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

[@SabineHossenfelder]

This video comes with a quiz which you can take here: quizwithit.com/start_thequiz/1687737623494x575496266320185500

[@kh9242]

Darn i missed two "Your score is higher than 22% of the people, who took the quiz! Good job!" I wanted a 100 i have PTSD now heeding to safe space

[@brycering5989]

Plot Twist, Sabine is from the other side of the Milkyway, and is trying to find a suitable mate ;) Hmmm, extraterrestrial extraspecie-al intercource, I think I personally would break the boundaries of C, but would do my best to not let my water hose spit out too soon.

[@RWBHere]

You can think much faster than light already. To prove it, think about our Sun warming the Earth. Now think about the Andromeda Galaxy, as seen through a telescope. You did both of those things in an instant, but sunlight takes over 8 minutes to reach the Earth, and light from Andromeda takes about 2.5 million years to travel to our telescopes.

[@firecat3613]

8/9. I could have gotten 9/9 but, although I knew the answer you wanted, I disagreed with it and a more accurate answer was available. But that's the wonderful thing about science, we don't always have to agree on everything. Often our disagreements can open the doors to new understanding and new advancements, for one of us, for both of us or - in some cases - for all of us.

[@firecat3613]

@@RWBHere The trick is determining what is occurring in the moment. Sure, it's easy to determine that the sun is still shining this very moment. It's not difficult to make an inference from something as recent as 8 minutes ago. But let us not consider Andromeda, but use something much closer as a reference. Imagine a star in our own galaxy. It is 50,000 ly away. We see it clearly with WEBB. The star is an unstable red giant. Is it still there? Is it still a red giant? Is it a white or brown dwarf? What is happening to that star, right now? Now consider Andromeda, a galaxy 50 times further away that that star. What is going on there?

[@robonator2945]

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.

[@alysdexia]

not plural, dolt

[@Kumagoro42]

I get the general sentiment, but I disagree about these videos feeling like ramblings. They feel meticulously prepared.

[@robonator2945]

@@alysdexia you know rambling can be a noun right dolt? Someone can start rambling, or someone can record a rambling. The noun form is just the conceptual object form of the verb.

[@alysdexia]

@@robonator2945 I said nothing about rambling, you wit/2. But I know that a gerund isn’t a verb.

[@robonator2945]

​@@alysdexia well that's bascially the only plural I used, soooooo. The only other plural I used was "those are the best ways to learn" which is a valid plural since I'm referring to the plural group of rambling *_s_* as a concept and not a single rambling. You could argue that it should represent a single "way" of learning but that point it's completely useless subjectivity and there is no "right" or "wrong" answer and it's just a classification problem. Equally however you could argue that a rambling is just a sub-set of the super-set of "passion inspired tangent from a professor" which can include other sub-sets and as a result wouldn't just be an acceptable plural but a demanded plural.

[@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...)

[@eonasjohn]

Thank you for elaborating.

[@jewelrybag4557]

Why would an advanced civilization use clunky spaceships to visit us? Won't they have perfected nanotechnology or quantum technology to achieve their goals?

[@tomcan48]

Sorry again, if we are looking ONLY at physical manifestations, then YES. But the speed-of-light can easily be exceeded through thought. Even those little Greys use that technology and even our relatives from the constellation, Lyra, which we originate from, use consciousness as the base means ships, similar to what we see on Star Trek. Unfortunately, outside the SSP, we are restricted to consider such things as impossible, due to our programmed viewpoint. Maybe someday we will be able to break through this forced programming.

[@jagpreetbatra5084]

Beautifully explained we need new mathematics to first work out in theory behind Ftl then Do some experimental work

[@eewls]

Thank you for this fantastic philosophy video, Sabine

[@onthefive5615]

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!

[@Levon9404]

You know the good saying, old man, better late than never, finally you can consider you were able achieve something in your life

[@DarkKnight_]

Never stop learning then your curiosity and wonder will never leave you.

[@MichaelJones-rg3hv]

Congrats! Always good to learn new and wonderful things.

[@sunbeam9222]

I experienced the same thing ( and also left handed ;)

[@Levon9404]

@@sunbeam9222 Physics is something, you have to have certain attractions to physical things, to understand how to find key to understand secrets they fundamentally exist and function.

[@tlan77]

There once was a lady named Bright, whose speed was much faster than light. She departed one day, in a relative way, and returned on the previous night.

[@984francis]

Very good❤️

[@patriciodasilva7902]

There once was a woman so keen, The quirkiest traveler seen. She looped through the stars, And back to the bars, With tales of where she'd just been. But the folks in her town couldn't cope, With Bright and her time-bending scope. They said, "How can this be? Did you travel for free? Or slip down some wormhole or slope?"

[@aneesahfurqan8544]

​@@patriciodasilva7902😊❤AWESOME!

[@ronbyrd1616]

Was a "quantum" leap forward ! 😊 !

[@jamestrent-nw9zb]

There was a young girl from Tbilisi, Who swallowed a bottle of 'squeezy' To add to her troubles, She kept farting bubbles... And this made her feel rather queasy. There was a young lady from Woking who couldn't stop Farting and Boaking, Not being her fault She tried Epsom Salt Which thankfully stopped her from choking. There was a young girl from Koblenz who drove a large Mercedes Benz. When driving one night she had such a fright... that she swerved and ran over three hens. There was a young girl from Vancouver, who shaved her fat bum with a Hoover then after ten weeks, of hoovering her cheeks. Her bum just got smoother and smoother.

[@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.

[@bazem]

It's also very useful to people who can read in English but are still learning the listening part. It can be hard to follow different accents and speeds while still learning. The subtitles help a lot with understanding the content and also training your ears.

[@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.

[@Zalemones1]

Time is meaningless at the speed of light. The very idea of time passing does not even make sense at the speed of light.

[@robertanderson5092]

Isn't distance also meaningless?

[@VivekPatel-ze6jy]

I think so... Time dilation really messes with my brain lmao

[@Chimwizlet]

As Zalemones1 said, time is meaningless at that point. The misconception comes from the maths which suggests that as speed approaches c the length contraction approaches the point where distance is 0 and so the journey is instant. But that doesn't mean it actually is 0 at c, at that point the equation is no longer valid in the same way 1/x has no value when x=0.

[@jitteryjet7525]

Exactly! Something travelling near the speed of light can cross the known universe almost instantaneously, from their point of view.

[@sriharsha5036]

Clicked on this one faster than speed of light.

[@michaelfried3123]

clicking on clickbait gets slow rolled by those of us who know better. this video is for the dummies out there...

[@faeancestor]

man

[@nonsequitor]

In what medium? 😉

[@Lilliathi]

@@michaelfried3123 Oh, I'm sorry superior being who likes his own posts. I bow to you.

[@MrYobII]

Not while your thumb was traveling through a medium

[@keigzerg743]

I'm a postgraduate student of high-energy particle phenomenology. This video is really fun to watch. I attended a summer school last year, there was a professor who said when a good popular science teller or writer tells something, half of it should be understood by the common public, the other half of it should be understood by actual scientists. And your video absolutely finds a perfect balance between this two parts. Thanks for your great video.

[@nickhartwell6889]

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.

[@austincriswell8480]

I fizzled out right around 5:15 😢

[@daveinpublic]

That’s called inflation

[@davibogner095]

That was really amazing

[@p.a.1675]

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

[@rajeevgangal542]

He was served beer but didn't drink. Why? Cause he was virtual

[@Existidor.Serial137]

that is a very good nerd joke.

[@bradysmith4405]

Did he walk in after because they go back in time?

[@MariosPOS]

lmfaooo

[@DeadlyKiss000]

Are Tachyons related to Klingons? Because if they are, then that is a sure fire recipe for a bar brawl! Tachyons ain't gonna take that, not being served!

[@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 🙂

[@johnself6435]

Yes but why is she hot?

[@Justin534]

​@@johnself6435Because of her binding energy!!

[@TestGearJunkie.]

Only 6..? I always thought there were an infinite number..?

[@pastor-tom-sims]

I will bookmark this video in several databases. I will refer to it every time I am deluded into the belief that I know anything at all. After listening 15 times, I may memorize it, but I will still not understand it at any level that will keep me from being in awe of Sabine. I seldom enjoy my head spinning any more than when she is doing her best to teach me something. If I ever learn anything at all, it will be from masterful, engaging teachers like her. I am addicted. This is the monkey on my back. Well done. I am convinced. Ask me tomorrow what it is about which I am convinced.

[@moosewild4239]

This conversation is way above my pay grade but I find myself listening anyway. Your knowledge and ability to share it is appreciated. Subscribed since it is never too late to learn.

[@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!

[@Scott-i9v2s]

Of course understanding an explanation is no guarantee of the explanation's validity... FYI: Whether Sabine is wright or rong is a totally-different issue.

[@JerryHoward88]

I'm pretty sure the aliens have put Sabine's videos on your feed. Grooming us to accept that they traveled here at faster than light speed.

[@RobertTowell]

@@JerryHoward88 lol

[@djdickey]

You don't remember hitting subscribe next week?

