Time Travel Impossible ?

[Hum]

Hong Kong physicists say they have proved that a single photon obeys Einstein's theory that nothing can travel faster than the speed of light -- demonstrating that outside science fiction, time travel is impossible.

The Hong Kong University of Science and Technology research team led by Du Shengwang said they had proved that a single photon, or unit of light, "obeys the traffic law of the universe."

"Einstein claimed that the speed of light was the traffic law of the universe or in simple language, nothing can travel faster than light," the university said on its website.

"Professor Du's study demonstrates that a single photon, the fundamental quanta of light, also obeys the traffic law of the universe just like classical EM (electromagnetic) waves."

The possibility of time travel was raised 10 years ago when scientists discovered superluminal -- or faster-than-light -- propagation of optical pulses in some specific medium, the team said.

It was later found to be a visual effect, but researchers thought it might still be possible for a single photon to exceed light speed.

Du, however, believed Einstein was right and determined to end the debate by measuring the ultimate speed of a single photon, which had not been done before.

"The study, which showed that single photons also obey the speed limit c, confirms Einstein's causality; that is, an effect cannot occur before its cause," the university said.

"By showing that single photons cannot travel faster than the speed of light, our results bring a closure to the debate on the true speed of information carried by a single photon," said Du, assistant professor of physics.

"Our findings will also likely have potential applications by giving scientists a better picture on the transmission of quantum information."

The team's study was published in the U.S. peer-reviewed scientific journal Physical Review Letters.

source

[Dan~]

Time Travel is possible. I remember went I went to the US not too long ago and seemed 10 years behind the UK!

[iuerg87yerg879e0rg9erugjer]

Time travel is possible, it has been proven that the faster an object moves, the rate of time slows down, so if you travel near the speed the light for x amount of months/years, you in theory have travel back in time :p

[yxz]

Time Travel is possible. I remember went I went to the US not too long ago and seemed 10 years behind the UK!

bahahahaha :rofl:

[articuno1au]

Time Travel is possible. I remember went I went to the US not too long ago and seemed 10 years behind the UK!

Baha, Nice :p

Time travel is possible, it has been proven that the faster an object moves, the rate of time slows down, so if you travel near the speed the light for x amount of months/years, you in theory have travel back in time :p

Nope, you forgot relativity.. You actually have to travel faster to start moving backwards. By everyone else relative position, you would be moving extremely fast but inside the normal bounds of space time >.<

I don't think this actually disproves the idea of faster then light travel, it just proves that photons can't :\ Remember that 20 years ago we were still struggling to understand some things that seem child play now days >.>

[Hum]

It's times like this when you really have to laugh at Science. :laugh:

Light is only a part of an even larger, unrecognized Electromagnetic spectrum -- not the 'fastest'.

And time travel has 'already' been accomplished.

Another case of "we don't know how to do it, therefore it must be impossible".

[Redz0ne]

Theoretically its possible, can we currently do it no.

[+Frank B. Subscriber²]

It's times like this when you really have to laugh at Science. :laugh:

Light is only a part of an even larger, unrecognized Electromagnetic spectrum -- not the 'fastest'.

And time travel has 'already' been accomplished.

Another case of "we don't know how to do it, therefore it must be impossible".

I prefer regular science to the obscure variants of science you're into, sorry.

[articuno1au]

I agree with the last line..

The rest of it shows Hum is still on the crazy pills >.<

[Tartan]

Although only currently theory, it has been scientifically suggested that a device that could warp space around a given object, would be able to get around Einstein's Law and go faster than light, because the object itself doesn't actually move.

As for time travel, well we could never go back in time, but certainly a one-way trip into the future is theoretically possible.

[Teebor]

They changed the result by measuring it

My beliefs are not changed

[Hum]

I prefer regular science to the obscure variants of science you're into, sorry.

I agree with the last line..

The rest of it shows Hum is still on the crazy pills >.<

I simply see a little further ahead in Time. ;)

[articuno1au]

That's when you go really really slowly right? ;) :p

[Pajter]

We've already mastered time travel. We just can't control the direction and speed (yet). :p

[thejohnnyq]

This was solved in Futurama, they just changed the speed of light, and bingo it works.

[bruNo_]

One of the last episodes of "Through the wormhole" (at least here in Brazil :p) was about Time Travel, have you seen it?

http://www.youtube.com/watch?v=yXsI2LloQLI

http://www.youtube.com/watch?v=qkyrw0DIs08

http://www.youtube.com/watch?v=tEDGHMnmV6s

[Crisp]

I've always thought, everyone says the speeds of light is the fastest known way to travel in the unviverse and that it's the only fastest known speed in existance. I find this be wrong. If the speed of light is the fastest known speed in existance then can one explain how fast the speed of the universe was with the "big bang". I'm pretty sure the speed of the debrey flying out from the "big bang" was faster, than the speed of light. Surely a fueled explosion of a huge scale would beat the speed of light.

