Antimatter universe?

[Sum0]

Not stricly astronomy, but near enough...

If the universe was mostly anti-matter, as opposed to matter, would we (as in a we composed of antimatter) notice? Would anything be different? Would everything be exactly the same as if the universe was mostly matter? Would I be gnipyt siht sdrawkcab?

[David Hall]

AFAIK, there's really no difference between matter and anti-matter appart from the reversal in polarity. All nuclear and chemical reactions function exactly the same, just in mirror images of each other. Gravity would remain the same as well. So an anti-matter universe should look exactly like our own.

That said, I'm no expert. Perhaps there are some quantum differences in anti-matter. Maybe quarks and such have different spins or "handedness" or something. I don't know. Perhaps someone amongst the know-it-alls here has an answer? [img]/phpBB/images/smiles/icon_smile.gif[/img]

[Silas]

As I recall, the universe displays an asymmetry in certain weak nuclear force effects. So, if we were in an anti-matter universe, some weak force decay events would appear reversed to us.

This was covered by Asimov in one of his (many) essays, so I'll have to start digging for it...

Silas

[mallen]

One difference, of course, would be that we would call antimatter "matter" and matter "antimatter".

<font size=-1>[ This Message was edited by: mallen on 2002-09-11 21:46 ]</font>

[Chuck]

That's good, because a PRINTED ANTIMATTER rubber stamp would cost more than a PRINTED MATTER stamp and my company would be bankrupt.

[David Hall]

The New York Times has this article today. It says CERN has suceeded in creating antimatter hydrogen under testable conditions. So now maybe we'll find out more about how antimatter behaves.

http://www.nytimes.com/2002/09/19/science/19HYDR.html

You'll need to register for it if you haven't done so already. I tried to find another source for the info but nothing came up.

I did however come across this older paper about matter-antimatter asymmetry that seems pretty nifty, though I don't understand everything in it:
http://www-news.uchicago.edu/release...301.ktev.shtml

[David Hall]

On 2002-09-12 10:45, Chuck wrote:

That's good, because a PRINTED ANTIMATTER rubber stamp would cost more than a PRINTED MATTER stamp and my company would be bankrupt.

Just be careful not to use the PRINTED ANTIMATTER stamp on your printed matter. There wouldn't be much of a company left to go bankrupt. [img]/phpBB/images/smiles/icon_lol.gif[/img]

[ILeaTHS]

Here is a link to info that you won't have to register for



http://www.space.com/scienceastronom...en_020918.html</p>

[chris l.]

Just exactly what is anti-matter? Did the term exist before Star Trek?

[Sum0]

The term antimatter did exist before Star Trek (BST?). Antimatter is nothing special. It's like matter, but opposite. Therefore electrons are positive (and known as positrons), protons are negative (I don't know the name for them) and neutrons are still neutral. Scientists have succeeded in creating antimatter, but it's the same as matter except with anti in front of the name.
If you mix antimatter and matter, there's a big explosion and lots of energy, which you can use to power some kind of faster than light drive.

[nayland]

Antimatter is nothing special. It's like matter, but opposite. ... Scientists have succeeded in creating antimatter, but it's the same as matter except with anti in front of the name.
If you mix antimatter and matter, there's a big explosion and lots of energy, which you can use to power some kind of faster than light drive.

is there anti gravity? antimagnetism?
antifusion and anti fission?

If you run fusion and antifusion in the same magnetic/antimagnetic vessel will there still be an explosion ? or nothing?

[traztx]

Here is some general information:
http://hepwww.rl.ac.uk/Pub/Phil/ppintro/ppintro.html

On 2002-09-19 12:53, Sum0 wrote:
Therefore electrons are positive (and known as positrons), protons are negative (I don't know the name for them) and neutrons are still neutral.

I don't know what they are called either. I'd vote for contons [img]/phpBB/images/smiles/icon_smile.gif[/img]

[SeanF]

On 2002-09-19 14:32, traztx wrote:

On 2002-09-19 12:53, Sum0 wrote:
Therefore electrons are positive (and known as positrons), protons are negative (I don't know the name for them) and neutrons are still neutral.

I don't know what they are called either. I'd vote for contons [img]/phpBB/images/smiles/icon_smile.gif[/img]

That's cute. [img]/phpBB/images/smiles/icon_smile.gif[/img] And the opposite of progress is . . . ?

I believe the antimatter protons are simply called antiprotons. Not real original, IMHO.

[JS Princeton]

On 2002-09-19 14:05, nayland wrote:
is there anti gravity? antimagnetism?
antifusion and anti fission?

No.

[mallen]

On 2002-09-19 19:18, JS Princeton wrote:

On 2002-09-19 14:05, nayland wrote:
is there anti gravity? antimagnetism?
antifusion and anti fission?

No.

Antimatter follows the same rules as matter with regards to Electromagnetism. It's just that the anti-particles have the opposite charge from their counterparts.

The rules of gravity are also the same for antimatter. That is all mass (normal and anti-) attracts other mass.

Fission would be anti-Fusion and vice versa. But those are just words that refer to breaking things apart and sticking things together. They are not properties of matter.

Basically, anti-matter is just like matter, except for the difference in charge. Anti-matter is not the opposite of matter, it is more of a mirror image.

[zwi]

I am pretty sure that the CP violations would be the other way around

Matter ( or perhaps antimatter) is left handed ( or pehaps right handed)

On the other hand.........

As a matter of fact (or antimatter of fact) it's the weak force that will tell you your arse from your elbow

Zwi

[beskeptical]

On 2002-09-19 16:12, SeanF wrote:
That's cute. [img]/phpBB/images/smiles/icon_smile.gif[/img] And the opposite of progress is . . . ?

That's good. Did you make that up? [img]/phpBB/images/smiles/icon_lol.gif[/img]

[SeanF]

On 2002-09-24 05:57, beskeptical wrote:

On 2002-09-19 16:12, SeanF wrote:
That's cute. [img]/phpBB/images/smiles/icon_smile.gif[/img] And the opposite of progress is . . . ?

That's good. Did you make that up? [img]/phpBB/images/smiles/icon_lol.gif[/img]

Well, I'd like to take credit for it, but my honesty prevents me from doing so. I heard it somewhere several years ago, but I don't even remember who said it (or wrote it, as the case may be) . . .