[@ronsirman6867]

She's brilliant

[@pressuredrop1]

Thanks Sabine. Very informative and well presented.

[@IAMSEYMOURMUSIC]

You have one of the best science youtube channels ever. Youre smart, funny, you are open minded, its all AA grade quality stuff. Thanks for adding all this value to the web

[@ericpeterson6520]

This reminds me of my favorite fictional justification for FTL travel, which comes from the book Way Station by Clifford Simak. It boils down to "Humans think that it's impossible to travel faster than light. Turns out they're wrong" And that's it. No further scifi technobabble needed, the "cosmic speed limit" was just an artifact of incomplete physics the whole time and you can just break it (in this universe)

[@onastick2411]

Good read as well.

[@trazyntheinfinite9895]

Funny thing is: we might be wrong. noone knows.

[@alessandrofregoso740]

and it works for unicorns end elves too!

[@defender399]

Speaking of sci-fi and its postulations, I rather like a Doctor Who explanation for apparent aberrations in the space-time continuum. “It’s a wibbly wobbly timey wimey thing.”

[@jamesh1758]

Sort of like how we used to think that heavier than air flight was practically impossible and that birds and insects had some magic or animal science we wouldn’t get. We figured it out for sure, but in a unique way. I suppose the problem is we’ve got 0 examples that this rule can be broken so we think it’s impossible but who’d have guessed we could see inside people’s body’s with x-rays and brains with MRIs before it was discovered.

[@fffffplayer1]

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.

[@YuraL88]

I think that closed loops can exist, you can even imagine some "universe" that lives in such a closed loop.

[@anywallsocket]

This is all half-cooked theory, built up from isolated models. Ironically she's using these to argue against the half-cooked nature of SM+QM

[@Duiker36]

They don't eliminate the closed loop. They make it reasonable to say there wouldn't be one. The closed loop itself is merely a reasonable conclusion to draw from special relativity, so that's the standard of argument she's aiming to meet.

[@danielbronsky]

I'm not at all educated in physics, so apologies for any mistakes, and take this with a grain of salt... but here's how I've heard it explained: According to Theory of Relativity, if events A and B are causally disconnected, they don't have a "true" order. Depending on your frame of reference, A may occur before B, or B before A, or they may occur simultaneously. Whether or not events are causally connected depends on the distance between them and the speed of light. For example, if you see two buttons, that are 1 light second apart, and then you see them pressed simultaneously, then they are causally disconnected, and depending on your frame of reference the order in which the buttons are pressed can change. On the other hand, if you see those same buttons, one is pressed, then several seconds pass, and another is pressed, then they *are* causally connected, because light managed to cross the distance from one button to the other in the time between the presses. So now the order the buttons were pressed in is certain and independent from your frame of reference. This behaviour may seem weird, but it doesn't actually cause any problems or paradoxes. If you get into your spaceship and fly from point A to point B, your departure and your arrival are two causally connected events (because you travel at sub-light speed), and so have a definite order. But what happens if you make an FTL jump from A to B? Well, now your departure and your arrival are completely causally disconnected! And in certain frames of reference, arrival *occurs before departure*. Look what can happen now: - Make the jump A --> B - You are currently in the frame of reference where departure occured before arrival (as it should) - Engage your ship's thrusters and accelerate until you are in the frame of reference, where departure hasn't occured yet - Make the jump B --> A - You traveled back in time and broke causality! Crucial point is that breaking causality requires *two* FTL jumps in *different reference frames*. So, could there be some (purely hypothetical) mechanism that would allow FTL, but prevent paradoxes? Yes! There simply must exist a special frame of reference, and all FTL travel must only be possible in this special frame of reference. This special frame could be whatever, but for the purposes of this thought experiment we can pick the Co-Moving Frame (CMF), because it is easier to visualize and is already somewhat "special" (as mentioned in the video). Look what happens now: - Accelerate until your frame of reference matches CMF - Make the jump A --> B - Engage your ship's thrusters and accelerate until you are in the frame of reference, where departure hasn't occured yet (weird, but no paradoxes yet...) - Make the jump B --> A... but wait! You can't make this jump, since in the previous step you left the CMF! - Match the CMF again - Make the jump B --> A. - Since both jumps occured in the same frame of reference, causality is preserved! This is my understanding. You can search "fixed frame FTL" for some more info. see also this FAQ on Relativity which touches on this topic at the very end www.physicsguy.com/ftl/html/FTL_intro.html

[@petermoore900]

I don't think it has anything to do with GR TBH. Rather if you can guarantee that everyone can only move in such a way that everyone's arrow of time always moves in the same direction, then you can zip around faster than light - but still not infinitely fast! - without causing paradoxes. How can you guarantee that while lifting the c limit? Basically you'd have to hypothesize that there is something akin to subspace or hyperspace, that it indeed absolute, and that it is the only medium through which an FTL mechanism could work. Could this actually be true? Well it certainly can't be ruled out. Let's say we did make a warp drive. That would cause spacetime itself to bend and move. The stress energy tensor in GR is Lorentz invariant (meaning everyone agrees on the geometry of spacetime and thus the strength of gravity no matter how fast they're moving). Perhaps that means that all warp drives would indeed be riding waves in the same fixed and absolute medium and thus no paradoxes would be possible. But critically, again, this speed would still be limited - not by a single arbitrary number but by how fast an external observer is moving relative to "subspace". This limit is c^2/v where v is your velocity relative to the absolute frame. Specifically, instantaneous movement in any frame appears to an observer moving at v relative to that frame as c^2/v. So if we assume infinity is the speed limit of subspace, then on earth that speed would equate to roughly 1000c (if we're moving 300kps). Any faster perceived speed would indeed require the traveller to be going back in time in the frame of subspace. This means Voyager's trip home from the Delta Quadrant could've seemed instantaneous to the crew but 70 years would've passed on earth. In other words you can't fully escape time dilation but now it would depend on how fast the third party is moving relative to subspace rather than how fast the ship is going relative to the observer.

[@prodiver7]

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.

[@audiodead7302]

I just asked ChatGPT to write a limerick about travelling faster than light and time travel. I like yours better!: There once was a physicist quite bright, Who dreamed of a journey through light. With a machine that could time travel too, He set off on an adventure anew. He broke the light barrier with ease, Zipped through the cosmos with such great sleaze. But when he arrived at his destination, He found himself in an odd situation. His time machine had worked too well, And sent him back to a time he couldn't tell. He realized with a start and a fright, That he was stuck in a time-loop of light. So, if you ever think to travel so fast, And attempt to journey through the past, Just remember this limerick quite well, Or you might end up trapped in a time-cell.

[@heyasasha]

the way the rhyme played I thought you might say something that ended in shi-ne a light

[@fairygodmothersdog]

@@audiodead7302 OMG #talesfroma21stcenturyfairygodmother uses through loops to save a place in time and space, but this ai actually touched on a funny notion that eventually all time traveler's get imprisoned and I forget where I read it, a meme or work of sci Fi, but that's so interesting that was generated. "Sleaze" is a bizarre word to use there.

[@fairygodmothersdog]

Prodiver7 I really liked yours. Did you write that?

[@subspaceanomaly]

@@audiodead7302 I would like to go on a sleazy trip across the cosmos

[@_vicary]

I love it when a physicist really explains the difference of Higg's field and Aether

[@imacds]

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

[@neurofiedyamato8763]

unfortunately true

[@DrorF]

Now I get it. Thanks.

[@GuyFromJupiter]

One of the 5 people here in the States that does!

[@HocusPocus6969]

I spit my coffee on that one. Love it.

[@luke_fabis]

​@@GuyFromJupiter One of the five people who can. Our rail network is in shambles. Forget high speed rail, I just wish we had a rail and trolley network like we had in the mid-1800s up until the automotive industry poisoned this country.

[@sciverzero8197]

Thank you Sabine for giving a name, the co-moving frame, to the concept I've been trying to explain to someone for a long time.

[@captainoates7236]

Wondering if it's got anything to do with Mach's theorum which I've seen videos about.

[@reasonerenlightened2456]

There is no use for science if it can not solve the issue of distribution of Wealth and Power among the citizens.

[@kraahk1928]

I'm German, so arguably I may not be adequately fit to make any judgement in these regards...but within my personal frame of reference, the amount and quality of jokes in this video was beyond outstanding. Making it both more digestible for amateurs and more funny for (semi -)professionals. Awesome job and thanks. :)

[@mirage4014]

As an English Man living in Germany! It's the first time I realised German people have a sense of humour 😂 Sorry just joking! Sabine is wonderful

[@gottrekk5798]

I am not German but I think in the last 100 years Germans made more scientific discoveries then all other nations combine.

[@creos42]

I'm from the US and love her humor. German ancestry may be to blame though

[@waen606]

I'm only part German ...its hard to know what I can say confidently and what I can't...

