is time travel possible?

Couple questions:

1. Math isn't quite my strong point but... Doesn't dividing by 0 give you infinity? if this is the case would your density tend to be near that and wouldn't that be bad, like universe collapsing in on itself bad?

2. I have heard theories composed of taking two wormholes (if they were able to be handled) and using the space-flight example and creating one that goes farther into time than the other thus creating a time travel device. But as the one returns the whole thing destabilizes and collapses. Does anyone know why this is?

3. Has anyone heard theories that wormholes do exist on a very small level in the spaces between quarks? It's based on some type of quantum foam idea.

In physics there are some equations dealing with relativaty and they state that if you could move away from the earth at a speed close to that of the speed of light which is 3 times 10 to the 8th power m/s then you would age slower than those left on earth. speed of light=180,000miles/sec.

Since gravity can curve space, general relativity allows the possibility of shortcuts: wormholes. Worm holes are taking an object and moving it at .9999999999 times the speed of light, in a circle. Time will move very slowly here. In the future anyone entering the wormhole can come back in time to when the wormhole was created. But you cant go back in time to a point before when you built the wormhole!

Though it is not practical with current means to build a wormhole. There are solutions of the equations of general relativity that include them. In principle, one could be made, but its not going to be easy.

If someone was in a space ship and moved away from earth at a speed of .995 times the speed of light. then 10 years pass on earth, only 1 year would have passed on the space ship.

When moving near the speed of light distance appears to shorten. Called length contraction. Those traveling in the ship moving near the speed of light would see everything around them shrink. The earth and moon would apear oval and would be close together.

i'm not trying to insult you...........

and from what i've read, this is what you've said: "time travel is not possible in our world, but in theory it is possible" i know this is not what you meant but thats what i've interpreted so far, and what debate could there be. i mean the fact is the only kind of time travel possible is time dilation. so whats there to debate?

and the whole thing with aging only 1 year when it ages 10 on earth, this is not time travel anymore than aging 10 years.

That's exactly what I am saying... we are barely intelligent enough as a species to even begin to grasp what we are talking about... so in our world, it is not possible. Alexander the great conquered "the World", an area roughly the size of the United States. Imagine in the future how our definition of "the World" might change. For right now it is outside of our understanding. We haven't even considered the possibility of other dimentions. We are only operating in 4 right now, but scientist say there are at least a few more. The secret could line in the properties of these higher dimentions.

Interesting to have some more intellectual conversation here. Anyways, loismustdie, what is your theory about restarting time?

Also live702, in math at least, dividing by zero doesn't yield infintiy. It is an inditerminate number, that is not the same as infinity. Basically, we don't know what anything divided by zero is (there is no limit or near comprehension of it either, we simply don't know). I assume this principle translates into physics, but I could be wrong...

And as for the 1 year, 10 year thing, that is up in the air. If I was cryogenically frozen for 100 years and then awoke, to me it would be the same as if i stepped into a time machine and sent 100 years into the future. This kind of "time travel" works because it is in the same direction as the flow of time, it is easier to paddle down a river w/ the current than against it, hence the difficulty in going backward as opposed to forward, the easier of the two. This comes down to what is your definiton of time travel... we "time travel" every second of every day. I guess you could say there is no such thing as "time travel" persay, but what we are discussing is the possibility of changing the velocity at which we time travel.

Dividing by 0 can be interpited different ways. It CAN be considered infinity. It also can be an instant, such as at t=26, Velocity=100, then also at t=26, V=120, acceleration, change in Velocity over change in time, denominator is 0. this can considered an inifnite acceleration, or a completely instanteous one. Both do not exist as far as i know.

I thought that there would be a different interpretation of this concept in physics. But strictly speaking (mathematically that is), dividing by zero is not infinity or indeterminate. But since we are talking about physics, that point is relatively pointless (no pun intended)

Dividing by zero is infinity in Calculus (Math) as well as physics. If a function is y = 1/x, let's say. At x=4, y=.25... correct. so in terms of the functions limits, as x tends to 1, y tends to .25. If x=some really small number, then y=some really large number... correct so far. So as x tends to 0, y tends toward infinity. If x is negative, same conditions, y tends to negative infinity. No negatives in the real world, beside, whether positvie or negative it is still infinity. The solution is: the limit of y = 1/x as x approaches 0 from the positive side of the y-axis is positive infinity, and as it approaches 0 from the negative side, the limit in negative infinity.

any number/0 is undifined, the indeterminant is 0/0...
0/x is zero
x/x is one, the identity
x/0 is infinity, undifined, whatever
so what is 0/0?

Are we not effectively travelling through time right now?

www.johntitor.com

Just thought I'd throw that out there if there were people here who'd seen it. Even if you don't believe the story it has a lot of information on the physics and mathematics involved in time travel. Good read.

I am taking a physics class right now and we are talking about relativity. Thus, we are talking about time travel and if it is possible. What I have said in my last post is what we know is possible. Theoretical physicists have came up with these equations and theories and I think I would believe them over anyone else. Time travel is possible considering on how you interpret time travel. There is no room for debate once you understand the relativity theory behind it.

