Faster than light travel.
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will1701-A wrote...
The question of traveling at light speed isn't about the physics behind it but could a human survive the amount of forces that are going on.Nope, it's most definitely about the physics behind it.
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Hanasaku
i should just die
"A particle that is moving at the speed of light is stationary in time, Similarly; A particle stationary in time is moving at the speed of light."
Stating that once you reach the speed of light, you are going against time.
If time is 1 second, then at the speed of light you move back in time 1 second, making you stationary.
That means if you move 2x the speed of light, you may go back in time?
Stating that once you reach the speed of light, you are going against time.
If time is 1 second, then at the speed of light you move back in time 1 second, making you stationary.
That means if you move 2x the speed of light, you may go back in time?
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Flaser
OCD Hentai Collector
nbian wrote...
Zero_Hour wrote...
Hmm, could light itself be accelerated faster that it is known to travel in a vacuum? Light traveling faster than the speed of light.Well, you can't really "push" light. For you to push it, it would have to have mass and light is massless. It's already traveling at it's maximum in other words. If it were to go though elongated space then it would seem to travel faster in space that is non elongated. (Space is more elongated near massive objects like Earth making gravity)
Edit: Also if light were to travel faster than itself in normal space, then you can send message back in time violating causality again making it impossible. Unless you don't believe in causality (some scientists say that if messages were to be sent back in time then they were already sent before in the first place so it is a natural part of the timeline)
That's not totally accurate. A particle of light is called a photon. It *does* have mass, and that's why big masses attract it. It just doesn't have a mass at rest. Light has both wave and particle qualities... however this duality is not limited to light, all particles show this, this is how quantum tunneling works (which is used in some transistors).
Also the lot of you don't get what relativity is about: The speed of light (in vacuum) is constant in *every* reference frame. That's it, but this has a lot of consequences:
1) Time is *NOT* independent of your reference frame. So different observers in different reference frames would observe things differently. So an event that would appear simultaneous in one frame may not appear so in another.
2) The speed of light can't be exceeded.
3) When particles with mass at rest go closer and closer to the speed of light in a reference frame their *observed* mass in that frame increases.
4) Under similar conditions objects undergo Lorentz contraction, that is they appear to be shorter (along the axis of their movement) than they'd be at rest.
5) Velocities can't be simply added up. If two rockets approach each other at 2/3 of light-speed, they *wouldn't* be closing at 4/3 light-speed.
6) Mass and energy are equivalent.This means, that the energy stored in an object at rest equals c-times the square of its mass. Conservation of energy implies that in any reaction a decrease of the sum of the masses of particles must be accompanied by an increase in kinetic energies of the particles after the reaction. Similarly, the mass of an object can be increased by taking in kinetic energies. This is why an object moving close to light speed "gains" weight when it's further accelerated.
FTL opens a whole can of worms as the saying goes:
Causality, Relativity, FTL - pick any two. So if FTL is possible it would break either relativity or causality.
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-It is easy to explain how scientists "slow down light". If light travels through any medium (say, for example, the distance between your computer screen and your eyes) it is going to encounter resistance from the matter that makes up the atmosphere. Yes, air is matter for those of you that didn't know.
-Light always travels at the speed of light relevant to any object that is moving. To give an example...if you were standing still and someone threw a football at you at 10 mph, the ball would hit you at 10 mph (to keep the analogy simple, let's not delve into declining velocity or whatever). However, if you were running at 5 mph away from the person throwing the football, and they threw it at you, it would only hit you at 5 mph due to the fact that your speed would "cancel out" the speed of the football (This is not a scientific analogy guys, just here for example).
ANYWAY it's a little bit different with light. Light travels at 299,792,458 meters per second. You might think that if you managed to travel 299,792,457 meters per second, light would only be traveling 1 meter per second more than you, however this is not the case. Light ALWAYS travels at 299,792,458 meters per second relevant to any object, no matter how fast it is traveling. So if you actually did manage to travel 299,792,457 meters per second, light would still be traveling at 299,792,458 meters per second in relation to you.
Basically, you can never catch up to light, let alone match it. Also, light photons are massless and do not transfer momentum, which is why they are able to travel at the fastest speed. Everything that has mass is therefore not able to accelerate to the speed of light because this would require all of the energy in the universe.
This may not be as coherent as I hoped...I've been awake for like 48 hours, which is a long time for me.
-Light always travels at the speed of light relevant to any object that is moving. To give an example...if you were standing still and someone threw a football at you at 10 mph, the ball would hit you at 10 mph (to keep the analogy simple, let's not delve into declining velocity or whatever). However, if you were running at 5 mph away from the person throwing the football, and they threw it at you, it would only hit you at 5 mph due to the fact that your speed would "cancel out" the speed of the football (This is not a scientific analogy guys, just here for example).
ANYWAY it's a little bit different with light. Light travels at 299,792,458 meters per second. You might think that if you managed to travel 299,792,457 meters per second, light would only be traveling 1 meter per second more than you, however this is not the case. Light ALWAYS travels at 299,792,458 meters per second relevant to any object, no matter how fast it is traveling. So if you actually did manage to travel 299,792,457 meters per second, light would still be traveling at 299,792,458 meters per second in relation to you.
Basically, you can never catch up to light, let alone match it. Also, light photons are massless and do not transfer momentum, which is why they are able to travel at the fastest speed. Everything that has mass is therefore not able to accelerate to the speed of light because this would require all of the energy in the universe.
This may not be as coherent as I hoped...I've been awake for like 48 hours, which is a long time for me.
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Flaser wrote...
6) Mass and energy are equivalent.This means, that the energy stored in an object at rest equals c-times the square of its mass
Pretty sure it's the other way around. E=mc2 and all that.
