Antimatter = antigravity?

On 15 Jun, 22:14, Pat Flannery wrote:
They are going to check up on what the stuff does in regards to a
gravity field:http://space.newscientist.com/articl...antimatter-app...

Pat

Not if General Relativity is true as I believe it to be. We know that
pure energy (light) is affected by gravity in the same way that matter
is. If antimatter were to fall upwards.

a) On an antiworld there would be no symmetry with the photon. The
photon here falls in the same way as an apple. Let me do a gedanken
experiment. Let me produce an anti GPS satellite. Now we know that
time is going faster because the satellite is at a high altitude.
Would we receive the same signals from ani GPS as we do from GPS.
Would an anti GPS satellite SLOW down. It is hard to see how it could,
after all if the radio waves from our anti GPS could be amplified by a
nearby satellite and passed to Earth. Those photons would certainly
speed up.

b) Following on from "a". The "a" paradox be have some quite strong
gravitational potentials if we look at the Universe as a whole. The
positron then would have a different mass to the electron.

http://wiki.answers.com/Q/What_is_th..._of_a_positron

This is not the case.

With the mass being the same I regard the question as settled.
Elementary particle physics is all about symmetry. There is symmetry
with gravity (mass would be different) the asymmetry is in the weak
nuclear force giving small (10^-12) differences in stereoisomer
chemistry.

BTW - If you want to search for life on Europa, all you need is a
laser to look for optical activity. You don't need to drill through
the ice.


- Ian Parker

In sci.space.policy, Fred J. McCall wrote:
Andrew Plotkin wrote:

:In sci.space.policy, Fred J. McCall wrote:
:
: Same here. Given that gravity is merely a bend in the space-time
: curve, there is every reason to expect antimatter to behave
: identically to ordinary particles.
:
:
:Read the article, did you? That's what it says, several times.

No, I didn't need to. I actually took a physics course or two way
back when.

Are you always such an ill-mannered **** or are you making a special
effort for some reason?

The coin came up "heads".

Seriously: I was pointing out a conversational disconnect. Also, I see
you are the sort of person who doubles down on perceived rudeness.

--Z

--
"And Aholibamah bare Jeush, and Jaalam, and Korah: these were the borogoves..."
*
Making a saint out of Reagan is sad. Making an idol out of Nixon ("If the
President does it then it's legal") is contemptible.

Andrew Plotkin wrote:

:In sci.space.policy, Fred J. McCall wrote:
: Andrew Plotkin wrote:
:
: :In sci.space.policy, Fred J. McCall wrote:
: :
: : Same here. Given that gravity is merely a bend in the space-time
: : curve, there is every reason to expect antimatter to behave
: : identically to ordinary particles.
: :
: :
: :Read the article, did you? That's what it says, several times.
:
: No, I didn't need to. I actually took a physics course or two way
: back when.
:
: Are you always such an ill-mannered **** or are you making a special
: effort for some reason?
:
:The coin came up "heads".
:

Time for a new coin? :-)

:
:Seriously: I was pointing out a conversational disconnect. Also, I see
:you are the sort of person who doubles down on perceived rudeness.
:

I've always been a big believer in the Golden Rule (of sorts).

Well, actually more like the Nineteenth Rule of Gunfighting:

19. Decide to be aggressive ENOUGH, quickly ENOUGH.

See what I found (posted elsewhere) that perhaps has led so many of us
to believe this was an already settled question.

--
"They made hypocrite judgments after the fact
But the name of the game is be hit and hit back."

-- "Boom Boom Mancini", Warren Zevon

On Mon, 16 Jun 2008 16:15:13 +0000 (UTC), Andrew Plotkin
wrote:

Are you always such an ill-mannered **** or are you making a special
effort for some reason?

The coin came up "heads".

....Andrew. Fred is a known psychotic troll. Most of us with any sense
killfiled him *years* ago, along with his spouse, Eric Chumpko. Do
yourself and us a favor by doing the same. The less people he has
who'll hear him, the more likely he'll just stick to wife-beating
Chumpko.

