Time travel Definition and 350 Threads

Let’s say we have a spaceship capable of traveling at the speed of light, and a planet we can visit 50 light years away. From earth’s perspective if we can track the ship we would be able to see it was traveling at the speed of light and we would also see it has taken 50 years to complete the...

I am going to give write an essay about time travel. What does science say? What is the arguments for possibility and against possibility. And what does General Relativity Theory say about time travel? Theoretical possible, but not practically?

I have recently heard of a theory that states that faster than light time travel is possible by disrupting the fabric of space-time using tachyons, to create a makeshift wave behind a future spacecraft of some sort. It states that by doing this, one creates a bubble around the spacecraft ...

This is the explanation I give people when they ask about time travel. I am only an undergrad so I just want to ask the more experienced people here if this is correct. Thanks... Time travel in the context of Einstein's relativity: So we all know that time travel into the future is easy...

Time time time Can the laws of gravity permit curving space and time in such a way as to make time travel possible. Einstein's theory of relatively states that the space/time continuum can be flat, but it can also be curved by gravitational fields. Perhaps time has three folds 1...

From what I've seen, most speculations of time travel seem to say that when you go back in time, everything else around you returns to an earlier state that it used to be. For example, if you stand outside your house and go back in time, the house will "un-build" itself and there will be nothing...

How is time travel possible? i understand that we can warp and modify time but i don't understand the concept... Is there any evidence to suggest that there are wormholes? if so how are they created?

First of all, my background: I am an engineer interested in physics; so I am not very well versed with the nitty-gritty details and the math of physics. These are my thoughts and would like your comments: In some sense, time travel, being able to move back and forward in time is the...

I don't know if this has been discussed before, but I offer this paradox to debunk time travel. If time travel was possible, given an infinite amount of time from the point of its discovery and perfection; then someone eventually would have traveled back in time and made its existence known...

Is time travel is possible?

Not sure if this will have anything to do with quantum mechanics.. but... Ok so if you're traveling faster than light speed, then what do you see? I'm not talking about the whole doctor who scenario, its like traveling faster than sound, if the jet pilot is traveling faster than the sound it...

i´m new in this fisics forum but, i would like tomake some questions about time travel...is there any specific place to put that kind of questions?

1.Light is moving so fast that is apparently stopped.But it ain't.Photons of light come and go. Now the question: Is light seeing us stopped?Like we arent moving? Thats a dumb question.Of course the light sees us stopped.If i ride a photon of light from Sun to Earth everything is stopped.8...

You all have heard of the paradox whereas when you travel to the past and kill your grandfather you should not have existed in the presence whatsoever because you have killed your origins. So far so good...but I thought of another case, which I believe is more interesting since so far the...

Why would time stop if you travel at the speed of light?

So I was watching a video on youtube. http://www.youtube.com/watch?v=QM28eErikAo" It says that the faster you travel through space, the slower you travel through time, and that if you went faster than light, you could go back in time. Is this true? Forget about it being impossible to go...

No pitchforks please (and lay off the caps with the big 'D' on them too) Following staying up until 4am (all good stories start like this), and making small talk with a friend doing a degree in physics, we both decided to harp on about theoretical theories such as string etc, and as hours...

I have thought of an interesting property of time travel based on Novikov's self-consistency principle. I'm sure it's not wholly original, but if someone has heard of it before, I'd really like to know the name given to it so I can research it: If you find yourself next to a future version of...

If you are traveling away from Earth on a spaceship near the speed of light, it is well known that the moving clocks on the ship run slower relative to stationary clocks on earth. I was wondering if while on the space ship, you could watch the news on TV and see events progress at a...

Someone here once said to me, via post, that "any compact spacetime must have closed timelike curves". Are there any good references out there on why that is / how that is derived? As an after thought... Isn't it true that a particle traveling in one direction in time is equivalent to its...

What are your thoughts about this?

In the movie, when superman flies near light speed, he manages to reverse time? Was the story-line just completely off from a physical perspective or is there some truth to this phenomenon? I understand that time would slow down for superman from a human's perspective. Maybe I just didn't...

I was just watching Ian Morison on Fora.tv about Time, in chapter 14 he talks about wormholes and time travel. You can see the time travel part here: http://fora.tv/2009/03/19/Ian_Morison_Its_About_Time#Journeying_Through_Space_and_Time_in_a_Wormhole Anyhow, in short he mentions opening a...

I was wondering the feasbility of time travel. Has it been proven not possible? Has it been proven theortically possible? I have always been interested in time travel, even if it seems like science fiction, but was wondering from scientist, professors, etc, if it has been an 'unsolved'...

How time Travel work ? ok i know some of the basic about speed of light... You can't get to the speed of light ... You can't reach the speed of light cause According to Einstein's special theory of relativity, and E= MC ^2 objects gain mass as they accelerate to greater and greater speeds. Now...

