The quiz for this video is here: quizwithit.com/start_thequiz/1697148954345x743164650631523500 We have a major upgrade to the quiz app coming up next week, it should be much faster then!

@AquarianSoulTimeTraveler

6 ай бұрын

Physical time travel not so possible in this time exactly like you said there's no receiver station. Soul Time Travel is always possible with a little bit of help and a lot of money and funding like I have... obviously not in this body but i am like elon musk on my homeplanet...

@AquarianSoulTimeTraveler

6 ай бұрын

If a fourth spatial Dimension exists then infinite three-dimensional Universal potentiality is possible... hard to tell if there actually is a fourth spatial Dimension but if there is then it would show itself in the form of Mandela effects which we observe... Mandela effects mean a switching of universe versions and is best proof we can get of a 4th spacial dimension.

@AquarianSoulTimeTraveler

6 ай бұрын

If the universe is a toroid on the other side of the singularity time goes in reverse... this allows for observations of accelerating expansion pass the speed of light up to 2x Lightspeed this is allowing for basically negative lightspeed.

@AquarianSoulTimeTraveler

6 ай бұрын

Time is 100% absolutely not a spatial dimension! Time has nothing to do with the logical progression of the spatial dimensions! The logical progression of the spatial dimensions for the fourth dimension would be infinite three-dimensional potentiality AKA a Multiverse of infinite Universal potentiality

@dalelerette206

6 ай бұрын

We're always traveling into the future. There is a ‘Present’ that is everywhere at once. Right now it is the Present. But if I wait a few seconds it is still the Present. And if I wait a Thousand Years, it’s still the Present. What divides the Past & Present yet retains so interconnected? Once upon a time I’ll pass on to the next For as soon as I am here I’ve left. However this is merely how you perceive. For I never really change and yet still continue to weave. I am reminded of that old poem from long ago: “Has it ever struck you that life is all memory, except for the one present moment that goes by you so quick you hardly catch it going?” Tennessee Williams

*Time Traveler's Motto:* _"Never do yesterday what can be done two weeks ago."_

@ReverendDr.Thomas

6 ай бұрын

Good Girl! 👌 Incidentally, are you VEGAN? 🌱

@OfficialGOD

6 ай бұрын

😮😮😮

@normanbell-br7nf

6 ай бұрын

yesterday I had a premonition that today I'd have deja vu

@prapanthebachelorette6803

6 ай бұрын

You got my greatest lol in a while 😂

@NMJCEO

6 ай бұрын

Soooo sooo funny

“We’ve already used up our negative energy on Twitter.” Oh Sabine, your humor is so lovable.

I'm a time traveler from the Past. I travel through time in real time. So far it's taken me 53 years to get to 2023 from 1970. True Story.

@xiutecuhtli15

6 ай бұрын

im secretly going back in time but doing everything in reverse so nobody notices

@classifiedtopsecret4664

6 ай бұрын

That's great, never heard that one before 😏

@seanhewitt603

6 ай бұрын

Yuh!, me too!!

@RunningMan630

6 ай бұрын

@@xiutecuhtli15 Is your name “Merlin”?

@jaikee9477

5 ай бұрын

You lucky one! It's different in my case. I reached 50 in no time.

The "reverse entropy to time travel" theory is used in the movie Tenet by Christopher Nolan and it's very amusing that virtually no one used this concept in sci-fi before (if anyone knows of any other examples - please tell me)

@Archipelagoes

6 ай бұрын

That one indie movie with box and time travel..basically the same but they just didn't use entropy word

@casthedemon

6 ай бұрын

Because it's kind of stupid ngl.

@aiperspectivenews

6 ай бұрын

Time Travel is possible. We just need to negotiate with Maxwell Demon / Coherence system. The quantum information rhealm acts like a dream, until we wake up and the coherent system states our consciousness as part of the system we are correlated with. Time itself doesnt exist in the quantum-information rhealm, time is the principle that the Demon defines information as classical behaviour. A constructor system-alike. So in order for us to travel back in time, we don't need energy. Energy is part of the demon constructor system. We need to study the quantum-field-information, for instance it exists inside a black hole. This quantum-field-information is what contains the information of time from an particle. If we could access such field, we could change this information and overwrite it. We would know if the object travelled in time if its energy signature changed. Entanglement for example is a way to access the quantum-field-information.

@haroldnaples

6 ай бұрын

Inception was also rather dumb, and derivative, but it did not stop the masses from thinking it brilliant and original. Faced with confusion, many if not most people will roll over, rather than try to get pass it. It helps to have big words and impressive visuals.@@casthedemon

@Isaac-zs3db

6 ай бұрын

Primer

"We used up all of our negative energy on Twitter " Deadpan and spitting facts! I love Sabine 😅

@srobertweiser

6 ай бұрын

I always thought that Twitter created negative energy.

I had a short email debate with Kip Thorne about the possibility of sending information into the past, back in the year 2000, when he was around 60 years old. When he expressed doubt about my proposed methodology, I replied: ''' That's what you told me at your 70th birthday party!'' (He thought that was funny)

@Steeyuv

6 ай бұрын

Now THAT is funny!

@goldnutter412

6 ай бұрын

I would just like to add that you would be sending data back. Not information.. if they meant the same thing they would be the same word.. Anyway, think about it for a bit.. now you send data back. Impossible, but let's suppose you do.. aaaand back to wasting time doing science at all really. The source of the data is the context of science itself.. meaning.. conclusions. So it's fine now when someone gives you data that they just made up.. nope I can't find the joke I was looking for. Why did the data cross the road ? that'll do

@SloverOfTeuth

6 ай бұрын

Data ... think about it for a bit ...