[@jimstewart3017]

As the old Beck's beer commercial goes, German's don't comedy, they do beer. kzbin.info/www/bejne/rqi7nZmqa9mCp5I

[@kevinflick61]

I appreciate so much the open mindedness that you have continued to maintain despite the fact that most scientists seem to accept scientific theories as theories that should not be questioned and even though I don't understand a lot of the really technical stuff, your realistic outlook at the world of science is so refreshing.

[@andrewrohde2373]

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.

[@stephencummins7589]

I got to 8’ and said: I am so glad you made this new video, it makes everything so much easier to understand, thank you Sabine, I love your videos.

[@widnyj5561]

It's the first time I heard the argument about higgs field condensation regarding FTL topic - and presented very clearly with solid hooks to dig deeper around this. Great movie!

[@gregmark1688]

I'm pretty sure " presented very clearly with solid hooks to dig deeper around" describes every one of Dr Hossenfelder's videos

[@natevanderw]

@@gregmark1688 Meh. Most. There is a few videos that I think weren't done well. Like her video on Elon Musk's "Population of Humans are too low video" and her conclusions at the end.

[@oiuyuioiuyuio]

@@gregmark1688 no

[@123Shel12]

Also my first time to hear about Higgs field condensation. I agree with you that Dr. H's explanation was clearly presented! She impresses the daylights out of me!

[@gregmark1688]

@@123Shel12 Me too! I feel kinda sad for all those losers who can't tolerate an intelligent woman and have convince themselves they're smarter than she is or whatever. Misogyny must be a miserable way to be.

[@blinkingmanchannel]

Are the following phrases equivalent? (1) We don't know what spacetime is "made of" because it's not clear whether or what "causes" spacetime to get curved around certain objects, assuming there is any causality at all... though at least Newton thought it would appear to be related to mass, somehow... (2) We don't have a theory of quantum gravity... (3) Wave Function Collapse doesn't have anything to do with spacetime itself... (4) It's illogical to assume that photons and neutrinos can only exist "in" spacetime, while in the same breath assuming that these objects have no mass...

[@hailynewma9122]

Gonna watch this over and over again just to hear that I am not mass but pure energy … and today is not even my b-day .. thanks Sabine :)

[@fruitbatcat]

I don't know how u do it, but often during ur vods I find myself thinking I'm not sure I'm really following this or just think I am, then u drag me back in, you seem to know when those moments are and clarify the point. It's a real talent. Wish more lecturers had it. Just wanted to say :)

[@ignaciosavi7739]

She is probably full of shit and trying to sell books or something

[@ignaciosavi7739]

I was right

[@MIck-M]

She somehow 'brings me back in' with her quirky lil jokes which I like a lot. Mind like a steel trap and rapier wit this lady has.

[@jamesmeppler6375]

Just wanted to say smile face? LOL thats a lot of words for just :) I don't think you get it but at least you can understand you don't get it. Peoples intelligence can be measured by how others write or type. You can use commas but still using U for you and ur for your is either lazy or shows you're still very young. Understanding and being able to use real words is part of understanding what she's saying here. If you read 20 min a day for 10 years you will have a high IQ, maybe even genius level. Your reading comprehension will be maxed out so you'd know every word she said even if you don't get science. Umderstanding is the beginning of science. And if you understand the words the you can understand science

[@mattlambert3118]

You're not following her. You think you're not following because she says stuff that doesn't make any sense to you and then she "clarifies" by telling you the conclusion she draws from the stuff she said that didn't make any sense to you. That makes you feel like you're following because you understand the practical upshot of how she's saying things work, but you don't really understand why she she's saying things work that way. If you understood her reasoning for thinking things work that way, you'd understand that she's spouting nonsense.

[@lobojk]

Sabine, this is fantastic and funny. I'm not sure I could answer any of the quiz questions... but I will watch you again. This presentation is crazy cool.

[@CharlieTheAstronaut]

For me as a half-German (the good half) that loves science and consumes most content in english, Sabine's channel is a blessing!

[@shelley-anneharrisberg7409]

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 ;) ).

[@BlueGiant69202]

kzbin.info/www/bejne/e6TUhIyOZ9uVbdU

[@DalbyJoakim]

Yes this got somewhere very new! But there is no condensation for a scalar potential field! The condensation only happens when the field can form a sufficient density of sufficiently similar structures within that field: Higgs bosons or something even more simple, arranging themselves as a single entity of space-time. Or four space-times really, but three of them flow superluminally within ours - so I guess they are light invisible but gravity visible. Can information be harvested somehow about superluminal structures? Is there a before and after to us for superluminal structures, when they have an ortogonal time within them compared to the time within our structures?

[@antonystringfellow5152]

So that's how I end up with an odd number when I always buy them in pairs!

[@levybenathome]

Socks are explained by multiverse theory. Somewhere there is a universe with all of our socks.

[@StoutProper]

I always find one is and one isn’t

[@Urroner]

I love the way you throw little throw away lines which are hilarious. You say one and then you just move on without any hesitation. People do that when they are making important points. You're the mostest bestest!

[@spoiler321]

I'm always amazed at how slow the speed of light is

[@edcunion]

Certainly to us sub light speed observers, but from its view it travels to Andromeda and back, millions of light years, in no time! It orbits black holes and nucleons and can pop out photons when either are disturbed, or capture or absorb them when a photon gets too close?!

[@j7m7f]

It is as meaningfull as saying that you are amazed at how small pi is. C is not small or big. It just is. If you think it is small then you are probably rather amazed at how big YOU are. Or Earth, or Solar system, or Milky Way...

[@ianokay]

Yeah, especially given the size of the universe. It's slow to us just getting from the sun to the earth... let alone anywhere else! It's even slow inter-planetary; slow enough we can notice the slowness just trying to send data from LA to London. It's abysmally and impractically slow. ​ @edcunion @Jarek F

[@kiefermattern917]

@@edcunion The nature of light means it has no rest frame. There is no photon's view.

[@mreese8764]

@@kiefermattern917 For the photond the speed of light is infinite. They are created and destroyed simultaneously. A photon that travel 10 billion light years and is absorbed on an earth based camera, the emission and absorption together are just one instantaneous process happening at the very same location in space. The photon didn't even travel at all. 🤯

[@Educated2Extinction]

What I love about this channel is " I think", I believe", "most plausible", etc.

[@Verrisin]

"we are too boring for aliens to observe us" - Have you met people? - Some have hobbies studying the most boring of things. Others like to study ant colonies, or worms, or geology, knitting, watching how plants develop etc... - Surely, if there are many aliens, SOME would be interested in us, no matter how boring we might be.

[@eekee6034]

Yeah, the "too boring" hypothesis can't work.

[@javiej]

This is the best video from Sabine, by far. Telling us her (very innovative) scientific opinion on a polemic subject like "faster than light travel", and doing it in a public KZbin video rather than writing an obscure paper she puts her prestige at risk. So thank you Sabine, only the brave change the world.

[@TheChzoronzon]

Au contraire, writing a serious paper will be the ballsy move... a YT vid is irrelevant crap

[@eekee6034]

Such a paper could never stay obscure for long, I don't think. Basically all the science KZbinrs would jump on it the moment they heard about it. There was a time I would have worried it might not get published, but now I can't imagine it being ignored in the prepublication paper exchange. Maybe if the title or synopsis were poor, but I'm pretty sure Sabine of all people could write those well.

[@berniv7375]

@@TheChzoronzon Few people read a serious paper and in that way the general public remain indifferent to physics. Many people watch KZbin videos and if complex subjects can be explained with clarity and relative simplicity then our collective intelligence is raised.🌱

[@Madrrrrrrrrrrr]

@@TheChzoronzon yep but the theory is not new. The big bang went faster than the speed of light.

[@RobOfTheNorth2001]

@@Madrrrrrrrrrrr space expanded fast than light. Not the matter within it.

[@empireempire3545]

I love this video Sabine. You've actually answered some of the questions and thoughts which i've been coalescing for a few years now but didnt have nearly as clearly posed as You did here! Thanks so much

[@mattwilson8298]

If you think we're too boring for aliens to visit, you've never met a biologist.

[@colingallagher1648]

this topic has fascinated me for the past few years especially with black holes and ideas of warping space time thanks for the video and all of your videos your uniqe voice is much appreciated.

[@Stone7C1]

just for anyone wondering. light inside a medium does technically not move slower than in a vacuum. its just a result of how were describing the process mathematically. whats really happening is, that light (photons) moving through a medium (at c) constantly collides with molecules and is absorbed by those molecules. there is a short delay (the average decay time of the excited state of the molecule) after which a new identical photon is emitted by the molecule that absorbed the previous one. this short delay is what were mathematically treating as light to moving "slower" through a medium, but not whats physically happening. in reality the photons are at all times moving at the same speed of light even inside a medium where they are repeatedly absorbed and simply stop existing entirely for brief moments. its like sometimes with electronic circuits you can either describe whats happening as negative charges flowing in one direction through a conductor, or you can pretend that positively charged particles are flowing into the opposite direction. mathematically it doesnt make a difference which of the cases you chose to describe whats happening, even though we know physically its electrons and not positively charged particles that are moving through the conductor. this is a good example to remember that the math were using is just a tool we use to describe physical processes and and can produce weird artefacts that do not accurately reflect what is physically happening in what we call reality but are still consistent within the mathematical model and still produce accurate results.

