Time travel - Speed of light

Just interested to hear from the scientists or physcists on the forum (if any), when they think mankind will be able to get close to travelling speed of light?

One of the most interesting implications of travelling at that crazy speed would be the possible ability of time travel. AFAIK, backwards time travel is not possible - travelling at speed of light or not. But interestingly, it might be possible to travel farther into time. I’m no scientist, but I think that’s because passage of time itself slows down as we move farther away from earth (due to gravity). So theoratically, you can have an astronauth blast away from earth at speed of light, return back, and the astronaut would have hardly aged. Meanwhile, decades or hundreds of years may have passed at earth. And I believe this theory ahs been proven scientifcally as they compared a clock on earth vs a clock on a rocket ship taking off from earth. The clock on the rocket ship was found to be lagging behind the clock on earth.

Re: Time travel - Speed of light

Hmm you just paraphrased Paul Langevin's twin paradox.

Re: Time travel - Speed of light

^ Ofcourse I did. What'd you think, I invented the idea while I was writing the post?

Re: Time travel - Speed of light

Well you sure do make it sound like that.

Re: Time travel - Speed of light

As closer you travel at the speed of light, the heavier your mass becomes and thus you need more energy to go faster and thus the amount of energy needed to go further becomes infinite

The only way possible is to have a secondary object propel you to light speed for which matter and anti-matter reaction is needed

Re: Time travel - Speed of light

Its not due to lack of gravity, but because it gravity that the time slows down. Einstien postualtes that a very fast accelarating object in space will make passengar press against the wall (if you may), kind of like gravity does.

So he thought that gravity and accelaration can be related to each oher

That is why he has special theory and General theory of realtivity.

Genral theory deals with the phenomenan of time slowing down in the viccinity of huge stars or black holes.

Special theory deals with the phenomenan of time slowing down in an highly accelarated object

Re: Time travel - Speed of light

May be some other genius will have the ideas we haven't about heard yet.

May be the equation Einstein created is not all true. Who knows.
After all in earlier ages people used to think that sun revolves around earth.

May be in year 2312 we will have people laughing at Einsteins ideas (if earth survived till then) :) .

Re: Time travel - Speed of light

^^ Maybe
But you have to admit that he was a gifted scientist. He called his Universal constant, (that he added into his equations, cause his equations were predicting expanding universe though he though that universe is static, thus added a constant to make his equations shows a static universe) the biggest blunder of his life.

Very recently, scientists realized that they want that constant back cause universe seems to be expanding far more rapidly then it should

Re: Time travel - Speed of light

Astronauts that travel around the Earth in Orbit have been known to loose body mass becuase of being in zero gravity, body starts to loose muscle............

When you dont use it You loose it........:)


Only thing that can travel at the speed of light is....................LIGHT.......:D

Re: Time travel - Speed of light

Highly accelarated space vehicle acually mimicks Gravitational pull inside it, so at that speed, space travel will at least not cause that problem.

Re: Time travel - Speed of light


Sure body starts to lose muscle, but you can have some sort of work out machines to keep up your muscle strength.

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How do scientists know universe is expanding? do they take snapshots are regular of intervals of different galaxies and compare the distance?

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Accelerating to the speed of Light…


That is where Einstien and Newton Collide…


Force = mass X acceleration…


When the body gets close to high/infinite acceleration the Force required to move objects like your limbs will also approach high/infinite numbers…and time stands still…Wallah Alam what happens next…:halo:

Re: Time travel - Speed of light

Peace All

Nice thread!

Here are my responses:

Post #1 - Time travel if achieved will be a defeating process ... guess how?

Post #2 - Funny

Post #5 - I think the warp principle applies here. The mass itself will need to undergo a change of state to generate the energy required for travelling faster. Light does however have a finite speed.

Post #6 - Correct

Post #7 - Relativity itself is now proven but if there is any thing more to it is yet to be investigated.

Post #8 - The Big Rip Theory - I like that one.

Post #10 - That is assuming the craft is always accelerating. There will come a point that a terminal velocity will be approached. The bonds between atoms will have hard time to stay in tact.

Post #12 - Spectral Shifts - It is the Doppler Effect of Light that shows that galaxies are receding from one another.

Post #13 - You could tear fabric of space, create hole become a singularity pop out of the other side but the onlooker will see a perpetual light beam. Most likely the person will die way before reaching near light speed so all is irrelevant. Unless they can recreate matter from anti-matter - matter explosions.

Re: Time travel - Speed of light

Its more complexed than that, but simply put when an object moves away from you, the light coming from that object tends to shift towrads the red bandwidth of the spectrum.

Faster the object is moving, greater the red shift is.

Scientist observeed that red shift, to conclude that the universe is expanding

Re: Time travel - Speed of light

I think there is a difference between being (highly) accelarated and travelling at high speeds. In the former, indeed it will mimick gravity, - but in the latter no matter what your speed is (relative to some reference point) you will not experience any 'gravity' and therefore start loosing muscle and bone tissue.

as far as time travel goes, scientisits have calculated that the russian astronaut (i forgot the name) who has spent more than three years in orbit, due to his speed relative to us has travelled further in time by about 1/50th part of a second

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you are right. I used the wrong wordings in my comment. When the speed is constant, you will not feel effect of gravity like pull.

Yesterday I was watching scince channels documentary about manned mission to mars. One of the ideas is that when the space ship is moving forward, its also spinining, creating centrifugal force, thus creating false garvity.

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define light to me and i will tell ya when? :clown:

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absence of darkness is called light :smiley:

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***YES!

Reminds me of Mohammad Ali the Boxer....once he was asked how fast He was?

His reply was................I am sooooo fast..........I can turn of the light in my bedroom at the wall switch.......

and be in bed****** before the light goes Off.........:biggthumb