So the answer is ...
1) Going forward is not big deal; happens all the time
2) Going forward and not aging is possible but not practical (energy!!)
3) Going forward and backwards can be done if there are wormholes
(certainly impractical!!)

That is exactly what i have said in my many posts, just in more simplified terms. Also, since we have no clue about the universe, what if the are regions of space-time where time is different from here on earth... say a place somewhere where one year passes, 19 pass on earth. some twisted pocket of the space time continuum. We know time is not the absolute in the universe, c is. Just mental candy here. Also, from a philosophical point of view... can we every really go back and change time, becasue even if we could, we would still retain memory of all the events and therefore the change would not be complete... so I'm sure philosophers would say that what's done is done, and cannot be changed.

ok well as i said we are in fact traveling through time, this process is called time dilation(e.g. from the time you strat reading this to the time you are finished you have traveld through time).

and if you know anything about string theory it requires, 10 or 11 deminsions based on how you interpret the equations, and all that good stuff. and string theory also creates a possibilitiy for several more universes(e.g. our universe is a slice of bread in a loaf of bread, and other universes are the other slices). many string theorists who believe in the big bang believe that our universe collided with another universe and this would have created enough of a force to move all the shit around and "restart time".

just for the record: i do not believe in the big bang

LMD, do you believe in alterante realities??
Such that if you were to flip a coin right now, it would spawn two new timelines, one where it landed heads, and the other tails, and then continue slowly diverging from one another, and that we are only in an insignificant one of the infinite number of realities? This creates at least a five dimention universe (x,y,z,t,q) q being the coordinate for which realitiy you exist in. Also, what is your theory on restarting the universe from the standstill?

no i do not. i find that idea absolutely rediculous, because this reality might be a tangent of another, and that makes little if any sense

I agree LMD, the reasoning that I have seen for that theory is full of holes. Its something where a causation was assumed from a certain occurance. In my opinion, that is not a rational or rigorous theorem.

btw. Deadlight, I cannot believe there is someone else on this froum that holds "Rejected" in such high regard. For those of you with a perverse sense of humor, watch rejected by Don Hertzfeldt.

time traveling is possible. you know the super-sonic jets called Concord (i believe thats how you spell it). well scientific test have show that when you fly in a concord from tha US to England, the people that get off tha plane in England are .000005 (i am sure that is tha number)of a second younger than everyone else. something interesting i learned in physics class

Again, it all depends on what your definition of time travel is. it could be simply existing, relative aging (like you said) or moving to other points in "time" that we cannot normally go to.

oh yeah, here is a stupid way to think of time travel. everyone does it. its called sleeping. you wake up in a completely different time. lol

two things... the concord jet comment, I know through mathematical means that it is provable, but what real-life test did they do to proove it?
second... what is everyone's definition of time travel?

my teacher did not say exactly. but i would guess clocks/watches with very detailed time, as in **:**.*********. something like that. my definition of time travel is getting or ending up somewhere when you (physically) are younger or older than the normal

personally i don't like that definition because if you were to jsut get younder and stay in the same place in time, you yourself would not be traveling through time, its only affecting your body, and this illistaration concerning the concord jet this is not due to the speed it is due to the direction of flight, you must be traveling from west to east for this to occur.

time travel- travelling to a point in the future at a faster rate than time dilation, or travelling to a point in the past.

i would like to say that slowing down time is not time travel

But you are saying it is travel at a faster rate than time dilation, this definition can be apply to traveling at a rate slower than normal dilation, which is a different case of the same phenomenon.

no i don't think so. i don't think that slowing down the rate at which time affects you is defined as time travel

But as of now the rate has a coefficient of 1, so wether you change that to less than 1 or greater than one you are doin the same thing, so time slower down or speeding up is the same thing, just multiplying by a number either larger than, or smaller than 1.

rate can be defined as (time relative to you)/(time realtive to rest of world)...
right now it is 1sec/1sec, it could be multiplied by 60, where as 60sec/1sec... 60 seconds pass for you as 1 second passes for the world. If it is divided by 60, then 1sec/60sec, for every second goes by, a minuet has passed in the world, so after a minuet for you, you have semingly "time travel" 59 mins farther relative to the outside world. This is time travel, the first case is also time travel, just a different kind, with a coefficient greater than 1.

actually, upon further reflection, isn't this whole argument basically pointless. Correct me if I am wrong, but are there not various theories of how time works? If so, how can we determine how to manipulate something we do not understand? Trying to figure out a way to "time travel" right now would be as pointless as trying to figure out how to build a nuclear bomb without knowing about atoms. What we should be discussing fundamentally is what is time.

but again, I may be wrong, so please correct me if that is so.

you are exactly right, in fact, i'd appreciate if you join me in a new thread!!!!!!!

of course its pointless, i was just asking if someone thought that feasible time travel was possible, now all examples given thus far could not prove useful for the advancement of mankind, so even though i think that it is not possible, i don't see how it could ever benefit the world, sure maybe it could benefit some guy who wanted to get his wife back or something, but its all relative.........

of course its pointless, i was just asking if someone thought that feasible time travel was possible, now all examples given thus far could not prove useful for the advancement of mankind, so even though i think that it is not possible, i don't see how it could ever benefit the world, sure maybe it could benefit some guy who wanted to get his wife back or something, but its all relative.........