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Flaser
OCD Hentai Collector
skoobadoop wrote...
-It is easy to explain how scientists "slow down light". If light travels through any medium (say, for example, the distance between your computer screen and your eyes) it is going to encounter resistance from the matter that makes up the atmosphere. Yes, air is matter for those of you that didn't know.-Light always travels at the speed of light relevant to any object that is moving. To give an example...if you were standing still and someone threw a football at you at 10 mph, the ball would hit you at 10 mph (to keep the analogy simple, let's not delve into declining velocity or whatever). However, if you were running at 5 mph away from the person throwing the football, and they threw it at you, it would only hit you at 5 mph due to the fact that your speed would "cancel out" the speed of the football (This is not a scientific analogy guys, just here for example).
ANYWAY it's a little bit different with light. Light travels at 299,792,458 meters per second. You might think that if you managed to travel 299,792,457 meters per second, light would only be traveling 1 meter per second more than you, however this is not the case. Light ALWAYS travels at 299,792,458 meters per second relevant to any object, no matter how fast it is traveling. So if you actually did manage to travel 299,792,457 meters per second, light would still be traveling at 299,792,458 meters per second in relation to you.
Basically, you can never catch up to light, let alone match it. Also, light photons are massless and do not transfer momentum, which is why they are able to travel at the fastest speed. Everything that has mass is therefore not able to accelerate to the speed of light because this would require all of the energy in the universe.
This may not be as coherent as I hoped...I've been awake for like 48 hours, which is a long time for me.
Good explanation, but you're claim that light can't transfer momentum is *plain* *WRONG*. Light, *does* transfer momentum, but it's a very small energy/photon, so it almost invisible most of the time.
However it *is* there and that's how solar sails work.
http://en.wikipedia.org/wiki/Solar_sail
Einstein proposed – and experiments confirm – that photons have a momentum p=E/c,[2][3] hence each light photon absorbed by or reflecting from a surface exerts a small amount of radiation pressure. This results in forces of about 4.57x10−6 N/m2 for absorbing surfaces perpendicular to the radiation in earth orbit, and twice as much if the radiation is reflected
By using huge surfaces (compared to the mass of the payload), even the infitestimal push of light can be harnessed to accelerate an object in orbit.
Yes, this have been proven. In fact if engineers didn't take this into account several space missions would have been in jeopardy as the light pressure would have pushed the probes off course.
GroverCleaveland wrote...
Flaser wrote...
6) Mass and energy are equivalent.This means, that the energy stored in an object at rest equals c-times the square of its mass
Pretty sure it's the other way around. E=mc2 and all that.
Flaser throws ash on his head and contemplates throwing himself on his ball-pen to atone for the shame... then goes back to browsing porn.
Anyway, good catch Grover.
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mibuchiha
Fakku Elder
So you guys are just stating special relativity over and over. No added info at all. ;3
Anyway, since to accelerate things to the speed of light (let's not talk about the impossibility yet) first of all you have to accelerate (duh) it. So the reference frame is no inertial. You guys might want to talk about GR instead. You know, spacelike, timelike, lightlike thingies. ;3
But all in all the conclusion is the same. You can't. So yeah, new physics anyone?
Anyway, since to accelerate things to the speed of light (let's not talk about the impossibility yet) first of all you have to accelerate (duh) it. So the reference frame is no inertial. You guys might want to talk about GR instead. You know, spacelike, timelike, lightlike thingies. ;3
But all in all the conclusion is the same. You can't. So yeah, new physics anyone?
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Flaser wrote...
That's not totally accurate. A particle of light is called a photon. It *does* have mass, and that's why big masses attract it. It just doesn't have a mass at rest. Light has both wave and particle qualities... however this duality is not limited to light, all particles show this, this is how quantum tunneling works (which is used in some transistors).
I was obviously making it simpler to digest for the masses. A photon IS massless, because its energy is not stored as mass. It has relativistic "mass", sure, but that is the same thing as saying that it has energy.
Edit: Also, photons do not feel the force of gravity but they can travel along warped space-time with a null geodesic and thus experience gravitational acceleration. The observation of starlight doing this around the sun during a solar eclipse is what made Einstein famous in the first place.
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mibuchiha
Fakku Elder
nbian wrote...
Edit: Also, photons do not feel the force of gravity but they can travel along warped space-time with a null geodesic and thus experience gravitational acceleration. The observation of starlight doing this around the sun during a solar eclipse is what made Einstein famous in the first place.I hope you do realize that in GR there's no such thing as 'force of gravity' to be felt.
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mibuchiha wrote...
I hope you do realize that in GR there's no such thing as 'force of gravity' to be felt.
nbian wrote...
Edit: Also, photons do not feel the force of gravity but they can travel along warped space-time with a null geodesic and thus experience gravitational acceleration. The observation of starlight doing this around the sun during a solar eclipse is what made Einstein famous in the first place.
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All i've gathered from this is that you can't travel faster than light in a vacuum and if anything even did, you wouldn't be able to see it...
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Essentially if E=mc^2 is true, Einstein's relativity function, and all of its implications are true then c cannot be crossed in terms of velocity. However, there might be hidden observations we haven't seen yet at "light speed" since we have not approached it with our own frames of reference (IE actually travelling that speed).
In order to travel faster than light you must either bend space-time or travel to the past (essentially). Nothing said time had to go one way.
In order to travel faster than light you must either bend space-time or travel to the past (essentially). Nothing said time had to go one way.
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The only real way to go faster than light is not to break relativity, but to bend the shit out of it. You would have to gain access to the whole power of Saturn to even make a subspace bubble that can allow you to even go close to the speed of light without becoming everything everywhere. The only other real way that it can happen is if Tachyon particles are proven, but as it stands, it's hypothetical.