[@jessejordache1869]

I don't think that's correct: if it was, when the photon was reemited from a particle that had absorbed it, the vector of the new photon would be random. If you looked at the bottom of a foot of water, you'd just see a big blur. The actual reason is electromagnetic interference: basically, the electrons in the medium share wavelengths with the photon, which, being massive, are necessarily going to be slower.

[@Stone7C1]

@@jessejordache1869 photons dont speed up or slow down. they move at a constant speed of light.

[@jessejordache1869]

@@Stone7C1 You weren't persuaded that after absorption, reemission would be take place on a random vector? Okay, tell me how the atom "remembers" which direction it was going.

[@jessejordache1869]

@@Stone7C1 Without beating it to death, it's REALLY HARD to account for an angle of refraction without the speed of light changing according to the medium it's traveling in. I'm aware that there are "absorption and reemission" explanations all over the internet: science is one area where there's no shortage of bad information. So here's a short explanation from two professors of physics (the game is which one can explain it better, more quickly). kzbin.info/www/bejne/eZqrf2OQjKpomM0

[@jessejordache1869]

@@Stone7C1 There's a post here by me that's missing. I think -- sometimes my own posts aren't visible to me if I respond in the dropdown. Anyway, I THINK I know what you're thinking -- that the speed of light is a constant and to maintain that constant, all other "laws" will crumble: time will slow down or speed up, the mass of an already massive object will increase, objects will become foreshortened in the direction in which they're traveling. That is true. It's also irrelevant to the fact that the 200,000 m/sec that we all know and love is only true in a vacuum. In a medium, light slows down, but it is still the universal speed limit, just only for that medium. If you think about it, the surface of a medium causing light to change direction is only possible if it's changing speeds; otherwise the law of conservation of energy is violated, since you'd have light taking an indirect path to its destination. If that can happen, then things can spontaneously fall uphill, light traveling from the sun to the earth can spontaneously loop-de-loop, planets themselves can suddenly decide to move to a higher plane of orbit, etc. But don't take my word for it. Neither should you look up "why does light slow down in a medium?" and accept what someone on Quora says. First go to a credentialed source -- any, and I do mean ANY physics professor will do. There are a ton on youtube. Find the answer there. For extra credit, check out how Jacob Bernoulli discovered the bachistacrone (his proof assumes different speeds in different mediums).

[@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...!

[@jesc1968]

I'll admit, it was a bit hard for a simpleton like to follow, but the time travel paradox explanation was great. Maybe now, movie companies will stop making them.

[@digitalnomad9985]

@@jesc1968 It does not follow that fiction does not make time travel paradoxes.

[@Yroc_Mahnud]

Before I start, i would like to say, i just met you, I love you, and i watched your full video and you seem like someone i could talk to for hours about topics no one else would ever dream to care about. I'm also a hot 44m. With that said, there is a way to travel faster than the speed of light technically (because distance is tricky when dealing with space) but in reality it's not really moving faster. I would need to explain a few things first to get to this point. Light has a direct correlation with time and time is an absolute constant. If you slow time or stretch time, light follows. The next thing is dimensions. This is important because it has the ability to tie quantum and string theory when it comes to matter. We are 3d objects that exist in the fourth dimension and cast a 2d shadow. Time is on the 0 axis, exists on 1 dimension and casts a fourth dimensional shadow, aka the past. Because of this, time can only move in one direction. The fourth dimension can be represented (xyz)P²C^4 where xyz is matter, P is the expansion and contraction on all parallel lines and time flows parallel to those lines. Because of this, matter has the ability to contract time and is the building blocks of gravity and expansion. Gravity basically being, time is slower at your feet than at your head when standing on a larger mass so you feel like your falling or sticking to this larger mass. Expansion is so much more fun. Within super massive objects time looks like it's moving really slow but its not. Its moving at the exact same speed but in a compressed state so it travels less distance per second. Now, let this massive object compress a billion years worth of time, wave your magic wand, and make the supermassive object disappear. Because time is an absolute constant, it will stretch itself out to catch up to relative time making objects appear to move faster, including light. This is expansion and the reason we will never catch up to the "great attractor" and a great way to explain why light traveled faster in the early universe. Another good example of mass and time interaction is if I was able to condense time so much between earth and mars that mars now appears to be within the same distance of the moon. It looks so close, like i could fly there in the time it takes to get to the moon but within this compressed time your traveling in, it would still take the same amount of time to travel there as if time was never compressed at all while mars is sitting in your face. I love you still but the later parts of the video i disagree completely for a few reasons. The graph depicts time and space with the speed of light being a 45° angle. The Rocket looks to be doing 180% the speed of light and bob at about 70%. The egg broke as bob and the red rocket passed each other so both saw it break and because bob is at only 70% the speed of light, he will never get to a point where he could see the egg again not broken. The rocket however can see the egg break, travel for a bit, put the breaks on, look back, and see an egg that was never broken, the same way that we look out into the stars and see millions of years into the past. The information paradox is an assumption that your going close to 300% the speed of light when again the 45° angle represents the speed of light. Ok, whatever, we can do that i guess but this is why I don't like this representation with what your explaining. You have the time, space, and 45º representing C, but.... then add a new plot to represent a new point in space and time but time is not relative to the destination. It's only a plot with in space so that plot would have to be on the x axis or space axis only, making the entire argument invalid because the line will actually never touch the plot but instead be reached when bob and the plot are parallel with time. This graph was really bothering me and took me 20 minutes to figure out why. In no way can moving faster than light move you into the past. We can never go to the past, we can only observe it. We can however go to the future, but we can never observe it. Well, unless we can figure out how to utilize the fourth dimension and slip within space to where time is not relevant. If you were able to do that you would be unaffected by gravity, could pass through objects, and could have every gun in the united states target you from 3 feet away, shoot every bullet ever made, and have every one of those bullets curve around you. While time normally would curve into matter, in this situation it would curve away rendering the bullets useless. Also you would create a 3d shadow instead of a 2d one where all sides of you are visible. I don't believe you would look like a picasso painting but instead more like a sphere or ball of light when the observer sees the reflection of light from all sides at once. Lastly, there is one more way to appear to break the speed of light. Super massive objects, if large enough to hold on to itself and not be ripped apart in there spin, create time dilation, with the contraction of time around matter. When this matter is spinning within this time dilation, it could have the ability to the observer on the outside for the spin to be breaking the speed of light. Also, light could never reflect off the object because it could never go fast enough to catch up to the spin within the dilation . I have a theory that if we see at 60 frames per second, and i had a camera that could shutter 3^26 fps you could actually see the frame of time through light as it travels and with that camera you can actually see the expansion and contraction of time around objects when you shine light from an object and to the object. Another thought, if you compress light to where it gains the mass of the smallest particles in the universe it now becomes a particle which would mean that photons could directly have the ability to give black holes mass and could explain a lot about how they got so big. Want to talk about it? Love you. Call me.

[@mind_of_a_darkhorse]

I love how you infuse humor into your explanations! It makes learning more enjoyable! Keep up the great work!

[@vickmackey24]

Do you actually laugh at her dry, corny jokes? Or do you just find them cute and endearing?

[@kszilvi86]

@@vickmackey24 Don't you happen to mix up "humor" with "laugh" tho? 2 verrrry different things...

[@mind_of_a_darkhorse]

@@vickmackey24 I find them endearing.

[@stevenbrown9185]

She is the absolute Queen of Deadpan

[@mikitz]

@@stevenbrown9185 Well, she is apparently German.

[@philippschwartzerdt3431]

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. 🙏🏻

[@jeechun]

"If you live in hte US..." hilarious. 😄

[@Axiomatic75]

Questioning one's beliefs is a rare trait

[@CARBON10]

You are the perfect person to subscribe to brilliant according to her

[@petertrebilco9430]

I love your style. I love your humor. I love how you make something that eluded me throughout high school digestible. I still don't get the maths...but at face value, your explanations clarify things in my mind. And, you're a very attractive presenter! Vielen dank!

[@traumflug]

Fascinating. You not only manage to find cracks in currently popular physics arguments and can explain that with math, you also manage to explain this with graphics for non-physicists.

[@ItsEverythingElse]

Where is her math that explains how mass could even reach the speed of light, let alone exceed it?

[@traumflug]

@@ItsEverythingElse Please watch 5:52 closely again: _"the only way you can move at the speed of light is when your mass is zero"._ And then she explains why the stuff we know as matter might have states with no mass.

[@dustinsoodak6238]

Thank you for pointing this out! This is exactly how i always thought about it. You only get time travel paradoxes if you have multiple FTL reference frames that you define to be indistinguishable in the same way that you can’t differentiate between reference frames in SR.

[@nosuchthing8]

Huh?

[@ananthan8951]

Why travel ftl, where you headed, when (and where)) y'r back?

