# Light is still the fastest (in Off-topic)

## Kefeck[Demonic Serenity]February 22 2012 6:39 PM EST

Super cool..

Hard to believe scientist will ever be able to really accurately track something going that fast. Especially when the distance is only 450 miles..

In a somewhat related note if your traveling at the speed of light your going into the future also ( according to stephen hawking)..

Correct?

## QBRangerFebruary 22 2012 6:47 PM EST

IIRC, if you travel at the exact speed of light, time stops relative to everyone else.

## Admin{CB1}Slayer333[SHIELD]February 22 2012 7:31 PM EST

I don't travel at the speed of light, and I'm going into the future too!

## QBPit Spawn[Abyssal Specters]February 22 2012 7:34 PM EST

Might and potential are mentioned in there several times, doesn't disprove their experiment...

## DemigodFebruary 22 2012 8:00 PM EST

IIRC, if you travel at the exact speed of light, time stops relative to everyone else.

And IIRC, if you travel at the speed of light, the physical Y axis stretches to infinity while the X (Z?) axis reaches nil. Shame I don't recall much about that from physics class many years ago. :(

## AdminTitan[The Sky Forge]February 22 2012 8:42 PM EST

And IIRC, if you travel at the speed of light, the physical Y axis stretches to infinity while the X (Z?) axis reaches nil. Shame I don't recall much about that from physics class many years ago. :(

I'm not sure that's exactly right; b/c 0*infinity = 0 right? If that's what I remember from my crazy math classes. And if I'm not mistaken you would have infinite mass if you were traveling the speed of light, which is interesting b/c the only object that travels the speed of light is massless.

## SickoneFebruary 22 2012 9:15 PM EST

Given an "uniform" time-space continuum (that is to say, the entire universe as we know it at this time, with the POSSIBLE exception of things inside the event horizon of singularities), in order to reach the speed of light you would need an infinite amount of energy (that is to say, you just can't do it), and your mass would tend towards infinity too, as more energy is being applied towards your acceleration.
At the same time, you would perceive outside time as accelerating more and more (or, in other words, everybody else at non-relativistic speeds would "see" your local time as slowing down towards a complete halt as you get closer and closer to light speed).
The only particles that can actually reach light speed are those that only exist when moving at light speed, and as soon as you "slow them down" to anything below the speed of light, they cease existing (i.e. they have a "rest mass" of zero). Extracting partial energy out of light-speed particles does not slow them down, it only reduces their equivalent mass.

Now, if you have a non-uniform space-time continuum, you could conceivably surpass the speed of light with regards to some particular reference system, but you would still not go faster than light compared to the area you're currently passing through.
And yes, if you could find (or create) some space like that (which is even theoretically almost impossible, let alone practically), combined with other factors (which are almost as difficult to pull off), you could conceivably achieve some limited "traveling back in time" effect.

## Zenai[Cult of the Valaraukar]February 22 2012 9:18 PM EST

And if I'm not mistaken you would have infinite mass if you were traveling the speed of light, which is interesting b/c the only object that travels the speed of light is massless.

So just a weird left field question: If there was a way to say suspend mass anything can potentially travel at the speed of light?

## SickoneFebruary 22 2012 11:31 PM EST

If there was a way to say suspend mass anything can potentially travel at the speed of light?

If there was a way to do even something barely approaching that, the applications are far more important than just lightspeed travel.

For instance, think about only slightly reducing mass of a plane - you can fit more people or cargo in it, making transportation cheaper (assuming the mass-reducing tech is not prohibitively expensive or voluminous, of course).
Think about reducing mass noticeably more - you suddenly get floating cars (you just need to make the contents of the car as light as or slightly lighter than air).
Reduce mass much more ? All of a sudden you get insane accelerations possible (even with live people) with very little energy expenditure, you get to travel to the moon and back in hours, if not minutes. You get to explore and colonize the entire solar system. Heck, you get to REORGANIZE the solar system any way you see fit !
Reduce mass to nearly zero ? Same as above, but on an interstellar scale. Even with 25% of lightspeed, that opens up not just colonization of other solar systems, but also some limited interstellar trade !
If you manage to reduce mass to actual zero... well... yes, lightspeed travel is possible - but not just that - INSTANT acceleration to lightspeed, so from the viewpoint of the traveller, they INSTANTLY arrive at whatever destination you select (stopping might prove tricky), since in their own reference frame, no time has passed at all !!!

0*infinity = 0
Indeterminate.

## QuyenFebruary 24 2012 3:35 AM EST

If you manage to reduce mass to actual zero... well... yes, lightspeed travel is possible - but not just that - INSTANT acceleration to lightspeed, so from the viewpoint of the traveller, they INSTANTLY arrive at whatever destination you select (stopping might prove tricky), since in their own reference frame, no time has passed at all !!!
teleportation!

## KingFebruary 24 2012 4:57 AM EST

INSTANTLY arrive at whatever destination you select (stopping might prove tricky)

"Speed has never killed anyone, suddenly becoming stationary... thatﾒs what gets you" - Jeremy Clarkson.

## SickoneFebruary 24 2012 6:21 AM EST

If you have zero mass, getting stopped is not a problem, just as getting instantly accelerated to light-speed is no problem.
You have no mass, remember ? :P
No inertia, no acceleration bad stuff, and so on and so forth.
That's the "trick" when you have zero rest mass, not just a very low mass.

Stopping *YOURSELF* when you're already traveling at light-speed however, THAT is what's problematic.

Why is it problematic ?
Well, remember that part about arriving instantly from your own viewpoint ?
Sadly, if nothing from "outside" stops you, you might as well keep on traveling until after the heat death of the universe (if that's what will happen to the universe, we're not sure, and recent evidence points to a heat death being unlikely, but that's another story) with NO TIME passing (from your own perspective only, of course).

Of course, making your own mass be really zero (or even just slightly lower) is, how should I put this, even theoretically impossible (as far as we know), so the entire discussion is purely academic either way.
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