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So you're saying that if a pilot travels in an aircraft at an extremely high rate of speed, at which the passage of time is known to decrease ever so slightly, once he lands the rest of the world will speed up to "catch" him?Quote:
Originally posted by Milo
Even if one were to achieve time travel, no matter how long they remain at that state, when they stop, everything will catch up to them.
Thats what it sounds like he means, Loki, but its not correct. The person would have to slow down below the speed of the earth through the universe for time on earth to "catch up"
Now, lets say the pilot travels around the earth in one continuous circle, say 14 times per second for 1 month. As soon as he lands, no matter where he lands... the person that is standing right next to the aircraft when it lands WILL see him WHEN he lands, because he would have had to SLOW down to 0 to land. He will still be in THIS earth, and in THIS time period. The only true time he would have been in time travel (even though it's not REALLY time travel) would have been when he was at the speed of circling the earth at 14 times per second. It's not really time travel anyhow because when one speaks of going into the "future" they mean to say that the person can experience things which we haven't seen yet... when in fact there is NO future dimension because we create that as we go along in life.
Milo you are being logical but it takes an einstein to explain the fact that when you are going faster than light you some how curve time due to an unexplainable force. I know logically travleing faster than light just means that you are going faster than light but it also means that you are changing pysics it self. And as far as time goes time is simply like the the frames in a movie it is the the division of action. There for time is a constant. tiem is not a measurement it is something we measure with "time" time and time are 2 different things. if everything were to stop so would time because time is change and to make every thing stop you must move faster than light meaning that time and light are now behind you and you now some how change physics and then einstein's thearies come in to play from there i can explain much more. This is all probably why black holes could be worm holes maybe it is just a spot where light moves so fast you can see it because it is moving fastert han light and as something speeds toward the speed of light it gains mass and with enough mass you can speed something faster than light with gravity. So maybe a blackhole is created when a star explodes and its particals move faster than light creating a mass so great it creates a black hole. The last part of this was just ravings so just ignore. It also i think my last post thourouly explains why time travel is immpossible.
Milo, I don't think you're grasping the concept. Let me put it another way...
The example I mentioned is not "time travel" in the typical, science-ficton sense. The pilot in the aircraft does travel forward in time... just we all do, every second of every day. The difference for the pilot, though, is that aboard the aircraft, while it travels at its high velocity, time passes more slowly than on the ground. Naturally, time seems to pass at the same rate to each of us no matter what velocity we travel at. But if the pilot synchronized his watch with a clock on the ground prior to taking off, he would find that, upon his return, a minute amount of time more will have passed on the ground than he experienced in his aircraft. (Obviously the amount of time differential here is miniscule, but would be drastically more noticeable if the pilot were to travel near the speed of light.)
I don't see why you mentioned that an earthbound observer could see the pilot and his aircraft, or that the craft would need to slow down in order to land... these things should go without saying. I'm further confused by your statement that the future doesn't exist. Of course it does. Maybe I'm just failing to understand what you're saying...
Some of us are talking about one thing, and some about another I guess. I was talking about not being able to physically "advance into another dimension". Wires got crossed I guess. :)Quote:
Originally posted by Ara-Loki
Milo, I don't think you're grasping the concept. Let me put it another way...
The example I mentioned is not "time travel" in the typical, science-ficton sense. The pilot in the aircraft does travel forward in time... just we all do, every second of every day. The difference for the pilot, though, is that aboard the aircraft, while it travels at its high velocity, time passes more slowly than on the ground. Naturally, time seems to pass at the same rate to each of us no matter what velocity we travel at. But if the pilot synchronized his watch with a clock on the ground prior to taking off, he would find that, upon his return, a minute amount of time more will have passed on the ground than he experienced in his aircraft. (Obviously the amount of time differential here is miniscule, but would be drastically more noticeable if the pilot were to travel near the speed of light.)
I don't see why you mentioned that an earthbound observer could see the pilot and his aircraft, or that the craft would need to slow down in order to land... these things should go without saying. I'm further confused by your statement that the future doesn't exist. Of course it does. Maybe I'm just failing to understand what you're saying...
