science fiction hour

merle van osdol
merle van osdol
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Topic 198224

Matter attracts, that's why we have gravity. Antimatter which is at the center of the universe and is a left over from the big bang repels, that's why we have an expanding universe. It is accelerating because the distance between matter keeps increasing. Well I'll keep on trying. Anyone else?

merle

What is freedom of expression? Without the freedom to offend, it ceases to exist.

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Jim1348
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science fiction hour

Antimatter does not repel. It attracts matter the same way that ordinary matter does, at least as far as the physicists know at the moment. The expansion of the universe is due to the kinetic energy of the bang, or whatever it was. Beyond that, an expert will have to weigh in (if I may say so).

Logforme
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Replace "antimatter" with

Replace "antimatter" with "dark energy" and you're golden. Since no one have a clue what dark energy is, it's good for anything you need it to be in your SF :)
(And to my limited knowledge it's currently thought to be behind the accelerating expansion of the universe)

Mike Hewson
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IF you believe old and

IF you believe old and distant supernovae behave like more recent ones

THEN the expansion of the Universe is accelerating ( ie. further pushing since the Big Bang )

AND IF you believe General Relativity applies at cosmic scales

THEN this effect is labelled "dark energy" ( due to the position of a factor in the GR equations )

BUT no one knows why ..... :-) :-)

{ NB General Relativity does not specify which sort of Universe you are in, but given that you have one at all, it will define how it evolves. }

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Zalster
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People worry about is it

People worry about is it expanding or is it contracting, is it dark energy or anti matter...

I worry about when the universe achieves constant universal temperature...

But none of us will be around to see that..

Mike Hewson
Mike Hewson
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Yes we will all be one with

Yes we will all be one with the environment by then, ashes to ashes ... dust to dust.

But in reality, for most of us, The Universe may as well be emitted from the left nostril of the Great Green Arkleseizure or the Easter Bunny's Favorite Uncle or whatever .... :-)

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

merle van osdol
merle van osdol
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If there was a large glob of

If there was a large glob of antimatter in the center of our universe would it be visible. I'll rephrase: Can we see antimatter through our telescopes?

Just curious.

merle

What is freedom of expression? Without the freedom to offend, it ceases to exist.

— Salman Rushdie

merle van osdol
merle van osdol
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Could we see an antiphoton in

Could we see an antiphoton in our telescopes assuming it had not yet collided with a photon? Could it be identified as an antiphoton?

merle

What is freedom of expression? Without the freedom to offend, it ceases to exist.

— Salman Rushdie

merle van osdol
merle van osdol
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http://phys.org/news/2011-04-

http://phys.org/news/2011-04-antimatter-gravity-universe-expansion.html

I just now found this article on antimatter.

merle

What is freedom of expression? Without the freedom to offend, it ceases to exist.

— Salman Rushdie

Mike Hewson
Mike Hewson
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RE: http://phys.org/news/20

Quote:

http://phys.org/news/2011-04-antimatter-gravity-universe-expansion.html

I just now found this article on antimatter.


The key here is somewhat buried in the subtle wording :

Quote:
general relativity predicts that the gravitational interaction between matter and antimatter is mutually repulsive


and

Quote:
providing the extension of general relativity to antimatter,


... or if you like in plainer speak, this theorist has embedded repulsion in his extension to classic GR. Not surprisingly this then gives the appearance of 'predicting' universal expansion when that was actually his input to the theory for that purpose. More accurate writing/reporting/rephrasing might be :

"a newly constructed extension to general relativity predicts that the gravitational interaction between matter and antimatter is mutually repulsive"

whereas :

Quote:
Villata’s proposal does not require changes to well-established theories


is absolutely plain wrong, given that Einstein constructed GR two decades prior to the discovery, or even postulation, of anti-matter. By all means extend GR, or not, as you please for some current purpose. But let's not pretend that GR had Villata’s predictions embedded all along.

Now there is nothing wrong per se with such speculation etc, that's what theorists do. At least he admits the biggest issue :

Quote:
The problem is that, so far, researchers have not observed antimatter in these locations. Villata plans to investigate this question in a future study on the invisibility of antimatter in voids.


So who has the "woolly concept" now, eh ? Undetectable antimatter replaces undetectable energy. What a huge stride forward.

In any case he lets drop that he is sci-fi author looking for a publisher, with his latest novel exploring the implications of his theory ......

.... and maybe, just maybe, phys.org ought take a few breaths before propagating ideas from anyone who thinks contradiction by reality is merely prejudicial to a theory :

Quote:
Antigravity has always been controversial, and likely it will still be so until we can get an experimental (or observational) response,†Villata said. “However, I hope that my work, in the meantime, can at least dissipate some prejudices against antigravity.


Hey .... the word your looking for is wrong by the age old measure in physics -> reference to reality. Or is that metric being redefined now ? This 'explanatory' technique is so common now, just buff the meanings of words to advocate away the real world. Yes, anything might be true inside a human mind ( that's what groupthink & cults are for ). Cue Area51 ....... absence of evidence becomes proof ..... I assert therefore you must disprove ..... future/unspecified evidence will arise to rebut ..... if only the universe was different then I would be right ....

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Logforme
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My flying car will of course

My flying car will of course use antimatter to produce lift.
I will name the first prototype the Hindenburg in honor of another aircraft that produced lift using totally safe means.

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