Alien movement (Warning Math)

[Mumon]

All right so this AI thing got me thinking.

Lets say that we are sitting in our lab and we look up into the sky with our equipment. We see an AI space craft, just sitting there doing nothing but shining a light toward us. Now this space craft we know isn't close to us, and we find out with some complex equipment and some equations that it's taking that light it's shining toward us 10 seconds to reach us from it's location.

Well, we watch it for days and it doesn't move, when all the sudden it just starts moving at half the speed of light toward us. Now we know that at half the speed of light it'll take 20 seconds to reach us. But we won't actualy start to see it moving until 10 seconds have passed and by that time it's already finished half the trip.

So after 20 seconds it's now right on top of us, but it looks to us like it did the trip in 10 seconds. All right pausing that thought for just a second before I come back to it.

If the ship had actualy traveled at the speed of light, we would not see that it starts moving until 10 seconds have passed, but by that time it would already be here. So we would see just as it's leaving it's location it being in everyplace inbetween here and there and then being here (Because 5 seconds ago it would have been at a place where it's light would only take 5 seconds to reach us, thus meaning all the light it sent out to us would reach us at the exact same time, making it look like it's in all those places at once)

Going back over to half the speed of light thing, at any given time after we start to see it move, where would it look like it was?

On anouther note, I know they say that you can't go faster than the speed of light, but for this thought lets pretend that you could. Lets say that the ship traveled twice the speed of light, so it reached us only after 5 seconds. It would reach us, and then 5 seconds later we would see it start to move. Not only that, but the moment it reaches us we would actualy see images of it moving backward back to it's start location over a period of those 5 seconds.

So heres the theory: The faster something is moving toward you, quicker the trip seems to take.

So next time someone is running and going to tackle you, just remember that he's not realy moving as fast as he looks so it's not going to hurt as much as you might think (Unless you also think he's lighter than he actualy is... but that's something else)

So one last time in case you missed it: at any given time after we start to see something move at a very high velocity, what places would it look like it was currently occupying?

[Oddysee]

So, erh... You want fries with that?






Tm

[Cowtipper]

I dunno Mumon, it sounds like you're confusing yourself.

If the light is taking a total of 10 seconds to reach Rubi-Ka, then that's 2,997,924,580 meters away from your viewing location. If they are going half the speed of light, then there's no way they can reach earth before or at 10 seconds. It would take them a total of 20 seconds as you said to make the distance, but you would also be able to see them moving the entire 20 seconds, because the light is travelling faster than they are.

I'm not so sure about things seeming faster, though. The human mind tends to slow things down as they occur, especially during bouts of adrenaline. So as you're standing there, mooing in the fields, and I am coming at you at a high velocity, and my massive muscular self with super tipping abilities is getting ready for a good shove before I run off, things might actually seem slower to you than than it actually is.

That'd be an interesting experiment, though. Have something like that happen to a test subject, then ask them how long they think the event occurred in and compare it to the actual time.

[Tacz]

Oh, and if it came STRAIGHT toware you at EXACTLY the speed of light, it would look stationary for the delay, then it would reappear as it slowed, an the entire path it took would be a blur of all the light that bounced off of it from any point in its journey.

[Mumon]

Yes if they had been moving at half the speed of light it would take 20 seconds to reach rubi-ka from that location

But from Rubi-Ka, you would not see them start moving until the image of the ship moving reaches Rubi-Ka. Witch would take 10 seconds from there original location. That's half the trip right there, we would only see them start moving after 10 seconds of them actualy moving, and for the next 10 seconds we would see them come speeding toward Rubi-Ka

It's a matter of prospective.

If you watched from the side you would see that the trip took 20 seconds, from Rubi-Ka though it would look to only take 10 seconds. From the ship it would feel like 20 seconds, look to be 20 seconds, and of the people on Rubi-Ka aging 30 seconds.

[Tacz]

Really, it would just look like they're accelerating.

[Korejar]

Is it just me or did he just perform a thought experiment that proves that Einstein's theory of relativity actually is true?

Well, the actually theory says that time itself DOES slow down as you approach the speed of light. There is or will be (Can't remember if it was launched yet) a high velocity sattelite that was (or is) to be launched that's job is to orbit the Earth at as high a speed as we can (safely) make it go for a long time. Should Relativity be correct, then it would stand to reason that the atomic clock aboard the satelite would differ from the ones on earth.

[Mummu]

interesting it gets when you try to figure out how things look seen from the ship.
especially when you pass the speed of light, and even ebtter when flying towards a point of highes gravitation.
that looks frelled!

ALL sci-fi movies are WRONG!

[Boinky]

Personally I would aim my giant death ray at them and then retire to the pool

or maybe sic Tacz on em - same diff

[Decavolt]

...On anouther note, I know they say that you can't go faster than the speed of light...

Before 1962, this was the theory. Now, we know differently. Tachyon particles breach the causaily barrier and travel at faster-than-light speeds.