[@viperswhip]

I think the whole time travel thing is stupid, the only difference if the information came to us faster than light is less lag, it does not mean the information at the origin source changed in any way, and it doesn't allow you to act on the origin either.

[@fiftyIceStates]

​@@viperswhip Neither you nor Dustin are making sense.

[@everythingisalllies2141]

@@viperswhip Not only is time travel nonsense , but every one of Einstein's theories is also nonsense, as well as quantum physics. its all BS. Most of cosmology is also BS. There is more BS on the list, but that enough for now.

[@setorious]

I wasn't blessed with the processing skills in my brain to understand things like you do but i really like these attempts to break stuff down and bring me along. Even with my limited capacity i am exposed to so much information and able to build on shoulders of giants without realizing it. Kings and everyone in past can only dream of knowledge and insights i've gotten so easily.

[@gzoechi]

I often get the impression that being, feeling or appearing smart is mostly about cutting through all the bullshit others put around things to make them look difficult - so it's more about perseverance than genetics.

[@SevenTheMisgiven]

@@gzoechi This is a really excellent approach. Never change! :)

[@gzoechi]

@@SevenTheMisgiven Thanks ❤️

[@thesybarite1]

I absolutely love your satirical dry humor. 😂😂😂😂😂 For lesser beings like myself it keeps me interested in topics which are normally so dull I don't even try to keep up. Thank you forg increasing my small knowledge of the universe around me and adding a spark of interest to my life.

[@benruniko]

Thank you, that makes a lot of sense! I always wondered why these questions were never asked in the “why FTL is impossible” lectures and videos.

[@darrennew8211]

It's mainly, I think, because physicists are convinced paradoxes are impossible. Cause and effect has to hold. On the other hand, there's various math that shows any quantum-level closed-timelike-curve can be solved with a consistent result. I.e., there's always a consistent loop. And I'd think that if one could go back in time, you'd keep "going around the loop" until you settled into a pattern in which everything is consistent, or it would change next time around. There's a sci-fi novel called Thrice Upon a Time (James Hogan) where the protagonist invents a machine that can send info back in time. And it causes sort of paradoxes. And ... yes? So? You receive messages that were never sent. So? It's treated as "this is the experimental reality."

[@totalermist]

Oh, they get asked alright, but the lecturer can't point at a theory that doesn't exist yet, so they stick with the current and incomplete one. Maybe it would be best to always add the disclaimer "according to our current and known to be incomplete models" to all of these.

[@darlenesmith5690]

It makes less sense than most people realize. As a simple example: E = mc^2 (1 / (1 - (v/c)^2)^0.5 - 1) Assuming that she is correct, the equation for this with values of v greater than c introduces an imaginary number into the equation. This would mean E = iE' where E' would be some finite energy amount. But what does i do here? How can a measurement of energy have an imaginary number in it? Worse than that, E' would be a small negative value as well. So the faster one goes beyond the speed of light, the less "negative energy" it takes assuming a positive mass. What would negative energy be? If E is positive energy, that in turn would require negative (imaginary) mass in order for E to be positive. It sounds nonsensical mathematically when discussing reality. At best, one would need to describe this as something like "using another dimension", assuming that other dimensions exist. Granted, the equation for energy above the speed of light might have a different equation completely. But typically, that is not the case in physics. At best, the equation has some more factors that zero out or some such at one extreme or another. For example, MOND. There are mathematical reasons why most scientists do not buy into unorthodox theories. Mostly, the math falls apart or other well proven theories have a conflict.

[@benruniko]

@@darlenesmith5690 you may find that simply because math has an imaginary number in it, that does not preclude it’s existence in reality. It is simply a two dimensional numberline with sqrt(1) on one axis and sqrt(-1) on another. You may not be able to hold i apples, but you cant hold pi apples either. But both are a part of the real world.

[@darlenesmith5690]

@@benruniko I think you missed the point. I agree with what you just wrote. Best that we know, infinity never exists in nature either, but it does show up in equations. Think of it this way. The energy for low velocities is low. The energy for high velocities near the speed of light is really high, but still finite. The energy for velocity at the speed of light is infinite (hence, not achievable). The energy for velocity beyond the speed of light is negative and/or imaginary, and/or the mass is negative and/or imaginary. The equation tells us that. How can these be negative, let alone imaginary, and how can the energy decrease the faster one goes? Another way of saying this is that the energy for velocity beyond the speed of light is undefined and a bit nonsensical. No known or even theorized energy or mass has those properties. The final value of E has to be a type of energy. Let me put it another way. When Voyager 2 went to the outer planets, scientists at the time thought that Neptune did not get enough heat radiation from the Sun in order to have any type of wind. It turns out that Neptune has the fastest winds in the solar system at about 1000 MPH. It took scientists nearly a decade to figure out how that was happening. My point? Whenever scientists guess at what is possible without solid facts to back it up, they are usually wrong. Nearly 100% of the time unless there is previous proven (relatively speaking) science that will practically force a given prediction. Science is based on observations, not guessing. The theory here is not based on observations, it is based on a series of unrelated ideas. In this video, she is throwing darts at a dart board in the dark where not only the distance and direction to the dart board is not known, but whether the dart board exists at all is not known.

[@washingtonradio]

I have always thought FTL limits were an artifact of our current theories. I'm reminded of George Box's comment, "All models are wrong, some are useful". To assume something is impossible because our current (incomplete and possibly incorrect) understanding says it is has always struck me as logical fallacy.

[@wills.9807]

This is such an excellent video. I've watched it 3 times now, and the concepts are so counterintuitive that to say I understand them wouldn't be honest. I thought your analogy to the formation of dew - condensing out of air as the carrying capacity decreases with lower temperature - to the Higgs condensate, the best I've heard yet. Great work!

[@edwardlulofs444]

They are easy to understand when you have had 4 years of graduate physics classes. After faster than light travel becomes routine, then, as an everyday experience for everyone, even children will understand it. Just as children now understand driving 70 miles an hour on the freeways.

[@inthefade]

I fully expect to listen to this 10x.

[@rodschmidt8952]

I would say: After video games showing faster than light travel become routine...

[@edwardlulofs444]

@@rodschmidt8952 I hadn't thought of that. People learn a lot from games. Thanks for your comment.

[@paulrockatansky77]

After first viewing, the only two things I understood about this lecture was the photo of Colombo and Sabine's summation how general relativity may present an incomplete picture until smarter brains have figured out the theory of quantum gravity.

[@bombheadgames9565]

The Lorentz transformations for speed, mass and length go totally nutty as v approaches c which is why you cannot travel AT the speed of light because your mass tends to infinity, so the kinetic energy you need also tends to infinity.. However those same formula say once v > c that mass drops sharply back away from infinity.. What this implies is it could be feasible for particles to tunnel from below light speed to above lightspeed, the same way electrons tunnel through impossible voltage gradients in Zenner diodes.

[@TheSourJam]

Just a small correction: as v approaches c, it’s the total energy that tends to infinity, not the mass, as we abandoned the idea of relativistic mass some time ago. The total energy of course just being the kinetic energy plus the energy from the mass (E=mc^2).

[@Henrix1998]

Imaginary energy let's go

[@HuyV]

So we just try to tunnel each of our atoms to FTL until we manage to do that for all of our 10^28 atoms and then try to sync up all of them travelling with different headstarts so they end up in a human shape again? Sounds like a plan

[@supercal333]

So do you end up in a parallel dimension after tunnelling through the singularity?

[@bombheadgames9565]

@@supercal333 I don't think so, your probably still passing through our space-time but the laws are different.. For example just the other side of the barrier if you shed energy you actually go faster!.. Sort of like star Trek subspace!

[@mememealsome]

I would have liked to see more about your solution to the time paradoxes. It seems that you say a spaceship can travel backward in time relative to bob, but then any space ship that visited bob’s past self would have been traveling forward in time. If they can travel backwards from “current” bob, what prevents them visiting past bob?

[@Athropod101]

You wouldn’t go back in time, but into ‘complex’ time. The term with the speed of light is a square root ( sqrt(1 - (v/c)^2) ). If your speed surpasses the speed of light, you end up with a negative inside a square root, leading to a complex number. Not a shred of a clue what complex time is, though.

[@rylandavis2976]

​@@Athropod101 yikes

[@jetison333]

Her solution is basically, hey if you allow faster than light travel in all reference frames, then it allows spaceships to travel backwards in time, so instead, lets just not allow faster than light travel in all reference frames, and just allow it in the comoving reference frame.

[@noneedtoknow5315]

@@Athropod101 the shoreline of the river were you can choose wich directon you go... theres more tan back and forth. you know that if you've astrally projected... that's "complex time".

[@GlanderBrondurg]

The solution to a time paradox is simply that they don't happen, at least on a practical level.

[@petermainwaringsx]

A quite unique way of presenting a scientific explanation. So much information mixed with some great humorous interludes. Thank you Sabine.

[@TML0677]

Very nice. I has a q; Is Bob Turkish Arab because of German collective guilt or of need for YT algorithm multicultural video?

