Faster than Light / Time travel
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Faster than Light / Time travel
Further to the thread on "Some thoughts on sound", which I enjoyed a lot, I would like to ask my learned contemporaries out there:- Is it possible to travel faster than the speed of light? And, on the same subject, (some say), is time travel possible? The floor is yours!
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Yes there is already something which travels faster than light. But it only happens at the quantum level. Its called 'action at a distance' and involves the uncertainty principle. The more acurately you measure the momentum or speed of a particle the less you can know of the other particle.
Current theory regarding time travel involves high density substances and super-gravity which bends space.
The numbers in space, as Slartiblartfast would tell you, are horrible.
For there to have been anything before the Big Bang, which of course there must have been, the theorists have to use 'imaginary time'.
Having now plotted the course if the start of the universe by the milli-second, and having measured the forces and masses required, and having now measured the mass of the universe as we know it(to be still expanding at its present rate)there is a slight problem. Nearly 90% of it is missing!
In my humble opinion it is highly unlikely that a species as primitive as Man will ever overcome these hurdles but I too would like to learn more about the subject.
If you want more practical faster-than-light travel you'll have to get into astral projection. As Jonathon Livingston Seagull's mentor says, "Perfect speed is being there!"
Now I need a lie down!
Current theory regarding time travel involves high density substances and super-gravity which bends space.
The numbers in space, as Slartiblartfast would tell you, are horrible.
For there to have been anything before the Big Bang, which of course there must have been, the theorists have to use 'imaginary time'.
Having now plotted the course if the start of the universe by the milli-second, and having measured the forces and masses required, and having now measured the mass of the universe as we know it(to be still expanding at its present rate)there is a slight problem. Nearly 90% of it is missing!
In my humble opinion it is highly unlikely that a species as primitive as Man will ever overcome these hurdles but I too would like to learn more about the subject.
If you want more practical faster-than-light travel you'll have to get into astral projection. As Jonathon Livingston Seagull's mentor says, "Perfect speed is being there!"
Now I need a lie down!
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Apparently, warp factor 10 is so fast that if you reach it you would exist everywhere in the universe. Bet your quantum particle aint that fast 
[ 28 July 2001: Message edited by: Bally Heck ]
[ 28 July 2001: Message edited by: Bally Heck ]
Traveller at Light Speed
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Theory doesn't rule out time travel. But particles with mass can't be accelerated to (or past) the speed of light according to present theories (but there can exist particles that always stay faster than lightspeed).
Glueball...what's a few hundred years when you are not aging.
Glueball...what's a few hundred years when you are not aging.
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It can be shown that as the speed of a body approaches the speed of light the approximation of momentum as p = mv becomes innacurate and its actual relativistic momentum must be used which is given by p = mv / root(1-sq(v/c)) . We can see that this approximates to p = mv at values of v<<c.
The above equation for relativistic momentum is sometimes interpreted to mean that a rapidly moving body undergoes an increase in mass.
relativisticmass =rest mass / root(1-sq(v/c))
And we can see that as v increases so does the relativistic mass and thus a larger amount of energy is required to increase the velocity further, indeed if the velocity were to equal c then the relativistic mass would be infinite and an infinite amount of energy would be required to take the velocity past c. Therefore to all intents and purposes we cannot travel faster than light.
The above equation for relativistic momentum is sometimes interpreted to mean that a rapidly moving body undergoes an increase in mass.
relativisticmass =rest mass / root(1-sq(v/c))
And we can see that as v increases so does the relativistic mass and thus a larger amount of energy is required to increase the velocity further, indeed if the velocity were to equal c then the relativistic mass would be infinite and an infinite amount of energy would be required to take the velocity past c. Therefore to all intents and purposes we cannot travel faster than light.
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Harry999,
You've dashed my hopes, as I'd hoped to be able to travel faster than the speed of light sometime next week. Thursday, actually. I'd better call it off to save embarrassment.
Glad to see that time travel is still on the menu. Maybe the week after, huh?
Meanwhile, I'll leave you with a question, seeing as you're into this physics thingy: The chap who works at my dry-cleaners once told me that if you separate two 'entangled' particles, say putting 'em at either end of the universe, then change the quantum state of the one nearest you, then the quantum state of t'other will change instantaneously, i.e. without 'speed' at all.
