Antimatter

[Xplorer877]

Yes to be On Topic Antimatter behaves no differently the normal matter in relation to gravity.

Yeah I agree.
I believe gravity only attracts, like the nuclear forces (the forces that hold protons and neutrons together in the nucleus of an atom).

Electromagnetism is a polarized force, so is can do both.

Bit off topic again but, it would be neat if we could somehow create a gravitational field opposite to that of Earths gravity. Perhaps the two fields would cancel out and all matter in the vicinity would be essentially weightless. You'd no longer need energy to levitate something.

I've thought about that ever since I was a kid. A helicopter has to burn gas to stay aloft, yet a table can hold something off the ground without power. According to the laws of physics you technically wouldn't need "power" to counteract the force of gravity and levitate something. I've built a magnetic levitater that floats a small magnet with out power or batteries of any kind.

I'll get a pic:

If it works for this little magnet, there is no reason it can work to make flying cars and such. The possibilities of powerless weightlessness would be immense!

-Tony

 

[millirad]

Kewl! I used to have one of those globes that floated between two electromagnetic poles, with active circuitry that adjusted the Gauss strength on the fly.

 

[Benm]

Why would gravity only attract?

The newtonian equations for gravity work well on objects of any significant size, and would also be perfectly applicable to an object made out of antimatter (like a marble etc).

Since the equation is

F = G * (M1 * M2) / r^2

it is obvious the force would be negative if one of the masses is positive and the other is negative. It confirms that two positive masses attract, and also that to negative masses would attract eachother.

It gets even more bizarre though: an object with negative mass would respond to a force inversely to what we are used to. For that reason an object with negative mass but positive charge, would be attracted to other postive charged and repelled negative ones.

This is all mathematically fine, but objects of negative mass simply do not exist.

 

[Xplorer877]

an object with negative mass but positive charge, would be attracted to other postive charged and repelled negative ones.

How do you figure that?
The polarity of the mass should affect only the gravitational forces, but it shouldn't affect the electromagnetic forces between them. Also black holes absorb antimatter, so either antimatter's mass is positive, which I don't see how it could be without violating E=mc^2, or somehow gravity still attracts negative mass.

If antimatter and regular matter repelled each other gravitationally then that may imply the existence of antimatter black holes, which would repel regular black holes.

Holy s#&t, imagine a collision between a black hole and a antimatter black hole. All of that mass converted completely into energy... That would be far larger than any Super Nova. :evil:

If the Higgs feild is polarized that would open a whole nother door... but I believe they don't think the Higgs Boson can have an anti counterpart.

Meh, who really knows... much of this is unknown by cosmologists.

-Tony

 

[magonegro]

If antimatter and regular matter repelled each other gravitationally then that may imply the existence of antimatter black holes, which would repel regular black holes.

Holy s#&t, imagine a collision between a black hole and a antimatter black hole. All of that mass converted completely into energy... That would be far larger than any Super Nova. :evil:
-Tony

If a negative mass antimatter black hole exist, it will never collide with a regular matter blackhole because they are repelled by each other. There are no things like an antimatter star, trust me. Think this way, at the beginnings of the universe all matter & antimatter were created, very close one to each other so they can combine in radiation, at this time there couldn't be remanents such large of antimatter. But for some reason the matter have won the fight against antimatter. Maybe the universe had from the start more matter than antimatter? or simply antimatter is a less stable state of the matter. I bet second.

So we have never seen massive stars repelling, nor signals traveling faster than the speed of light, nor white holes, nor monopoles :yabbem:

 

[Xplorer877]

I think the universe does exists because of that imbalance. I've never read about antiblack holes though. Huh, you'd think all of the antimatter would have been destroyed by now. Gravity is still a weak force, I can't comprehend how a large collection of antimatter can exist in such a large region of regular matter.

BTY, this explanation does claim there are particles that have negative mass.


-Tony

 

[chipdouglas]

sorry for the going slightly off topic... but magnetism was brought up... do you think they will ever invent a 1pole magnet...meaning it is only a north pole or south pole magnet?

michael

 

[Coherent Light]

Why would gravity only attract?

Gravity might be independent of the other forces, and not be affected by Them. What accounts for Matter and Antimatter collisions if they don't act like negative and positive charges other than Gravity?

 

[Benm]

How do you figure that?
The polarity of the mass should affect only the gravitational forces, but it shouldn't affect the electromagnetic forces between them.

