Thread: OK so i think that this sounds completely logical. =)

Lets pass this up on here lets say that time travel is possible into the future and into the past. All right so we got that now. Say that i am in my house in my living room and i travel in time backwards lets say a minute(amount of time is not really as important for this discussion}. I would be traveling in time but not in space space would be moving while i was completely still. so it seems likely that when i were to arrive the earth would have moved as well as possible expansion or contraction of space itself. One could expect himself to be imbeded into the make up of his couch or 40 feet in the air. There fore assuming that time travel has been created space manipulation would also need to be incorporated. This seems possible if a space craft be created and calculations would need to be completed on exact "coming to the other side" of the time travel location. there are many other issues with this but lets go ahead and talk it out. =]

Only time travel to the future is possible. Not the past.

i think that you couldnt travel into the future because it has not happened yet. traveling into the past could be possible except the moment you got there time would change and you would be in a different time line than you previously were. like an alternate dimension. but you never know. have you ever seen the movie time line?

Traveling into the past isn't possible because the past already happened.

Traveling into the future is possible. Just wait a minute.

I'm betting that if you time travel to a time and location where you've already been, you smash into yourself. It probably causes some kind of nuclear explosion (on the future end, not the past end). Some conspiracy theorists believe in that effect, but it's probably not worth citing them, since they are.... conspiracy theorists.

If time travel is possible, then it's a very complicated process. You can't change one part of your reality independent of all of the others.

Originally Posted by permifry

Lets pass this up on here lets say that time travel is possible into the future and into the past. All right so we got that now. Say that i am in my house in my living room and i travel in time backwards lets say a minute(amount of time is not really as important for this discussion}. I would be traveling in time but not in space space would be moving while i was completely still. so it seems likely that when i were to arrive the earth would have moved as well as possible expansion or contraction of space itself. One could expect himself to be imbeded into the make up of his couch or 40 feet in the air. There fore assuming that time travel has been created space manipulation would also need to be incorporated. This seems possible if a space craft be created and calculations would need to be completed on exact "coming to the other side" of the time travel location. there are many other issues with this but lets go ahead and talk it out. =]

I guarantee you, if time travel were possible(And I'm not saying that it is), it would work like this:
The device would only allow travel to points in time when the device exists. The earliest you'd ever be able to travel to is the moment the device was activated, and the furthest into the future would be the moment just before it is deactivated. You'd walk into it at one time a walk out another. So the device itself acts as a "bridge" between the time periods. So you don't have to worry where you'll end up as it will be wherever the device is.

This also answers the question: "If time travel is possible, why don't we see traveler's from the future?". No time machines have been built yet so "now" is outside the range of any future time machine.

I really like that last answer and hey it keeps the possibility of time travel opened which while it is highly unlikey something that exists today, or in any near future could still be possible. Obviously we are all currently traveling into the future right now so to travel backward in time you could say what you may need to do is slow down your relative speed of traveling into the future as compared to all the other matter around you. So you would need some kind of space/time bubble to reside within while time outside the bubble past you by. Perhaps time still passes to you within the bubble as normal time being relative and like light being the speed limit of traveling forward in time there is a limit to how fast you can travel backward in time. Therefore the farther back in time you want to go the longer you have to wait within the bubble for normal spacetime to pass you by. So if you are waiting in the bubble maybe there is a way to monitor the passage of spacetime outside the bubble and in that way you could determine the environment into which you will be exiting. Also you will hopefully be able to cause this bubble to move in relation to matter outside the bubble or like the previous post it would need to be a device in which the bubble exist that would determine the relationship of space and matter to which you would exit.
I think current theory holds that if time travel is possible it would either require going faster than the speed of light which directly is impossible or to warp space which would require an almost unimaginable amount of energy so that you could travel to a previous location of space time and if space and time are in deed one then by traveling throuh the warp hole you are not only going to a different space but also time.

I guarantee you, if time travel were possible(And I'm not saying that it is), it would work like this:
The device would only allow travel to points in time when the device exists. The earliest you'd ever be able to travel to is the moment the device was activated, and the furthest into the future would be the moment just before it is deactivated. You'd walk into it at one time a walk out another. So the device itself acts as a "bridge" between the time periods. So you don't have to worry where you'll end up as it will be wherever the device is.

This also answers the question: "If time travel is possible, why don't we see traveler's from the future?". No time machines have been built yet so "now" is outside the range of any future time machine.

This would be by way of wormholes, no? It is also the reason why people have been talking about when the LHC gets fully underway, that it could possibly the first time time travellers from the future might be able to link to us, provided the first recorded wormhole is created by an energetic enough collision?

Thinking of time as a dimension that can be travelled along makes no sense to start with.

