is time travel possible???
No, it's not possible. Time is a string of moments. Past moments represent the universe in a string that does not exist anymore. Future moments represent the universe in a state that doesn't exist yet. Only the current moment truly exists.
As for relativistic effects, they are not time travel. If we both are on earth we share a common frame of reference, therefore time is the same for both of us. If you sit in a plane and zip through the atmosphere we don't have the same frame of reference anymore, but you will still age a second in a second. It is only when you join a common frame of reference with me that we see differences. The faster your plane goes, the bigger the difference.
Relativity is all about frames of reference. BTW, gravitational fields are good for relativistic effects too.
So the answer is no, time travel is not possible. Whacky theories exist that involve black holes, strings and whatnot, but there is no practical idea for timetravel (wich means, there is no practical way to alter the state of the universe to a state it would have in the future or had in the past).
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Well I know this has been answered but I think that one day it could be possible! -Already we know that Einstein's Theory of relativity (e=mc2) is correct and makes sense, until we show it the Big Bang or Black Holes -If we use the theory, then TIME, MATTER, DENSITY and PROPORTION (size etc.) = infinity. -If we can ever simulate a black hole or the big bang, scientists can actually observe infinite time: Time with no limit! -The theory is based on relativity, only the are around which the black hole effects will be in that time zone -But with infinite time, there is no set point: It is time without limit! Therefore, perhaps time travel could one day be possible?
You are already travelling forward in time. So the answer to your question of "is time travel possible???" is yes.
Only if you have a source of negative energy density; see Morris, Thorne and Yurtsever (PRL 1988).
do u mind givin me examples of negative energy density??????????black holes??????????????
Black holes are the endpoint (limiting state) of graviational collapse. If you have a large sphere of matter (like a star) it will contract under its own gravity. Normally, that compression heats up the material (which is what gets stars burning in the first place), and the pressure then holds them up.
If enough material is involved, though, gravity can be strong enough to overcome that pressure, and (especially if the burning material explodes) you can end up with a collapse all the way to a point.
Very close to such an object, gravity can be strong enough that you can't escape from it, and even closer, no even light can escape. That's why it's called a "black" hole.
Everything I've described above is rather theoretical (though the math is solid enough that we don't doubt that it's correct). In space, we have observed many candidates for black holes, ranging in mass from 5-10 times the mass of the sun, up to millions of solar masses (such as the one at the center of the Milky Way).
Negative energy density (or rather, "exotic matter which violates the weak average energy condition), is a purely theoretical construct, where you use a minus sign instead of a plus sign. No one has ever observed anything like it. The negative is requires to create a "pressure" that prevents a black hole/wormhole from collapsing, and letting you travel through it like a time machine. But as I said, it's just playing with math.
nice one.u seem to know pretty much.i'll be bringin more question far more intriguing.but for now lemme ask you a question 'Do u think Einsteins Theory of Relativity is true?do u actually believe dat nuthin can cross the speed of light??
PS-May I Know Your Designation If Ya Dont Mind
I want to add my opinion too. We can actually predict relativistic effects and systems with Einsteins work. A good example are GPS sattelites. Checkout how the system works on Wikipedia and be amazed that GPS sattelites actually seem to travel in time (wich they do not, they just have left our frame of reference).So, for physics Einsteins theory is good and quite often tested. However, there are many things that can not be explained yet with his works, just like Newtons work could not explain everything. But for now it's the theory that explains what we measure and see best.Stuff like speed of light is the highest speed and E=MC² however will most likely not change anyways, just like many of Newtons works was and still is correct. I think the next big theory will be a addon ;).
You can follow the link with my username to find out more about me. Relativity is almost certainly correct; I use it in my work every day. Here's some more discussion on that subject: http://www.pbs.org/wgbh/nova/einstein/toda-kelsey.html
Yes. Let's say that you live in London, and it's 10:00 AM. If you somehow manage to go to Wellington in a second, it would be 9:00 AM. SO yes, Time travel in technically possible.
Yes but only into the future - not the past.
As Bigev says we normally travel through time into the future at a rate of one second into the future for every second of our time but it is perfectly possible to travel into the future at a faster rate.
If you get into a spaceship and zoom away from the earth at a phenomenal rate then turn it around and whizz back to Earth your journey time might be, lets say, a couple of years in space but, when you get back to Earth, you will find that many many years have passed - thus you have travelled into the future! This is real.
Time travel into the past is strictly not allowed! Ever! Not Never! Cannot happen. Take it from me - I've tried.
What do u mean u tried?anyway i know about the spaceship.But there is a problem the spaceship must be travelling at the speed of light which is(according to theory of relativity)not possible.
and i also agree to what kelseymh said but can u give such examples of high energy density other than black holes??
No, this relativistic effect can be measured with speeds much lower than lightspeed, like a flight to the moon or even a plane. Of course the effect is quite small in those cases. But it was actually measured in experiments with highly accurate clocks.
Not any more...
Yes. Unfortunately, we are only capable of traveling in one direction at a set speed.
look up ronald mallet. He is trying to make a time machine using a heck of a lot of lasers. Something about a vortex of light simulating gravity and frame shifting, and closed time loops. You could try travelling dangerously close to a black hole too.
Related question, might be informative?https://www.instructables.com/answers/How-can-i-build-a-time-travel-machine-on-the-cheap/L
I guess so! I answered this before you asked the question.