Under the general relativity principle, If you take a wormhole, put one end into a gravitational well, then take it out, there would be a time difference between the two openings of the wormhole. But, what effect would it have on the wormhole if you keep the middle area of it near a...

I don't know much about physics, but I was wondering the other day whether what I was thinking was a popular theory. If time is like a one dimensional line and it starts at the orgin and it grows like a vector along the line as time progresses, then wouldn't it only be possible to travel back...

Theres the Butterfly effect and Grandfather paradox which makes logical time travel into the past difficult. Is there any theory or anything which suggests it may be possible?

I'm doing some research into time travel for a presentation I have to give in a month or so, and I'm currently looking at the compatibility of Time Travel and the Laws of Conservation. Sending an object back in time would increase the mass - and hence the energy - in the Universe at this...

If time is a curvature in spacetime as described in relativity, then picture this. If there is a curvature in spacetime time is going in one direction (let's call this curvature 1) but then could time travel not be possible by having a second curvature in curvature 1 but going in the opposite...

Okay, I read this on a blog so I'd post it the way it ias with the link: "There is one aspect of time travel that nobody considers, whether in science or science-fiction (at least, i am not aware of it), something that has the potential of rendering time travel, even if it is possible...

if it is possible to travel faster than the speed of light will we be seeing the future or the past?

First of all, (following Einstein's theory of Gravitational Time Dilation (I'll just call it GTD,)) objects (such as us) age slower near strong gravitational fields than in empty space. The higher the local distortion of spacetime due to gravity, the more slowly time passes. So according to GTD...

I found a decent page explaining this but it's a little deep for my understanding. I think I understand the basics of special relativity where the speed of light remains constant regardless the velocity of 2 observers, the laws of physics do not depend on location or motion, and that length...

Since I only learned special relativity but not yet general relativity, please bear with me that our discussion will be limited to the scope of special relativity, that is, suppose we would not utilize special spacetime topology, such as worm hole and black hole. I ran into some video about...

I had a thought that I wanted to run by physicsforums so all of you can tell me that I'm wrong and make me feel better. One of the main issues with the concept of time travel into the past is that we don't know whether is breaks any physical laws in the process. Here is what I believe...

Is time travel possible quantum world?

Hi, I want to know from proffesionals if time travel is physically possible. Thanks, Tony

Homework Statement Identical twins Speedo and Goslo join amigration from the Earth to Planet X. It is 20.0 light years away in a reference frame in which both planets are at rest. The twins, of the same age, depart at the same time on different spacecraft s. Speedo's craft travels steadily at...

If we have two balls, a red and blue ball, and the red ball passes the blue ball at 99.9% the speed of light, would "time" for the red ball pass slower than it does for the blue ball? If it does, and if speed is just relative, couldn't we say the blue ball is passing the red ball at 99.9% the...

i would just like to know where to get some good info on possble time travel and some people personal views on it. Thanks.

Just wondering what the connection is between them, I understand that it relative to what we see but time in general? why not the speed of sound as its only another sense right? Just interested to know why light is so special? thanks guys, :smile: Sorry messed up title should be speed of...

Two objects lie motionless in an isolated frame. One object accelerates to a speed v, then then holds that speed for an amount of time t. This causes the accelerated object to travel a time t_s into the still motionless object's future. v=\frac{c\sqrt{t_s^2+2t_st}}{(t_s+t)} If you're...

I'm no theoretical physicist or physicist of any kind, but I have some basic grasp of how the universe works and after thinking long and hard about time travel, I don't think we have to worry about the paradoxes which are inherent to time travel when time traveling into the past. If we are to...

I've been told that as a person approaches the speed of light, time relative to others being viewed slows. when you make the speed of light ( if possible, I’m aware of distance change and mass increase and of the immense amount of energy needed to possibly reach this speed to push that mass)...

I think I know why we can't time travel backwards. I have been researching like mad at my skool and I think i have the answer. If I'm wrong, PLEASE tell me. This is for a research paper, and I am trying to navigate my way out of the math and stuff: We are in the present, while physical...

Hello, I’ve been browsing these forums for a while now; I like physics and I get really interested in all sorts of physics stuff. My main interest is space because I find it really fascinating. I have two questions that I’ve been curious about for a while now; The first question is about...

Hello everyone, I am new to this forum and would greatly appreciate your expertise in answering (or attempting to) a few questions for me. I don't care if you focus on one or all of them, but any answers are appreciated! These are about time travel, with a focus on traveling BACK in time...

Hello everyone, I am new to this forum and would greatly appreciate your expertise in answering (or attempting to) a few questions for me. I don't care if you focus on one or all of them, but any answers are appreciated! These are about time travel, with a focus on traveling BACK in time...

the basic theory is that if you travel fast enough then time will go slower for you then the rest of the universe. doese anybody know if this is true or not?