"The future ain't what it used to be."

Time travel in past doesn't sound relastic


Time travel in past doesn\'t sound relastic

Time travel in future sounds logical to me. It is possible because for an astronut, when he comes back to earth from a space journey, he might spend 300 days only but his wife who stayed on the Earth might spend 305 days.

Thsi is possible because of time dialtion. Similarly if somebody travel near speed of light, he can jump 5 years instead of 5 days. We can take that event as time travel.

But when it comes to TimeTraveling in Past, it doesn't sound realistic. Is there anybody who can make explain "timetravel in past" as limply as I explained "tiem travelin future."
RE: Time travel in past doesn\'t sound relastic

You view illustrates the idea that most people hold that time is linear. it's hard for most of us to imagine that it is not when that is the very basis of our world. But if time is linear it doesn't explain a lot of ideas, like relativity for one and infinity for another. For time to be linear, it must have a beginning and end, but infinity by it's very definition doea not. Try exploring other avenues of thought rather than relying on what humainty tells you.

RE: Time travel in past doesn\'t sound relastic

All my life,I have been flying very high and exploring all the possibilities. Reading different articles, Doing Research. It is not that I don't think the time is not linear.

Theory of relativity makes the curve on time itself and most of the physics rules fail under very high gravity or near light speed. Only thing I did not see is time going backward. Or let's say time going in a loop.

Let's suppose I made a device which goes in light speed, theoritically time stops for me relative to the people who are on Earth. My body mass will increase and theoritically it will become infinite. Now if we increase our speed, our body mass will remain infinity and time will stay still(compared to The Earth Time.)

I am making this statement because light can travel faster than light under certain conditions, which means all the hypothesis made by assuming that light speed is constant fails under this condition.

Another thing is I red a lot of aritcles in this forum but most of them sounds like dream, very few of them are relastic. If we want to reach somewhere we have to learn to walk on the ground, then only we can reach somewhere. I am a open minded person, so lets investigate.......
RE: Time travel in past doesn\'t sound relastic

The thing is there could be time loops, or a reversal going on. But we wouldn't know about it.
RE: Time travel in past doesn\'t sound relastic

I agree with you Lara, but let's start with what we know then we can jump into the field which we don't know.

I agree that time is not linear and it started sometime in infinite. The way I see Time travel right now is possible only by travelling in very high speed. But no matter how fast you travel when we come back to the Earth or simply reduce the speed to normal speed, the TIME becomes linear from that point.

This proves that the time is inversly proportional to the speed for that object. But we measure speed WRT time so if we draw a graph for time and speed we will have a curve. Not a straight line. That simply proves time is not linear.

Has any one got this solved????
If anybody is confused about curvature of time I am still here.

Now we already know that time is curve, can space be curved just like time????

If the answer is yes, we will not be able to travel very fast in a straight line because of the curvature of space.
RE: Time travel in past doesn\'t sound relastic

We know space is curved, because it expresses it self as gravity. Any travel through space has to take that into account.
RE: Time travel in past doesn\'t sound relastic

I kind of disagree with your opinion. When I explained space-time curvature I actually ignored gravity.

Curvature in Space is possible without the involvement of gravitational force, and if you had read last topic very carefully, I think I had made myself clear.

Lots of people like to read about fancy stuffs about Science, but I am trying to investgate the facts. Right now I am talking about time and space, no gravity is nivolved.
RE: Time travel in past doesn\'t sound relastic

You disagree with my opinin that travel through space has to take gravity into account?

If you talk about curved space-time, you have to talk about gravity. It's not that I'm not listening to you, but it's just accepted fact that curved space is the basis of it.

Really, gravity is at the core of time dilation, and can't be ignored.

<This message has been edited by Lara (edited 27 April 2001).>
RE: Time travel in past doesn\'t sound relastic

Let's say what you are saying is right. If I travel close to the speed of light. My time will be slowe than yours if you are on the Earth. There is time dilation, without involvng the gravity at all.

Time travel through black hole is a different theory and this is different. yes, theoritically space-time can be bent under very high gravitational field.
RE: Time travel in past doesn\'t sound relastic

As a body approaches the speed of light, its mass increases to infinity. This increases the curve on the space around it and represents itself as gravity. At infinite mass, the universe would collapse. Therefore, even time dilation through high speed travel involves gravitational forces.
RE: Time travel in past doesn\'t sound relastic

Right but time dilation is possible only when we travel in 0.1% of light speed and at that speed our mass doesn't increase that high to create big gravitational force but time dilation is still possible, isn't it.