@JonYeoAU

6 ай бұрын

​@@SloverOfTeuth😂

Good. video and on topic. I’m happy that Sapine pointed out that entropy decrease isn’t impossible, just very unlikely. I think a lot that has been said about entropy for general consumption has just confused the public and led to hold entirely erroneous ideas about the subject.. I make it a rule as a music teacher never deliberately to tell a falsehood to a pupil no matter how young or inexperienced or even slow the pupil. Most of my peers make no attempt to observe this rule, and the consequence is that even professional musicians (in fact, most professional musicians) are mistaken about very basic principles of music theory.

Back as a teenager I read Thrice Upon A Time which did the "you can only send a message back to when the machine exists" and the "you can't send stuff, but you can send a signal" ideas. Interesting concepts.

@doughboywhine

3 ай бұрын

Gonna make a machine that generates random messages and claim it's a time machine. We'll only let people input messages that have already been generated

The video finished at 17:39. I restarted it at 00:00. I'm now waiting for my Nobel Prize in Physics to drop through my letterbox.

I appreciate the effort Sabine puts in to explore other non-physics topics in her videos and to branch out her content, but realistically this is what I'm personally really here for: physics! Esoteric, no-nonsense physics to be precise. So this episode was a real treat and reminded me why I've subscribed in the first place. Thank you for all you do Sabine, you make these mind-boggling topics so accessible to us laymen. As for the topic of time travel, it's pretty much the typical "in principle it's not forbidden, but practically it's incredibly unlikely and/or we don't have evidence for it". Like all the other fun esoteric topics of parallel universes, negative energy, all kinds of infinities, black hole shenanigans and so on, the theory doesn't forbid it, but we don't have any evidence or even hint of evidence for it so we can't exactly work with it to build a working, practical theory. It's all speculation in the end, but it is impressive how much we've been able to figure out so far. The real question is how deep does the rabbit hole really go and how far along it have really fallen already.

@vladzaitsev9257

6 ай бұрын

I agree it is complex but very interesting topic.

@johnh539

6 ай бұрын

more speculation for you. space-time being all one thing what if it is imposible to see because we can only perceive it in our own time.

@hugegamer5988

6 ай бұрын

@@johnh539 that is literally the mainstream view and the reason we constantly refer to the visible universe. The “edges” of the universe are always x distance from where you view it meaning your own two eyes see slightly different edges a couple of nano light seconds of the visible universe the other eye cannot see at the same time.

@mrgalaxy396

6 ай бұрын

@@johnh539 There's this thing called the cosmological horizon. It is the boundary of space-time in our universe where events can influence us here on Earth. Anything past that, whatever happens will literally never influence us (according to our current understanding at least) here on Earth, making it by definition unobservable as we can never interact with it. That's where the term "observable universe" comes from, it's the region inside this boundary that we reside in. The reason for this is the observed expansion of the universe, the space-time voids between galaxies and galaxy clusters are stretching at a rate faster than the speed of light and this boundary is where things from the hypothesized t=0 (the bang in Big Bang) can ultimately reach us before expansion makes it impossible as those regions diverge from us. What lies beyond is anyone's guess. We assume it's the same universe that we know inside the boundary, but we don't know (and by definition will never know unless we uncover some brand new physics) how far does the total universe stretch. It's either finite or infinite, unfortunately we will likely never have the evidence for either.

@LuisSierra42

6 ай бұрын

I've been living in this timeline for 10 years but I come from the year 2248. I came here to escape nuclear war as a time refugee

Sabine. Your channel is my favorite regarding scientific topics. I like that you get in depth without to much complexity to us, the average viewers with many topics that are presented, which is the contrary case as for other science communicators such as Kaku or NDGT as they just say this is like this just because.

@everythingisalllies2141

6 ай бұрын

I'm absolutely baffled as to why people actually think this woman is smart. She has no idea other than the BS she was taught, namely Einstein's nonsense.

How about a particle entangled. One particle in the past and one in the future. One changes and the other charges as well. There you have it faster than light change. (Travel)

Imagine she actually makes another time travel video next month.

@Steeyuv

6 ай бұрын

Imagine she makes it six months ago!

@proto-geek248

6 ай бұрын

Imagine she made this video a year from now.

You mentioned that in theory it is possible to reverse particle interaction. I have always wondered how that can be true in the case of an unstable atom that decays into a spray of resulting atoms and particles. If you reverse that, there is no guarantee that those atoms and particles won't decay, themselves, on the way back, because their life times are also subject to quantum random decay.

@SabineHossenfelder

6 ай бұрын

The evolution of the wave-function is time-reversible.

@Ken00001010

6 ай бұрын

@@SabineHossenfelder You are saying the model can be run backwards, but the map is not the territory. I agree that the probabilities may be reversible, but for a case of N=1, that may not be true.

@hugegamer5988

6 ай бұрын

@@Ken00001010 it’s the same as thermodynamics, you can have heat flow from cold to hot it’s only statistically very very unlikely. So it’s time reversible but the probability of it happening is so close to zero it might as well be. In fact it’s so certain it won’t on any kind of a scale over a couple of particles on very short timeframes we actually call it a law of physics and is likely related to the arrow of time itself.