[@DaCarnival]

@@TML0677 Or because the average male on Earth is brown? Or because why default white to appease paranoid culture warriors like you?

[@reasonerenlightened2456]

There is no use for science if it can not solve the issue of distribution of Wealth and Power among the citizens.

[@kakistocracyusa]

No actual, competent, physicists would agree with you. If so many people actually think this channel's hand-waving, sophomoric and often false narratives qualify as an "explanation" , much less as competently presented hypotheses for creating new physics, then the human race is in trouble.

[@bvrulez]

Großartig! Ich schaue so viele Dokus darüber, und trotzdem findet man, wie hier, immer wieder eine erstaunliche Neuigkeit in den Details.

[@jab-gn3sw]

Her humour is always good as her explanations are 😁

[@garytyme9384]

That, and she is completely wrong.

[@rekik2936]

@@garytyme9384 Enlighten us then🙄

[@garytyme9384]

@@rekik2936 Light does not have a speed, it has a rate of induction i.e., hysteresis of the medium. Take Red Shift as an example of Hysteresis of the medium.

[@neurotic3015]

@@garytyme9384 Dude, even if you believe that you can't just say she's wrong- Light having speed is so widely believed by people and scientists that you can't simply say everybody is incorrect without an extremely extremely good argument with paragraphs of wording and elaboration and good papers with variety to back the claims. We have far more reason to believe that light has speed than we do to believe it doesn't. For example- If light is simply inducted, than why do we get afterimages? Afterimages are produced because light from where something was and is hits your eyes at the same time, causing an effect of seeing an afterimage, but if we simply induct light, then we'd not see afterimages and instead we'd see everything perfectly as it moves.

[@garytyme9384]

​@@neurotic3015 Oh dear. I am chatting to a moron. Actually, you see the attribution of light i.e., illumination, and even then you are seeing the reflection of that illumination of the surface of the object you are looking at i.e., the illumination the object did no absorb. Hence, the after effect you are talking about is to do with the over stimulation of the eye. An afterimage is an image that continues to appear in the eyes after a period of exposure to the original image. These can be either negative or positive afterimages. In most cases, this is an eye-related phenomenon, although there are some cases in which it is related to an issue called palinopsia. Negative afterimages occur when the rods and cones, which are part of the retina, are overstimulated and become desensitized. This desensitization is strongest for cells viewing the brightest part of the image, but is weakest for those viewing the darkest. When you look away, the least depleted cells react strongest, and vice versa, and you see an image with colours that are the reverse of how the image originally appeared. Many optical illusions take advantage of negative afterimages. For example, if you stare at a yellow, green, and black American flag for 60 seconds, then look at a white background, you will see the flag with its correct colours. A positive afterimage is when you see the image, but it is the same colours as the original. Unlike with negative afterimages, it is believed positive afterimages are caused when your rods and cones have no stimulation, such as when the illumination abruptly go out. BTW: Answer me this Einstein - without breaking the law of conservation of energy. If illumination has a speed then explain how illumination returns to the same rate of "speed" after it exits glass or water? Bet you can't, lol,.. well not unless you factor in the hysteresis of the medium and illumination not being a particle, wave, or wave-particle duality. I say this as Nature does not work the way the mathematicians have tried to convince you of. I bet next you will say the quantum realm is a real thing and pigs can fly.

[@tonywarren7940]

I would be very interested in a future video in which you say more about how mass is "created" by the condensed Higgs Field and the implications for how we think about the world

[@tylermacdonald8924]

Yeah this sounds kinda crazy

[@rainerzufall42]

Can you imagine a world only filled with plasma and energy? No protons, no neutrons, just quarks or even less "condensed" things? Because all the energy makes it so hot, that high level structures cease to exist? Think about it!

[@davisongeorge]

@@tylermacdonald8924 because it is, the binding energy of matter is actually negative, it was released when the matter was bound together into matter (at least for all non-transuranic stable matter) Now it's just negative potential energy. eg: it takes a huge amount of energy to unbind matter into it's constituent subatomic particles and even more energy to separate it into even smaller quantum particles like the higgs. That negative potential energy actually DECREASES the mass of matter, it doesn't create it, it's called the "mass defect". And honestly it seems like she switched the sign somewhere because if you plug that into the force equation, it takes more energy to accelerate to the speed of light, not less.

[@MindRebelion]

I love the way you carry a conversation and your demeanor, and your confidence is off the chart's admirable qualities of a scientist, thank you!

[@norfolknchance657]

why is the word "charts" possessive?

[@johnlusth193]

Thanks!

[@EarlWallaceNYC]

I loved this episode! But I don't (yet) understand it. This channel is a blessing to my life because: "It makes me to think". And, "thinking" is the joy of being human. Thanks.

[@nadamuchu]

agreed, I appreciate Sabine pushing us to the edge of our average Joe knowledge, but the second half of the video really lost me with some of the examples, especially the graphs of Alice and Bob. I'll rewatch it but not very hopeful I'll understand it more.

[@Felixr2]

@@nadamuchu Don't have a good resource readily available but if you want to get a better understanding of the graphs you can look up 'Minkowski diagrams', that's what those are called. I will tell you though that it's pretty much impossible to understand why all the lines move the way they do without understanding the mathematics behind special relativity, which is probably why Sabine didn't give a detailed explanation for that in the first place.

[@jonathonshanecrawford1840]

@@nadamuchu Is she thinking *outside the box?*

[@democratictotalitariansoci1462]

moral of the story is- while something can travel faster than light, it can't travel faster than time. If you send information at the speed of light to someone on a nearby planet, even if you get immediate response traveling faster than light, you'll receive that response in a future, no matter if it travels faster than light.

[@jonathonshanecrawford1840]

@@democratictotalitariansoci1462 Like emails, they may travel at the speed of light, but it may take minutes to receive due to connection speed, or even hours to respond, depending when one reads the emails, or replies in

[@ukaszbartodziejski3662]

Sabine is the type of teacher who brings both knowledge and humor to the table - best mixture if u ask me in terms of learning experience :)

[@Martial-Mat]

Dry humor at its finest.

[@havenbastion]

The humour bit is doubly impressive given thatEnglish isn't her first language and Germans are well known not to have any.

[@meangreencarpetcleaners3558]

I must've missed the humor 🤔

[@malcolmberke4862]

God has a sense of humor too. As we understand more of the physical universe, especially quantum physics, we also begin to understand the spiritual universe. This journey is however within ourselves. Our understanding that everything in the universe is conscious is a relatively recent development. As spiritual beings, we are made of energy. We can manipulate and control energy and matter. For example, without moving, think about raising your right hand. Now do it. It was your THOUGHT that made your hand move. You manipulated the physical with a thought! Likewise, the ability of remote viewing or astral travel can take you anywhere in the universe instantly. We are merely individual viewpoints of the universal consciousness. We are entangled with everything. Warp speed (faster than light) can occur because we think it. We simply must be practiced at moving scalar particles to manipulate the fabric of space to create a gravity well in front of the ship. Try this method the next time you go on a long drive. Spot a spot in front of the vehicle. Just pick a spot up ahead and then bring it in to your body. Repeat this process throughout the trip. This simple manipulation will reduce the amount of time to your destination (without speeding). We can not understand the physical universe until we first understand that we are the ones who create it.

[@Martial-Mat]

@@malcolmberke4862 🤣

[@levelrod]

I will never wrap my head around all this, but you sure to help get me tiny little bits closer. Thank you!

[@richardwarren449]

She talks way too fast and covers so much ground that my little brain is left way behind. Math & physics was many decades ago.

[@tmst2199]

Keep chipping away at it. Things go faster as you progress. It could take centuries but you have forever to get it.

[@robertkiss5461]

What I appreciate the most by Sabine? Her dry and sarcastic humor. On the other hand, her explanations show confidence, that she chowed through some scary mathematical themes (they are scary at least to me since I studied them many decades ago and had no time to chew and then digest them). Me myself am capable to understand many issues, which she talks about, but Einstein’s theory of relativity goes against our human understanding or perception. I go through the argument and everything is correct, but still have a “stupid” feeling about it. That spacetime invention or the notion that the gravity is not a force, but an accelaration is somehow not human like.

[@perrywilliams5407]

Sabine, you have become more snarky over time - and I love it!! Very informative - concise, well reasoned and understandable. And humorously entertaining!

[@xanider5098]

ive always been thinking this. you cant be two places at the same time so when you leave, you light stays behind you but you will ALWAYS be ahead of it, just because "someone" can see something doesnt mean its actually there (assuming youre travelling faster than light)

[@dragonl4d216]

Light takes time to travel so whatever you see is not happening in real-time but the time taken for the light to travel the given distance to reach you. Some of the stars in the night sky may no longer exist at present even if you can still see them and its because they are a few hundred to thousands of light years away, hence the light from them that reaches us is a few hundred to thousand years behind.

[@jonathonshanecrawford1840]

It like flying from Auckland to Sydney, you get there before you leave - time zones!

[@reasonerenlightened2456]

There is no use for science if it can not solve the issue of distribution of Wealth and Power among the citizens.

