Crazy Theory From A Non-(any Kind) Physicist.

I'm not going to pretend that I understand all aspects of physics; after all, I chose a BBA. But something sparked my brain after seeing Paranormal Activity tonight (unrelated to the crappy film). I'm actually needing some clarification from some of you theoretical and astrophysicist (and those aspiring to be); so please bear with my incompetence on this massive matter and flood of information.

Gravitation has the ability to bend light and other transverse waves, and we can look at matter as energy (thanks to Einstein). But what fascinated me was the ability for particles or EM waves to move faster than the speed of light.

Then I read that for FTL particles to exist, they would have to had existed and moved faster than light from the beginning, with no chance of slowing down, and also have infinite energy.

So my brain started to think about gravitation. What if we looked at gravitation as a particle that moves faster than light? If the particle is moving faster than light, then whatever trail the gravitation particle left, the light would be forced to follow it. This would allow for the light to be bent or moved by the gravitational force. The concept would be similar to how water running through a creek would be forced to follow the creek's path.

We look at gravitation as an effect for shaping space time, but what if gravitation was a particle that is space time?

It's midnight in the CST so my brain could just be in the fritz, but I wanted to know why this theory is wrong.

Thanks,

Yeshua

1. Tachyons (particles which travel faster than light) are highly theoretical and controversial at best. In most cases, if a theory predicts tachyons, it's broken.
2. EM radiation never moves faster than the speed of light.
3. Gravitation moves through space at the speed of light, this has been experimentally verified.
4. Assuming a tachyon exists, there is no reason to think that light would be forced to follow it's trail.
5. Even if light was forced to follow in the trail of a tachyon, it would not explain gravitation, as the trajectories of gravitons would not match those of light being bent by the gravity.

There's 5 reasons off the top of my head.

Try to make sure your next post isn't pushing some crank theory.

This post has been edited by MjolnirPants on Oct 17 2009, 05:31 AM

For 3 are you referring to the Kopeikin and Formalont experiment?

This post has been edited by brucep on Oct 19 2009, 07:38 AM

If he was referring to a single experiment, that would not necessarily rise to the level of a factual claim. He is most likely referring to the total history of experiments which validate GR.

Close binary neutron stars are a good laboratory for measuring this.
http://math.ucr.edu/home/baez/physics/Rela...grav_speed.html

I was interested in the Kopeikin experiment and was disappointed there was such controversy wrt what was actually being measured. Following this experiment an amateur, such as myself, could come to understand how important consensus is for validating scientific literature. I mean consensus among accredited experts. Such consensus leads to a form of objective truth. You can always tell who is actually interested in science by their level of interest in the scientific literature. Cranks completely ignore the scientific literature.

There's no reason to suspect tachyons exist. The tachyon is a mathematical possibility, not necessarily a physical possibility. Inverses are sometimes mathematically valid solutions to a problem:

• black hole vs white hole
• energy vs negative energy
• mass vs negative mass
• etc

It doesn't necessarily mean that any of these actually can exist. The tachyon is like the opposite of a normal, subluminal particle.

Not exactly. You know how, for a normal particle, the faster it's going, the more energy is required to accelerate it even faster? And if it were to be accelerated up to the speed of light, it would require infinite energy (and therefore, since there is no such thing as infinite energy, it could never be accelerated up to the speed of light)?

Well, a tachyon is just like that, except reverse. It's a particle that, at it's lowest energy is traveling at infinite speed (is everywhere in the universe at once), and requires more and more energy as it slows. To slow it down to the speed of light would require infinite energy so it will never be able to slow down that much.

Though we're moving into the realm of some pretty hardcore mathematical concepts it's interesting to note that such things as vacuum expectation values giving rise to spontaneous symmetry breaking (aka Higgs mechanism) can be viewed in terms of tachyons. They are 'tachyon condensates' and despite being defined in terms of faster than light signals there is no failure of causliity as the system conspires to prevent information moving faster than light.

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

As Wiki says, they also turn up in the context of D-branes in string theory but the specifics are pants wettingly complicated and whenever a colleague and I have been browsiing ArXiV and come across something related to such notions our eyes glaze over.

rpenner

There is a very easy solution to the reference you gave. Gravity could be a stationary field (like a magnetic field) that is affected from the outside inward at the speed of light. The outside portion of the field is affected first so Newton and relativity are preserved.

[Moderator: Lies.]

This post has been edited by rpenner on Oct 19 2009, 05:51 PM

In fact, I was. Thank you.

I'm familiar (on the level of familiarity any non-mathematically proficient layman can be, which doesn't go much beyond "it's a concept in string theory which is way over my head") with the concept of tachyon condensates. That's why I didn't deny their existence outright. It's my understanding that the concept of tachyon condensation is one which allows the prediction of tachyons in a theory to be expressed in terms of particles with a positive mass quared, removing the need for actual physical tachyons. On that note, anything more you have to say on the matter would be quite interesting.

No, the easy explaination is that its invisible fairies pushing around pixie dust in just the right way that it looks like relativity but isn't.

See, I can come up with a vacuous BS explaiantion too. The fact I didn't bother to use any buzzwords or try to make it vaguely believable doesn't mean your 'siimple explaination' is any more valid. If its so simple then can I assume you have a working quantitative model?

I would imagine not....

AN,

The invisible fairies are the tachyons right.

Since gravity has its affect at a distance first what is your conclusion?

[Moderator: Everyone is welcome to reply, of course, but consider answering at length, since this poster has been suspended 10 days for being unreasonably obstinate in ignorance.]

This post has been edited by rpenner on Oct 20 2009, 02:11 AM

I don't want to play Devil's Advocate, but this isn't 100% true. Although the group velocity of an EM wave will remain at c, the individual phase velocities within the group velocity can exceed c, at least in a mathematical sense. I remember this distinctly in my EM class because it sounded so bizzare...

But neither the power nor the signal moves faster than c.

Indeed, you can even get the phase velocities to be negative.

Exactly, so long as the group velocity remains at c, you can even have wacky negative phase velocities. It's one of those "W T F" concepts for me...

This post has been edited by mmax on Oct 20 2009, 05:41 PM

It's over a year old but its new to me.

Wikipedia placed a new animated gif up comparing the two:

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