How come? Why doesn't the C constant apply in this case? Are these particles being a bit naughty? Something should be done about it, that's what I say.
TW
You've dashed my hopes, as I'd hoped to be able to travel faster than the speed of light sometime next week. Thursday, actually. I'd better call it off to save embarrassment.
Glad to see that time travel is still on the menu. Maybe the week after, huh?
Meanwhile, I'll leave you with a question, seeing as you're into this physics thingy: The chap who works at my dry-cleaners once told me that if you separate two 'entangled' particles, say putting 'em at either end of the universe, then change the quantum state of the one nearest you, then the quantum state of t'other will change instantaneously, i.e. without 'speed' at all.
How come? Why doesn't the C constant apply in this case? Are these particles being a bit naughty? Something should be done about it, that's what I say.
TW
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Time, Distance, Speed is all irrelevant if you wish to travel to the nearest galaxy or whatever. As humans we have to have a reference to something, just to be able to try and comprehend it. Mr Moto is on the right track when he refered to the latest ideas on super gravity etc, bend space!!
Bring that galaxy to you!!, thus no need for travel at the speed of light.
P.S Im not a scientist or proffesor of physics, i just fly a quadrapuff!!
Bring that galaxy to you!!, thus no need for travel at the speed of light.
P.S Im not a scientist or proffesor of physics, i just fly a quadrapuff!!
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TW,
I think you need to bring your dry cleaning friend up-to-date; Bell's Inequality was put into serious doubt by the results of Alain Aspects' experiment in 1982. I believe our only hope(s) of time travel will come from Everetts Many Worlds Theory.
I think you need to bring your dry cleaning friend up-to-date; Bell's Inequality was put into serious doubt by the results of Alain Aspects' experiment in 1982. I believe our only hope(s) of time travel will come from Everetts Many Worlds Theory.
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I posted this one Turbofans thread on sound, but it applies here more as it was to do with faster than light travel etc. Bear in mind this is just my unserstanding of it so if I am wrong just let me know 
"......that is where E=mc2 comes in. And also the rocket will reach a constant velocity when its forward speed is equal to the speed of the gases being emitted from the rocket, as it is newtons reaction (equal and opposite) that makes the rocket accelerate.
.....with reference to the speed of light, scientists have already found particles that travel faster than the speed of light, called quarks, but they only exist for microseconds, but I was theorising that maybe we can only detect them for microseconds because due to traveling faster than the speed of light, they are traveling through time, or maybe they are flicking in and out of sub either, or even existing in more than one place at a time due to traveling in the 4 th dimension....that being time........Just some food for thought 
"
Gravity powered ships would be a good start, considering that balck holes are so strong that even light can't escape them!!!!
"......that is where E=mc2 comes in. And also the rocket will reach a constant velocity when its forward speed is equal to the speed of the gases being emitted from the rocket, as it is newtons reaction (equal and opposite) that makes the rocket accelerate.
.....with reference to the speed of light, scientists have already found particles that travel faster than the speed of light, called quarks, but they only exist for microseconds, but I was theorising that maybe we can only detect them for microseconds because due to traveling faster than the speed of light, they are traveling through time, or maybe they are flicking in and out of sub either, or even existing in more than one place at a time due to traveling in the 4 th dimension....that being time........Just some food for thought
"Gravity powered ships would be a good start, considering that balck holes are so strong that even light can't escape them!!!!
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HARRY999...Of course according to the textbooks all of this is absolutely true...However in forming his theory on relativity, Is it not true to say that EINSTEIN took the speed of light (c) in your expression as an absolute i.e. nothing can travel faster than light ...not even a lightwave notionally launched from the crest of another lightwave....so until someone comes up with some alternative that works better than the current theory...we shall continue to live in a bounded universe...
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Blimey. Absolutely brilliant everybody, keep it up. I'll have to re-read A Brief History of Time again just to keep up. I really don't understand how time travel can be possible because if one travelled back in time and then changed the past the whole issue could be completely different. We would possibly be living different lives, presuming we were born at all. But we must have been, in order to travel back through time in the first place. See what I mean?
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Interesting thought TR3.
Being a rather bored and sad individual I have done a few back of the envelope calculations to see how much younger a pilot might be at the end of his career compared to somebody with a stationary desk job.