Originally Posted by Janus

Originally Posted by permifry

Lets pass this up on here lets say that time travel is possible into the future and into the past. All right so we got that now. Say that i am in my house in my living room and i travel in time backwards lets say a minute(amount of time is not really as important for this discussion}. I would be traveling in time but not in space space would be moving while i was completely still. so it seems likely that when i were to arrive the earth would have moved as well as possible expansion or contraction of space itself. One could expect himself to be imbeded into the make up of his couch or 40 feet in the air. There fore assuming that time travel has been created space manipulation would also need to be incorporated. This seems possible if a space craft be created and calculations would need to be completed on exact "coming to the other side" of the time travel location. there are many other issues with this but lets go ahead and talk it out. =]

I guarantee you, if time travel were possible(And I'm not saying that it is), it would work like this:
The device would only allow travel to points in time when the device exists. The earliest you'd ever be able to travel to is the moment the device was activated, and the furthest into the future would be the moment just before it is deactivated. You'd walk into it at one time a walk out another. So the device itself acts as a "bridge" between the time periods. So you don't have to worry where you'll end up as it will be wherever the device is.

This also answers the question: "If time travel is possible, why don't we see traveler's from the future?". No time machines have been built yet so "now" is outside the range of any future time machine.

Now, suppose after we figure out how to build such a machine, we start to be able to identify natural time machines in nature, when we find them. Could we manipulate one of those to take us back in time even further?

Of course, there's no saying we would ever find one. I'm just thinking that if we understood the theory behind it, we might find that time machines have been present in nature all along. We just didn't know how to activate/use them.

Originally Posted by permifry

Lets pass this up on here lets say that time travel is possible into the future and into the past. All right so we got that now. Say that i am in my house in my living room and i travel in time backwards lets say a minute(amount of time is not really as important for this discussion}. I would be traveling in time but not in space space would be moving while i was completely still. so it seems likely that when i were to arrive the earth would have moved as well as possible expansion or contraction of space itself. One could expect himself to be imbeded into the make up of his couch or 40 feet in the air. There fore assuming that time travel has been created space manipulation would also need to be incorporated. This seems possible if a space craft be created and calculations would need to be completed on exact "coming to the other side" of the time travel location. there are many other issues with this but lets go ahead and talk it out. =]

in one minute... The earth will have moved approximately... 1100ish miles, so you would be likely WAY out beyond our atmosphere or, equally likely, deep inside the earth. Either way, you'd be a long ways off from your couch. That calculation was done assuming that The distance from the Earth to the Sun is about 92 million miles, and that it takes about 365.25 days for the Earth to travel about one revolution around the sun. meaning we are moving at about 66,000 mph, for the rotation of our planet, assuming the sun isn't revolving around the center of our galaxy.

Originally Posted by kojax

Now, suppose after we figure out how to build such a machine, we start to be able to identify natural time machines in nature, when we find them. Could we manipulate one of those to take us back in time even further?

Of course, there's no saying we would ever find one. I'm just thinking that if we understood the theory behind it, we might find that time machines have been present in nature all along. We just didn't know how to activate/use them.

Or here's a thought:
Assume such natural time bridges occur and the distance between the two ends is always equal to the distance that light would travel in the time period between the two ends. For instance, if traveling from one end to the other takes you back 1000 yrs, you also end up 1000 ly away from where you started. You step in one end and end up at the other. The time traveled from one end to the other is fixed.

Further, assume that due to the stress that these bridges place on spacetime, the ends of individual bridges can not be any closer than this same distance. (If you have a bridge that spans 1000 yrs, you cannot have an opening for a second bridge closer than 1000 ly away from either end.)

You can step into one end, and end up 1000 ly away and 1000 yrs ago. Nothing you do in the past can affect anything you did before you stepped into the bridge, as it would take a minimum of 1000 years at the speed of light for the effect to propagate back to where you started.

Daisy-chaining bridges together won't take you any further into the past, as you will spend more time traveling from one to another than the time span between ends.

"Time travel" is allowed, but causality is preserved.

Causality is not preserved. I can travel 2000 years into the past be walking the same bridge twice in your example.

Originally Posted by Arcane_Mathematician

Causality is not preserved. I can travel 2000 years into the past be walking the same bridge twice in your example.

Maybe I wasn't clear enough.
If you walk through one way, you end up 1000 yrs in the past, if you walk through the other way you end up 1000 yrs in the future. It is a bridge that "connects" two points in spacetime. If you enter one end in 3000, you walk out the other 1000 ly away in the year 2000. You stay until the year 2001, walk back through, and end up back where you started in the year 3001. Walk back through again and end up back in 2001. The two ends maintain the same 1000 year separation.