Fictitious Forces

Light is a constant. Relative to light you will be accelerating. I'm pretty sure just because you don't assign a FoR to an object doesn't mean that it isn't going a constant rate.

Erm, I dunno what you're saying, but remember that all reference frames see themselves at rest...no matter what speed they are going at relative to something else...

Erm, I dunno what you're saying, but remember that all reference frames see themselves at rest...no matter what speed they are going at relative to something else...

Ok i've remembered the debate. He said only acceleration affects spacetime, but also your speed relative to another object should bend it. Unless I am completely wrong. The site has been down for days and I can't remember my point. Sorry.

Erm, if its moving at a constant velocity, it can be considered at rest, Raist. No matter what speed its moving at, because from another FOR, it's at rest, whereas another may consider it moving at near light speed. The only thing that all groups detect is acceleration.

Momentum also causes a distortion in spacetime. 

Momentum-energy, you speak of? I forget this part, because it can't bend space time, otherwise we have a master reference frame, which I know did not exist. Unless different IRF's detect different gravitation, which I don't remember...

I'm pretty sure momentum itself doesn't bend spacetime, as no energy is involved there...

EDIT: I just wanted to note that, for the people who were having the same misconception as we were, yes, the relativistic mass is affected by momentum, which is fixed by having different observers note different gravitational pulls. In actuality, this difference is hard to see, because well, we don't deal with relativistic speeds often, now do we.

So I take it you are not a FET then?

You're going off-topic. Now, care to answer my question?

Momentum-energy, you speak of? I forget this part, because it can't bend space time, otherwise we have a master reference frame, which I know did not exist. 

Master reference frame?  All frames of reference are equivalent, but just because you get to claim you are at rest does not mean you are.

I'm pretty sure momentum itself doesn't bend spacetime, as no energy is involved there...

E=pc. 
Where E is energy, p is momentum and c is the speed of light.

Well?

No dissagreement here.

Meh, I don't remember this part, but momentum is simply mass times velocity, so the mass is the thing with the energy. Not the speed itself. And the part about getting to claim rest, what makes your reference frame any better than mine? I am at rest from my POV, and you are moving. I could care less what you think

Meh, I don't remember this part, but momentum is simply mass times velocity, so the mass is the thing with the energy. Not the speed itself.

So...you realize that you were wrong?

And the part about getting to claim rest, what makes your reference frame any better than mine?

Nothing.  But I already said that.

I am at rest from my POV, and you are moving.

Right, but that does not in any way mean you are correct, just that the frames are equivalent.  This should be evident to you now that you have learned that momentum brings with it energy.

On the first part, probably. I'm just qualifying my remarks by noting that I'm not sure about this part.

On the second part, I'm sure. I don't know, maybe we're arguing semantics, but to say that I'm not correct assumes a master reference frame. The way I see it, I am correct, and so are you. I'm at rest, and you are moving, and you are at rest, and I'm moving. To say that my reference frame is wrong implies that there is a correct reference frame. Which doesn't exist...

Then you have just unsolved the Twins Paradox.

On the first part, probably. I'm just qualifying my remarks by noting that I'm not sure about this part.

The famous e=mc^2 equation: Look at the full equation, the one that does not assume an object is at rest.

Then you have just unsolved the Twins Paradox.

No, that one just dealt with the false assumption of IRF's when none existed. There is no such thing as a master reference frame.

No, that one just dealt with the false assumption of IRF's when none existed.

What?  No inertial FORs?

There is no such thing as a master reference frame.

Which is what I have been saying.  I don't know why you feel the need to repeat it.

Which is what I have been saying.  I don't know why you feel the need to repeat it.

So we agree. Glad to see that.

I don't remember ever saying otherwise.  Perhaps you can show me where I did.

Quote from: fshy94 on March 13, 2008, 12:10:53 PM

No, that one just dealt with the false assumption of IRF's when none existed.

What?  No inertial FORs?

Quote

There is no such thing as a master reference frame.

Which is what I have been saying.  I don't know why you feel the need to repeat it.

Well?

Referring to page one, im confused. Are you saying that the earth is constantly accelerating in an upward fashion. If so what is the "force" responsible for this motion? It seems to e that these "fictitious" forces explain such phenomena as pull towards the ground better than your baseless "the earth is accelerating" notion.

In both FET and RET, the Earth's surface is accelerating up. See: general Relativity and its justifications. In RE, it doesn't mean the Earth is expanding; acceleration, being the first derivative of velocity, barely has anything to do with change in position. The accelerating surface exerts an upward force on us, transforming our inertial frame of reference into non-inertial.

Is the earth rotating in FE, or just moving up?

The FE does not rotate.

Since reading the gravity thread I have been thinking about gravity as fictitious force. We can think of gravity as a fictitious force because of the equivalence between inertial mass and gravitational mass. However it is important to note that this is an interpretation available to us because of this equivalence, the equations tell us how we describe something, not necessarily how it really is. Any complete Lagrangian describing the motion of a particle must have a gravitational term in it. Which begs the question can we make gravity fit more in line with the standard model lagrangian of particle physics. In someways this is important because it is the standard model that generates the inertial mass of particles through their Higgs coupling, at least thats what is thought to be the case. So can we do the same for gravity? Yes, gravity can be viewed as a quantum field in the same way as the other fundamental forces, with the graviton its exchange boson. Unfortunately general relativity is not renormalizable (you get infinities in some calculations), to cut a long story short superstring theory is marketed as the most likely solution to the merging of gravity and quantum field theory.

As an aside Kaluza-Klein theory was an attempt go the other way, in some respects, and describe electromagnetism as a geometric theory. For reasons I don't really understand this theory has problems describing fermions (electrons, protons neutrons, other very important things) so has fallen out of vogue. However searches for large extra dimensions are taking place at the large particle colliders.

The question about whether gravity is special is an open one I think. I don't know it will be answerable until a full description of quantum gravity is available I suspect it is in black hole like situations where we will discover it. Though I think it would be tidy if gravity did allow us to couple the objects in the universe to its structure, in my mind there is something elegant about that. Though the bigger question is what any of this has to do with the shape of the Earth, none as far as I can tell. Gravity really dislikes disc shaped objects. End of story (and rant).

Question if an asteroid in space is accelerating due to UA and hits the planet how come it is no longer affected by UA and appears  to be attracted to the planet.

This question has probably been asked before, but if gravitation is caused by mass bending spacetime. Then how come the Earth in the UA theory doesn't exert a gravitational force on to the other plants in the FE theory?

This question has probably been asked before, but if gravitation is caused by mass bending spacetime. Then how come the Earth in the UA theory doesn't exert a gravitational force on to the other plants in the FE theory?

Since the mechanism of gravitation is still unknown, the FE doesn't generate it.  Therefore, with the blessing of Einstein's equivalence principle, the UA was invented as a substitute.

Quote from: hi on March 20, 2009, 01:10:32 AM

This question has probably been asked before, but if gravitation is caused by mass bending spacetime. Then how come the Earth in the UA theory doesn't exert a gravitational force on to the other plants in the FE theory?

Since the mechanism of gravitation is still unknown, the FE doesn't generate it.  Therefore, with the blessing of Einstein's equivalence principle, the UA was invented as a substitute.

Ah I see.

But just because we can't find the mechinism for gravitation doesn't mean it doesn't exist, which is something that really annoys me with the FE'ers on this forum...

But just because we can't find the mechinism for gravitation doesn't mean it doesn't exist, which is something that really annoys me with the FE'ers on this forum...

"Just because you can't see it doesn't mean that it doesn't exist" sounds like someone's lame excuse for the existence of ghosts.