@GenesisAria

6 ай бұрын

@@SabineHossenfelder time reversible mathematically speaking, but you can't prove that it is actually reversing in time and not just progressing forward in time by replicating an inverse evolution. thinking of it as a simple abs.

@Ken00001010

6 ай бұрын

@@hugegamer5988 Yes, we know that if you treat thermodynamics as Newtonian mechanics plus statistics, it is theoretically reversible, although too hard to ever actually do. However, on the quantum level, our models are *only* probabilistic, and for individual events to be truly reversible, particles would have to have "hidden variables" that count time backwards, which current theory says they don't.

Having someone comment your new book with the words "Better than a new particle collider!" has to be a career defining moment. Thanks for the video!

Great video and the book, thanks for the recommendation. Bought it straight away. The type of the explanations in the book, with diagrams, good questions to engage the reader and articulate on that is one of the best experiences as a reader. And I have read many books on this topic, (and studied astro back in bachelors) and I think this is the most original type of physics book I have read.

@85altant

6 ай бұрын

Just finished the book in 2 sittings, amazing !

Sorry Sabine... we HAVE NOT used up all the negative energy on Twitter as human beings are sources of infinite negative energy and all other manner of paradoxical peculiarities. 😂

@francescosancetta2043

6 ай бұрын

I disagree on the "infinite". The level of negative energy increases till a war is triggered as if a saturation level is reached after which the status changes

@classifiedtopsecret4664

6 ай бұрын

"Paradoxical peculiarities"? that's a new one 😬

@netgnostic1627

6 ай бұрын

​@@francescosancetta2043 I think we have reached a status change already - it's no longer Twitter, but X. This may mean that it now has a new, undepleted source of negative energy

@francescosancetta2043

6 ай бұрын

@@netgnostic1627 in the specific of X I don't disagree. My comment was in general

I’m time-traveling all day! Flying back to Europe from the US works… Finally grazing a superheavy rotating black hole works too!

@EffySalcedo

6 ай бұрын

😂 + 1 day

@czarquetzal8344

6 ай бұрын

Hahahaha, yeah, that's right.

Oh my goodness! I just discovered you... and I clicked subscribe 10 seconds in... You are so good at what you do! I will have to binge all your videos now. GREAT STUFF!

Sabine: Great video as usual. Besides the infinities that are needed, I was under the assumption that time travel for matter is impossible due to the violation of the same matter occupying two time-space simultaneously. The passage of information on the other hand is intriguing and more plausible if it does not require matter.

Thank you for telling us about Robert Nemiroff's book! I'm always looking for good reading material on Relativity and Quantum Mechanics, and since I grew up in Michigan (and have a friend who went to Michigan Tech), this book has extra, personal appeal. I have already bought the Kindle version!

@mikeguilmette776

6 ай бұрын

Son of an MTU alum here . . . I didn't know about Robert Nemiroff, but I was familiar with his work. Good to know he's over in Houghton.

I hope this video untangles all my confusions about time travel. 😵 Otherwise I'll take yesterday to read more about the topic.

@srobertweiser

6 ай бұрын

Yesterday, all my troubles seemed so far away.

@justanerd414

6 ай бұрын

​@@srobertweiseryou can deal with them tomorrow

@bastiaan7777777

6 ай бұрын

People always want to go forward🚀🕙 or backwards🦕🕡 in time. Or stop the time.⌛ I want to go sideways in time, maybe a few degrees to the right? 🧟And slightly up. 🧙‍♂Non linear time travel. Thanks. 🌌👩‍🚀👩‍🔬

@andrewfarrar741

6 ай бұрын

​@@bastiaan7777777You are right where you need to be. The atomic ninja collective is legitimate and you already know the code. Welcome aboard. The space|time for departure is whenever everyone feels nice.

I liked the video,it is very well structured and inspiring. Excellent recap on all possible ways of time travel.

Hahahahaha! 5:41 "We've already used up all our negative energy on Twitter."

I‘ve been studying for a couple years a wormhole at my favourite bar. Timespace destination seems random, but further investigation is required before any conclusions.

@PrivateSi

6 ай бұрын

Is (s)he genuinely attractive though, this wormhole, or is it just the beer goggles...?!

@HomestarCrawler

6 ай бұрын

​@@PrivateSiEw, gross 😂 I'm pretty sure he wasn't talking about that "wormhole". He was talking about waking up in a different time and space after visiting his favorite bar.

@PrivateSi

6 ай бұрын

@@HomestarCrawler .. silly me!

@andrewfarrar741

6 ай бұрын

​@@HomestarCrawlerWhat if The Language™️ really is a hoax? Would that mean that even if what we say doesn't matter, what we say really does count?

Hi Sabine! Thanks for the awesome video! Not sure if you’ll see this (or perhaps a knowledgeably commentor), but could cosmic strings be another area where closed time loops occur? Thanks!

Was at a lecture by Lawrence Krauss a few days ago, he jokingly mentioned that even if we had a Time Machine it would also have to be a space ship because the earth travels around the sun at 30 km per second and the sun about 200 km per second around the Milky Way. So most likely we would appear a long way from home in that era.

5:50 “…and we’ve already used up all our negative energy on Twitter…” I was dying brah. Brilliant video, with killer humor! Keep on rocking Sabine! 😎🚀☀️🙏

Sending just a few bits back in time could have massive computational repercussions. Consider a machine that does part of a computation and sends the partial solution back in time to continue the computation. In principle, any computation that is executable in finite time could be made executable in an arbitrarily small time frame.