[@littlebitfix4511]

Great! You've described an after image 👍 They certainly are neat

[@Nworthholf]

For me, the best explanation was imagining teleportation instead of moving. If your information (or even object) appears on the other side the exact same moment as it departed - you can not send it back in time even tho your speed is infinite, thus slower speeds can not cause it too.

[@scifiguy810]

Thank you for this clear explanation regarding why the time travel paradox argument doesn't hold up. I've always felt those diagrams don't describe FTL motion with regards to time properly. We also know that space itself can (and is) expanding faster than the speed of light. I think the Alcubierre Drive is the closest thing we've got to working FTL theory today.

[@geoffstrickler]

It’s inaccurate to state that space is expanding FTL, it’s expanding at a relatively slow rate, however, because the universe is unimaginably large, that expansion means there are parts of the universe which are getting farther apart from each other at an effective rate that APPEARS to be FTL. It’s similar to the classic flashlight (ok, a REALLY bright laser beam) that you sweep across the moon very rapidly thought experiment. That beam can appear to “move across” the moon at a speed greater than C, but in reality, no particle, no photon, nothing moved FTL. Yes, there are important differences with the expansion of the universe, in that some items currently within our visible universe will gradually slip outside the area of visibility because the co-moving distance between earth and those distant points is greater than C, but nothing is actually moving faster than C. Yes, it’s a subtle distinction, but it may be an important one. But the result is that space itself does APPEAR to be expanding FTL, and for all practical purposes IS expanding FTL. But losing sight of the details can sometimes lead to flawed assumptions and conclusions.

[@scifiguy810]

@@geoffstrickler yes - the distinction is well understood. Two objects can appear to be moving away from each other faster than the speed of light because of the expansion of space, but no object itself can move faster than c. However- there is no limit on the expansion of space itself - The restriction that “nothing can move faster than light” only applies to the motion of objects through space. The rate at which space itself expands - this speed-per-unit-distance - has no physical bounds on its upper limit.

[@ItsEverythingElse]

Those diagrams describe moving through space-time just fine, sub-light speed or FTL. But forget time paradoxes, what about the energy barrier? It requires infinite energy to even get to the speed of light, therefore by definition you can't even go that fast, let alone faster.

[@CeePritch]

@@ItsEverythingElse Did you even watch the video? Sabine explains why this is a shaky conclusion.

[@essentiaYT]

Alcubierre drive requires negative energy which doesn't exist.

[@UFOUAPMagnet]

There once was a lady named Bright, who could travel far faster than Light. She left one day, in a Relative way, and returned home the previous night.

[@josephnwilson]

“If you wanted to be at rest with the universe you’d have to run at 300 kilometers per second” I sure feel that. Ain’t never fast enough is it.

[@chrisdonnell7200]

POV: you're Sonic The Hedgehog

[@dylanwight5764]

@@chrisdonnell7200 The problem with being faster than light is living in eternal darkness. Sad Sonic noises.

[@scipug3048]

@@dylanwight5764 actually not sure if it does... if you move towards a lightsource at exactly the speed of light, the wavelenth will be squished to 0, which leads to photons with infinite energy... but if you are OVER the speed of light, the wave should just be inverted right? if i turned the light on and off making pauses of: 1sec 2 sec 3sec and 4sec at some exact "over lightspeed"-speed you would recieve: 4sec 3sec 2sec 1sec pauses. in the same way the interval between wave peaks should change from 1ns below lightspeed, 0ns at lightspeed, to 1ns again just in the oposite direction for over lightspeed.

[@ananthan8951]

Don't carry the head for all this. With the bulk unexplored, the space expanding. Have nowhere to go travelling FTL or even supersonically. Metaphysics appears, delusively perhaps, more real. "The manifest universe is a mental construction". Existence - Consciousness is the fundamental reality, all else is dependent reality; appearances in Consciousness. It is that which underlies and pervades wakefulness, dream and deep sleep (and like states of experience of absence).

[@michaellowe3665]

Officer, I wasn't speeding. I was attempting to reduce my speed relative to the universe.

[@nathanbritto9960]

On the UFO argument: A lot of people might find apes boring, but there's still people that travel to find them just to watch them do their thing

[@Smurfyy24]

Same as North Sentinelese island, it's illegal to go there and protected, but people still try to go hoping the natives won't kill them.

[@rehatas6059]

you are thinking too shallow. for aliens, we may be like one of the rocks on the beach. who would scrutinize a plain rock and not enjoy the summer beach instead

[@Smurfyy24]

@rehatas6059 The difference between the size of our galaxy and the distance to the nearest galaxy is the only thing that stops me believing that though is that we're Inhabiting a planet, pretty heavily too, we're fucking it up and that's probably obvious from afar. If you mean above universe levels of celestial being then maybe but I feel if there was a civilization in our galaxy they would be inhabiting a planet or multiple, so we'd be fairly equal. Who knows who could be in other galaxies though.

[@nathanbritto9960]

@@Smurfyy24 The estimatives for planets able to harbor life in our galaxy only sits on the tens of millions. Maybe there are a couple hundreds of Earth like planets with similar looking apes, we just don't know of them. Besides, we are still on the 'looking for neighboors' phase, beaming left and right, sending probes and all. Maybe a more advanced species know for certain of other intelligent lives, so they keep their noise to a minimum. I mean, its naivety to imagine that any species of aliens follows the same human-made morals- a society of wasps would have a very different view of right and wrong. And I honestly would want to avoid meeting with warp-speedable wasps.

[@nathanbritto9960]

@@rehatas6059 Geologists

[@SapioiT]

Please enable the automatic translations in the default settings for new videos. Enabling the automatic translations and setting the language to english will allow people to use the auto-translations, to help those with hearing problems (slight or not), those who are hard of hearing, people who are learning the english language, and people who want to know how one term is written, because the automatic tranlations shows each word at roughly the time it is spoken, which makes it easier to make the connection between spoken words and written words.

[@davelightman]

This video is better in all but two respects than the original. Anyone who has seen the original upload, will - I suspect - agree with me. Keep up the great work Sabine!

[@Sorceress_Sellen]

Sabine, i just want to say i absolutely love your content. I have always spoken up about how i disbelieve things in class with assumptions like sending things back in time because to me, the math doesn't say that at all. That's just incorrect math. And i always thought i was stupid because i was not on the same page as others. Now i may still be stupid, but you at least make me feel like I'm not the only one who disagrees with my peers.

[@wefinishthisnow3883]

That morning condensation analogy was perfect for a layperson like me to understand. Great stuff Sabine!

[@antonystringfellow5152]

I liked that too, though it wasn't quite correct. Hope this won't spoil the anaology as it's generally a good one, but here goes.... If you observe an area of grass or plants that has an object above it, a tree, a roof or whatever, on a morning with dew, you'll notice an absence in that area. This is a clue as to how dew actually forms. When air cools down so much that it can no longer hold all the water vapour, it condenses into mist but mist is not necessary for dew to form. What happens is that opaque media (in this case grass) radiate heat away faster than transparent media (the air). So, grass exposed to the sky loses heat faster than the air around it. During a windless night, all solid surfaces become colder than the surrounding air. The surrounding air may still be warm enough to hold the water vapour but not once it comes into contact with these surfaces. So, the water condenses on these surfaces. Any opaque objects between the grass and the sky prevent the radiated heat escaping into space, so here, the grass loses less heat and may remain dry.

[@lo1234-w9r]

Agreed, but I think her analogy might make better case for ether rather than the higgs theory.

[@waynesworldofsci-tech]

Following you is really easy. You do a fantastic job Sabine!

[@user-yh6wk3ho8i]

I love her detailed and logical explanation though it’s still a little hard for me. And also, she is much more humorous than I firstly thought about. 😁

[@8888Rik]

This is a marvelous video. I've been a fan of Hossenfelder for about a year, and I enjoy her videos more than any of the alternatives, such as they are.

[@ambition112]

0:00: 🚀 The possibility of faster-than-light travel and communication is explored in relation to the existence of extraterrestrial life. 3:33: 🚂 The speed of light is constant and cannot be surpassed, requiring infinite energy to reach it. 6:16: 🔬 The theory of relativity allows for faster-than-light travel, but it is difficult to accelerate from a speed slower than light to a speed faster than light. The concept of infinity in physics is often seen as a mathematical artifact, but in this case, it is not. Most of the mass in objects comes from the binding energy of particles, rather than the actual mass of the particles themselves. The remaining mass comes from the Higgs field, which is different from the concept of ether in the 19th century. 9:53: 🌌 The Higgs field condensate and the ether are different in that the Higgs condensate is the same for everyone, while the ether was considered a fluid with different perspectives. 12:49: 🚀 The argument that traveling faster than the speed of light would cause time travel paradoxes is not technically correct. 15:47: ! The argument against faster-than-light travel causing time paradoxes is flawed in the context of general relativity. 18:56: 🚀 Traveling faster than the speed of light does not necessarily imply time travel, and physicists should consider the possibility further. 22:11: 📚 Passively watching KZbin videos won't get you far, but actively engaging with Brilliant's interactive courses on science and math can help you learn and understand complex concepts. Recap by Tammy AI

[@101perspective]

16:37... Isn't her time diagram flawed anyway? She shows the first traveler flying on a negative slope. For that to happen they would have to travel faster than infinity... right? I mean, infinite speed (instantaneous) speed would be a line parallel with the X axis. Or do I have that wrong? If that is correct then the information would get to the other ship in zero time... then that ship would bring the info back in zero time. Meaning it wouldn't arrive in the past but at the same time you sent it... assuming there is no transmission delay.

