Traveling at the speed of light...

[Leapold]

This is a much better analogy. I go west at 200,000,000 m/s. You go east at the same speed. So general relativity tells us you are going 400,000,000 m/s relative to me. But time dilation will slow your clock by 1/4. So one second for me, is .75 seconds for you. Therefor, relative to me, youre going 300,000,000 m/s.

These calculations are not exact. But if they were, this would be fact.
And yes, time dilation is entirely testable. Deriving the equations all by yourself is not very hard at all.
http://www.drphysics.com/syllabus/time/time.html

 

[pullbangdead]

Aha!, I don't have to write anything, here's an answer to your basic premise: http://math.ucr.edu/home/baez/physics/Relativity/SR/velocity.html.

Maybe it's just how you've worded it, but I'm reading your description as having a very different meaning, and the logic coming from a different place, than what the math actually says.

 

[ossumguywill]

BTW, matter can't go at the speed of light because it would require infinite energy. Your mass goes up exponentially as you approach c. As speed approaches c, mass approaches infinity. Therefore the energy required to move is infinite. Perhaps if we discovered a way to get rid of mass, matter could go the speed of light, but that introduces a whole new set of problems. And if you traveled faster than light you would go back in time, which violates quite a few principles.... time is not reversible.

 

[Ash]

BTW, matter can't go at the speed of light because it would require infinite energy. Your mass goes up exponentially as you approach c. As speed approaches c, mass approaches infinity. Therefore the energy required to move is infinite. Perhaps if we discovered a way to get rid of mass, matter could go the speed of light, but that introduces a whole new set of problems. And if you traveled faster than light you would go back in time, which violates quite a few principles.... time is not reversible.

This (mass) concept is something that I have been trying to figure out for a while.
Now, we don't actually have to have an object with zero mass to travel at (or above) the speed of light. That object simply has to "appear" mass-less to the physical universe. How we accomplish that is TBD.
For years I have been convinced that it is possible to appear "without mass" by creating an extremely efficient electro un-magnet [TBD]. This may be achieved by passing large amounts of current through superconductive (solid) Mercury (cooled to <4.2 Kelvin using liquid helium) in a disk-shape around a central core.

Quote about superconductivity and magnetic fields:
"When a superconductor is placed in a weak external magnetic field H, and cooled below its transition temperature, the magnetic field is ejected."

In this case, the object containing the charged superconductive Mercury would appear mass-less in proximity to any magnetic field (due to it's repulsion/ejection of magnetic fields).

Plausible, or a pipe-dream? :tinfoil:

 

[Fonduman]

This (mass) concept is something that I have been trying to figure out for a while.
Now, we don't actually have to have an object with zero mass to travel at (or above) the speed of light. That object simply has to "appear" mass-less to the physical universe. How we accomplish that is TBD.
For years I have been convinced that it is possible to appear "without mass" by creating an extremely efficient electro un-magnet [TBD]. This may be achieved by passing large amounts of current through superconductive (solid) Mercury (cooled to <4.2 Kelvin using liquid helium) in a disk-shape around a central core.

Quote about superconductivity and magnetic fields:
"When a superconductor is placed in a weak external magnetic field H, and cooled below its transition temperature, the magnetic field is ejected."

In this case, the object containing the charged superconductive Mercury would appear mass-less in proximity to any magnetic field (due to it's repulsion/ejection of magnetic fields).

Plausible, or a pipe-dream? :tinfoil:

you would have to keep the magnet attached to it, and thats gonna have mass. unless you can produce a superconductor that provides its own magnetic field. and then the electrons flowing in it might affect it.

 

[Leapold]

@pullbangdead
I'm not sure how you are interpreting what im saying, its very simple.

You add the velocities just like general relativity tells you, and you multiply by '1/1 + uv/c2' depending on whether the objects are moving towards or away from eachother. This basically is using the time dilation formula, just all in one. Notice the '1/1+v^2/c^2'

I have Einstein's book 'Relativity' right next to me, it describes all of the math in great detail.
Youtube also has many simple experiments using a fast train and someone walking on the train.

-----------
I have been talking about two objects moving away from eachother, and their speeds relative to eachother. Not relative to a 3rd person watching them, this was given.
Sorry.

 

[ossumguywill]

@pullbangdead
I'm not sure how you are interpreting what im saying, its very simple.

You add the velocities just like general relativity tells you, and you multiply by '1/1 + uv/c2' depending on whether the objects are moving towards or away from eachother. This basically is using the time dilation formula, just all in one. Notice the '1/1+v^2/c^2'

I have Einstein's book 'Relativity' right next to me, it describes all of the math in great detail.
Youtube also has many simple experiments using a fast train and someone walking on the train.

-----------
I have been talking about two objects moving away from eachother, and their speeds relative to eachother. Not relative to a 3rd person watching them, this was given.
Sorry.

yes, if you have two objects moving away from each other I believe the apparent speed of the other object must be calculated with the relativistic velocities addition formula. That's what you're saying, right?
@ash-yeah, a good trick would be apparently ditching your mass, as I said. I should have been more clear on that lol.

