About Time Traveling..

[intro]

I've heard a lot about time travel and I've been pretty interested about it. But as Einstein said if you can go at a speed faster then light the time around you "slows down". But after hearing this many other scientists said that if you travel faster then the speed of light you may be able to Reverse time itself. But if what i'm thinking is right the reason Einstein said that time slows down is because your moving at a faster speed then everything else around you.<br /><br />Example: In normal speed it would take you about 5 minutes to walk to the mall (in my case). But if you travel at the speed of light or faster, then you'll be able to get to the mall at about 0.0001 seconds or whatever the calculation is. Thus you slowed the time down by gettin to the mall faster then you would have when traveling at normal speed.<br /><br />So what I'm saying is that It may be able to Slow Down time but technically I think that it is impossible to Reverse Time. <br /><br />Any suggestions???

 

[observer1]

i dont know if your on target, but the thought of being able to go back in time is just down right cool. i would love to go back and warn myself off the ex-wife and cigerettes!!!

 

[Leovinus]

Getting to the mall faster is not what is meant by slowing time down. Heck, you can get to the mall faster by taking a car rather than walking.<br /><br />I believe that tachyons are theoretical particles that are said to go faster than light by going backwards in time. Don't know much about them, however. <div class="Discussion_UserSignature"> </div>

 

[kelle]

How much time slows when travelling at a certain speed can be found with this formula:<br /><br />t = t0 / sqrt(1-(v^2/c^2))<br /><br />t0 = normal time<br />sqrt = square root<br />v = speed<br />c = speed of light (3*10^8 m/s)<br />t = the "new" time<br /><br />So if you move at... let's say 0.6 times the speed of light for 1 minute<br /><br />t=60/sqrt(1-0.6^2) = 75<br /><br />A person standing still with a watch would count 75 seconds have passed, while your watch would show only 60 seconds have passed. So you would slow 15 seconds each minute compared to people standing still relative to you. Though it is not possible to go back in time by going very fast, even if you have the exact speed of light, you would only stop time, not reverse it. And, as Einstein said, it is not possible to go faster than light.<br /><br />Uhh... it's a long time since I had physics last so someone correct me if I'm wrong about something here.

 

[jcdenton]

<font color="yellow">And, as Einstein said, it is not possible to go faster than light.</font><br /><br />Actually a team of physicists at Princeton observed a laser beam travel faster than the speed of light in a cesium chamber (click here for more information). Somehow the chamber acted as a speed catalyst for light, but it wouldn't apply to physical objects, so there's still no application yet. <img src="/images/icons/frown.gif" /><br /><br />However the theory about the speed of light (c) being the absolute constant in a vacuum still holds true. <div class="Discussion_UserSignature"> </div>

 

[observer1]

hum........interesting.

 

[iron_sun_254]

That looks like quantum tunneling to me. In any case they admit they don't know if the light which leaves the chamber is the same that entered it so nothing was truly moving faster than light.

 

[mooware]

I thought it was that the faster YOU go, the slower time goes for you, not everyone else..

 

[jcdenton]

<i>Previously, experiments have been done in which light also appeared to achieve such so-called superluminal speeds, but the light was distorted, raising doubts as to whether scientists had really accomplished such a feat.<br /><br />The laser pulse in the NEC experiment exits the chamber with almost exactly the same shape, but with less intensity, Wang said.</i><br /><br />-<br /><br />It was a physicist at the University of Toronto who was skeptical about the experiment, not the team that conducted it. <div class="Discussion_UserSignature"> </div>

 

[nacnud]

I realise that tachyons don't officially exist but do you realise that a positron (the anti-matter equivalent of an electron) obeys the same equations as an electron but with time reversed. Take a look at Feynman diagrams to see what I mean. Spooky <img src="/images/icons/smile.gif" /><br /><br />There are also certain solutions to general relatively that allow backwards time travel but most are impractical, for example having a rotating universe (thanks to Godel for that one) or an infinitely long rapidly rotating ultra-dense cylinder, Wikipedia has a good overview here.<br />

 

[nacnud]

<font color="yellow">I thought it was that the faster YOU go, the slower time goes for you, not everyone else...</font><br /><br />Close. It always appears that to an observer that they are moving through their own frame of reference at the rate of one second per second. However differences appear when two observers try to compare times. In that case it will appear to the slower moving of the two observers that time is slowed in the faster moving frame, while the faster moving observer will see time moving faster in the slower moving frame. However both will view time as moving normally in their own frame.<br />

