View Full Version : Antigravity


Reiku
01-24-08, 06:52 PM
Time reversal invariance and Antigravitational Forces

A symmetry of the fundamental equations of motion for a system; if it holds, the time reversal of any motion of a system is also a motion of the system. With one exception (KL meson decay), all observations are consistent with time reversal invariance (T invariance).

If a movie is taken of a phenomenon, the corresponding time-reversed motion can be exhibited by running the movie backward. The result is usually strange.

Take for instence a jar with gas. Let us suppose that there is a billion billion billion gas atoms confined. As time passes, the atoms will displace more, and they will become more chaotic. The chances of the atoms (in time) to ever going back into their original placements is astronomical.
However, if the system is sufficiently well observed, the direction of time is not obvious. For instance, a movie which showed the motion of the planets would look just as right run backward or forward. The apparent irreversibility of everyday phenomena results from the combination of imprecise observation and starting from an improbable situation (a state of low entropy, to use the terminology of statistical mechanics). The Cosmological Arrow of Time, ''due to very low entropy'', shows us that if the arrow had been pointing in the oposite direction, due to Hawkings calculations, would have resulted in a universe thriving in antimatter. This reversal property shows us that the arrow of time depends, not on mass, but rather the state and type of mass depended on the arrow.

If time reversal invariance holds, no particle (a physical system with a definite mass and spin) can have an electric dipole moment. A polar body, for example, a water (H2O) molecule, has an electric dipole moment, but its energy and spin eigenstates (which are particles) do not. No particle has been observed to have an electric dipole moment; for instance, the present experimental upper limit on the electric moment of the neutron is approximately 10-25 cm times e, where e is the charge of the proton. Even smaller upper limits have been reported for the electric moment of some nuclei.

The electron however is said to have a magnetic dipole moment. This is because it generates a magnetic field which is mirror-symmetrical to very small current loop that are generated. But as far as i know, the electron's magnetic moment is not due to such a loop, but is rather an intrinsic property... A bit like how spin is an intrinsic property.

If time reversibility holds, then by the CPT theorem CP invariance must hold, that is, invariance of the fundamental equations under the combined operations of charge conjugation C and space inversion P (parity). Conversely, violation of CP invariance implies violation of T (time reversal invariance). In 1964, Croner discovered CP violation. The decay of the long-lived neutral K meson out lived its antiKaon. Though, i would like to state, even though they recieved a Nobel for their discovery, i am not sure it is what it means; afterall, the antiKaon is still the mirror image of its neutral partner is it not? There we will find always very small quantum changes, some we find even in physics, relationships between particles that seem to have quite a few differences, but we can still link them together with counterpart relationships.
From this it was deduced that the interactions which violate CP are very weak and are evident in KL Meson decay only because there are two neutral K-mesons that have practically the same mass and are therefore easily mixed.

But if all of this is correct, then what about Time-Reversed Mass=Antigravity and Antimatter?
Well, we believe that nagitive energy is making the vacuum accelerate. We call this exotic matter, even though there is nothing quite exotic about it. Negative mass would both have anti-gravity as a property, but would also respond negatively to force... Just a little problem we would need to fix i would presume.

It would also have negative energy and tension, and negative quantum wavelength; but I am not sure how that would manifest itself. I have even proposed an anti-inertia. This principle inerests me most. I am not sure why yet.

One possibility I can think of is that if an object of negative mass were to be travelling backwards in time, would it then appear as an object with positive mass to someone travelling in the opposite direction in time? We find similar strange goings on as we pass through the boundary of a black hole. Gravity unravels quantum effects so much, that space and time reverse. And if we where a Tachyon for a moment, making our way past the inner boundaries, we might be lucky enough to catch an antitachyon coming in from a parallel universe...

I have very good reasons to believe that anti-matter is actually matter travelling backwards in time, and if this were the case then maybe it is a requirement for anti-matter to be regarded as having negative mass... What would a time reversed peice of antimatter mean? Would we notice it moving backwards in time? I don't think so... It would be like watching the planets rotate backwards in time. From a laymans perspective, it would still look like the earth was rotating round the sun no matter which direction in time it was moving through.

BenTheMan
01-25-08, 08:31 AM
I have very good reasons to believe that anti-matter is actually matter travelling backwards in time, and if this were the case then maybe it is a requirement for anti-matter to be regarded as having negative mass...

Mass is generated from a Yukawa coupling to the higgs field, and (by the CPT theorem that you described, no less!) the couplings of the particles and the anti-particles are the same.

You can't just pick and choose which bits of quantum theory you like and which you don't.

Reiku
01-25-08, 12:30 PM
I'm not - and i am...

For starters, i do not believe in the Higgs particle, and since it hasn't yet been observed, you yourself are choosing what you like.

If you take an electron-positron creation inside an atom, the positron would rush away from the nuclei and out of the atom. This exhibits very much like antigravitational forces at play.

In fact, it's a bit like Einsteins Elevator Thought-Experiment... You simply couldn't tell whether one is moving up or down. The only reason why the electron stays around the nucleus is because of their attraction with the protons (which are always equal in number). The fact that a positron can be formed and is pushed away, shows similarities to antigravitation - (The force of pulling away from each other).

BenTheMan
01-25-08, 02:06 PM
Now you're mixing gravitational and electromagnetic interactions, which are two distinctly different things.

Reiku
01-25-08, 02:28 PM
Yeh, except we haven't found a graviton or even its waves... so... it just seems very suspect to me. I am saying that perhaps we have this whole idea of gravitation wrong, from such a fundamental point of view.

Gravitation is undeniably a tension of spacetime, and is why a ''thing'' falls into a curved well, or round a swealtered star, but this is caused by what?

The pertinant question i have is why we haven't seen gravitational waves... considering that they should permeate spacetime...

Not only that, but they should be very frequent when it come to black hole collisions. They would ripple spacetime - shudder the very fabric - and yet, alas, we haven't seen any evidence for this.

Just a thought or two.

BenTheMan
01-25-08, 03:26 PM
I am saying that perhaps we have this whole idea of gravitation wrong, from such a fundamental point of view.

Ummm...probably not. Gravitation is a distinct phenomenon and has been experimentally confirmed as so (i.e. neutral objects still attract each other).

The pertinant question i have is why we haven't seen gravitational waves... considering that they should permeate spacetime...

You're about fifteen years too late (http://nobelprize.org/nobel_prizes/physics/laureates/1993/press.html).

Reiku
01-25-08, 03:37 PM
Right... Firstly:

''This change was presumed to occur because the system is emitting energy in the form of gravitational waves in accordance with what Einstein in 1916 predicted should happen to masses moving relatively to each other. According to the latest data, the theoretically calculated value from the relativity theory agrees to within about one half of a percent with the observed value. The first report of this effect was made by Taylor and co-workers at the end of 1978, four years after the discovery of the binary pulsar was reported.''

Is not evidence that we have detected them for sure. It is an evidence that they might exist. I know this, because it was only a few months ago i was reading a scientists column, a string theorist saying precisely, ''We have never seen one.''

''Ummm...probably not. Gravitation is a distinct phenomenon and has been experimentally confirmed as so (i.e. neutral objects still attract each other).''

Neutrality was a concern i had, but like forces attract like forces - just as much as we have some forces that do not... the proton and the positron. They will inexorably push away from each other, and is the closest thing we have to antigravitational-like behaviour. This might not need be a problem.