Nope

You can't travel faster than the speed of light.

In theory you might be able to if you didn't accelerate to the speed...
But that i also impossible...

The speed of light is based on the movement of the atoms. It has been measured in the last fe hundred years to be slowing down. The reason why you can't detect the slowing down with today's atomic clocks is because the atomic clock also work on the movements of the atoms. Hence you have a bent ruler problem.

Would you be able to see your headlights? No, because you would be traveling faster than what the light can propagate.

Ignoring the fact that time dialation means time stops for anyone moving at the speed of light and that E=MC^2 means that at the speed of light, you become pure energy, and finally assuming that Einstein was right nd the speed of light is a constant, not related to the movement of it's source, to the traveller in the vehicle, forward and reward facing lights inside and outside the vessel would cease to produce visible emissions as the light would never leave the source, but would dissipate at the source or they would leave so quickly in the opposite direction as to stretch into the invisible side of the infrared spectrum. And other lights would become streaks towards the rear of the vessel with appropriate amounts of ultraviolet or infrared doppler applied to them.

why would you turn your headlights on?

What was before the big bang?/What is outside of the universe?
What do you find at the end of a rainbow?
If you could divide by zero what would 20/0 be?/What if the value of pi was different?

What ifs about situations that dont make sense just can't be answered, in the same way "what is the shape of peace" cant be answered. This is different to what ifs like "what if you were king of the world?"/"what if hitler died young?"
It's not that we don't answer because it couldn't happen and so dont think it's worth considering, but because they just don't make sense

Om, Kestas, you can divide by zero. You just can't divide zero by zero. But all other divisions by zero are infinity.

And the hypothetical question regarding FTL travel may not be impossible. We just haven't the means to do it yet.

Positive infinity or negative infinity? Why?

It's oddly related really, because going at the speed of light being impossible in physics is easiest to explain by showing how it means dividing by zero. Then to go further than that I guess you have to think divide by zero gives a meaningful answer, or say physical theory is wrong (and then probably start making vague statements from New Scientist about the latest anti-gravity device that some lab is developing, damn you New Scientist)

Draugner: Not true. Consider:
infinity = 1/0 = 1/(-0) = - 1/0 = - infinity
doesn't make any sense, for example.
see also: http://en.wikipedia.org/wiki/Division_by_zero

I hope you don't trust everything out of wikipedia. When I was in school (granted 25 odd years ago), 0/0 was indeterminate (or undefined if you like) and any non-zero number divided by zero was infinity, either negative or positive depending on the sign of the non-zero number. This was done by showing that, as the denominator approached zero, the result approached infinity, ergo 100/0 is infinity.

But, I'm just a software developer who avoids division by zero like the plague. Computers don't handle irrational or undefined numbers very well for obvious reasons.

Of course you can say 1/x -> infinity for x->0. But you can't say 1/x = infinity and treat infinity as a number (as you see above: otherwise -infinty would be the same as +infinity).

Actually, that is one of the views I believe. -infinity = +infinity. I believe our universe is rounded on the additional dimensions and that, in theory, if you traveled to infinty (and beyond!, sorry Toy Story & TS 2 is in 3 in the theaters right now) you would wrap back to your point of origin.

Draugnar: sin(x)/x approaches 1 as x gets closer to 0, but you wouldnt say sin(0)/0 is 1 because of that

chs42: technically lim[x->0](1/x) doesnt exist, because it is infinity if you approach from 1 but -infinity if you approach from -1, but I'm nitpicking

@ Draugnar: I'm sorry, but either you have a bad recolection or you had a bad professor.

Yes, it is usually stated that n/x -> infty as x -> 0, but the actual operation 1/0 is undefined, as infty is not a number in most mathematical structures.

Riemman's Sphere is the only exception to that.

I think we should slow the speed of light down a little so that we can understand it. I need everyone to start asking everyone they know to close their eyes at GMT midnight on the 27th January 2010. If my calculations are correct and everyone on here tells all their friends and all their friends tell their etc, everyone in the world should know to close their eyes on the 27th January 2010. Why am I asking you all to do this? Well as you all know light is being emitted from everything around us (literally at the speed of light) and this light is being detected by our eyes and converted/translated by the elcetrical imulses in our brains into images. However, if we all closed our eyes the the light just wouldn't have a purpose for zooming around so quickly, it may take a break, ease up a little, maybe even take a short holiday. And that is when we would catch it unawares, at 10 past midnight we could all open our eyes and catch light dauddling a little, and observe it before it had time to get back up to speed. Then we might understand it just a little bit more.

If you think this is far fetched think back to this morning when you first opened your eyes, was everything just a little blurred and hazy? That was light just taking a little break, it didn't take long to get back up to speed and I imagine it is now racing round at 'c' as we speak/type.

We would also have to switch of all CCTV cameras and the like for just ten minutes. I'm sure no one would take advantage of this little science experiment to rob a bank or anything.

Sorry, that I know of.

This was high school. Only have an Associates in Comp Sci. The most advanced mathematics I took was Calc 1 and the Calc A/B test out exam in high school. So, much of my mathematical knowledge is simplified and I don't claim to be an expert. I can write code to do any equation you want, but don't ask me to understand why a given equation works. I've written Gaussian theory code, but I don't necessarily understand Gaussian theory, just how to process the data and iterate it into the equation.