 

[killium]

"In that case it will appear to the slower moving of the two observers that time is slowed in the faster moving frame, while the faster moving observer will see time moving faster in the slower moving frame"<br /><br />What is the reference used to know wich of the two is going faster ? If i quit Earth at 50% light speed, isn't that true that the "Earth is leaving me" at 50% light speed ? I would see Earth time going slower, as well as Earth inhabitant will see my time going slower.....humm.... some thing doesn't jive here, i must be missing something. Someone ?<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[jcdenton]

If you're leaving the Earth at a certain speed, time in your frame of reference will pass slower than that of Earth's, since you are moving relative to the Earth. If someone was moving at the same speed parallel to you, there would be no time discrepancy between the both of you. <div class="Discussion_UserSignature"> </div>

 

[igorsboss]

Do we have to continue to talk about time travel?<br /><br />It just seems like I've been hearing the same exact story again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again<br /><br /><img src="/images/icons/wink.gif" />

 

[killium]

Yes, someone going parallel to me would be in the same reference frame as me. But if we look back at the Earth, shouldn't we see Earth's time going slower ? In our frame reference, it's the Earth that is going away. <div class="Discussion_UserSignature"> </div>

 

[jcdenton]

No, you would see Earth's time passing by more quickly. The distance between you and the Earth is growing, but you're the one in motion. <div class="Discussion_UserSignature"> </div>

 

[killium]

"but you're the one in motion"<br /><br />well maybe not...... in my frame of reference, i don't move. Now, what is the frame of reference used to tell wich is moving ?<br /> <div class="Discussion_UserSignature"> </div>

 

[astrophoto]

It's all relative. Everything is in motion compared to -something-, you just need to pick the right thing.

 

[jcdenton]

<font color="yellow">Now, what is the frame of reference used to tell wich is moving ?</font><br /><br />From the perspective of every other object relative to Earth, you're the one moving. <div class="Discussion_UserSignature"> </div>

 

[observer1]

IGORSBOSS, this whole thread is about time travel. it said so on the title. does anybody REALLY think a time will come when we can input a certain time and day and be able to step into it?

 

[kelle]

I think travelling forward in time will be a possibility. But travelling backward in time, I think will never be possible. It just makes too many "If I kill my grandfather"-types of paradoxes. Though perhaps it is possible by that when we travel back in time (or just send a message back in time), a new universe is created, where the future is affected by your timetravel, but YOUR world will never change (like in the book Timescape by Gregory Benford). This is very science fiction-istic, but hey, it may be possible.

 

[nacnud]

Hum... I suspect that I've messed up a bit some where in there, have a play with this website to see if it helps

 

[igorsboss]

I'm just sayin' that when it comes to time travel, if I tell you once, I've told you a million times.<br /><br />(the paradox: travel back in time only to tell yourself how to travel back in time.)

 

[jcdenton]

<font color="yellow">I'm just sayin' that when it comes to time travel, if I tell you once, I've told you a million times.</font><br /><br />More like an infinite number of times, considering the recurring time loop. <div class="Discussion_UserSignature"> </div>

 

[jatslo]

<font color="yellow">A person standing still with a watch would count 75 seconds have passed, while your watch would show only 60 seconds have passed. So you would slow 15 seconds each minute compared to people standing still relative to you. Though it is not possible to go back in time by going very fast, even if you have the exact speed of light, you would only stop time, not reverse it. And, as Einstein said, it is not possible to go faster than light.</font><br /><br />The problem with speed is, if you take off too fast, the gravitational forces will reach havoc on your body, and if you are traveling through other particles, like oxygen, the particles hitting you will cause damage to your body.<br /><br />Theoretically, you could apply force that is equivalent to the Earth's gravity, and accelerate constantly forever if you wanted, except there's a little problem with paradox. Some people think you will bounce off yourself, and others think you will move through dimensions, and yet, others think that when you switch dimensions, something else will enter our dimension.<br /><br />If time travel is to be proved or disproved, it will be done within a quantum computer.<br /><br />Here is some info on time loop:<br /><br />http://en.wikipedia.org/wiki/Time_loop_logic<br /><br />I am playing around with quantum computers on the following:<br /><br />http://uplink.space.com/showflat.php?Cat=&Board=businesstech&Number=179696&page=9&view=collapsed&sb=7&o=0&fpart=<br />