I reckon that a pilot doesn't even save himself a second. Perhaps you would like to check the maths.
Based on a pilot of a 747 with a cruise speed of 600mph = 270m/s who spends perhaps 15 hrs per week in the air and does so for perhaps 30 years, i.e. 84 x 10^6 seconds. Now I'm not a pilot (soon to be rectified fingers crossed) so don't quote me on the above stats.
The pilots time is given by lorentz transormation:
t'= t/root(1-sq(v/c))
where t' is time experienced by pilot and t is that experienced by our office clerk if you will.
t'=84 x 10^6 / root(1-sq(270/3x10^8))
And by my reckoning the difference in time is a mere 0.000034 seconds. So nothing to get too excited about eh?
Being a rather bored and sad individual I have done a few back of the envelope calculations to see how much younger a pilot might be at the end of his career compared to somebody with a stationary desk job.
I reckon that a pilot doesn't even save himself a second. Perhaps you would like to check the maths.
Based on a pilot of a 747 with a cruise speed of 600mph = 270m/s who spends perhaps 15 hrs per week in the air and does so for perhaps 30 years, i.e. 84 x 10^6 seconds. Now I'm not a pilot (soon to be rectified fingers crossed) so don't quote me on the above stats.
The pilots time is given by lorentz transormation:
t'= t/root(1-sq(v/c))
where t' is time experienced by pilot and t is that experienced by our office clerk if you will.
t'=84 x 10^6 / root(1-sq(270/3x10^8))
And by my reckoning the difference in time is a mere 0.000034 seconds. So nothing to get too excited about eh?
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Bloody 'Eck......am I on the right site!?
Interesting stuff chaps......
Dont forget the paradox of time travel.....if you travelled back into the past from the now, then the past will include your arrival from the future, and ips facto you should still exist in the future, because you came back.......
Hope that helps, and before anyone quotes maths at me, Remember that I am only an O Level boy made good!
Tailwinds
Interesting stuff chaps......
Dont forget the paradox of time travel.....if you travelled back into the past from the now, then the past will include your arrival from the future, and ips facto you should still exist in the future, because you came back.......
Hope that helps, and before anyone quotes maths at me, Remember that I am only an O Level boy made good!
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Oh, and just another quick question for you thorists out there.....
If I could notionally drive my car at the speed of light in a dark tunnel, and turned the headlights ON, would the light still illuminate in front of the car. Would the speed of light emitted from the lamp be added to the speed of the vehicle?
Tailwinds
If I could notionally drive my car at the speed of light in a dark tunnel, and turned the headlights ON, would the light still illuminate in front of the car. Would the speed of light emitted from the lamp be added to the speed of the vehicle?
Tailwinds
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At the quantum level time doesn't exist or rather that the flow of time is irrelevent, one way or the other.
Also, due to certain particles being the anti-particle of others you have particles that only exist for a moment.
Thus, we have the basis for many worlds.
Anyone for Schrodinger's cat?
Also, due to certain particles being the anti-particle of others you have particles that only exist for a moment.
Thus, we have the basis for many worlds.
Anyone for Schrodinger's cat?
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SkyYacht;
Yes and No.
Yes your headlamps would be on and anyone stood infront of your car would see the light from the headlamp (slightly before being splattered into a million pieces!)and no you would not see the effect of your headlamps being on (assuming you were the driver) as the speed of your car will not add to the speed of the light being emitted; which means if it was dark you would not be able to see where you were going and would mostlikely end up killing yourself fairly quickly (at the speed of light perhaps!)
Yes and No.
Yes your headlamps would be on and anyone stood infront of your car would see the light from the headlamp (slightly before being splattered into a million pieces!)and no you would not see the effect of your headlamps being on (assuming you were the driver) as the speed of your car will not add to the speed of the light being emitted; which means if it was dark you would not be able to see where you were going and would mostlikely end up killing yourself fairly quickly (at the speed of light perhaps!)
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HARRY999...I'm impressed with your calculation...Imagine what the world would look like if one travelled at~c for say 4 years ...Icarus...what you have said is true however, to avoid an absurd mathematical expression c or the speed of light is accepted as absolute...HARRY999...could maybe you tell us why...??? ~