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I want to know how there is a certain distinction between the Doppler effect, and the other examinations. If you see the theory you say went over my heard, which was it? I will be glad to read it again, or the first time if I missed it.
We all agree the galaxies are moving farther apart. I don't believe there are boundaries as such. I was pointing out such an impractical argument someone implied before. How do you make infinity any larger? that's why I also stated "known universe."
What the question seems to be that everyone dances around, is what is causing the expansion. That isn't so much the issue to me as is why are they trying to explain what appears to be normal red shifting via the Dopper effect as something else.
It is accepted that this "dark energy" is the reason the galaxies continue to move away from each other and why it is accepted that gravitational forces will not pull them back. Now, we either consider this dark energy what the ancients would call "aether," which would be a medium to change the wavelength of photons, or it has no effect on the photons, and the red shift we see is from the Doppler effect, except for other possible reasons that either change the space-time, or other influences that change molecular vibrational frequencies.
I want to know how there is a certain distinction between the Doppler effect, and the other examinations. If you see the theory you say went over my heard, which was it? I will be glad to read it again, or the first time if I missed it.
Well, there's a few known facts to dance around. For example, we know for a fact now that Einstein was right about space-time being interwoven and magnetic fields like the one around the Earth causing a vortex that change space-time (verified just last month). As such, we know for a fact that space-time changes due to black holes, neutron starts and the like.
When you talk about "change molecular vibrational frequencies" you're not talking about photons, are you? Photons are not molecules. They're an elemental particle that has no mass. We also know that while they have certain 'wave-like' features, they're not necessarily classical waves (for example, they don't need a medium to go through, and don't decay spontaneously in empty space).
You can use the Doppler effect to measure any distance. The reality though, is that you can get better precision with other methods as far as space is concerned. You can use the Doppler values of known distances to build a scale that would let you use it for distances not measurable by other methods. There's obviously a few more known caveats of using the Doppler effect in outer space (which are outlined in it's respective Wiki entry under Astronomy).
I said what went over your head is the fact that nobody think all this stuff is fact. At the same time, nobody dismisses it because "it's just a theory" and "we've disproved many theories". We've proven many theories before too. If you're going to dismiss it, the least it's asked of you is to point out clearly what's flawed about the theory, and hopefully propose a theory that works around all the flaws. Normally this is work done by trained scientists that work with this stuff every day, and are able to test (technology-permitting) and prove/disprove factually the flaws. Now, you're certainly free to create your own competing theory. Unfortunately, in science you need more than just an opinion to be taken seriously.
Its been mentioned several times, but once again the cosmological redshift is not a Doppler effect.
Aside from koriwhat? Nihilism would be my only rational answer.
Does anyone else find it most telling that WC does not appear to understand what a photon is?
WC, given what we now know about physics, I don't think there will ever be a way to determine what, if anything, is "on the other side". If we could sense it, it would become part of our universe, and automatically exclude it from being "on the other side". (Of course, who knows where science will go next.... quantum physics defies a lot of intuitive laws as is.)
So you are making my point.
I get tired of you assuming I don't know what's happening just because I skip severl steps when I say something. If you need me to spell things out step by step, you are wasting my time.
The photons wavelength is determined by the elements and molecules that are excited. To my knowledge, these red shifts are being determined by the spectral frequencies (photons) of elements and molecules. All elements have a specific known vibrational pattern. Hydrogen for example:
Therefore, the red or blue shift is determined by how this changes, increasing or deceasing in nanometers. You have to have a known element or molecule to compare. The frequencies may change, but the spacing remains proportional of the affected wave numbers.
No Sherlock. I know all this already.
OK, the fact that people make fun of my questions and cannot answer them is not an indication that they fail to understand.
Got it.
I know that. So please explain what causes it if it's not the Doppler effect.
As far as I can make out, they are just renaming the Doppler effect.
I don't think there's another side. I just brought that up as food for thought.
ha ha...
Think you're funny huh?
Uhm... but a photon isn't an element, or a molecule. It's... energy. It doesn't have a chemical makeup. Maybe I'm just not reading you correctly.
Except that photons aren't elements or molecules, so you can probably throw out anything that's referencing elements or molecules. Like others have said, photons are truly unique creatures.To my knowledge, these red shifts are being determined by the spectral frequencies (photons) of elements and molecules. All elements have a specific known vibrational pattern. Hydrogen for example:
Therefore, the red or blue shift is determined by how this changes, increasing or deceasing in nanometers. You have to have a known element or molecule to compare. The frequencies may change, but the spacing remains proportional of the affected wave numbers.
Now, as you said, the redshift relies on the FREQUENCY of the wave, right? So your understanding is that the redshift/blueshift can only occur due to a wave freq change, which most often occurs due to a change in medium in "normal" waves.
So why would photons wavelengths "lengthen" if they weren't passing through some sort of media? The answer to that is gravity. Photons on the farther edges of space are most likely moving through less dense/gravitic space, becoming redshifted. No "medium" is needed.
http://en.wikipedia.org/wiki/Gravitational_redshift
Again, I'm only speaking as someone who studies this stuff as a hobby. The other smart people in here can expound/elaborate/correct me.
Remember, even though light is "massless", it still is affected by gravity. Otherwise, there'd be no such things as black holes.
No Sherlock.
Others mentioned gravity, and I did too previous post.
Gravitational red-shifting has nothing to do with the changing terminology.
Last edited by Wild Cobra; 06-07-2011 at 11:42 PM.
Thanks for being so polite.
So why can't gravity cause redshift/blueshift without a medium required?
What changing terminology?
No you don't. You keep saying you know things and you keep proving you don't.
Look, there are too many overlapping sub topics here. Outside of how gravity affects the wavelength, how does the redshift of the expanding universe differ from the Doppler effect with vector math applied?
No, I'm actually being quite serious. You keep comparing photons to "elements" and assigning them properties of mass as a springboard for your fallacious theories.
No I'm not.
The spectral radiation emitted by the elements is in the form of photons.
You know, light...
WC you either have some of the worst command of the English language I have seen or you simply don't know what you're talking about. Its probably a combination of both.
What is causing the cosmological redshift? Um, whats the OP about?
this is really not that 'big'. we already pretty much assumed the existence of both dark energy and matter. what we have now is observation, or tautology, not anything revealing about the nature of the two.
Well, then your knowledge is wrong. There's no elements or molecules that make up a photon. A photon is a massless elementary particle, as such it has no subcomponents. You need to wrap your head around that concept first.
Photons have certain wave-like properties, like frequency (and thus wavelength), angular frequency, momentum, etc, but they derive such values from the quantum model (Planck constant, Dirac constant) and not the classical molecular model.
In the case of molecular structures, you do. In the case of non-molecular measurement, you build the baseline measurement scale by comparing against known measures obtained by other means.
You got your questions answered, multiple times. You're just being obtuse.
How many more times people have to tell you to stop associating classical wave models with photons?
What you're doing is akin to trying to understand Einstein's Theory of General Relativity by using fundamental concepts from Newton's Law of Universal Gravitation.
Ditto. Another reference:
http://en.wikipedia.org/wiki/Relativistic_Doppler
Sorry, I've wanted to check in a bit more but I'm attending an International Nuclear Medicine meeting at the convention center. The open bar > than ST.......
It's distinctly different. We don't use a relativistic version of the Doppler equation to explain cosmological redshift, rather we use an extension of special relativity formalism. When considering Doppler relativism, you have to consider that "v" cannot exceed "c".
Your comments on spectra are correct (mostly), they just lacked the proper context.
Interesting discussion, yes yes.
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