What is your perception on time travel?

[lucid121]

My perception on how time works is that: even if you go back in time it will still not change what is happening in your time. So if person A decides to kill himself in his past self, he will not be affected by what has happened and when he goes back in time it will be just as normal as any other day. And when person A decides to go to the future and kills his future self( lets call him person B), it might effect him, since it never happened, therefore it still can happen which may influence his future. What I am not sure about is whether or not his future self would know about him visiting the future, since his future self already has done everything. So he will know, but the confusing part is, wouldn't his future(Person B) self have succeeded in killing his future self(Person B's future). The chain has to start somewhere, right? Argh, this is so confusing. What is your perception of time travel(future and past)?

[El Dildo]

just don't think about it.

 

nobody really knows how time works.

Einstein couldn't figure it out and he was the smartest bastard on Earth just a few decades ago.

[poklane]

Doesn't exits, and it will never exist. Why? If it exists, wouldn't we have been visited by someone from the future? That's all I think about time travel. And if time travel would be possible, it wouldn't be 'time travel', it would be traveling between alternate universes. So yes, if I would travel back to like 1938, kill Hitler and return, WW2 would still have happened as it has happened now, I only would have saved that other universe.

Edited September 9, 2013 by poklane

[El Dildo]

yeah but how do you know we haven't already been visited from the future?

 

any time someone goes around claiming they're from the future, we lock them up in the crazy hospital.

maybe one of them is telling the truth!

 

we'll never know...

[poklane]

yeah but how do you know we haven't already been visited from the future?

 

any time someone goes around claiming they're from the future, we lock them up in the crazy hospital.

maybe one of them is telling the truth!

 

we'll never know...

Simple, ''PICZ OR IT DIDN'T HAPPEN BRUV''

If we ever get visited by someone from the future, I would expect humanity to be smart enough to have some awesome proof.

[018361]

Maybe we can't be visited by someone in the future until we create time travel machines/devices.

[Shah Sam]

The people from

 

 

yeah but how do you know we haven't already been visited from the future?

 

any time someone goes around claiming they're from the future, we lock them up in the crazy hospital.

maybe one of them is telling the truth!

 

we'll never know...

Simple, ''PICZ OR IT DIDN'T HAPPEN BRUV''

If we ever get visited by someone from the future, I would expect humanity to be smart enough to have some awesome proof.

 

They're invisible.

 

Or maybe in the future they'll find a way that we can only travel to the future.

[poklane]

The people from

 

 

yeah but how do you know we haven't already been visited from the future?

 

any time someone goes around claiming they're from the future, we lock them up in the crazy hospital.

maybe one of them is telling the truth!

 

we'll never know...

Simple, ''PICZ OR IT DIDN'T HAPPEN BRUV''

If we ever get visited by someone from the future, I would expect humanity to be smart enough to have some awesome proof.

 

They're invisible.

 

Or maybe in the future they'll find a way that we can only travel to the future.

Wouldn't be surprised if some day (probably nobody here would still live that day) they invent a device to freeze a human body and unfreeze it in the future, without the body aging in the time it's frozen.

Edited September 9, 2013 by poklane

[Tyler]

Conceivable but ultimately the technology is not really possible for now. I mean from a technical standpoint we're always time traveling but I'm assuming you speak of the science-fiction inspired, going-to-the-past type. I don't think going to the past will be possible in any literal sense. Using near-light speed travel to fling yourself into the far future is something to think about though, maybe. Definitely not in our life, any way.

 

If you want to travel to the past, though, you really just have to consider our sense of memory and how we experience other memories through society. We can yearn for a time we never even lived in. Our mind can create this coherent image of another world, even if it's flawed. Then again who's perception of the world isn't in some way flawed or incomplete, right? So what's the harm in losing yourself to the memories of society every so often?

[Kiffster]

We haven't been visited by someone from the future, because the future hasn't happened yet. The future does not exist. And no one discovered time travel yet to travel to the future for someone from the future to use time travel to travel back to the past, by which I mean present time. Does that make sense, cos my brain hurts

 

Anyway, I don't think time travel is or ever will be possible...

[El Dildo]

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

 

actually time travel is very possible in theory.

if you understand a little about quantum mechanics or Einstein's theory of general relativity then you know that time is a tangible force; it's like an object that can be manipulated and changed.

 

the only problem is that our technology today doesn't allow us to produce ANYWHERE NEAR enough energy to begin testing the theory. but we know that - given the right amount of energy - time travel is entirely possible in a physical sense.

[epicluca]

Whilst I think to myself "if time travel existed then someone would have been visited by now" I also think "there has to be a first time someone time travelled" like to put it simpler, when someone hypothetically time travels theyre coming from, say the year 2050 but they lived in the year 2013 and were visited by future themselves, and it becomes a paradox, a constant loop really. But obviously that loop had to start at some point.

[TheIllaDopest]

The 4th Dimension. If youre able to control the speed of life, its possible. I believe this is how aliens travel from great distances. Also why they can abduct humans easily as well as place them back.

[na89340qv0n34b09q340]

If you think of time dimensions like a flowing river, all dimensions flowing downhill at the same speed, it's very improbable that anyone visited our dimension anyway. Each instance of time (smaller than a picosecond even) would have it's own dimension, so the chances of anyone visiting the past visiting our past is 1/a-very-very-large-number.

[OysterBarron]

We are constantly traveling in time. It's all down to perception of time.

[K^2]

Doesn't exits, and it will never exist. Why? If it exists, wouldn't we have been visited by someone from the future?

