is life like a program?

[bradpitz]

If the law of physics allow us to travel back in time and meet the people thousands of years ago, are we some kind of computer program?

[slyrat]

I am not sure the laws of physics allow us to travel back in time. Especially not in any feasible or useful way.

As for life being a program, how would we tell? You could also say we are all the dream of a higher being. Either one would be (as far as I know) impossible to prove from inside the program or dream. You could probably get some mileage out of this topic in General Philosophy. Especially if you propose life as a dream by a higher being, capable of dreaming each of billions of lives. Jesus could be a part of that being that became a lucid dreamer, and realized the nature of the dream and the dreamer.

I'm curious what made you connect time travel with life being a program.

[bradpitz]

ThanKS sir. I'm a little confuse many physicists believe we can travel back in tme and travel to future.If it is true then our future is already exist and our past still exist that we can even see it if we are able to create time machine.

[slyrat]

I understand now. I wouldn't worry about it. There is a hypothesis I heard once that I like. I was told about it by a friend in college, and I will try to remember enough about it to look it up, if you wish. Basically, it says that the future does exist, but as potential. Every random quantum event has it's own potential future. You can't travel to them because they don't exist in reality, they are just possible futures extending from random events. You will never know which future becomes relevant until the random event happens.

This is basically an extension of the Shrodingers Cat thought experiment, which Shrodinger ironically put forth as a protest against the Copenhagen interpretation of quantum physics.

[Bignose]

I'm a little confuse many physicists believe we can travel back in tme and travel to future.

I wouldn't use the adjective "many" there, personally. There appear to be some models out there that seem to allow some solutions that travel back in time. But, we know that those models aren't completely right, because some of the predictions they make are just plain wrong. That is, the models are good at predicting some thing (look at general relativity or quantum mechanics), but extending those models beyond the domain where they are good can be tricky. This is why experiments are conducted, to see just how large or small a domain the models are good. So you've got some known-to-be-imperfect models that maybe make some predictions in some known-to-be-not-very-wellverified domains, and no obvious way to test the models in those domains.

 

In short, most physicists won't accept such relatively weak conjectures that time travel is really valid until we can get strong, well-verified models and straight-forward statistically significant ways of testing those models.

 

Time travel is a staple of science fiction writers, but in actual physics today, a good physicist would have to agree that it is a very unsupported idea. Does that mean it can't happen or will never be discovered? Certainly not, but based on the knowledge we have right now, it doesn't seem too likely or feasible.

[Sensei]

I'm a little confuse many physicists believe we can travel back in time

 

Who exactly? Names..

I don't know any.

 

Theoretical consideration is not the same as "believing in".

 

Scientists generally don't "believe". We use scientific methods and analyzing set of repeatable data to create physical laws describing observations.

Edited March 26, 2014 by Sensei

[ajb]

Most of those that I know of and some personally that work on "time machines" are really pushing the classical ideas in general relativity to their limit with the hope that it will point to some new physics. This is particularly so when one looks at semi-classical gravity, that is including quantum fields on the curved classical background.

 

The only exception to the above I know of is Mallett. He is actually trying to build a time machine!

 

That said, it is not completely obvious that time travel to the past is not allowed, though to my knowledge all constructed theoretical examples seem sick in some way or another and will not work. But I am not aware of any proper proof of this for all cases and this lead to Hawking's chronological protection conjecture; time machines are not physically realised.

[bradpitz]

Please correct me if I'm wrong, according to Einstein a body that travels faster than the other the tme will be relatively slow compare to the other. It has been proven already. I've watched Professor Brian Green in you tube about the illusion of time according to him time is like a series of snap shot and every moment in the past still exists and the future is already exists.

[ajb]

Please correct me if I'm wrong, according to Einstein a body that travels faster than the other the tme will be relatively slow compare to the other.

Yes, this is called time dilation.

 

It has been proven already.

Again yes, this has been observed for example in comparing decay rates of particles found in cosmic rays and those produced in the lab.

 

If you google time dilation I am sure you can find lots more information.

[Delta1212]

Please correct me if I'm wrong, according to Einstein a body that travels faster than the other the tme will be relatively slow compare to the other. It has been proven already.

This is true and needs to be compensated for when calibrating clocks that need to be very precise while orbiting the Earth.

 

I've watched Professor Brian Green in you tube about the illusion of time according to him time is like a series of snap shot and every moment in the past still exists and the future is already exists.

This is speculative and doesn't have much bearing on the above.