Another light speed problem

Incredible speeds? Yes. But it'd just be faster to have one ship have a larger fuel source. This is the whole concept behind the xenon engines. Whilst they don't have much push, the acceleration IS constant, and will last for a long time - which makes it in the end go faster.

The only problem with most ships is that they don't have the fuel capacity - and even if they did, stocking them with enough fuel would be pointless.

That, and you could achieve incredible speeds, but you still wouldn't hit light (even though every time you got closer to it, you wouldn't slow down, it's that your acceleration would be less from an outside observer).

And Viendin, your very right. I don't normally go into how you would percieve time to change and all that. Though there's a fun example for that as well.

I'd like to see the way in which you answer this. Imagine that the speed of light is 2m/s. You can walk at 1m/s, and there is a conveyor belt that moves at 1m/s. Whilst we both know that you can't travel at or past the speed of light (2m/s), what would be percieved by the travellar, and what would be percieved by outside observers, when the travellar walks on the conveyor belt in the same direction it is moving?

Exactly the same thing would happen as if there were a conveyer belt that moved .5*299,792,458m/s and I could walk that speed.

I would observe the conveyor belt to not be moving in my frame. I would then move at 1m/s forward, perfectly within physical limits of space and time. I would not notice anything out of the ordinary, unless I was simultaneously measuring the world around me, because it could appear that the whole world would slide together along the vector of the direction of my travel. It wouldn't slide right together, just become more .. erm, "densely packed".

Someone from off at the side would undoubtably observe you moving very fast, by their terms. They would see you, albeit, a more 'densely packed' you, moving along the conveyor belt at .. this is where it gets hazy for me, if you were actually moving at 2m/s then they would just 'see' a beam of light, in all likeliness, but, if you were moving 1.9999999m/s, then they would likely see you moving very, very fast.

The problem is, I'm no expert on this. I've just got a slightly above-average understanding of it from .. well, the masses. I can't really give definitive answers to anyone but them.

I don't really know anything about General Relativity, and that covers acceleration. I feel that I'd need to know it to properly answer this.

Sorry!

Well you may not, by your own standards (though I doubt by other's), get General Relativity - but you got your Special Relativity down pat!

Yeah, people would see you going almost, but not quite, 2m/s - and in fact would see you as if time had slightly slowed down for you. Alternatively, you would see yourself going at 1m/s, but (assuming you can see around you), you would see everyone else moving at a bit faster pace than they should.

The real deal is that you would also see them slowing down (if we count that you're travelling at almost, but not quite, the speed of light, and so can't really see well around you) - but that once you get off the conveyor belt, they would very quickly "snap" back to where they actually are (as the light catches up to you), whilst people ahead of you suddenly go from seemingly moving very fast (since the light from them reached you sooner), to slowing down (since light is now once again coming at you at a normal pace).

Ah, physics.

That sounds like a multistage rocket. It has been done before, but not to reach incredible speeds, just to maintain a near constant speed for a certain a certain amount of time.

You have any source for this? This would highly surprise me. What I have heard of are neutrinos expected to arrive before photons in the event of a supernova, because neutrinos have almost no interaction with matter and hence leave the core of the collapsing star immediately, while electromagnetic waves are absorbed and reemitted meaning that the speed in the star itself is lower than the speed in vacuum. This hasn't been measured yet though. Another possibility is that neutrons are formed before noticable (visible or otherwise) radiation is emitted, not that neutrons are actually faster than light.

[edit on 4-2-2006 by Simon666]

You can't travel at the speed of light itself. But say indeed you'd hypothetically be travelling closer and closer to it. What would happen then is that your field of view would be narrowing, objects to your side would seemingly be more towards the direction in which you're travelling. Objects in front of you would also appear blue shifted. For an interesting site explaining this, try below or just google.

math.ucr.edu...

Wiki says, 'Autodynamics and VSL.'
"Are there any other constants which are disputed as being so?"
'Yes, Fine-structure

If you were in a spaceship travelling at near lightspeed and shone a light beam in your direction of travel, you would notice nothing at all different about the light.
If a stationary observer (not on the ship) saw this, he too would measure the speed of your beam at lightspeed.
The speed of light is always the same, independant of the reference frame of the observer.

Harte

Great Thread! Always a question that sat at the back of my head, what would it look like travelling the high velocities seen in science fiction for years, there is an OpenGL program out there that simulates lightspeed, you guys maybe interested in that, here is the link

LightSpeed OpenGL

The problem isn't seeing whats in front of you, the light we see on earth has been traveling for a long time to reach us too, the objects ahead of you have been reflecting light a long time before you happen upon them too, so there will be "old" light coming from them.

The problem is knowing exactly where you are and being able to callculate your relative position to whats ahead taking all things into account.

The real question about lightspeed travel that remains imho, is that, when you travel at the speed of light (which would require infinite energy and give you infinite mass), and you impact photons coming at you at the speed of light, won't the energy with which they impact your ship be infinite too?

Lightspeed travel is something we should waste time on, there are to many infinites wreaking havoc on us when we do.

Warp, hyperspace, subspace and wormhole travel are the only things we should look at, actual light speed travel is a waste of time.

Btw, did you know that theoretically, with warp travel, your actually standing still?

Fascinating, i must admit subluminal theory has always went over my head, i do not think i have the mind for it, could you explain the standing still warp theory, if you don't mind.

With warp travel you create a space/time bubble around your vessel and motion is obtained by manipulating its shape and density. Inside the bubble things don't move, its the space/time bubble you created, in which you are contained, that moves trough space.

You obtain motion by making space time more dense on one end and less dense on the other, warping the fabric of space/time (hence the name warp travel)

The inside of the bubble stands still because you could consider it a separate pocket of space/time, decoupled from the universal space/time.

Have you ever seen a bubble of water float on a pool of water? This usually happens in the bathtub when there is soap to create a film around the bubble which keeps it afloat for a while. Thats kinda how you separate yourself from the universal space/time when creating a warp bubble.

Hope that explains it, else I'll try to have another go trying to put the science behind this in non scientific words. (something I suck at :p)

No it's all good i got the general just of it, it all sounds horribly complicated mind you

reply to post by Yarium

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The MIchaelson Morley experiment did not disprove the existence of the ether per se. They got a null result which basically said that they could not detect an ether in their set up within experimental error.

What many people don't know is that there were a series of follow ups to this experiment performed by Dayton Miller that did seem to show the existence of an ether. Dayton speculated that the ether may be dragged through space by a large body like the earth and therefore one should do your experiments ideally in space or at least on a tall mountain.

He chose a tall mountain and got a positive result. The Michaelson Morley experiment was done in a basement with equipment not as sensitive as Miller's. However by then Einstein's theories were widely accepted and Miller's results were viciously suppressed. That's how science is done folks, it's politics and consensus. You have to have hardware flying in the academics face before he'll accept it. Remember Scientific American posted a hit piece on the Wright brothers saying heavier than air flight was scientifically impossible, even after the Kitty Hawk demonstration.

www.orgonelab.org...

reply to post by Viendin

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This is just to say that I thought your first post in this thread was excellent. You have my admiration, and a star for the post. Your physics was correct, your explanation would have put many of my old lecturers to shame and the speculation was pretty much on the nail, too -- in my opinion.

And I love your signature.