Given that we eventually do come to understand what time is, I think that there may be a sporting chance for us to learn to manipulate it. Also, it's not all relative, but that's another discussion, and one which involves mostly the rules of logic.

Joseph1082- sure, but where would we put the thread. Also if it concerns time theory, here may be just as good a place as any...

I LOVE Ender's Game. I gotta re-read that sometime.

Same here. I read Speaker for the Dead, (the sequel) I didn't finish reading Xenocide, which is the sequel to Speaker.

Good books but I still liked Ender's game and Ender's Shadow the most. The idea of corrupted childohood innocence just got my attention.

To travel at the speed of light. Your mass should not be infinite ! it must be zero. apply einstiens equation
E =mc2/ sqrt(1-v2/c2) and it will also be clear that travel into the future is possible !! BECUASE once you near the speed of light time goes slower for you from an outer reference point of view and the same for the people on the earth and thus when you return you are in the future as you might be 12 when you left and now you are 13, but on earth 34 years have passed. This also means that time travel into the past is not possible. Apply limits to see for yourself.

But have you ever seen the equation
m/(1-Vsquared/Csquared)
this is from special relativity, and mass tend to infinity as V appraoches C.
I'm not sure where you got your equation or what it means. E=mCsquared is a different equation stated the ratio between matter and energy, two states of the same fundamental substance.

no machine will ever be capable of time travel


the past is just a memory.

but if a machine was built, i imagine the drivers body would be ripped to shreds and tossed into a pit of nothingness

Ummm, machines aren't the only way of manipulating space or time theoretically. There are other means by which to play with the fabric of time.

no machine will ever be capable of time travel





lol tell that to the doc....& Marty Mcfly, but that is true I belive that time travel is indeed impossible, at least in our life time

in my opinion yes, me and my friends are convince that traveling through worm holes(i don't think will kill you) and black holes(which would kill you) will send you back into time, we have also soncluded that it would be impossible to travel forwards in time.

the theory that is the basis for this conclusion is: "time slows down when speeds close the speed of light are reached, and when the speed of light is reached time theoretically stops." and our conclusion is that when traveling in excess of the speed of light time will turn backwards.

it would be impossible to calculate how far back in time you would travel when traveling at certain speeds though. i do not believe we will ever travel back in time though.


theoretically, yes...Practicallity, still pending..

you see...If you were to travel in space at the speed of light for 1 year, then slow down for 1 year, then come back at the speed of light for 1 year, slow down for 1 year then arrive back at earth, 4 years would of passed in your life, but over 10,000 would have passes on earth.

You may not realize this but time travel is possible. We are all doing it each and every single moment of our existence. As long as you have the capability to envision the future, you can bring the future to you. Today, tomorrow, the future is all in our mind and what we want it to be. The better you build your machine today, the further it take you to your destination tomorrow. When your there, think back. There's your time machine.

hasheesh will work too. ok, enough for me. **disclaimer** i am not responsible for you actions.

It has been brought up in this discussion several times the reasoning of why we will travel backwards in time given that we exceed the speed of light. I would have to disagree with those who have held or made this point. I believe that traveling back in time is a fairly limited view of the fourth dimension. Viewing it as only a linear progression may not fully explain it qualities. What if exceeding the speed of light made you travel to some random point in time? I guess that I assuming that those who made this point meant that you essentialy travel backwards much as if someone were to rewind a video. Please, if I wrong correct me, I hate to misinterpret people's intentions.

Anyways, i would explain the fourth dimension more comprehensively, but at one point when I fully understood it, my head imploded.

Well, I dimention by definition is linear, so time is indeed linear. It may exist in a T,Q plane, or a T,Q,R space, Q and/or R being other further dimentions, Q for instance standing for different quantum realities. So if one was to tranverse more than just time, say the T,Q palne, then you would end up in some random point.

Well, I dimention by definition is linear, so time is indeed linear. It may exist in a T,Q plane, or a T,Q,R space, Q and/or R being other further dimentions, Q for instance standing for different quantum realities. So if one was to tranverse more than just time, say the T,Q palne, then you would end up in some random point.

Well is it possible then that time as we know it (or do not know it yet) is not only defined by the fourth dimension? I mean we define reality, I mean out physical world in three dimensions. It is not possible that time follows a similar path? Of course what i'm suggesting is really the theory of multiverses, something that I don't yet buy but for the sake of argument...

i always thought that in order to travel in time you would have to get from point a to point b in 0.000000000000.....etc sec :2cents: