Time Machine

[Tossica]

*edit:: Original Post asked if it was possible to go back in time and kill your grandfather, This was a poll on Time travel, but the original post from Gidan was corrupted and I needed to delete it. -Lyion***

No, you'd be killing the grandfather of the you that you left behind when you travelled. You would now have to be a copy of yourself in an "instanced" reality.

[Gidan]

No trick question. Mostly just wanted to see what people think, or have ever thought on the subject. It was a fascinating conversation when I had it, though I had it with a group of people really into quantum and astrophysics so it got a bit theoretical.

I will post my opinion later when I have a little time to write it out. Though it could be fun to see people toss around ideas on this, especially with some of the religious crowd. Nothing against the religious, but the other people I talk to are not religious so I think thei opinion could be interesting on this.

[Yamori]

No, you'd be killing the grandfather of the you that you left behind when you travelled. You would now have to be a copy of yourself in an "instanced" reality.

I'd have to agree with Tossica.

IF backwards time travel were possible (and thats a big if, because as far as I understand it only forward time travel is theoretically possible), and you killed your grandfather, I think it would create a new future, but it would not affect the current you that is back in time.

[DESX]

Theoretically it's possible to travel forward into time but not backwards. If you can go outside of earth's orbit and go faster then the speed of light everything outside of you will slow down.

"The ship approaches the speed of light. Time for you seems to pass as it always has. It takes you about five seconds to tie your shoe. But to an observer on Earth (assuming he or she could watch you), you are moving at a snail's pace. It takes hours to tie your shoe."

"In our second and third train examples, the speed of light turns out to be exactly the same for both you and the observer standing along the tracks because time, as measured by your watch, ticked along at a slower pace than time measured by the observer. Not only that, distance changed, too. For the observer, a one-foot ruler whizzing by on the train would have measured less than a foot.

The weird thing is that, for you on the train, time wouldn't seem to be moving slower and your ruler wouldn't be shorter—all would appear normal. However, time on the rest of the Earth would appear to be ticking along slower and its rulers would be shorter."

[Diekan]

I noticed that theory being put to use in the modern version of "Lost in Space" - a decent movie to boot. Only it was in reverse.

[Narrock]

I noticed that theory being put to use in the modern version of "Lost in Space" - a decent movie to boot. Only it was in reverse.

The first hour of Lost in Space was the shred. After that I fell asleep.

[DESX]

Exmple: you travel at 10% the speed of light to proxima centauri on a space ship at age 7 when you got their and back you would be 15 years old but you would be a few days younger then your brother.

Now let's say for example that you traveled at 100% the speed of light and you wanted to go to proxima centauri on a space ship (closest star to our sun) and you where 1 year old and your twin stayed on earth and was also 1 year old. By the time you got their and back you would be 1.0108 years old and your twin would be 9.8452. This is all from Eienstiens theory of "time dialation". The closer we get to traveling at the speed of light the more time would slow down for us relative to something not moving.

To make it as simple as possible: Time can slow down but never go backwards.

[Diekan]

You mean Alpha Centauri?

And, I thought the differences in time would be measured in millions of years, not just a *few* years.

[DESX]

Edit: Actually proxima centauri and alpha centauri are the same with 2 names but yeah time is still only measured in tens of years.

[Diekan]

ahh yes, my bad - alpha is the tri-star system which proxima is a part of.

but, still not sure on the tens of years comment. i am pretty sure it's measured in millions - but I could be wrong - you got a source? not saying you're wrong - just want to read about it - since this is a subject that interests me a great deal.

[DESX]

The equation is V=D over T

and exmple of usage: 10 mph(v)= 10miles(d) over 1 hour (t)

http://www.pbs.org/wgbh/nova/time/think02.html

[Martrae]

IMO off the top of my head...even if Time did allow for travel it still would not allow for paradox.

[veeneedefeesh]

Just out of curiousity Gid, were you tripping when you were discussing this topic? If you weren't I think you would probably be able to groc it a whole lot better with the liberal application of some LSD

IF (notice the IF) it were possible to travel back in time, and you COULD kill your grandfather (I strongly suspect that the universe has safeguards against paradox, no real reason to believe this, but it makes sense) you would probably create an alternate reality. I tried to read Stephen Hawkings book on time, and I was totally bewildered, but the only thing I walked away with was that if you thought of reality in a hourglass shape with the top being the future, the bottom being the past, and the skinny part in the middle being the present changing something in the past would per force slide the middle a little bit to the right, not neccessarily eradicating the present, but changing it slightly.

If you killed your grandfather then your grandmother would probably marry someone else still producing children which would evenbually produce you, or maybe if you killed who you thought was your grandfather you would find out that you are from an entierly different lineage when you returned to the present. This discussion is much better suited to someone with massive amounts of hallucinagens

[mofish]

Well, seeing into the past and actually going there physically are two different things. Just seeing into the past, like with a time telescope, wouldnt create paradoxes.

As far as actually tavelling into the past. Who knows. Itll be centuries before M-theory is fully understood, and by then, who knows what rules we'll be able to bend. We have 7 more dimensions possibly to explore. Those will change everything. Time is the only asymmetrical dimension. It is the only dimension that isnt the same one way as the other. We are just beginning to really understand why. Also remember, that time acts differently, just like other dimension do, at very small sizes. Cause and Effect are not the lawful rules that we think they are when distances become minute.

