The Quantum Mechanics of Time Travel

Dr. Seth Lloyd, an MIT professor and self-described "quantum mechanic," describes the quantum mechanics behind time travel during a guest lecture at the Institute for Quantum Computing, University of Waterloo. Recorded on Nov. 4, 2010, this is the entire lecture entitled "Sending a Photon Backwards in Time."

Dr. Lloyd also sat down for a one-on-one interview at IQC, during which he discusses the weirdness (and beautiful simplicity) of quantum mechanics, and the incredible importance of quantum information research. Excerpts from this interview are below:

Seth Lloyd on Quantum Weirdness:

Seth Lloyd on the Simple Beauty of Quantum Mechanics:

Seth Lloyd on the Universe as a Quantum Computer:

Seth Lloyd on the Importance of Quantum Information Research:

Find out more about IQC!

[aky]

Great video. I hated physics in my college days. Years latter, I've gone through my old physics with calculus textbook twice!! Took me a few years but I now find my self appreciating everything and understanding laws of the universe far more clearly.

[starsdancetv]

Dr. Seth Lloyd, an MIT professor and self-described "quantum mechanic, " describes the quantum mechanics behind time travel during a guest lecture at the Institute for Quantum Computing, University of Waterloo. Recorded on Nov. 4, 2010, this is the entire lecture entitled "Sending a Photon Backwards in Time."

Dr. Lloyd also sat down for a one-on-one interview at IQC, during which he discusses the weirdness (and beautiful simplicity) of quantum mechanics, and the incredible importance of quantum information research. Excerpts from this interview are below:

Seth Lloyd on Quantum Weirdness:

[TGC]

Delayed choice shows that the universe does time-travel constantly, and gives you a template of how you are required to accomplish the same task. The universe is never wrong, it's that simple.

Where the information goes, when it doesn't arrive to destroy itself, and whether it splays evenly throughout the universe, and what effect happens to the universe, in such cases, is still on my mind.

I once had a weird dream, with hockey and quantum mechanics. I had to step away from my computer when the hockey stick came out, as this is exactly how I would have told myself that my future time-travel was/will be successful.

[aj-tg]

This guy laughs at 9:59 phase shifted and interfered with itself.

[petermoon]

The best part of this lecture is precisely at 1:07:51 when you hear him giving this rather bizarre laughter, which he did one before in this lecture only once (but for a comparatively short time). It is a distinct laugh. I can see people have made negative comments with regard to his theoretical as opposed to hands-on approach. Perhaps you can find some context and joy in his laughter. I do realize, however, some might find it unsettling. I was amused and wish I could can it. It would make a great laughing loop.

[ThinkTank]

I am a Ph.D. computer science student, but I studied physics as an undergrad. Physics has always been my passion, since literally as far back as I can remember (2-3 years old). I invented the flywheel at age 4. Spark-gap radio transmitter at age 5. I have a very deep knowledge of physics and mathematics now. I don't think I was pedantic. I find it very hard to believe, given your comment, that you understand this stuff. You've got a LOT more learning to do.

[SDGamerZone]

I love the relation between thermal dynamics and the quantum mechanics of time travel, very cool.

[Alex_]

His laughter is so nerdy. I liked this lecture, very informative and intuitive

[ironmaiden]

StarsDanceTV9 months ago
Dr. Seth Lloyd, an MIT professor and self-described "quantum mechanic, " describes the quantum mechanics behind time travel during a guest lecture at the Institute for Quantum Computing, University of Waterloo. Recorded on Nov. 4, 2010, this is the entire lecture entitled "Sending a Photon Backwards in Time."

Dr. Lloyd also sat down for a one-on-one interview at IQC, during which he discusses the weirdness (and beautiful simplicity) of quantum mechanics, and the incredible importance of quantum information research. Excerpts from this interview are below:

Seth Lloyd on Quantum Weirdness:

[marinarepan]

Great that I found this video. I translated Seth Lloyd's book Programming the Universe from English into Ukrainian. Now it's a pleasure to listen to things Seth Lloyd says. If only they gave me more of his books and others' ones to translate. The book is just terrific.

[nosuchthing]

Apparently CTC (closed time like curves) are possible, as is actual time travel. The problem is that the energy required is prohibitive now. Godel found solutions that lead to time travel almost as soon as Einstein unveiled his theory.

[Gromwald]

I studied various subjects related to time travel including a masterclass on philosophy of time. I am planning on writing a course on time travel.

[WingMan]

For those interested I had a time travel experience when I was a kid which I am 95% sure was an OOB experience though (which I used to have many of) and not a physical one. I do actually have my doubts regarding physical time travel. Anyway for the open minded here that might trust in my experience the one thing I noticed of importance is the loop. So the scenario was that aged 8 i enter a wormhole that for some unknown reason appears in my bedroom, and travel 15 years in time play on a game boy in a dept store (hadn't been invented yet) go back to being a kid. 15 years later I re-lived that same day as a adult. So here is my hypothesis. To time travel that took place and the information i was exposed to was bi directional. So I took a peek into the future when I was a kid and no doubt could have changed the future by for example persuading the Gameboy maker to call the toy a Gamegadget! In which case 15 years forward would mean i would end on playing on a Gamegadget and not a Gameboy. What blows my mind is how free will is sill possibly in a closed time-like curve!?

[walterchavez]

Another paradox (maybe not the correct word to use) could be that things going into the past will add extra matter and probably energy to ( at least to the past's ) universe. This probably breaks matter creation laws and would be a possibility of filling the universe with matter.

I believe the 'Unproven Theorem Paradox' described at around 13 minutes into the video is also often referred to as a 'Bootstrap Paradox'.

[mjojo]

Anyone else notice the subliminals (sm)?
This was a great lecture hard not to learn something.
I look forwards to more.
Donidorko (movie) is a greak example of the coffee cups handle as he is in a time loop after death and returned to that resting or natural state as he returns to the original time line.
Something similar may be the case with black holes but can't be indefinitely proven.

[CalvinHikes]

Don't be disrespectful of Hot Tub Time Machine! 7:40

[AniRhythm]

that's actually what I was thinking about when I made this post - and the data didn't travel faster than the speed of time. - this also means it can travel to another time zone instantly - thus traveling time in a practical non fiction way. - ie I'm not 12 hours older traveling from the US to Europe. The only way imo to amplify that effect is with greater distance

[KeyOfAm]

19:30 The electron/positron thing blew my mind

[vibration]

Sir, we are able to watch this beautiful lectures which recorded in past, but somehow ( yotube ) we are able to watch in future without harming anyone .

[ZiplineShazam]

Dash Rip Rock played Buddy Holly's "Not Fade Away" at The Grant Street Dance Hall in Lafayette, La. in the year 1989 . . .and it was Euphoric.