If you traveled in one direction forever you would wrap around, but thats just because of the shape of our universe. (And this isn't really "travelling to infinity", which doesnt make sense)

But this is approaching something where your use of "infinity" is the same as my use of "makes no sense", and it's an argument about words

Isn't this an old Stephen Wright bit anyway?

" This was high school. Only have an Associates in Comp Sci. The most advanced mathematics I took was Calc 1 and the Calc A/B test out exam in high school. So, much of my mathematical knowledge is simplified and I don't claim to be an expert. "

Good. Then please accept the fact that you have been corrected by people who do know more than you about this particular matter. You are, obviously, allowed to go around thinking that 1/0 = infty, but if you post it again, someone will go there again, to correct your mistake again, and it really is no fun.

Ok, so an irrational and unexpressable number makes no sense. Yep, I'd agree with that. But back to the speed of light travelling issue. It isn't breaking the laws of physics to travel at or beyond lightspeed. It is only breaking the laws of physics as we understand them. Given time, we might find other laws that take precedence over the current set and allow them to be altered.

That is true, in a way.

However, if you studied the History of physics theory, you'd see that usually, the laws stated by the great minds (Newton to here, mostly) were a subset of the laws found by their succesors (IE: Einstein, Schrodinger, etc.).

So, even when it is certain that there are many things we don't know, it is most likely that that wich we do know is still contained in the laws that we don't know.

This means that it is most likely impossible to reach the speed of light through normal acceleration. Wheather or not we may find another way to move that is different from F = m * a remains to be seen, but I get the feeling that if we do, the OP's question will become irrelevant.

@Xapi - no problem. That's why I laid out the details of my limited knowledge. Being educated by the likes of the folks here in things where my education still lacks is a good thing. It's how I (and I hope others) learn. That's one reason to have these discussions. Now I know that ANY number divided by zero is undefined, not just 0/0.

True. even SciFi doesn't propose normal acceleration (well, except for Trek's using the sun to exceed the speed of light and go back in time) for FTL travel. Most use hyperspace or warp drives or (my favorite) folding space (Dune!).

In Futurama, the entire Universe is accelerated as the ship remains still, or something like that.

"Trek's using the sun to exceed the speed of light and go back in time"

That is really lame...

Yes, yes it is. But that is how they supposedly went back and saved the whales in ST IV. then they used the same technique to go forward again (yeah right, like they can chose how speed affects time dilation...)

I'm sure they just went at "that specific speed".........

For those interested in time travel paradoxes: http://www.mjyoung.net/time/index.htm

Kestas said: "If you traveled in one direction forever you would wrap around, but thats just because of the shape of our universe."

isn't it too firm an statement? I mean you're talking about theories. Well, if you say it, I'll certainly order my fleet in Barents to MidAtl

> It isn't breaking the laws of physics to travel at or beyond lightspeed. It is only breaking
> the laws of physics as we understand them
Draugnar that's like saying mathematics might advance to a point where dividing by zero actually does give a real value (42 maybe), but we don't know the math well enough yet.

Also hyperspace, warp drives, zero-point energy, etc, always end up sounding less realistic the more you look into them. Neat plot devices, not so good applied to reality :-(

I thought that was the consensus gallando (correct if wrong). But there are theories and then there are "theories"

Note there is a potential difference between moving at or beyond the speed of light and travelling faster than light. While it may turn out to be impossible to move at speeds exceeding the speed of light, it may still be possible to go from point A to point B faster than light could. Whether it be teleportation or going through a hole in the folds of space or whatever.

This all sort of reminds me of something I heard on the radio a few months back. These people were positing that the fact that we haven't run into any time travelers combined with an assumption that we will someday advance technologically far enough to travel through time is proof that humanity is doomed. So many things with this theory they were espousing which all come down to thinking they know more than they really know and making all kinds of absurd conclusions because of it.

I'm not saying that everything said above is absurd. Just pointing out who silly it can be to be sure of something we just don't know based on what we, even a consensus, thinks. To be honest, I'm not sure I'm sure of anything. And I like it that way.

Google for Alcubierre Drive. If you had enough (negative) energy - several times the mass of the universe converted into (negative) energy would be required - you could move a ship from A to B faster than light would get there. The drive compresses and stretches space, so the ship itself doesn't move inertially (it doesn't accelerate) so you avoid the infinities that prevent a "normally" accelerated ship actually reaching or exceeding c.

@Alderian
We could invent a time machine that could only be used to travel back to the date of tis invention. So the human race isn't doomed

@db (to many people with those initials here <grin>) - that is currently the accepted theory of potential time travel. I think it most likely would also never let you travel farther back than where it would be in the time stream based on how long it has been around. In other words, the moment you leave, time continues to tick. If you are gone three days, you cannot return to your origin, but three days later.

With regards to the past, I believe that we will eventually have a way to view (but not interact with) it, maybe even close up like a "ghost" amongst the inhabitants and events, but without a means to influence them in any way.

@Draugnar - "a "ghost" amongst the inhabitants and events, but without a means to influence them in any way"

You should read "The Light of Other Days" by Clarke and Baxter. It's a very good read.

I love the discussions on this site. I have no idea what you all just said but im really impressed and the next time i get my car into space and hit the speed of light, ill let you all know what happens :)