@StephGV2

6 ай бұрын

CTC (closed timeline curve) computing was brought up in Stephen Baxter's 2004 book, "Exultant". "But Nilis had assigned her to another part of the project, the development of his 'CTC computer' as he called it, his closed-timeline-curve time-travel computing machine." There should be a mandatory science fiction reading class for all physics and engineering students.

@victorrielly4588

6 ай бұрын

@@StephGV2 I will look into that book suggestion. Thanks, but I would also be interested in any more rigorous consideration of the possibility. What assumptions about time travel would be necessary/sufficient to provide some sort of benefit to computing, and what might such a computer look like? Physicists look at theory under certain as yet unresolved assumptions of the laws of physics all the time. This seems like a possibility fruitful thought experiment. It may even provide restrictions on time travel based on known restrictions on computation.

"We just talked about time travel next month." :-)

The talk of spinning black holes reminded me of John Titor, a guy in the late 90's who claimed to be a time traveler and then vanished.

Good discussion on a field requiring fuzzy logic. And then there are the tachyons with their negative time. Thanks

One possible usage of time travel of particles (assuming that time travel of particles turns out to be possible) that I'd like to see someday would be net faster than light communication by relaying the messages into the past. That'd make populating the rest of the solar system a lot easier.

@Wtfukker

6 ай бұрын

that would make my financial situation a lot easier too.

@andrewfarrar741

6 ай бұрын

​@@WtfukkerI already have dibs on 🔮 all of the money trees located on [🌎bizarre🌏Krypton🌍] your 🌐 planet.

Sabine, if I were captain of the Enterprise, you'd be my first science officer 😁😉

"and we've already used up all the negative energy on twitter"🤣🤣🤣🤣 brilliant.

I look forward to viewing Sabine’s weekly videos. They are informative, funny & don’t always follow the well rehearsed narrative. However, I must take umbridge with this video on 2 fronts. 1. Black holes - Isn’t it about time we stopped calling them black holes? A black hole is not a place to enter another dimension or universe or a singularity. In this case a singularity is simply a euphemism for the math is giving us gibberish. If we prescribe to the QFT & all particles are excitations of a given field then a black hole may be visualized as a place where the separation between the excitations is close to or zero. That is ALL. wrt time travel - let’s go I step back & define time. The time we measure with the clocks is the numerical order of events. 2. ALL man-made clocks are affected by gravity, the perfect gravitational clock is a sand clock & that virtually stops as we go up further from earth's surface. i.e. the opposite of what we measure with an atomic clock. The only "real" clock that is reliable is the rotation of earth around the sun. I would bet that if a person was located 10 km beneath earth's surface & was able to live for 1000 years and you compared him to the person living on top of Mt Everest 8.8km above Earth's surface, OR next to a black hole then after 1000 years, they would both be 1000 years old! I will also bet that in 100 years time dilation & warping of time will be considered one of the greatest errors in modern mathematical physics theory. Refer to Amrit Sorli's derivation of Einstein's field equations WITHOUT a time component www.researchgate.net/scientific-contributions/2160836237_Amrit_Sorli www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjq7c-JuoLqAhXUR30KHb3gAXQQFjALegQIAhAB&url=https%3A%2F%2Fwww.preprints.org%2Fmanuscript%2F201912.0326%2Fv1%2Fdownload&usg=AOvVaw2bedH3i9twthXrL5BH43Ga I’d like to add 3 points: 1. I would argue & paraphrasing Amrit that : Time is NOT the 4th dimension of space-time BUT it is merely the duration of motion in space. Time ONLY requires memory & motion! 2. Entanglement only happens in space NOT time p.s. just because one can fit data using a mathematical model doesn't mean that the mathematical model is a valid interpretation of reality. Like my old maths teacher used to say, you can fit anything given enough polynomial variables OR simply, until we can apply Occam's razor all proposed models are just that.

Negative energy=Twitter/X😂

I liked your video very much when I saw it in 3 years!

Sabine, you are awesome! watched your videos here in year 2089 and your theories are still holding up! awesome!

The humor is timeless! Bless you Sabine!

The problem I have with Many Worlds is that an infinite number of alternate realities branch off from each event. It's like a tree with infinite branches. So if time travel were possible, we'd be inundated with time travellers from different realities that can be traced back to an event in our present.

@ElijsDima

6 ай бұрын

In principle, because the mapping is from (one present) to (infinite futures), we should experience an infinite amount of time travellers coming to our present. Even if a small part of those infinite futures create time travellers, a small part of infinity is still roughly infinity.

@jorgmintel3060

6 ай бұрын

In physics it doesn’t really matter in which direction time flows; you can always put a negative number into t. With that in mind, why should a timeline only branch in one direction and merge in the other direction? Shouldn’t timelines merge and branch constantly, no matter whether we go into the future or past? So, when I timetravel into the past, there are at least two pasts: the one I traveled into, and the one I didn’t travel into.

@seanspartan2023

6 ай бұрын

@@jorgmintel3060 For you perhaps (because you're traveling against the arrow of time), but not for the rest of the universe.

@jovetj

6 ай бұрын

"Many worlds" doesn't imply infinite branches. Only thing things that are possible could happen. I'm currently sitting in my chair in Nebraska. There's a chance that my right arm could fall off. But the chance that my third arm could fall off is zero because I don't have a third arm. While there are a large number of things that _could_ happen every Planck time, those things are countable. Having written that, I believe Many Worlds to be bunk. The universe is lazy and all those worlds seem like a LOT of work.