That's because you are picturing a machine that goes back in time with the traveler, which is nonsense.

 

We don't understand everything about time travel, but we've gotten far enough with it to understand a few things about it. The most important is that time machine needs to be built before the time to which you are heading. So say I build machine in my garage on Tuesday. It stays there until Friday. On Friday, I can walk into the time machine and exit it on Wednesday. But I can't go back to Monday, because time machine isn't there. It's like a subway through time. You can't take subway further than the tunnels extend.

 

In terms of paradoxes, we are somewhat limited in what we can describe. The worst kind of paradoxes are the ones that involve construction of the time machine. Say, I travel to a few days ago and destroy the time machine I used to arrive. Then there isn't a time machine for me to use to go to the past. This looks like classic grandfather paradox, but it's actually a lot worse, because it affects the possible trajectories between past and future. This kind of paradox has to be resolved with quantum gravity, and we simply don't have the theory to cover that. In other words, nobody knows what would happen for sure, but most people lean towards this being resolved the same way as standard grandfather paradox.

 

So what about the grandfather paradox? What if you go into the past and kill yourself or one of your ancestors? Well, nothing interesting. You effectively end up with a new time line. The actual paradox is resolved on quantum level, and I don't want to get into details, but it's fairly straight forward once you understand quantum field theory in curved manifolds. That's a considerable barrier to understanding, certainly, but there are enough people who do specialize in that sort of thing to make time travel something that's relatively well understood even if, at present, not feasible.

 

Will we ever have time travel? That's an open question. Currently, all known approaches involve General Relativity and warping space-time. There are two categories there. Methods that involve huge amounts of mass, think black holes here, and methods that involve exotic matter. Since we have no evidence of exotic matter yet, it kind of puts the damper on things. But in the future, who knows? Recent research on warp drives shows that there are ways to dramatically reduce the amount of matter required to curve space-time, so we might be able to find a workaround.

[GTA_stu]

I read somewhere that if you travel at the speed of light, or near the speed of light, that time travels slower for you. So let's say I travel at the speed of light for 5 years, and return to Earth, would that be like time travelling? Or what would actually happen?

 

psssst K^2, I was asking you.

[OysterBarron]

I think you are correct stu I watched something about that the other evening. I beleive it's supported by some of einsteins findings. They used an example of coming back to earth and you would be like 200 years in the future whereas time has stayed relative to your perception.

 

I think if you looked back at earth while traveling at that speed you would see earths time flowing faster to an extent.

Edited September 10, 2013 by oysterbarron

[K^2]

Yes, when two objects travel at near light speed relative to each other, funky things happen to time. The fact that you have to accelerate and decelerate also plays into it so that the net effect is, indeed, comparable to time travel. It's more a matter of aging at different rates, though. Think of it more like suspended animation. Earth aged, the astronaut didn't.

 

I think if you looked back at earth while traveling at that speed you would see earths time flowing faster to an extent.

Actually, you'll see time flowing slower on Earth. It's on the return trip that you'd watch it catch up.

 

This is fascinating stuff and not just for realms of science fiction. GPS satellites have to account for differences in time flow on Earth and on the satellite both because the satellite is moving rather fast and because of Earth's gravity.

[lil weasel]

Considering that 'science' thought that Heavier Than Air flight was 'impossible' and that people would die if they went faster than 60 mph, why not have time travel?

[K^2]

"Science" never thought that.

[OysterBarron]

The concept of time can also be brought into question. I read of some experiments where a group of people were placed in a completly black room for a length of time. Most after a few days lost track of what day it was and what time it was there body clocks got seriously knocked off the norm. So you could argue that light is also a crucial part of time because without it you cannot actually percieve time.

Edited September 10, 2013 by oysterbarron

[Finn 7 five 11]

Considering that 'science' thought that Heavier Than Air flight was 'impossible' and that people would die if they went faster than 60 mph, why not have time travel?

Wtf? Are you serious right now?

[JOSEPH X]

Do we travel through time, or does time travel through us?

[K^2]

Do we travel through time, or does time travel through us?

Does film move through the pictures, or do the pictures move through the film? It's neither. Each moment in time has its own snapshot of the world. What actually propagates from one moment in time to the next is information. Your memories of the world around you and of your own thoughts and recollections are what is actually responsible for the perception of time flow.

[OysterBarron]

Your memory isn't very accurate. Everytime you recolect an event chances are you will add something to it and then that get saved into your memory instead of the actual event as it happened. So you are bending time with your own will maybe.

[K^2]

Perception of time flow is a matter of recalling immediately recent events. Say you pushed a cup off the table. As you watch it fall down, you can recall it being on the table. After it smashes into pieces, you can recall watching it fall and recalling that it was on the table before. This process of recalling a recollection is what sets up a definite sequence of events that you feel are progressing. Does that make sense?

[Mr. Scratch]

I think time travel is relatively diluted.

[OysterBarron]

Perception of time flow is a matter of recalling immediately recent events. Say you pushed a cup off the table. As you watch it fall down, you can recall it being on the table. After it smashes into pieces, you can recall watching it fall and recalling that it was on the table before. This process of recalling a recollection is what sets up a definite sequence of events that you feel are progressing. Does that make sense?

I think so in that case then using that as an example. If you push the cup off of the table then look away. You then can recall before the cup smashes that you know the cup will break when it hits the floor can that be classed as predicting the future?

[ha! ha! ha!]

I heard there are few theory, so, what I really wonder about is someone still working/ trying to build up time machine? seems like everyone give it up never heard sensational news recently. the progress still 0%??