I Think Faster Than Light Travel is Possible. Here's Why.

If you've been following my channel for a really long time, you might remember that some years ago I made a video about whether faster-than-light travel is possible. I was trying to explain why the arguments saying it's impossible are inconclusive and we shouldn't throw out the possibility too quickly, but I'm afraid I didn't make my case very well. This video is a second attempt. Hopefully this time it'll come across more clearly!

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00:00 Intro
01:51 The Speed of Light as Limit
06:12 The Speed of Light as Barrier
12:44 Time Travel Paradoxes
20:47 Quantum Gravity and Summary
21:54 Learn Physics on Brilliant

#science #physics

[robonator]

The thing I love about this channel is half the time it doesn't feel like a youtube channel, or even a documentary channel, it just feels like a professor's mid-lecture ramblings that they spend half the class talking about because they're just so damn interested in it they completely lose track of the discussion and if you ask me, those are the best ways to learn.

[SabineHossenfelder]

Hi All, I realized too late I should have added a word about quantum mechanics: Quantum mechanics has the same speed limit (barrier!) as special relativity, and special relativity is where this barrier comes from. Therefore, quantum physics doesn't change anything about what I explained here. (Which is why I forgot to even mention it...)

[p.a.]

“Hey, we don’t serve faster-than-light particles in here.”
A tachyon walks into a bar.

[nickhartwell]

I really appreciate your pause in discussion at around 18 minutes to recap the present topic. You knew right when my head was starting to lag while absorbing this information. Phenomenal teaching.

[Termini_Man]

Thank you for having a full transcript for the close captions. You have no idea how much I appreciate. So many channels don't, so the subtitles aren't accurate, or maybe they don't even have any. I have auditory processing disorder, so I have issues understanding talking sometimes.

[sriharsha]

Clicked on this one faster than speed of light.

[onthefive]

Not understanding physics has been a drag all my life. For instance, I've been all into plate tectonics theory since the late 60s, and while I seemed to excel at logic, physics was a brick wall halting my ability to explain and argue my reasoning. That brick wall (my thick skull - or being lefthanded -according to teachers and parents) later interfered with my passion for studying oceanography and geology as deeply as I wanted to in the 80s and 90s. So my college degrees were light om math studies. I'm telling you this because watching your videos, the way you describe and explain things led me to discover how physics works. I can now say, at 74 years old, that I get it!!! I'm so grateful, thank you!

[miami]

Her dry jokes are cute. She just says them with a dead pan feel. Thanks Sabine. Love your videos and humor

[imacds]

"if you live in the USA, make that 20"
as someone who commutes by train, I felt that.

[tayzonday]

Isn’t speed always infinite from the perspective of the photon? Like, a photon from the early universe might take 13 billion years to reach us from our viewpoint— but from the photon’s view, the journey is instantaneous. Thus, our perception of “speed” (distance over time) is just an artifact of our motion experience.

[MartinBica]

This is the most awesome mixture of super high quality information and super dry super funny humor you can experience in this and all 6 parallel univeses. I love the style of Sabine 🙂

[ItsShooty]

I came here for the science and stayed for the dry German humor. 10/10

[prodiver]

There was a time-traveller named Wright who travelled much faster than light. He set off one day in a relative way, and arrived on the previous night.

[tzerpa]

A train at 200 km/h. "If you live in the United States, make that 20" 😂 So funny, and so true.

[shelley-anneharrisberg]

One of the best yet! Really well explained, especially the Higgs Field Condensate and the time paradox! Guest appearance by Columbo with "Just one more thing" just really topped it off! (As did the socks in the washing machine - I like to think mine are in a state of superposition: they exist and don't exist at the same time. When I open the machine, their wave function collapses and I find they are there, or not - sorry Schrödinger, I just couldn't resist ;) ).

[RobertTowell]

I do not know why youtube decided to start putting these videos in my feed. But I am loving them. She does an excellent job of explaining things in a way I can follow. Great channel!

[andrewrohde]

I watch Dr. Hossenfelder's videos in the same way that I read "A Brief History of Time." In the hope that I'll learn something, definitely not all, but something. And I usually do. Thanks Doc.

[fffffplayer]

Could you elaborate on how General Relativity and a Co-Moving Frame eliminates the closed loop? I feel like this is the main point to showing FTL could be possible, but you went over it really quickly. I think we'd really benefit from understanding how that transition works, rather than just being told it works.
Also, could you explain why the Co-Moving Frame can only be defined in GR? Couldn't we just measure the average velocity of all stuff without gravity, too?

I feel like this was a good video for introducing the problem, but a second video to give more time to providing the answer would be very useful.

[philippschwartzerdt]

It’s great to listen to you and I love your dry sense of humor.
I believe that I am learning a lot from your videos based on real knowledge.
What’s even better, I am learning to question my position on many matters I took for granted without having to disappear in a rabbit hole.
Thank you for making your community a little smarter with every video you post. 🙏🏻

[djayjp]

I think the 1 minute section on the bombshell claim that no time travel paradoxes arise from FTL communication/action according to GR rather than SR, needed a bit more unpacking...!