

Bo.

 

Sadly, I don't seem able to handle postscript!

 

Not that it probably makes much difference. My maths is a bit ropey.

 

Still I can imagine that maths would deny it. The progress of what i could call "Absolute Time" can't vary over time in any meaningful manner. We can only have variability of time as measured by a time that doesn't vary along with it. We have something that is not governed by this time. In short we are visualising a variable time, and another absolute time.

 

The difference with this rather improbable theory would be that "Absolute Time" includes everything, and "Variable Time" excludes light. The argument would be that as light does not experience time, it can't vary. Time dilation would dilate the "Variable Time" effect too. Naturally I doubt that this is in accordance with any established equation, least of all one of Einstein's.

[Uncle Martin]

I've always thought that time only applies to light from an observers point of view. The dilation for a photon is 100%, correct? So if a photon could experience time, even if it travelled 13.7 billion light years it would percieve leaving and arriving at the same time,... instantly.

[BlameTheEx]

Uncle

 

Very True.

 

That is why I proposed it as a candidate for freedom from "variable time". If it were not free, then its frequency would rise with the proposed speeding up of time, as received light acts like a clock. One tick for the time for one wave to pass by.