As for the theory, I myself do believe it is possible for something to travel faster than the speed of light, I just do not believe "Time is slower than the speed of light." You know what's really fascinating? -- black holes. :eek:
What he is saying is very simple. He is saying that since the pilot is moving at the speed of light, HIS TIME, slows down. So he would see stuff around him going incredibly fast, however, if we were outside the plane, it would almost not appear to move at all - hence time flow outside is undisturbed, so when the pilot THINKS he has traveled around the earth for a month, HIS TIME, he has actually been "suspened" in time moving very slowly around the earth for years.
Quote:
Originally posted by Remington
What he is saying is very simple. He is saying that since the pilot is moving at the speed of light, HIS TIME, slows down. So he would see stuff around him going incredibly fast, however, if we were outside the plane, it would almost not appear to move at all - hence time flow outside is undisturbed, so when the pilot THINKS he has traveled around the earth for a month, HIS TIME, he has actually been "suspened" in time moving very slowly around the earth for years.
http://www.danroadman.com/explode.gif
Quote:
Originally posted by Remington
What he is saying is very simple. He is saying that since the pilot is moving at the speed of light, HIS TIME, slows down. So he would see stuff around him going incredibly fast, however, if we were outside the plane, it would almost not appear to move at all - hence time flow outside is undisturbed, so when the pilot THINKS he has traveled around the earth for a month, HIS TIME, he has actually been "suspened" in time moving very slowly around the earth for years.
uuhhhh i believe the speed is the same both to the person inside and the stationary observer. lets say the pilot gets from point a <---> b, the speed observerd by the observer would be (b-a)/Tobs. the T does change for the pilot (shorter) but length also changes for the pilot so in fact it's a shorter trip with a shorter time interval and if you do the calculations you get the same speed
you are right that the movement of the pilot would be slowed to you, but his speed relative to you is the same. if that is what you meant then disregard this please.
You're right, but this concept is difficult to grasp, so I'll say it another way - the speed of light was found to be a constant in space regardless of the frame of reference of the observer. That means that when taking measurements, two observers moving at different speeds will have to measure a different DISTANCE and TIME for the same event.Quote:
i believe the speed is the same both to the person inside and the stationary observer. lets say the pilot gets from point a <---> b, the speed observerd by the observer would be (b-a)/Tobs. the T does change for the pilot (shorter) but length also changes for the pilot so in fact it's a shorter trip with a shorter time interval and if you do the calculations you get the same speed
The experiment that proved this was the Michelson/Morely experiment. The two of them built an accurate device for measuring the speed of light (at the Naval Academy in Annapolis, MD) - pre Einstein I think. The device measured the speed of light in north-south and east-west axis. Because of the rotation of the earth, they expected to measure the speed of light as either faster or slower along the east-west axis than the north-south axis (depending on which direction they measured it), since the rotation of the earth lenghtens (or shrinks) the distance the beam of light is traveling. But the speed of light was shown to be constant regarless of the axis they measured it on or the frame of reference used (considering the test aparatus stationary or moving). The only way that is possible is if BOTH distance and time are variable.
As for the time travel thing, it has been measured that at higher speed, time slows down. What this means for a human is easier explained with a watch: An astronaut goes into space for a period of time, when he comes back, his watch is BEHIND an identical watch on earth because during his trip time was advancing slower for him and his watch than it was for the identical watch on earth. When he slows down and lands, the rate of the passage of time accelerates back to equal the rate on earth - so assuming he gained a second, his watch will forever be one second behind the identical watch on earth.
Actually gentlemen, lets not forget gravity. Gravity is said to play a major role in the perception and passage of space/time. If an observer was in high orbit around the earth for say 10yrs. He will be a few milliseconds younger than an observer residing on Earth for the same period. Very accurate atomic clocks can pick up the time dilations even when only a few metres off the ground. The difference of course is only measurable in hundredths of a nanosecond. This can be explained since the Earths gravity weakens the farther you are from the surface.
Having said this, it is possible then to time travel many hundreds or thousands of years into the future by approaching a very dense object, it is said that a nuetron star would probably shave off a few hours if you remained in close orbit for several days. Of course the gravimetric forces would be incredible. On the other hand a black hole would be the ultimate vehicle for time travel. Lets say for arguments sake, a pilot could survive approaching a black hole, it is said that even a few seconds exposure could apparently throw the hapless traveller many thousands or millions of years in the future.
Of course "throw" isn't an accurate description, it is more like allowing the passage of time to almost freeze for the test subject, and the closer one approaches the event horizon the slower time passes, until it almost seems that time stops, by which time it is possible for the person to experience eternity itself, if he isn't crushed by the indescribable gravimetric forces.