@seanspartan2023

6 ай бұрын

​@@jovetjYou're right, of course. The number is insanely high but not infinite. I was being lazy...

If we send someone back in time, there's no reason to assume they'll appear in the same place on the globe, or even anywhere near the globe. And even if they manage to end up in the same logical place, what happens to the air in the space where they appear?

@joserigobertogonzalez1991

6 ай бұрын

100% agreed. We tend to see time-travel as space-travel, which is wrong. We would have to ask: what/who will be traveling? My entire body, including clothes and umbrella in case it rains? And if I go to tomorrow, will there be two selves then, or is it just the same "advanced" self?

@MelindaGreen

6 ай бұрын

@@joserigobertogonzalez1991 That depends upon the technology used

Bought the book. I normally skip sponsor segments but this one was good!

6:11 There is the theory of The Mobieus; a twist in the fabric of space where time becomes a loop.

My headcannon for the grandfather paradox is the universe autocorrects itself based on timeline. If your original timeline you were born, and go back and kill your grandfather, the universe would split into different timelines. One where you were originally born, and one where you killed your grandfather and werent born. You would either still exist because it was a different timeline, or the universe would autocorrect itself deconstructing you down to the atomic level to be used elsewhere in space-time

@tonybrantley

6 ай бұрын

Well that was interesting !!

@michaelschonhofen622

6 ай бұрын

It would be rather like: No time traveller is able to kill their grandfather, because those who would do, don´t exist.

@oskarskalski2982

6 ай бұрын

Actually there is something similiar, it is Chronology protection conjecture posited by Hawking (autocorrection by the universe).

@ErikNielsendk

6 ай бұрын

@dakotafrazier2985 If you could change the time when the ovum and sperm fuse together( It has of course to be the exact same ovum and sperm that made me as I am ) get me out of sync with my own timeline as a result ? Being either younger or older when I return. I am just a simple guy that love to gather knowledge and think about all these things. Sorry if I am asking a stupid question. While here, I want say Thank you for all the comments people here are making, it really helps to understand what Sabine is talking about And the jokes makes it more enjoyable.

@deltadom33

6 ай бұрын

I find it stupid if you do time travel I wouldnt even know what my grandfather looked like and I wouldn't want to kill him I find this one of the most stupid paradoxes ever or excuses why scientist can't create a time machine You may time travel in a continent in which your family do not even live Practically trying to find your relatives in the past is impossible I think the time travel paradoxes (excuses) because if you think about them for five minutes they are stupid say I went back and time travel where I am from , my relatives could be 100 of miles away and I wouldn't know what they looked like

The thing about time travel is it would also have to be travel in space. If you traveled back in time a week and popped out at the same spacial coordinates you would be quite some distance from where you started due to how much the earth, sun and galaxy moved during the interval.

@NeovanGoth

6 ай бұрын

But what are these "same spacial coordinates"? In relation to what? The aether? We already know that no such thing exists. One fundamental insight of Relativity is that there is no preferred frame of reference. A position in space can only be defined in relation to something else. The same goes for motion, there is no such thing as an absolute velocity in relation to "the universe", there is only relative velocity in relation to something else; like the Sun, the center of the Milky Way, the Great Attractor, or the Cosmic Background Radiation. All these relative velocities are different: Since I am sitting at my desk while writing this, my relative velocity in relation to the Earth's surface is zero, while my velocity in relation to the Sun is about 30 kilometers per second, my velocity in relation to the Great Attractor nearly 1000 km/s, and my velocity in relation to objects at the Cosmic Event Horizon even the speed of light - in every direction!

@propheinx2250

6 ай бұрын

​@NeovanGoth So because everything in the bottle is moving, and you can't see the outer edge, there is no bottle? Do you realize how asinine you sound?

I really like the quiz! Is there a way to check which questions you didn't understand too well?

I've thought for a long time that we think about the interior of black holes the wrong way around. The effect of time dilation is to bring the t and x axes closer and closer together at a diagonal vs far away where they are closer to orthogonal. At the event horizon, they become collinear. If you continue the process, what happens is a swap of the x and t axes as t continues on past x until they are orthogonal again at the singularity. Taking that seriously, you'd invert the axes in the equation. That gives you a finite, removable singularity. One that stops dead in the local time axis as the rest of the curve evolves in time. It's not so obvious how to do that with potential without a piecewise equation but it's relatively straightforward with time dilation. You can use something like Re(sqrt(1-2/|x|)-sqrt(1-|x|/2)) to visualize what I mean for the Schwarzschild metric. If you multiply the second part by i and remove the Re, you can convert the result to a complex potential (square it, subtract 1, divide by 2) and take the real part of that. The end result is equivalent to the piecewise V=-GM/r for r>=r_S and r/(4GM)-1 for r

This video is capable of time travel, it dilates time and brings us into the future quickly through the power of fun.

@LuisSierra42

6 ай бұрын

I am a time traveler

@CarletonTorpin

6 ай бұрын

I'm now enjoying a new, imaginary version of Huey Lewis and the News' theme song for Back To The Future: "The Power Of Fun".

Not only your shadow can travel faster than light, also your laser pointer can move faster than light across the face of the moon…

@hugegamer5988

6 ай бұрын

Lol. Funny but not true. None of the actual particles move faster than light.