OM
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Pat Flannery wrote in
dakotatelephone:



Greg D. Moore (Strider) wrote:

Weird, I could have sworn reading about such experiments in the works
20+ years ago and when they finally occurred, confirmed that
anti-matter behaved in the same way as matter in a gravitional field.


You'd expect it to behave exactly the same, as the electrical charge
reversal shouldn't affect its mass, or how the gravity field affects
that mass.
I also thought that they had worked this out long ago.
Maybe they didn't have enough antimatter to work with, and were basing
a lot of their ideas on theory.
Physics has gotten a lot weirder over the past twenty years, so maybe
they figure its time to recheck things to make sure their assumptions
are still right.
I'm still queasy about CERN getting ready to make quantum black holes
late this summer, in case we don't fully understand them either.

Isn't advanced physics exciting? (loud sucking noise coming from the
hole where Switzerland used to be...)

It'd be nice to know in detail how antimatter reacts to gravity; I'd
think there would be no difference at all, but any difference at all
would be newsworthy and perhaps Nobel-worthy. Especially if it went
sideways at some consistent angle.

So far I think only extremely tiny quantities of antihydrogen have been
created. I have no idea if neutrons can be plugged into antimatter to
help make heavier anti-elements.

--Damon

On Mon, 16 Jun 2008 13:56:41 -0500, Damon Hill
wrote:

So far I think only extremely tiny quantities of antihydrogen have been
created. I have no idea if neutrons can be plugged into antimatter to
help make heavier anti-elements.

....From http://en.wikipedia.org/wiki/Antineutron :

"The antineutron is the antiparticle of the neutron. It was discovered
(in proton-proton collisions in the Bevatron at Berkeley) by Bruce
Cork in 1956, a year after the antiproton was discovered. An
antineutron has the same mass as a neutron, and no net electric
charge. However, it is different from a neutron by being composed of
antiquarks, rather than quarks. In particular, the antineutron
consists of two anti-down quarks and one anti-up quark."

....Which means, of course, that a neutron is still positive matter,
and cannot be substituted for an antineutron, although during the
process of creating antihydrogen an electron is used as a
"placeholder":

http://en.wikipedia.org/wiki/Antimatter#Antihydrogen

....There is a theory that oscillations between the neutron and
antineutron states may occur, but this would play a bit of havoc with
baryon numeration:

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

....Or, to put it another way, yet another imbalance in the already
unbalanced loads between matter and antimatter in the observed
physical universe.


OM
--
]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[

"Damon Hill" wrote in message
...

It'd be nice to know in detail how antimatter reacts to gravity; I'd
think there would be no difference at all, but any difference at all
would be newsworthy and perhaps Nobel-worthy. Especially if it went
sideways at some consistent angle.

So far I think only extremely tiny quantities of antihydrogen have been
created. I have no idea if neutrons can be plugged into antimatter to
help make heavier anti-elements.


Off hand, can't think of any specific reason they couldn't be.


--Damon




--
Greg Moore
SQL Server DBA Consulting Remote and Onsite available!
Email: sql (at) greenms.com http://www.greenms.com/sqlserver.html

Ian Parker wrote:
If antimatter were to fall upwards.

a) On an antiworld there would be no symmetry with the photon.

There would also be no antiworld as gravity is what causes the normal
matter to coalesce into a planet in the first place.
The antimatter atoms would be scattered about in the vacuum of
intergalactic space - trying to stay as far from any gravity source, and
each other, as possible.

Pat

"Pat Flannery" wrote in message
dakotatelephone...
They are going to check up on what the stuff does in regards to a gravity
field:
http://space.newscientist.com/articl...e-fall-up.html

Antimatter is not "opposite matter". It's matter with an opposite electrical
charge. It still has mass. There's no reason to expect antimatter to behave
differently than a similar amount of matter, other than effects due to the
charge.


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