[@Patatmetmayo]

@@101perspective From an outside observer's perspective the speed is not infinite, the speed is actually the same as the speed of light when the line is parallel with the X axis. So the one in the ship flying at that speed will feel like zero time has past until they arrive at the other ship, while for the other ship it took as much time for the ship to arrive as normal light would travelling that distance.

[@kakistocracyusa]

How about 22 minutes of vague, hand-waving flim-flam using diagrams from a sophomore-level modern physics course.

[@MrConformation]

Light speed cannot be surpassed? ........Only on the grounds as we limited humans think we know.

[@kakistocracyusa]

@@MrConformation We gotta keep this stupid UFO hoax alive, physics be damned.

[@Li.Siyuan]

One of your most thought-provoking episodes. Thank you, Sabine!

[@brianrajala7671]

Above my pay grade too. Either I was not born with enough of the right brain cells, or fed them the wrong foods, or else I slept through class the day these principles were discussed ... but I still find your lectures very interesting.

[@klosnj11]

Most of your jokes are dry enough that they dont get more than a smirk out of me, but the socks in a washing machine punchline made me laugh out loud. Very nice. Also, i love the videos lately. Keep it up.

[@Nevermore144]

I just found this page a week ago. Amazing work! I love the monotone deliverance of your jokes. Keep up the great work.

[@The_Ragequit_Cannon]

You remind me of my highschool physics teacher. She made learning fun, and I always learn better when I'm enjoying what I'm learning

[@gleaming999]

My College history teacher would do this. For example, when the pioneers went west they took the space shuttle to California. The teacher wouldn't wait for anyone to get the joke, he just kept going on with the lesson.

[@jriver64]

How exciting and wonderful that Dr. Sabine Hossenfelder makes physics a lot easier to understand with her gifted oratory lectures both with humility and with a great sense of humor that manages to come alive with the beauty of her majestic approach, in understanding the world of physics and everything else we all experience in this universe. Thank you so much, Dr. Hossenfelder.

[@freyawildesciencefictionau8156]

This might be my favorite talk by you Ms. Hossenfelder, thank you.

[@czhillimedia2391]

The message I just received from the Andromeda galaxy makes so much more sense now. Thanks Sabine!

[@peetiegonzalez1845]

This is probably the best video I've seen on your channel. And that's saying a lot! You still didn't explain why you think it might be possible to send information faster than light... you just outlined reasons why doing so would not cause a paradox, under general relativity. I like this new take. The "speed of causality" is a one-way street. I think I'm going to have to watch this one a few times. Despite all the corny jokes ;P

[@schadenfreude000]

Yeah, I think the title could've been different. She didn't explain why FTL travel is possible, but rather very eloquently explained why it isn't impossible. So maybe a better title would've been: "I think faster than light travel isn't impossible." Excellent content as always.

[@jefferiestubeladd3261]

16:29 A timeline closed loop, got me to sit up straight and pay attention.😶

[@gregtitus2467]

Loved it! Even though I understand very little, I love the delivery and the humor. BTW, "Consciousness is All There Is" Tony Nader, is a good read.

[@dichebach]

You're crossed an important threshold in the quality and value of your presentations Professor Hossenfelder! A few more videos like this and I suspect your channel is going to explode . . . metaphorically speaking of course!

[@sf4137]

This is still a little too dry for the majority of humanity. Stepping stones.

[@deadsetdickhead]

@@sf4137 Maybe, but I bet a lot of those people would not be interested in the content anyway. Additionally, this "dry" method of presenting can be a good thing in itself and it seems her current subscribers really like it. She wouldn't be the only KZbinr to gain a huge subscriber count with minimal flair. Look at penguinz0. Besides, she has over 800k subscribers. That's pretty huge already.

[@rhondaeverett8284]

271,000 views on this so far!

[@andcheck]

@@rhondaeverett8284 I see 266,473 views right now. Am I moving backwards in time? Na, probably just the KZbin algorithm.

[@2ndfloorsongs]

@@andcheck I think you're right, the algorithm probably incorporates negative views, just like some physicists use negative energy.

[@tzerpa9446]

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

[@stargazer7644]

We have trains in the US?

[@Thomas-gk42]

You have to work on it

[@jamiegagnon6390]

@@stargazer7644 I think they all crashed somewhere...

[@word6344]

rip any transport that isn't cars

[@jimbryce6982]

@@stargazer7644 Yes, but no Kilo Metres.

[@lowballa2861]

First time watching any of your videos and I gotta say thank you for the effort and knowledge you bring with balance of thoughts/arguments. It really show through the videos! Can’t wait to learn more on what you offer.

[@theresas4867]

So these videos blow my mind. I am horrible at any mathematical mathing lol😅 but she describes equations to where I can almost wrap my head around them. I am very intrigued when it comes to space/time, time travel, and just anything space-related and these videos are very appealing. Side note...I feel like I'm in high-school listening to my physics teacher again. Nostalgia at its finest! I do wish you'd do a video for dummies...I'm sure that's what these videos actually are to the super brainiacs but I love learning..explain the big words please ❤

[@justinhaines7083]

KZbin randomly brought me to your channel. I suspect my phone was listening to a theoretical conversation I was having the other day. It’s been a couple of decades since I learned about some of the basic stuff you talked about in this video, but you made it really easy to understand even after all this time. Subscribed!

[@justinhaines7083]

Also.. loved the Columbo reference!

[@HansLemurson]

I've always wondered why going faster than light would be any different from all the other examples of objects moving faster than the wave-speed of their medium. We have supersonic planes, and this doesn't create "acoustic paradoxes", just some slightly wierd effects.

[@rodschmidt8952]

And--as no coincidence--sound waves have mass! At least, the medium has mass

[@brunonikodemski2420]

@@rodschmidt8952 And also a mass-differential, thus some areas move foster than others, locally.

[@DawidUliczny-ro7eo]

Sabine, thank you for giving me back the hope that humanity may still yet one day reach the stars. After learning about causality paradoxes, chronological protection conjecture, etc. I slumped to the idea that we wiil occupy this piece of rock forever until some space rock will evaporate us. It gave me minor existential dread, since it wouldn't affect me personally but merely my specie. All healed now.

[@wanjanechtangroeger]

Haha, same here! Maybe we will never see anything different than this planet, but it is good to know that those who come after us will one day.

[@B33t_R007]

we can roam the galaxy without FTL though. some relativistic speed would certainly be useful, but it can be done with generation starships for example. also, you can expect massiv breakthrough in life expectancy in general. also, preserving at least the brain and hooking it up with artificial bodies is well within reach, 100-200 years maybe. this will allow for a very different approach to time and distances. IMO: uploading conciousness is realm of fantasy. but keeping the brain working for a long long time and connecting the nerv stem to something else should be possible.

[@walterbushell7029]

Nothing last forever. The heat death of the Universe will end all anyway.

[@wanjanechtangroeger]

@@B33t_R007 Tbh I am not sure if massively longer livespans would actually be a good thing. So far people have trouble accepting new concepts and ideas. For example even Einstein himself didn't believe in plate tectonics and quantum theory. Therefore I think it is good that younger generations take over after a while and the old ones die out. Or maybe we just have to learn to be more flexible mentally :D And yes, generational starships are a possibility but that would still mean that each human is forced to live out his whole life on one planet - or in one ship. And interaction between different planets would be very limited.

[@wanjanechtangroeger]

@@walterbushell7029 Maybe. But maybe there are things far beyond our current understanding that may allow us (whatever "us" has become by then) to escape even that. We will find out out in the very far future - but to have chance of getting there we have to become a multi planet species.

[@beau3010]

This is a really cool topic. I think she did a great job with this video & explaining how the math works.

[@OnHoldAt50]

I laugh at every one of your dry jokes. The smarmy undertones and flawless timing/continuance into the next topic, keep me glued to your presentations. Your content is equally thought provoking. Hot smart scientist willing to share her theories. Thank you a million thank yous.

[@m1k34g2]

W rizz OG. Shoot ur shot like Devin Booker.

[@lillyanneserrelio2187]

Bob gets on a train going 200km/hr ....make that 20km/hr if ur in the US. OUCH. Felt that burn all the way in Florida and down here we're USED to sunburn.

[@lillyanneserrelio2187]

2:46 Bob gets on a train going 200km/hr ....make that 20km/hr if ur in the US. OUCH. Felt that burn all the way in Florida and down here we're USED to sunburn