DARK ENERGY

The non amateur stuff. Hawking, black holes, that sort of thing

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Vick
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DARK ENERGY

Post by Vick »

Hi all. Thanks for the answers to my about extra-solar gas giants.

Now on to dark energy. How can energy be ‘dark’? Surely, given a suitable sensor pointing in the right direction, energy can be detected?
Richard McC
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Post by Richard McC »

Hi Vick.

I'm with you on this one.
I suppose the easiest analogy would be to ask a cave man to detect uranium radiation.
The word 'dark' implies that it can not be observed (at the moment).
Maybe 'dark' should be replaced by 'mysterious'.
I have on occasion seen both words used together.

Or as Doron would say "3.1423876 X hubbles constant"

Rich.
Go placidly amidst the noise and haste, and remember what peace there is in silence....(and true darkness, without cloud cover).
Mike Feist
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Post by Mike Feist »

Hi All

'Dark Energy' is just a tag for a mysterious glitch in someone's theory. I think anyway.

Regards Mike
joe
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Post by joe »

'Dark Energy' is just a tag for a mysterious glitch in someone's theory. I think anyway
Yes, perhaps the same kind of glitch that Copernicus re-named the Heliocentric System, Kepler re-named his Laws of Planetry Motion and Einstein re-named the Theory of Special Relativity?

Regards,
200mm Newtonian, OMC140, ETX90, 15x70 Binoculars.
Vick
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Post by Vick »

So it may be just a matter of time before we observe what'a accelerating the expansion of the universe?

Just a shame that dark matter and dark energy can't balance each other out ?!?!?!?!?!?
joe
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Post by joe »

Dark Energy is what's left in the universe after you take out all the matter we can see and all that we can't see. It has also been called the energy of the vacuum; particles popping in and out of existence for minute amounts of time and the effect this has over large scales. We can't just point a sensor in any direction because, like gravity, it can only be detected by how it affects other things, i.e. accelerated expansion. In between galaxies, where there is little gravitational force, you would be hard pushed to come up with a theory of why those stars in the distance were all held together because you would have no direct experience of gravity. That's why cosmology is so interesting to me, it always reminds me that the universe is mostly.... not what we are used to.

I should add that the effects of these particles popping in and out of existence have been measured in the laboratory.

Hope there's not too much there that's b****cks. :D
200mm Newtonian, OMC140, ETX90, 15x70 Binoculars.
Cliff
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Post by Cliff »

Dear al
Why is everybody picking on poor old(or new) "dark energy" ? I thought they were still trying to find gravity ?
Has anybody definitely observed "gravity waves" yet ?
Did you watch the TV programme about Galileo last week? According to that poor old Galileo soon changed is tune when they showed him the old thumb screws.
As for Copernicus apparently nobody read his book and anyway he pinched all his ideas off Harry Starkus.
Best of luck from the Grumpy Old Codger Cliff
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