Note: the following blue section was going to be my question regarding the following question, it is still here because i hate destroying things i have worked at so hard :)
Quote:
i believe the speed is the same both to the person inside and the stationary observer. lets say the pilot gets from point a <---> b, the speed observerd by the observer would be (b-a)/Tobs. the T does change for the pilot (shorter) but length also changes for the pilot so in fact it's a shorter trip with a shorter time interval and if you do the calculations you get the same speed
I dont understand how speed can be the same for both observers.
FasterD = Faster Dude (the observer in the aircraft going at high speeds)
SlowerD = Slower Dude (the observer sitting on the groud)
Speed1 = normal speed of time
Speed0.5 = speed at 0.5 the normal time (now im just picking this number for the ease of argument and by no means do i think it is correct)
FasterD has slowed reactions, slowed in everyway if i understand it correctly, by that i mean that his atomic particles would be slowed and lethargic, aka chemical reactions are slower, and as such he is operating at Speed0.5.
There is a slight delemia with this though, the faster he goes the slower his engines will work and drag factors will increase from the time differencals, so lets assume that he has no friction.
Now SlowerD is sitting on the ground with a good spotting scope looking at FasterD in his aircraft.
During this SlowerD (who is operationg at Speed1) will appear to be moving at twice the normal speed when FasterD (who is operationg at Speed0.5) is looking at him, and FasterD will apear to be moving at 50% the normal speed to SlowerD.
So when FasterD looks out the window he would see himself moving at twice the speed as SlowerD would see him moving at, so he would eat up ground at twice the speed....
Ok, i think i understand and agree with the above quote :)
"You're right, but this concept is difficult to grasp, so I'll say it another way - the speed of light was found to be a constant in space regardless of the frame of reference of the observer. That means that when taking measurements, two observers moving at different speeds will have to measure a different DISTANCE and TIME for the same event.
The experiment that proved this was the Michelson/Morely experiment. The two of them built an accurate device for measuring the speed of light (at the Naval Academy in Annapolis, MD) - pre Einstein I think. The device measured the speed of light in north-south and east-west axis. Because of the rotation of the earth, they expected to measure the speed of light as either faster or slower along the east-west axis than the north-south axis (depending on which direction they measured it), since the rotation of the earth lenghtens (or shrinks) the distance the beam of light is traveling. But the speed of light was shown to be constant regarless of the axis they measured it on or the frame of reference used (considering the test aparatus stationary or moving). The only way that is possible is if BOTH distance and time are variable."
I think i dont understand what you mean by both distance and time being variable(or do i and its just not clicking in my head?).
Actually, gravity slows time - so the affect of being in orbit would increas the rate of the passage of time due to less gravity. However, speed is the overriding factor, making the net time rate decrease.Quote:
Actually gentlemen, lets not forget gravity. Gravity is said to play a major role in the perception and passage of space/time. If an observer was in high orbit around the earth for say 10yrs. He will be a few milliseconds younger than an observer residing on Earth for the same period. Very accurate atomic clocks can pick up the time dilations even when only a few metres off the ground. The difference of course is only measurable in hundredths of a nanosecond. This can be explained since the Earths gravity weakens the farther you are from the surface.
You probably understand it, but its not clicking. I highly recommend you read A Brief History of Time - Hawking explains this stuff very well (though it can still take a couple of reads to make it click). I have mine here....Quote:
I think i dont understand what you mean by both distance and time being variable(or do i and its just not clicking in my head?).
Correction: The Michaelson/Moreley experiment was carried out in Cleveland (in 1887).
The idea of distance being a variable is easy though (maybe too easy). If you play ping pong on a train, how far is the ball moving when it crosses the net? That depends on your frame of reference. For the players, it might move 8 feet. For an observer on the gound, it might move 80 feet.
That is a good book. I've yet to finish it, though, despite numerous attempts.Quote:
Originally posted by russ_watters
I highly recommend you read A Brief History of Time - Hawking explains this stuff very well (though it can still take a couple of reads to make it click).
I bought Steven Hawkings latest book, Universe in a nutshell. I am gonna get stuck into it soon. One interesting observation is that our power consumption is growing exponentially. By the year 2600, the Earth should be visible from its dark side for several million kilometres, due to the unimaginable levels of power consumption in the form of night lighting etc.