@meino6465

6 ай бұрын

That's true, but it doesn't break any laws of physics. Stuff like your shadow or a streak of dots on the moon doesn't describe any actual continuous group of particles, and as such, you can't say it's going faster than light. For the laser, each particle is going exactly at the speed of light as it travels to and from the moon, and the dot you see on the moon consists of different particles at each moment. For your shadow, it's simply the absence of light, so when it "moves," there are no particles that could be breaking the speed of light. Most importantly, both those examples can't be used to transmit information faster than light could.

@DrDeuteron

6 ай бұрын

If you really believed that was something moving, you’d be disturbed by phase velocity > c for all kinds of waves

@hugegamer5988

6 ай бұрын

@@DrDeuteron yea phase and group velocity can be a bit misleading because neither focuses on individual particles.

@srobertweiser

6 ай бұрын

My cat seems to move faster than the speed of light whenever I move a laser pointer around.

Something that people talking about time travel never mention is the fact that the Earth is moving at several hundred thousand KM per second (when you add together the speed of Earth's rotation/ orbit, the sun's travel through the galaxy, the galaxy's movement, our local cluster's movement, etc.) So if you were able to travel even one day back in time, you would be millions of KM away from the earth in space. Another thing that never gets mentioned is, when talking about the speed of light limit, does the speed limit apply to the individual approaching the speed of light, or to the observer? Speed has as part of its definition time (KM per hour, etc.) If you are approaching the speed of light, your time begins to slow as compared to the outside universe. So if the speed limit applies to the individual approaching the speed of light, then the slower that individuals time becomes the farther past the speed of light it would appear that they were traveling from the outside. As far as time travel paradox goes, once a time traveler had removed themselves from the time stream (meaning having traveled out of time to go into the past or future) they are no longer subject to it. Imagine a record album, with the groove being the time stream. To move to a "past" or "future" song you need to lift the needle up off the record to travel to the new song. If you travel into the past and kill your grandfather, you would not "simply vanish" because you have removed yourself from the time stream. But if you traveled back to the present you would discover that you and your parents no longer exist there, and you would have no official identity, your home and belongings would be gone and everyone who knew you.

In the early 1960s, the great science fiction edtor Terry Carr, who was then a struggling writer, wrote a short story titled, "Brown Robert." In it, the titular character creates a suit that will allow him to travel through time. He plans to use it to enact revenge on an enrmy from his past. He sets the suit to arrive three days in the future and activates it, sure that soon veangeance will be his. Three days later, the suit returns, but all that's inside are the remains of our protagonist. He dies within seconds of his arrival because he had assumed that he would find himself on Earth in the future. But the Earth hadn't yet arrived where it was to be, so there was nothing at the end of the jump but empty space. The cold and the vacuum killed him even before the radiation could. People who dream of time travel never take into account that all of space is in comstant motion!

This episode was insane. First time I've taken a quiz voluntarily lol amazing concepts, hope I get to meet you one day Sabine!

@junaidsajid8867

6 ай бұрын

Hahahaha looking forward to it actually@@alindegren6144

From all the parallel universes I've visited so far, this is the one that is fixated the most on time travel instead of expanding the theories to multiple universes. Note: I may not be able to answer questions as I have a train to catch last week in another world.

I really liked next month's video, but somehow this is even better!

Threading a Rindler cylinder between two Alcubierre drives would have some interesting effects.. I read a paper that used metamaterials to simulate time travel in the universe and they found if you went back in time you would mismatch place and vice versa.

How did she know what she talked about "Next Month" .... did Sabine travel forward ?

@stevemawer848

6 ай бұрын

It's called humour (or humor in the US).

@paultracer3787

6 ай бұрын

I am aware of that and was merely pointing out that it was a clever thing to say.@@stevemawer848

If you create a simulation so accurate down to last subatomic particle would that be recreation

@brothermine2292

6 ай бұрын

Recreational activities should be more fun, less tedious.

Bravo. You are the first person to mention entropy I've heard. For a long time I have thought time travel was not possible because of entropy. Of course what would I know with only a BS and MA in political science and public administration fifty years ago.

I want a poster of that hour glass graphic. It was beautiful. I hope it's as mesmerizing scaled up.

The fact that you would always need something infinite to go back in time answers the question I've had for a while now: If you want to go back in time; what happens the moment time gets zero, just before you move back in time.

@goldnutter412

6 ай бұрын

If you want to go back in time, find another hobby.. very large post above, hope it helps

@ratbullkan

5 ай бұрын

At zero you'd be stuck but then quantum mechanics would kick in an throw you in either direction I guess, so technically there is no zero

@ermarch

4 ай бұрын

I've come to the conclusion that as time neares zero, so do all strengths of the forces we know. So one would disintegrate into photons. That's what I think would happen.

@ratbullkan

4 ай бұрын

@@ermarch That's probably when you employ classical field-force equations with a smooth time variable, while on quantum scales time maybe is quantized and discreet, or it isn't even clear what time means there

@ermarch

4 ай бұрын

@@ratbullkan Yeah, I just read the news article on 'Wobbly Spacetime'

We just talked about time travel next month!! 😂 The problem with developing time travel is not physics, it’s language. Once we get the language right, developing the technology would be easier

@srobertweiser

6 ай бұрын

That language is probably Japanese, I always pictured them figuring out time travel for some reason.

This is my favorite video of yours, and that’s saying something! ❤️ Thank you

If you "travel to the future" via acceleration you're not disappearing from this space time, it's just that your experience of time has been relative to you compared to everything else. You could be observed the entire time and come back, shake hands with someone and just be younger....in the same space time. The tip of times spear is always the same in my opinion, you can experience time differently but the collapse of the wave function within space time has to happen now, now, now, now, now........ Irrespective of how you have experienced time or are currently experiencing time now is always now in space time.