 

[chipdouglas]

BTW, matter can't go at the speed of light because it would require infinite energy. Your mass goes up exponentially as you approach c. As speed approaches c, mass approaches infinity. Therefore the energy required to move is infinite. Perhaps if we discovered a way to get rid of mass, matter could go the speed of light, but that introduces a whole new set of problems. And if you traveled faster than light you would go back in time, which violates quite a few principles.... time is not reversible.

i don't think you would go back in time... as you approch c and keep travelling the world would advance into the future at a normal rate and it would slow to you. depending on how far out you traveled, you would only be 10 years older while returning to an earth that is lets say x years older.


michael

 

[Fonduman]

i don't think you would go back in time... as you approch c and keep travelling the world would advance into the future at a normal rate and it would slow to you. depending on how far out you traveled, you would only be 10 years older while returning to an earth that is lets say x years older.


michael

nope, you're talking about time dilation thats already been mentioned several times here. he's talking about moving faster than c.

there could potentially be lots of particles moving faster than c. how would we know if they were? maybe c isnt as fast as we can go, maybe its just the point at which you stop moving forward in time, in which case it would appear fastest to us since we're moving forward also. i wonder what we would observe if a particle suddenly moved backwards in time. i guess we'd have already seen it lol. maybe all particles only exist through time paradoxes, and everything we see is actually something from the future moving back in time. well, not likely, but perception of reality is a very precarious thing to base fact on.

personally i think its likely that the moving back in time theory is possibly just the maths going a bit wrong when applied to numbers its not meant to be.

 

[chipdouglas]

what is your definition of "going back in time"?

also, i read a great way on how to slow time...

I say we all go to one of the Earth's poles, attach all 22 (twenty two) GTR engines to the pole, affix the mount to the ISS, and then slow the earth so that night lasts for a few days! THEN you can sell these blue laser diodes more easily once everybody realizes that they need light that can reach far in these long nights. Just my 2 cents.

michael

 

[ossumguywill]

Fonduman:I have a theory that W bosons and other momentary particles are moving back in time. I'm not saying I agree with that, but it's a thought. And also moving matter back in time violates energy conservation, entropy and a few others unless you never stop moving IMO. That's how W bosons don't violate the basic rules, they disappear (Or keep on going back in time ) after they break stuff up. However, it's hard to explain why they would be coherent with the standard direction of time for a short period (when they interact with matter). And again, I'm not saying any of this is true just that I pondered the idea.

 

[Moptsp]

Unpossible. With our current understanding of the universe, nothing with mass can travel at or above the speed of light.

Yeah, wouldn't you just gain mass as you "push" forward?

 

[Fonduman]

you mean, gain more mass than infinity?

i wonder if theres some way to jump speed slightly, to bypass the acceleration inbetween

 

[Moptsp]

Wouldn't that be impossible? How can x being the set of reals be greater than infinity if infinity is the set of all reals? xD I'm guessing though that you thought that's just what I meant.

But na, I was taking into account the laws that you can't reach the speed of light and that you were getting "closer" to it. It was in response to the train example. Though he mentioned the trains AT the speed of light, so maybe that's what brought your question. I must have missed that. So I guess I was asking if you were near the speed of light and decided to push your self forward, you would gain mass. Though aren't you always able to go "faster" it's just that the change in your acceleration is just made smaller (closer to infinitely small) every bit so that you never do reach 100%?

i wonder if theres some way to jump speed slightly, to bypass the acceleration inbetween

I think when Michio Kaku was talking about time travel he was saying something about cutting a slit out of time and hopping over. If this is possible, that would be also I think. However; when your talking about reaching the speed of light, you find all these weird things going on, and almost wonder if light has to do with time more than we think. If that's the case, something is telling me that the jump will not work, at least not to exceed the speed of light.

And that annoys me. Here I just said the speed of light, when it almost seems light works with time. And speed is a measurement of change over time. So how can light have a speed if it is part of the inner workings of time? lol I must be thinking weirdly. xD
Though maybe that has some sense in it on how you can't go faster than light as it is the "speed", (quoted for obvious reasons), of time it self?

Ah, but maybe I'm talking crap. :crackup:

 

[Fonduman]

well it must be linked with time somehow: relativity is pretty much defined from the fact that light travels at the same speed in all frames of reference

the lhc experiments could be important in this respect. if theres a particle causing mass then we may find a way to effectively remove an objects mass. although to me it just sounds like they made the particle up to fit things. i know thats a fairly common thing, just the sound of a particle giving another particle what is normaly thought of as an intrinsic property seems a bit far fetched.

 

[Cyparagon]

what is the sound of speed?

More importantly, what is the length of weight, the torque of volume, or the friction of pressure?