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Ok, so you see it too as an effect and not necessarily something real. There seem to be a lot of effort going into finding Mickey Mouse and friends in stead of improving our understanding of gravity!

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It's not an either/or situation. There is a wealth of hypotheses and proposals on both ends of this spectrum, awaiting the capability of testing. Dark matter makes specific, testable, and distinct predictions that differ from those that would derive merely from tweaking gravitational theory alone. And at least some of those predictions have been confirmed, and none have been falsified.

Dark energy may be a little more nebulous, there's a lot more room in either direction for specific theoretical explanations, but I don't think it's fair to say one concept is is being neglected in favor of the other. Scientists will gravitate to ideas that allow for the richest explanatory environment, and those that are the most productively testable. Anyone who comes up with an elegant, explanatory, and testable new theory of gravity will find themselves getting lots of attention.

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The Dark Matter postulate dates back to the 1930s. I have not found Dr Einstein’s position on it.

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During Einstein's life there were no good measurements of the size of the Universe or the distribution of matter within it -- Even the Big Bang theory was still controversial. Any dark matter postulate would have been tentative and undeveloped, and I'm not sure that Einstein would have been aware of it.

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What was this mr Einstein's take on the source of dark energy?

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I'm pretty sure the speed of light is relative to the size of the universe.

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Someone did. His name is Einstein and in 1919 he became a world famous celebrity beyond anything seen recently. One could compare it to when the Beetles came to America. People who knew nothing of physics learned of his car route and came out to the streets just to see his car drive by. People in Japan who did not speak German packed auditoriums to hear him speak for 4 hours.

His theory is called General Relativity.

http://en.wikipedia.org/wiki/General_relativity

And we are still testing it.

http://en.wikipedia.org/wiki/Gravity_Probe_B

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I hope I word this carefully enough not to cause confusion, but from what I understand, while the speed of light is indeed a constant according to all current knowledge and observation, the speed of space/time inflationary expansion did exceed the speed of light. Perhaps calling this expansion a "speed" is wrong because neither matter nor energy, as such, are involved, only the "fabric" of space/time itself.

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"Believe in" isn't exactly the way I would phrase this, as though I were "believing" in ghosts or UFOs, or "believing" in a deity.

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You're not alone in this. There was a science show a couple of months ago about a physicist whose alternative to the inflation theory of the Big Bang hinges on the speed of light being vastly greater then than now. His hypothesis is that c has been slowing down ever since as the Universe expands.

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Rats. I thought it was speeding up

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The problem I see with this idea, aside from the lack of any motivation (it's perfectly OK for the Universe to expand faster than c -- nothing physical is actually moving), is that such a theory would have to explain how photons from distant quasars and photons from, say, the Sun would have *exactly* the same speed when they reach the Earth. Or, more simply in your hypothesis, how could the size of the Universe determine the speed of light measured in a benchtop experiment in a physics lab?

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The speed of photos from different sources (if there is such a thing ) should be the same when both is measured at the same time.

Say you drop a rock in a pool and the waves reach the shore in 30 seconds. If you somehow stretch the pool while the wave travels the wave will still reach the shore in 30 seconds, its wavelength would increase (red shift), but it would have traveled a much further distance so one can say that it traveled faster during the later stages of the expansion of the pool.

If this crazy analogy even makes sense.

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The Dark Matter postulate dates back to the 1930s. I have not found Dr Einstein’s position on it.

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This is my point - perhaps we are lacking in a proper graviational theory that includes the accellerated expansion. And sorry, I meant Doctor

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If the speed of light was relative to the size of the universe we would not be able to tell that the universe is expanding. We observe that the speed of light remains the same but the wavelength gets longer due to the expansion of space. This is why objects farther away look redder.

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I wrap my brain around dark energy by considering it a fifth fundamental force. Consider: Strong force holds atoms together. Weak force holds molecules together. Magnetism is stronger than gravity, but only effective at very small distances. Gravity weaker still, but effective at extremely large distances. Dark energy weaker than gravity, but effective at cosmological distances.

DE differs from the other 4 as it appears to be repulsive, rather than attractive.

(I may have my descriptions of Strong & Weak not quite right, but the logic should still follow.)

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I'm with you there, but most of us think that there should be a unified theory showing the source of all forces. It all lies in the atom and the fabric of space. I'm telling ya

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That's what I mean, from my point of view (as a wet newbie to all this) it seems there is a belief needed in order to accept that dark energy and matter exist - plainly because nothing has been found or conclusively proven.

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Not really, but it's an understandable -- and nearly universal -- misconception. "Belief" is the wrong word to use here because acceptance of these ideas is always conditional, always contingent, and always subject to new information and better explanations.

The concept of "proof" doesn't really enter into theoretical or experimental science, because in actuality you can never completely and rigorously "prove" any proposition the way a mathemetician can prove a theorum. At best, the strongest ideas happen to survive every criticism and every attempt at falsification thrown at them, but there is always, at least in principle, some possibility that they will be proved wrong.

So accepting a scientific theory is nothing more than acknowledging a negative -- the theory has survived a certain level of difficult testing based on its predictions, and has not yet been falsified.

That's the case so far with dark matter and dark energy. Both theories make predictions, and both can be tested based upon those predictions. Dark Matter, so far, has led to some fairly in-depth predictions, which on observation, have turned out to be supported. Dark Energy has done the same, although probably to a somewhat lesser extent. Both theories remain valid -- both are deep and at least potentially explanatory, without having yet been falsified. Both might still be falsified as new observations allow us to fine-tune those predictions, better understand their implications, and develop new and more challenging tests for them. And both are still too incomplete to really provide a satisfactory explanation for anybody.

What we CAN do, as theories began to show a certain level of experimental support, is base practical applications upon those predictions, and so make them valuable to us. Once we start making the assumption that the predictions work, and that the results of our engineering can be consistently useful, then we can be said to "beleive" in those predictions.

I don't think either of the "dark" theories are at that stage yet.

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"S.O.E." (Sauron's Other Eye) 16" Royce conical mirror: A permanent work in progress.
10" Homebuilt dob, old Coulter mirror


Next Project: The "Eye of Sauron" Observatory!

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