Thank you for the video.

The idea that things can time travel at a small scale suggests to me that things could also travel at a large scale if we had total absolute control over a system. I also read recently it's possible to bias the wave function collapse of a particle, which to me implies it's not truely random.

@ParadoxProblems

6 ай бұрын

Yeah, it's the same argument for the ability to put full humans in a superposition, thereby proving many-worlds. Also, that bias thing sounds interesting. If you happen to find where you'd read it I'd be delighted to read it.

13:17 if we use maybe say resonate frequency and used something like a music to diagram a pattern we could make a machine that we could use to change entropy.

Sea shells, not just Janospira, are space-time machines, because of their behaviour at bifurcation. [ see Illert and Santilli ] In fact shells would crack and explode if they used ordinary 3-D Euclidean space geometry. Santilli came up with ISO-Euclidian geometry to show shells don't/can't take the shortest path. "They've mastered both directions of time," he asserts. page 115, Foundations of Theoretical Conchology. Ruggero Maria Santilli's hadronic mathematics comprises the following branches for the treatment of matter in conditions of increasing complexity: 1) 20th century mathematics based on Lie’s theory; 2) IsoMathematics based on isotopies of Lie’s theory; 3) GenoMathematics based on the formulation of Albert’s Lie-admissibility; 4) HyperMathematics based on a multi-valued realization of genomathematics with classical operations; and 5) HyperMathematics based on Vougiouklis H_v hyperstructures expressed in terms of hyperoperations. Additionally, hadronic mathematics comprises the anti-Hermitean images (called isoduals) of the five preceding mathematics for the description of antimatter, also in conditions of increasing complexity. His telescope has concave lens and takes pictures of otherwise invisible antimatter objects on Earth, he claims. He interprets it as invisible beings. lol. Well, he is 88.

I always thought black holes are strongly related to worm holes. I bet, if humanity survives for long enough, we can find a way to use black holes as worm holes.

@LuisSierra42

6 ай бұрын

They are definitely related as both have massive gravity and singularities

@jorriffhdhtrsegg

6 ай бұрын

😐the idea of wormholes was created by thinking about blackholes. It is called an Einstein-Rosen bridge, a black-hole IS a wormhole in this, yes?....although its also a white-hole too, at the other end...which means its only a one-way wormhole.

@johndododoe1411

6 ай бұрын

​@@jorriffhdhtrseggAccess to a one way wormhole to earlier in our causality cone provides a workaround to to time travel and FTL travel to anywhere in the causality cone of the exit: Slow travel to the entrance then slow travel from the exit to the destination . Needs infinite lifetime though .

@skorpiongod

6 ай бұрын

​​​@@LuisSierra42the only relation a wormhole singularity and a black hole singularity has is that we dont understand them in the least bit. Because that's all a singularity is, something where math breaks down. Assuming wormholes actually turn out to exist, they probably have nothing in common except being extreme objects. If you could even call a wormhole an object.

I can't help but love you. I just can't say exactly what I love more about you...Whether it's your content or your craft. You make physics sounds friendly, when it doesn't seem to be. Anytime I watch you talking physics, l lose track of time...( I TRAVEL AT THE SPEED OF LIGHT) --- since I don't know how much time has passed. I'll keep loving you.

I accidentally found ur channel and wow just wow its amazingly explained . Now i am way too curious

Honestly anything you conceptionally envision is possible it's just a matter of the how!!!! If you can see it in your mind than it does exist🙂

@srobertweiser

6 ай бұрын

You edited your comment and still it says 'than' instead of 'then'. But I do agree with your theory anyhow.

Sabine, it's seldom I can catch you in an error, but if a person accelerates (proper acceleration) at one g they will experience serious time dilation after only about a year of proper time, no pancaking needed. I'll be putting up a video about this within a few weeks for the tensor calculus course I'm teaching. Nice to see you!

@seijirou302

6 ай бұрын

And that person would definitely be flat. The flattening is from the velocity, not the force of the acceleration. Length contraction. I believe she was making a dry joke as she often does.

@wkgmathguy218

6 ай бұрын

Probably so, but I do like my fun 🙂@@seijirou302

@SloverOfTeuth

6 ай бұрын

​@@seijirou302Flat to which observer?

@seijirou302

6 ай бұрын

@@SloverOfTeuth to Sabine, naturally.

Loved the opening joke. Reminds me of one of my favorite movies, a time travel movie, one of the characters asks one another character, are you hungry? Im starving, i havent eaten since later this afternoon!

>Sending a few bits into the past Reminds me of "Anathem" from Neil Stephenson

I wonder if there is a gravity mirror or parabola that an immense space telescope could see our reflection in, looking back in time.

@ianokay

6 ай бұрын

That would be a fun new approach for historians

@thallmeister

6 ай бұрын

Using a mirror to peer into the past is like a child harnessing sunlight to burn ants - a powerful tool in the hands of innocence. I intended this to be playful, but upon rereading, it does come across as rather dark.

@jok2000

6 ай бұрын

@thallmeister Your concern made me think that we should actually install a a few large mirrors out by Mars' orbit so we could look back a few minutes for various purposes. At least when the sun is up (at a particular spot on Earth)

I had a device to travel in time but each journey took an hour to move 60 minutes into the past.

@thebooksthelibrarian8530

6 ай бұрын

Typical...