That is exactly what makes it weird:

A negatively charged object is attracted to a positive charged one with a force that depends on the charges and distance between them. Lets just call that F for now, is size is not important.

The resulting acceleration is given by:

F = m * a or better stated:
a = F/m

Clearly if m is negative, so is a.

If antimatter and regular matter repelled each other gravitationally then that may imply the existence of antimatter black holes, which would repel regular black holes.

Antimatter has positive mass, so that doesnt work.

If you had matter with negative mass, you could have a black hole with negative mass too, and that would indeed repel positive mass. A black hole has only 3 properties: mass, charge and angular momentum.

The charge can be negative or positive, and angular momentum could be considered positive or negative (clockwise or anticlockwise)... i don't see any mathematical reason the mass could not be negative, the practicle problem is that matter with negative mass isn't around - at least not long enough for any practical application or even study.

 

[magonegro]

Monopoles are one of the things that the LHC could clarify. See this: In search of the magnetic monopole: Large Hadron Collider experiment could rewrite laws of physics

Regarding Hawking's radiation, it could also be considered a quantum tunnel effect, and this way no exotic explanations for negative mass/virtual particles are required. I don't mean scientists are wrong, just want to say that when scientists try to explain a very complicated issue to a non-expert they tend to simplify their speech too much. A complicated theory can be condensed in a simple & elegant speech, the inverse is not possible. So, don't take to the letter all you hear, specially when we are talking about unconfirmed theories; just brainstorming...

 

[HIMNL9]

Gravity is a direct product of mass, so it can be negative only if the mass is negative (and as far as i know, we can produce antimatter, but we are still unable to produce a negative mass particle ..... )

 

[Coherent Light]

If You could make a suit of negative mass particles..YOU COULD FLY!!!!

 

[HIMNL9]

If You could make a suit of negative mass particles..YOU COULD FLY!!!!

At the condition that it's negative mass, but not antimatter .....

..... well, being precise, you can fly also if it's antimatter, but probably not in a way that you like too much (see the above KABOOM )

:crackup: :crackup: :crackup: :crackup: :crackup:

 

[Benm]

Regarding Hawking's radiation, it could also be considered a quantum tunnel effect, and this way no exotic explanations for negative mass/virtual particles are required. I don't mean scientists are wrong, just want to say that when scientists try to explain a very complicated issue to a non-expert they tend to simplify their speech too much.

Indeed, when you over-simplify something, the results become very counter-intuitive.

The concept that a pair of particles sponatnously forms near the event horizon, with one having positive mass, and the other negative, is clearly a bad explanation for hawking radiation. The main problem is that in this model the black hole attracts the positive mass particle, and repels the negative mass particle. If this were so, black holes would emit particles with negative mass from the even horizon - clearly not the case.

Anyway, antimatter as it it commonly described has positive mass. We know particles like positrons and anti-protons to exist. They have positive mass, but opposite charge to their 'normal' counterparts (electrons and protons). They behave like normal particles too, forming anti-hydrogen atoms and even molecules.

What is called matter and what is called antimatter is entirely arbitrary - its just convenient to call the rare stuff antimatter and the common stuff matter, but there is nothing that suggests it is impossible to have a universe that is made of mostly antimatter.

 

[Coherent Light]

@HIMNL9:

I prefer to keep my molecular cohesion when I fly, And would not be interested in having My atoms fly in multiple directions. The KaBoom Field Effect is overrated if You ask Me.

 

[magonegro]

Indeed, when you over-simplify something, the results become very counter-intuitive.

The concept that a pair of particles sponatnously forms near the event horizon, with one having positive mass, and the other negative, is clearly a bad explanation for hawking radiation. The main problem is that in this model the black hole attracts the positive mass particle, and repels the negative mass particle. If this were so, black holes would emit particles with negative mass from the even horizon - clearly not the case.

Totally agree. Also keep in mind that this particles could also be photons, and photons antiparticle is itself. So, no antimatter involved this way. Besides this we are forgetting an important thing, TIME. If this particles were real, due to the time dilation in the event horizon from what moment of the past they could come? Also remember the red-shift would be extreme, making this photons a very very low energy ones. Virtual pairs are lent to the universe for just a little time, and the time is inversely proportional to the energy lent. Taking in consideration the Plack's distance, it should be a limit on the energy of photons emerging from the event horizon. Photons travel at the speed of light, but if this particles had mass... not probable to see much of them escaping the event horizon... Expect only low energy photons from the past.