About universe, galaxies and antimatter

[kikinho]

I was lately thinking regarding the physical laws about the Universe. What I wanted to know is if the physical laws of other galaxies are identical of the Milky Way, or if the physical laws vary of galaxy for galaxy. Antimatter galaxies exist? If so, perhaps then the antimatter can also form stars and planets, as well as the matter does. And finally, do you think other Universes exist, or the Universe is unique?

[Cham]

kikinho,

the physical laws are the same everywhere, and at everytime, or else they aren't "laws", but "phenomenons". They do not vary from galaxy to galaxy. Laws are the same at any location.

Antimatter galaxies do not exist, apparently, in the observable universe.

Other universes may exist, but there's no proof of that, and it may be just pure metaphysics speculations. However, many modern theories about the creation of the universe state that they may be an infinite number of "parallel" universes, with probably different physical laws in them. Some may have, for example, 6 dimensions (instead of 3 in ours), or 51 dimensions, or any other number actually. In some of them, the fundamental constants (light speed, Planck constant, fine structure constant, cosmological constant, gravitational constant) may have other values too. We just don't know yet.

Personaly, I strongly suspect those parallel universes DO exist. Ours is just a tiny universe (!) lost in an infinite set of possibilities. Our universe isn't unique.

The real "Multivers" is looking a bit like soap foam. Each bubble is an entire universe, with its own laws, fundamental constants, space-time dimensions and topology, etc. It's about thermodynamics, really.

[rthorvald]

do you think other Universes exist, or the Universe is unique?

Well, according to Matt Groenig, other universes do exist. Only one more, though, and it is 100% identical to our own - down to the last detail - exept that everybody there is wearing cowboy hats.

rthorvald

[t00fri]

I was lately thinking regarding the physical laws about the Universe. What I wanted to know is if the physical laws of other galaxies are identical of the Milky Way, or if the physical laws vary of galaxy for galaxy. Antimatter galaxies exist? If so, perhaps then the antimatter can also form stars and planets, as well as the matter does. And finally, do you think other Universes exist, or the Universe is unique?

I think it would be a great challenge for a talented young artist like yourself to design an /ANTI-matter/ galaxy.

There is an even more challenging task for you , however:

Try to design a galaxy that entirely consists of DARK MATTER!!! That means it is totally invisible for visual observations.

I have reported recently about the spectacular and quite convincing recent discovery of such a DARK-MATTER galaxy here:

http://www.shatters.net/forum/viewtopic.php?t=7235

Waiting impatiently for your inspiring results,

Bye Fridger

[ElChristou]

... exept that everybody there is wearing cowboy hats....

[ajtribick]

Who says the physics of other universes will lead to anything which can even vaguely be described as matter or antimatter anyway?

If we restrict ourselves to universes which have laws of physics similar to our own, then it seems that antimatter universes are ruled out because of slight asymmetries between the properties of matter and antimatter which makes antimatter slightly less stable, and that is enough to tip the balance in favour of matter.

Hmmmm... a dark matter galaxy, that's where I left my cowboy hat... I really liked the press releases associated with the dark matter galaxy, given that you couldn't tell whether that was actually the location of the galaxy in question, or they'd just slapped an ellipse on a random starfield...

[t00fri]

Who says the physics of other universes will lead to anything which can even vaguely be described as matter or antimatter anyway?

If we restrict ourselves to universes which have laws of physics similar to our own, then it seems that antimatter universes are ruled out because of slight asymmetries between the properties of matter and antimatter which makes antimatter slightly less stable, and that is enough to tip the balance in favour of matter.

Hmmmm... a dark matter galaxy, that's where I left my cowboy hat... I really liked the press releases associated with the dark matter galaxy, given that you couldn't tell whether that was actually the location of the galaxy in question, or they'd just slapped an ellipse on a random starfield...

A microscopic explanation of the huge observed Matter-Antimatter asymmetry in the Universe, is one of the greatest challenges in particle-cosmology besides explainig Dark Energy and Dark Matter.

Let me just state that there are /three/ prerequisites that have to be met in order that such an asymmetry can arise:

At the early time after the BB when the matter-antimatter
asymmetry built up,

a) Baryon number conservation must have been violated
b) The Universe must have been out-of thermal equilibrium
c) The discrete symmetry of time-reversal invariance must have been violated

For particle physicists trying to explain the matter-antimatter asymmetry there is the challenge to construct scenarios where the requirements a)-c) are true, naturally.

In the framework of so-called GUTS (Grand-Unified Theories) a) holds automatically, but b) and c) requires more creativity...

Bye Fridger

[kikinho]

If we suppose an universe made only with antimatter, may stars and planets could form, because such universe wouldn't have the presence of matter. So astronomers that live in this universe will think that their antimatter is normal to occur and that is more stable than matter.
I don't believe antimatter is less stable than matter only because the eletrical charges are inverted. I think matter may have some particle that antimatter don't have, to be more stable.
I read an interesting book, and part of this book have a woman told that her father created antimatter using the particle accelerator with about 27km diameter, and put the antimatter inside a small tube that have a dispositive that protect antimatter from matter with an eletrical magnectic field. If this dispositive is turned off, the antimatter will stop floating in the vaccum and will drop, hitting matter and causing a big explosion that emit gamma rays and raise to high temperatures, vaporizing all things near the explosion. But this father created this antimatter to try to prove to the Catolic Church and scientists that some part of the Bible is possible to happen, the Genesis book, and to finish with the comfront between them. What he really wanted was to mix science with religion.
So because of this book that I posted here.