[Tarryk]

...On anouther note, I know they say that you can't go faster than the speed of light...

Before 1962, this was the theory. Now, we know differently. Tachyon particles breach the causaily barrier and travel at faster-than-light speeds.

Eep, gotta discount that a bit. While you are technically correct, it's still a bit different (think "Event Horizon" here...). The speed of light is the limit for anything and everything, however if something is small enough to occupy and utilize the curled-up dimensions (as is the working theory), then the particle can move from one place to another seemingly faster than the speed of light only because it is circumventing space and time during it's trip.

In order for a particle with a mass equal to or greater than the photon to travel at the speed of light, it must have come into existence travelling at that speed, or it must build up to that speed on it's own. But, as the theory of relativity displays, the only way for a particle to retain the energy neccessary to build up to the speed of light would require that particle to have an INFINITE amount of mass. Therefore it's just not possible to accelerate to the speed of light.

[Coltess]

Actually,

- the mass of an oject travelling at relativistic speeds increases with the speed. So if you could accelarate a mass to close enough to c, you could make your very own travelling black hole

- time only "slows down" for an observer not travelling at relativistic speeds. So if you were on the spaceship time would be the same as if you were standing still, but if you could see a clock inside a spaceship going .25+ c, it would seem to be "ticking" slower.

- the distance travelled at relativistic speeds seems shorter than it actually is, seen from inside the space ship. So our stationairy observer (outside the spaceship) would actually see a shorter spaceship going by. This is only applies to the length (parallel to the travel direction), not width or height.

I think I got this right, but it has been 5 months since I had relativity, so maybe I remember it wrong.

[Tarryk]

You're hitting it pretty close to the mark there, Coltess, thank you. And while you could be correct about the "travelling black hole", that's really entirely dependant on whether or not you put spatial limitations on it. The reason for that black hole would BE that it had a nearly infinite amount of mass in it's attempt to approach c. Or you could just as easily say that it would become "one with the universe" upon hitting c, disappearing entirely as it absorbs itself into a form of radiation. the term "infinite mass" can be explained way too many ways.

If peeps are interested, I absolutely LOVE the "four-cup theory" of dimensional travel in relation to velocity and time. I'll start a thread on that and explain it some time.

[Decavolt]

...On anouther note, I know they say that you can't go faster than the speed of light...

Before 1962, this was the theory. Now, we know differently. Tachyon particles breach the causaily barrier and travel at faster-than-light speeds.

Eep, gotta discount that a bit. While you are technically correct, it's still a bit different (think "Event Horizon" here...). The speed of light is the limit for anything and everything, however if something is small enough to occupy and utilize the curled-up dimensions (as is the working theory), then the particle can move from one place to another seemingly faster than the speed of light only because it is circumventing space and time during it's trip.

In order for a particle with a mass equal to or greater than the photon to travel at the speed of light, it must have come into existence travelling at that speed, or it must build up to that speed on it's own. But, as the theory of relativity displays, the only way for a particle to retain the energy neccessary to build up to the speed of light would require that particle to have an INFINITE amount of mass. Therefore it's just not possible to accelerate to the speed of light.

Tachyon's accelerate as they lose energy, and once a tachyon reaches zero-mass it achieves infinite speed. They don't need to have infinite mass or energy in order to accelerate to such speeds, since the more energy a tachyon aquires, the more it slows down. When traveling at hyper-light speeds, they give off radiation (read: lose energy, in the form of expelled Cherenkov radiation which, by definition, is radiation emitted at faster-than-light speeds) which just accelerates them more. The speed of light is the limit for almost anything and everything. If tachyon's followed the traffic laws like most of all known matter, then yes, they wouldn't actually be faster than light. They're bad drivers. They ignore the speed zones and tear around the universe anyway. You're correct in that they do circumvent space-time, which is why their infinite speed-state is usually called "transcendent", but they do so by mass acceleration beyond the light barrier, rather than squeezing though the cracks at sub-light speeds.

[Tarryk]

That's an interesting take on it, Deca. Definitely something from a point-particle theory, but definitely a good theory in and of itself. Do you have a source on that by any chance? I wanna read.

[Decavolt]

I'd say anything on Cherenkov radiation, and papers by Sudarshan and Bilaniuk on tachyons. Google for those and you should get lots of hits.

[Dragonfruit]

You know in metal gear solid, when the guards get that question mark pop up over their head?


lol... the speed of light err..... would mean that you wouldnt see it move. ingame especialy from FPS lag.... same with half the speed of light... well okiden

[Redningsmand]

aint this just the Einstein theory? moving the speed of light makes time stand still and moving faster then light towards the light would make you go back in time to the point the light happend?

[Mumon]

I give up on tring to explain it.

X=Y but looks like Z when viewed from R and X
This does not mean that X=Z only that it looks like Z from R