Seth Lloyd - Is Time Travel Possible?

Some scientists take time travel seriously. Should you? What does time travel reveal about the nature of space and time? What about the laws of physics under extreme conditions?

[winstonchang]

It always seems like we are asking about our physical bodies time traveling....
And we assume that you remain "intact" when you time travel....

[libertangolyrics]

One of the few science lecturers that makes learning fun by throwing in a lot of humour and mentioning many brilliant different aspects.

[Basilisk]

I believe sound can be heard before it is played. Late one night (one of those deathly quiet ones) I became aware of a sound effect much like an 80s video game. It was extremely feint and kept repeating in a 5 second loop. Never heard it before. The next evening a film was on our TV in which the very same sound occurred - it was a kid playing a video game in the background of the film. How can I possibly hear that 24hrs before it was played? The sound was definately in my room and the only thing that was on was the room light. I will never forget it.

[RickDelmonico]

If we describe time in terms of information, it would be the rate of change. If we describe space in terms of information, it would be these regions where the relationship of a difference between two or more things live. In a network the dimensions are not discrete and there is no way to determine the number of dimensions involved in complex systems.

[AllenProxmire]

Seth Lloyd seems like a descent and cool person

[REDPUMPERNICKEL]

Seems to me that time is precisely and only
a very convenient, very useful concept for
thinking about vast amounts of things moving relative to other things.
Now I think about it,
those "vast amounts of things" includes every thing.

Now all the physicist have to discover is why things move differently under different circumstances.
For instance, why clock movements move less when they are in orbit.
It's not 'time' that changes up there (for location has no effect on a concept),
it's just the amount of movement of the parts increases.
Perhaps gravitational fields simply affect movement.

[robotaholic]

I never saw an interview in front of hot water heaters before. lol But still very fascinating... thank you for uploading!

[innertubez]

The older I get, the more I think that even if time travel is (will be? was?) possible, we would never know. If anyone changed something in the past, the subsequent universe would go off on a different course and even if one could somehow interview someone in that other reality, they would have no awareness that anything had "changed" - since history would be a sort of "self-sealing" sequence of events.

[StanTheObserver-lorx]

He left out that the Universe is expanding...so going back in time the whole Universe has to be rewound. Unless the Universe is a hologram and everything past and everything to be is recorded already. Then time travel is just crossing a few atoms of thickness.

[DirtyNewYorker]

He didn't say the most important thing about that. All of this ideas share common feature - thay can't be used to send any real information. It works for quantum state, but when you trying to measure it - you always have completely random thing. And you can't avoid it somehow, cause it will make quantum mechanics inconsistent. So really, the answer is - No, you can't :(

[argile]

How about a continuously unfolding present moment always being now? Time dilation is simply the slowing down of the unfolding of the present moment. But it's still always Now for you. Even if you go near the speed of light and things slow down for you.

[sidepresang]

Are people working on measuring and analyzing (hopefully one day decoding) Hawking radiation, if it's practically detectable at all?

[mycount]

2nd law of thermodynamics, conservation of matter and energy. by going back in time you are creating matter as the atoms were there before you arrived

[TBirdTurboCoupe]

interesting. I remember a guy who called himself John Titor kind of explaining how micro-singularities made time travel possible some 15 years before this guy... AND, he said CERN would be the one to discover it! He said the Many Worlds Theory was correct... coincidence?

[tusharycos]

I have done time Travel in future, Really I have many experiences of Time Travel in future, it's not a hypothetical... If you interested in me then I will be share my experience and secret of time travel...

[KuljitIssar]

is time travel to past future really possible and how please tell can u help me out to do

[charlesbrightman]

Also consider this:
If a person went back in time, they would not have gone back into an exact replica of the time they thought they were going back to. That time did not include them being there. To truly "go back in time" it would seem one would have to hit the rewind button on all of the universe itself. Otherwise, one would still be going forward in time, but this time the past includes them being there as a backwards time traveler. A "new" forward timeline would have been created at that "new" beginning, without erasing the past forward time line that already occurred. Get it?

[sithsmasher]

On relativistic ct-x diagrams you need to go faster than light to go back in time and that is from a pure mathematical perspective even. Nothing goes faster than light, so it must be impossible I guess.

[i.k.]

Complex information coding the structure of an entity is lost in the Hawking radiation.

[thetherorist]

intelligence can travel in time...not the body....intelligence is all we are, the body is just a vessel for this the answer period the end. and they know this