I have thought about that too. See the thing is we need some kind of curve or some new ways to achieve that kind of speed. Now the question is; is it easy to gain tremendous speed or to create very high gravitational force?????

My suggestion is if we can use the curvature of space to increase our speed and the increased speed will create bigger gravity, Hence we will have bigger curvature in the space. That curvature will let us travel faster in the space; Physically we covered a huge distance using the curvature.

If we can Practically apply this chain, we can break the boundry of linear travelling(I mean in a straight line).

Main advantage of this chain will be we will be able to control the tremensous speed and the tremendous gravitational force. But as you mentioned before, (practically)we will not be able to gain very high speed because we will collapse into our own gravitational force.
RE: Time travel in past doesn\'t sound relastic

I'm not saying time dilation isn't possible. It's already been proven. But its possible at any speed, not just 0.1%c. Ofcourse, it's not practical at anything less than a significant percentage.

Using curved space to atain near light speed is impractical, because you would need a pretty big curve, and that equals out to a gravity well strong enough to destroy any craft within its influence.

I'm of the opinion that using high gravitational forces or relativistic speeds is not practical at this point in time because of the energy required, and another method needs to be found.

The original post, I think, was if there was a way to simply explain time travel to the past. If you can travel to the future, you can travel to the past, but it means doing away with the illusion of tomorrow and yesterday.

The old proposal of a time machine using wormholes is a good example. Leave one end of the hole on earth, and put the other end on a spacecraft traveling at near light speed. Eventually, the moving end of the wormhole could be pretty far in the future.

One from that time could than jump through and arrive in the past.

<This message has been edited by Lara (edited 28 April 2001).>
RE: Time travel in past doesn\'t sound relastic

Don't worry about the nuts and bolts. We're a long way from that point yet. Let's assume that it "is" possible, or rather, "will be" possible. Does it make any sense to attempt time travel into the past? In other words, do the possible benefits outweigh the risks? I'm not sure, and here's why. First, and most important, any trip into a time period before the device/mechanism exists that permits time travel is a one-way trip. It's pretty unrealistic to believe that a mechanism capable of generating a temporal rift in the space-time continuum could fit in your pocket. Once you arrived, you'd have to wait for such a mechanism to be built to travel through time again. Plus, your very existence in that earlier time line could alter events in unconceivable ways. I'm not going into paradoxes because I'm now convinced they can all be "adjusted to" by the altered time-line. The only benefit of traveling back in time would be to transfer the knowledge of successful temporal mechanics to previous generations and "hope" it will not be abused.
No, the only way to go is into the future. By starting from the point of successful time travel and moving forward, you are relatively assured of a possible trip back since the mechanism which made it possible will still exist, hopefully refined to work even better. The risk factor of going into the future is also no greater than the risk you currently pose in this time line. Even the paradox thing is pretty much neutralized. You have to ask yourself the question, "If time travel may some day be possible, why haven't we been visited?" Some would say, "Maybe we have." I believe we won't, since the risks outweigh the benefits. Long story short, answer the big questions first...then we can worry about what color to make the seat.
RE: Time travel in past doesn\'t sound relastic

Any risk involved with time travel to the past is the same as travel to the future. After all, any event is really just another events past. By travelling 10 years into the future, we could unknowingly prevent the universal vaccine from being invented 5 years after.
RE: Time travel in past doesn\'t sound relastic

HimaliYeti and Lara have bring the real red meat in this forum.

This is why I come here half of the time (on this forum of TT; to see some discussion, get some action. 99% of the time, people dosen't want to get wet (in a fight). I don't say that to promote violence but because I'm simply think that we only get further (in knowledge), when we compare our idea with conviction ...

Anybody does not agree?

Read meet.
RE: Time travel in past doesn\'t sound relastic

Time travel in past has a lot of paradox and logically (if we think totally rationally) there is no answers, those are just hypothesis which are more likely to be true for those people who like ot fantasize.

Now let's assume that time travel is possible in future, so there is no point if that person can't travel back to the present time. So???.....