All in all, we don't need the speed of light to go fast, wasn't it proven shortcuts within space was also a possibility by using Wormhole paths through Hyperspace to reach another part of the universe without the speed / time factor.

[iuerg87yerg879e0rg9erugjer]

I've always thought, everyone says the speeds of light is the fastest known way to travel in the unviverse and that it's the only fastest known speed in existance. I find this be wrong. If the speed of light is the fastest known speed in existance then can one explain how fast the speed of the universe was with the "big bang". I'm pretty sure the speed of the debrey flying out from the "big bang" was faster, than the speed of light. Surely a fueled explosion of a huge scale would beat the speed of light.

All in all, we don't need the speed of light to go fast, wasn't it proven shortcuts within space was also a possibility by using Wormhole paths through Hyperspace to reach another part of the universe without the speed / time factor.

warp speed is about 3x fast than the speed of light, though its only theory

[.Neo]

I prefer regular science to the obscure variants of science you're into, sorry.

Agreed, although he does have a point when it comes to the "Another case of "we don't know how to do it, therefore it must be impossible". I have often been amazed by the arrogance of some researchers in documentaries where they claim with 100% certainty this and that won't ever be achieved. A lot of things we're doing today were deemed impossible not too long ago.

[stevember]

I've always thought, everyone says the speeds of light is the fastest known way to travel in the unviverse and that it's the only fastest known speed in existance. I find this be wrong. If the speed of light is the fastest known speed in existance then can one explain how fast the speed of the universe was with the "big bang". I'm pretty sure the speed of the debrey flying out from the "big bang" was faster, than the speed of light. Surely a fueled explosion of a huge scale would beat the speed of light.

All in all, we don't need the speed of light to go fast, wasn't it proven shortcuts within space was also a possibility by using Wormhole paths through Hyperspace to reach another part of the universe without the speed / time factor.

Wormholes are just fantasy and wishful thinking.

Regarding your theory that things must be faster than the speed of light because of the big bang is incorrect, it is very hard to comprehend an exploding star let alone the big bang but the truth still remains it would not have been faster than the speed of light.

If it was faster than the speed of light we would not be able to see anything when looking away from the origin of the big bang relative to us as the light would not be able to travel back to us. Plus the expansion is speeding up so therefore it is going at a faster rate than the original big bang. That's one of many reasons.

I don't think people quite understand how fast light is. The big bang albeit on a massive scale was just a chemical explosion, we can reproduce similar on earth but not to the scale, we are able to film/see it therefore light must be faster.

Agreed, although he does have a point when it comes to the "Another case of "we don't know how to do it, therefore it must be impossible". I have often been amazed by the arrogance of some researchers in documentaries where they claim with 100% certainty this and that won't ever be achieved. A lot of things we're doing today were deemed impossible not too long ago.

Scientists don't normally say if we don't know how to do it therefore it must be impossible, amateurs maybe, media and maybe some teachers.

[Rudy]

It's possible guys, I've done it but it's over rated :/

[articuno1au]

Wormholes are just fantasy and wishful thinking.

Regarding your theory that things must be faster than the speed of light because of the big bang is incorrect, it is very hard to comprehend an exploding star let alone the big bang but the truth still remains it would not have been faster than the speed of light.

If it was faster than the speed of light we would not be able to see anything when looking away from the origin of the big bang relative to us as the light would not be able to travel back to us. Plus the expansion is speeding up so therefore it is going at a faster rate than the original big bang. That's one of many reasons.

I don't think people quite understand how fast light is. The big bang albeit on a massive scale was just a chemical explosion, we can reproduce similar on earth but not to the scale, we are able to film/see it therefore light must be faster.

Scientists don't normally say if we don't know how to do it therefore it must be impossible, amateurs maybe, media and maybe some teachers.

No, they say it all the time, they just don't mean it >.<

Let's build a plane with 0 wings and super magic powers!

It can't be done :\

Where as they (actually) mean "It can't be done with our current technology" >.<

The issue is semantic, not scientific >.<

[Matrix XII]

It's times like this when you really have to laugh at Science. :laugh:

Light is only a part of an even larger, unrecognized Electromagnetic spectrum -- not the 'fastest'.

And time travel has 'already' been accomplished.

Another case of "we don't know how to do it, therefore it must be impossible".

What?

[DocM]

If it's electromagnetic it's light, be it radio waves, visible or gamma, and therefore limited by the speed of light. Duh.

[PNWDweller]

To prove if it is possible or not, let me wait here for my future self to come back and tell me. I will let you know when it happens. ;)