Another thing to remember. Just because an event has moved from the present to the past, does not mean it is somehow erased from the universe. The past still exists in a real sense, not just a philosophical one.

[Diekan]

Yes, you CAN actually see into the past, because light does have a defined rate of speed which can be measured.

If you were standing on Alpha Centauri right at this moment... and were looking through a telescope large enough (theoretically) to capture the light that's been reflected from the Earth - you'd be seeing Earth as it was 4.5 years ago. This is because Alpha Centauri is 4.5 light years from the Earth... Keep in mind a light year is not a measure of time, but a measure of distance.

.

[Samboa]

Question. . .if time travel is possible and will happen in the future, then why haven't we seen any evidence of people travelling back in time?

[Tossica]

If you had a telescope powerful enough, you could have a visual record of the birth of the universe. You could record it and watch it over and over again. If I was god, I'd do that.

Actually, telescopes are like time machines... if we had a high enough resolution telescope, you could see what is happening on a planet across the galaxy at this very moment, right?

Hmmm... You'd still need "light" to see what was happening but you would have travelled there instantly so you would have gotten there 4.5 years before the light actually left the planet. I don't think the speed of light is meant to be broken... hehe.

[Eziekial]

I don't believe time travel is or ever will be possible.

[xaoshaen]

To clear up a few misconceptions being bandied about in this thread:

- Relativity is not time travel per se.

-The actual discrepancy in time passed between different frames of reference is dependant upon the discrepancy in velocity (v) between the frames. The most basic calculation (special relativity) is proportional to the value gamma (sqrt(1 -v^2/c^2)).

- Note that the gamma factor becomes 0 once you reach the speed of light, which makes several of the relatavistic transforms undefined. The transforms explode asymptotically as v approaches c.

- The speed of light in a vacuum is currently theorized to be unbreakable by normal matter,

- You don't need to "go outside of earth's orbit" to reach relativistic speeds, though with any objects of significant mass it's much easier... theoretically.

- You don't need to "go faster than the speed of light" to reach relativistic speeds, which is a good thing as most theories agree that tachyons are the only theoretically predictable particles that travel faster than c, and they are believed to experience comparable relativistic transforms as they slow down to approach c.

[10sun]

Question. . .if time travel is possible and will happen in the future, then why haven't we seen any evidence of people travelling back in time?

Instances.

[Graecus]

i have a time machine...no, really!

i just set how far in the future i want to go(i can only seem to get it to work for a max of 24 hours at a time), lay down, close my eyes, and next thing i know, my time machine starts making noise...ITS SO CRAZY. i usually set it for about 6 hours in the future. Sometimes more, sometimes less.

works great, i can sell this one to whoever wants to buy it...im thinking... 2 easy payments of $69.99 USD

[xaoshaen]

- You don't need to "go outside of earth's orbit" to reach relativistic speeds, though with any objects of significant mass it's much easier... theoretically.

Actually you do read a lil more on it and you will find out. you can only reach those requirments in space.

I'm sorry, but that's simply untrue. What evidence we've gained for relatavistic effects has been garnered in laboratories right here on earth. If one of us needs to study up on relativistic effects, I'd suggest it's the person who suggested you need to exceed the speed of light (as if it were a constant) to experience them...

[horendus]

I didn't read the rest of the posts but here is my take on the subject.

Supposing you CAN go back in time, the theory is that you cannot change history. The reasoning in that is not so much that history protects itself, its simply the fact that what you are attempting to do never occurred, therefor it will not be possible to do.

Assuming you went back in time to 'kill Hitler' before he could do what he did, history has shown that no one has done that, so it cannot be accomplished. Instead what would happen is one of many things: a) you are captured/killed on your way there, b) you end up killing a body double, c) you have a heart attack and die, the list can go on and on.

The same thing occurrs if you were to go forward in time to 'learn the future'. If you brought the knowledge back to attempt to gain from it, history would keep this from happening, UNLESS it is something that does in fact happen, which if it were to happen, you could just look up information on yourself in the future to find out if it worked... thereby saving all the effort, and possible frustration from even trying.

Another theory is, yes, the instances. The space-time continuum is made up, theoretically, of infinite choices which take account for the many choices we all make in our lives. Going back in time to kill your father in essance orphans you from your reality, you slip into an alternate universal timeline where you were never born.

Theory also dictates that if you were to orphan to another universal timeline, something from that timeline would have to come in to being in your original timeline to keep everything in balance since matter an energy cannot be created or destroyed it would have to be moved or swapped.

[Drem]

i have a time machine...no, really!

i just set how far in the future i want to go(i can only seem to get it to work for a max of 24 hours at a time), lay down, close my eyes, and next thing i know, my time machine starts making noise...ITS SO CRAZY. i usually set it for about 6 hours in the future. Sometimes more, sometimes less.

works great, i can sell this one to whoever wants to buy it...im thinking... 2 easy payments of $69.99 USD

i want it

[Ganzo]

Best Time Machine i ever seen was in Napoleon Dynamite