What's the Fabric of space made out of?

True ... has it ever occurred to you that the one other common element in almost all those situations is you? "Stalled argument" and "buzsaw" have a very strong corellation. Hummm... Yup. Appears to you. A certain amunt of vagueness is inherent in the description in English rather than mathematics. The rest of the vagueness arises from another source. A clear view of our moon is pretty white, which means it has plenty of red in it. The reddish appearance is caused by subtracting other colors, not adding red. My stars and little fishes! All this time and you don't have the vaguest idea of what redshift is!Redshift is not a reddish appearance, nor is it a state of having more red wavelengths than others. Spectroscopy clearly shows that by shifted elemental absorption and emission lines. Redshift is the shifting of all wavelengths toward longer wavelengths and has nothing to with the color red; many very-high-redshift obects appear blueish or white or yellowish in visible light. Spectroscopy and redshift. The math is modeling it and, alas, it's sufficiently complex and counterintuitive that anything other than the math is going to introduce vagueness and potential for error. The model is the math. You up for it? Brushed up on multidemensional tensors recently? Familiar with Friedmann-Robertson-Walker spacetimes? You're comfortable with Schwarzschild metrics? Neither am I; and I can't understand the model completely.Sylas has done yeoman's service in laying out excellent explanations of complex subjects that can be understood by those with a moderate amount of background information and a willingness to learn and putting up with your lack of any background information and willingness to learn and your aggressive and insulting behavior. He deserves a medal. I wouold have blown you off long ago.

The longest wavelengths of the teeny tiny portion of the electromagnetic spectrum to which our eyes are sensitive are red. Here's a graphic of a lot of, not all of, the electromagnetic spectrum: Note how small the visible light area (below the "P" of "SPECTRUM" in the "Common name of wave" line) is.A very detailed electromagnetic spectrum poster is available as a graphic and a PDF from Electromagnetic Radiation Spectrum Poster. I'm not absolutely sure what you mean by "moon and sun models". If you are referring to the fact that the moon and sun appear reddish under certain circumstances, that's not a redshift. It is absolutely impossible for the phenomena that make the moon and sun appear reddish to be the cause of the cosmological redshift.Here's a high-resolution picture of the light our Sun emits in the part of the spectrum that we see (from Astronomy Picture of the Day 2000 August 15; if you click on the "above picture" link you can get higher-resolution versions). This should really one incredibly wide but not tall picture, but to make it fit they've cut in into strips and stacked them up on top of each other. Start at the top left and read left-to-right, going down to the left end of next line when you reach the end of the line, just like reading English. You can sort of see that the maximum brightness is in the yellow area; that's why the Sun appears yellow. But there's green and blue and red, too, just not so obvious. But what are all those black lines?Those are called Fraunhofer lines, after Joseph von Fraunhofer (1787-1826) who first discovered them. Here's one of his original drawings: With modern equipment we see lots more. The Sun is generating light at the frequencies where we see those black lines, but the light is being absorbed by various atoms and molecules and ions before it gets to us. Furthermore each atom/molecule/ion has a characteristic set of frequencies at which it absorbs light, and we can identify atoms and molecules and ions by their patterns of light absorption. (Helium was discovered in this manner, in the Sun, before it was discovered on Earth.)So, what happens when the Sun appears reddish when it's low in the sky? The atmosphere is absorbing blue and green components, so the same spectrum of the Sun taken late in the day might look like this: where the blue components are almost gone, the green components are cut way back, but the red components are still strong … so it looks red. But the Fraunhofer lines are still at the same wavelengths; the ones that were in the red are still in the red, the ones that were in the yellow are stil in the yellow, and so on. We can tell from the pattern of the lines.What would it look like if the Sun were moving away from us really fast, and its light was redshifted? Well, it would look something like this to us (I've cut off the blue end because it's really difficult to put it in): Now we see the red and yellow and green (and blue, if it hadn't fallen off the bottom of the picture) components at about the same brightness as the original; but the Fraunhofer lines are in different colors! We can tell because of the patterns of the lines. The lines that were in the yellow are now in the red, the lines that were in the green are now in the yellow, the lines that were in the blue are now in the green.So it's trivial to tell the difference between what makes the Sun look red and what the red shift of something moving away from us looks like. The distant objects in our Universe are red shifted by their motion, not by some of their light having been absorbed. {ABE: Some objects are red or blue shifted by their motion, more distant objects are red shifted by the expansion of space).By the way, there was a "tired light" theory, in which the red shift was caused by light getting "tired" after traveling long distances. That didn't work out either. No, not even comparable. Math is the language of science; much if not most of science is mathematical models. The math is something which can be manipulated, checked against experimental observations, and used to make predictions of future observations (not necesarily future events) (which observations might falsify the model). If you come up with a mathematical model of complexity of DNA pointing to intelligent design which could be manipulated, checked against experimental observations, and used to make predictions of future observations, and could be falsified, maybe you'd have something. Dembski's tried, and he's failed miserably. Wrong topic.{Updated links to pictures}This message has been edited by Admin, 03-06-2005 11:29 AMThis message has been edited by JonF, 03-07-2005 11:16 AM

OK, that's what my post refutes.One thing that I did not mention is that we can oftehn see the effect of all that haze and stuff. Light picks up another set of Fraunhofer lines if it passes throuhg a dense-enough cloud; the Fraunhofer lines are red-shifted by the velocity of the cloud relative to us and the amount of the expansion of space between the cloud and us. Probably. I have no idea what it is. The process that causes it is called scattering. Redshift is defined as "the systematic increase in the wavelength of all light received from a celestial object". Redshift may be due to any of (or any combination of):

• The body moving away relative to us
• The light having to "climb out of" a gravitational field to get to us
• The expansion of space between us and the body

The third only applies to objects that are far enough away that the effect is fairly large and (I think -- I might be wrong) is larger than the effect of the second possibility. Note that if a body is moving towards us the effect is a "blue shift", which is the negative of a red shift and can cancel out a red shift or a portion thereof.The first and second possibilities have been measured within the Solar system (albeit the amounts are very small) and on many other scales.

Wow, does that bring back memeories. We must be similar ages.

"White" is a label for something that has no objective existence. It's sort of misleading to say "white light is being produced". It's more accurate to say that "something near to a black-body spectrum is being produced, and our eyes are sensitive to the wavelengths near the peak of the emission and we call the presence of all those wavelengths 'white' ". (BTW, it's not particularly surprising that our eyes evolved to be sensitive to the part of the spectum in which the Sun puts out the most energy). If we had evolved on a planet around a very different star, we would see a totally different range of wavelengths and call them "white".The Sun is radiating energy at a rate that is almost exactly like a black body (a theoretical construct that radiates energy in a way that is characteristic of its temeprature) at around 5700K (9,800°F). See Black Body Radiation, especially the pictures at the end.

OK. The absorption and emission of light by changing energy levels from atoms and molecules and ions is quantized (not quantified) by the energy levels of the electron orbitals. The vast majority of the light emitted by the Sun is emitted by a plasma (I forget the name of the layer) in which the electrons have all been stripped from the nuclei, and there are no electron orbitals. It's just pure thermal emission. Acceleration of charged particles, like the nuclei and nucleons found in the plasma, produces electromagnetic radiation. The light is, of course, emitted in quanta (otherwise we'd be back at the ultraviolet catastrophe) but the wavelengths are not quantized. IT's very close to the famous "black body' emission curve:Incandescent bulbs are mostly pure thermal emission, but there's some energy-level stuff going on; that's why "sodium" street lights are distinctly yellow.The outer layer of the Sun isn't hot enough to be a plasma, or hot enough and dense enough to produce significant thermal radiation on its own. So we see its absorbtion bands in the light coming from deeper in the Sun.See Black Body Radiation and Applet: Blackbody Spectrum (requires Java).

Yup, that's a pretty good summary.

Yes. So, as Sylas already pointed out, "tired light" is wrong. It doesn't agree with experimental results.