@whothefoxcares

6 ай бұрын

Invest in the Daylight Savings Plan.

@richtheobald4390

6 ай бұрын

I saw your documentary: Primer

Well, two things I know to be true are: 1. Time & space are an illusion 2. You can not go backward in time I'm curious if high velocity travel even decreses your travel through time. What if it's merely changing the rate of vibration of atoms; thus, causing a clock to calculate vibrations slower.

From what I've read, if there were two time dimensions, closed time loops would be possible. Also, I keep on thinking whether we thinking we live in a 3+1 spacetime instead of a spacetime with more dimensions is because in of those time dimensions we might be traveling at the top speed so we do not experience one of the space dimensions and one of the time dimensions just like photons do not experience the dimension through which they are traveling (it is like time has not passed and the length of the travel is shortened to 0 due to length contraction). For me, it is far more sensible to think of a 4+2 spacetime in which one of the time and one of the space dimensions are contracted to 0 than to think of one single time dimension but several space dimensions, many of them being curled (at least from an Occam's razor perspective). Besides, multiple time dimensions is not something we are unfamiliar with. Inside a black hole, the 3+1 spacetime becomes a 1+3 spacetime. Some people seem uncomfortable with the fact that two time dimensions would break causality, but couldn't we just be taking causality for granted like we used to take absolute time and simultaneity of events for granted in the past?

I've long thought that the movie version of time travel couldn't happen without the time machine also being a space machine. Eg. Going back in time 10 minutes from your lounge room in a time-only machine would have you appear in space where your lounge room will be in 10 minutes (followed by a crash and burn into the earth). Solving that issue would probably need faster than light travel. Seems unlikely.

@noob19087

6 ай бұрын

Yes, but that idea relies on the existence of an absolute frame of reference, which there isn't.

@justinhunt3141

6 ай бұрын

There is no proof that an absolute frame of existence does not exist

@AugBrown

6 ай бұрын

@@noob19087 Good point, another thing to think about

@AugBrown

6 ай бұрын

@@justinhunt3141 Good point, another thing to think about

@casthedemon

6 ай бұрын

​@@justinhunt3141except the burden of proof would be on you to prove there is one. That's how science works.

If an object "turns around in time," a normal observer would see two identical objects approaching each other and disappearing upon contact. Sounds familiar...

@Richard-bq3ni

6 ай бұрын

So, antimatter is just matter going backwards in time?

@WWLinkMasterX

6 ай бұрын

​@@Richard-bq3ni That's an interpretation used in Feynman diagrams, because at small scales it's impossible to tell the difference within the idealization of the model. My question is whether or not that's _just_ a convention, or part of a deeper reality. Note that physicists knew about "Lorentz transformations" for a while, but what Einstein did was develop a comprehensive theory of how space and time really and truly were warping.

@douglaswilkinson5700

6 ай бұрын

​@@WWLinkMasterX*Spacetme* is a single construct. It's described as an interwoven fabric.

@WWLinkMasterX

6 ай бұрын

​@@douglaswilkinson5700 In general relativity, yes. But I'm talking about special relativity at the time of its proposal.

Thanks for covering subjects like time travel.

The SCP universe has a fun take on a time machine. The SCP foundation contains anomalous objects, one of them is a device that can send messages to the past and receive them from the future, with messages being more distorted the further in time they traveled. The Foundation has received 3 or so distorted messages from the far future via the device, and while they weren't able to discern what was meant they decide that the device must never used since they reason as long as the machine hasn't sent those three messages then there is still someone alive to send them.

Sabine giving the people what they want, more videos on edge science!

Time travel forward exists: it's called sleep... Time travel backwards would mean duplicating fundamental particles, because most the stuff that composes your body is there since the BB.

@hugegamer5988

6 ай бұрын

This video dilates time and brings us into the future more quickly through the power of fun.

The key thing in this discussion seems to be the idea of causality. Is causality a hard requirement in current physics theories? Or is it merely an artefact of the fact that time travel is not something that occurs regularly in nature? I prefer the interpretation of causality as: cause always precedes effect, moving forward in time. So: if you travel back in time and kill your grandpa… nothing happens to you. Cause and effect only travel forward, your parent and yourself are never conceived, but you are still around because nothing *in your past* causes your un-being. No paradox, no violation of cause and effect.

The paradoxes come from the sci-fi fantasy of travel backward in time while THE OBSERVER'S time travels forward. For example, if you traveled back 200 years, then you wouldn't exist (yet).

Astrophysicists just seem to be the nicest people. Thank you for the education and facts about time, Sabine.

Time travel talk is all about the clickbait.

9:18 From the 90s onwards, the inner ( Cauchy) Horizons of both rotating and charged black holes have been shown to be unstable ( Poisson et al, Ori et al, Dafermos et al, Hamilton and others, to mention only a few of the experts that analysed this "mass inflation" instability phenomenon). Actually, Roger Penrose had already predicted this from the late 60s, he called it " blueshift" instability. So, no, we don't even need quantum effects , this classical instability turns the would be inner Cauchy horizon into a Null ( or even Spacelike) singularity . No closed timelke curves inside realistic Rotating Black Holes exist. Kerr metric describes an eternal isolated rotating black hole vacuum spacetime, so it's actually an idealisation.

Sabine, i have questions I do not understand. What is 'standing still'? Where is a spot in space that is moitionless? How do we measure movement with nothing to base our measurement on? i.e. If Earth is moving in a solar system that is moving in a galaxy that is moving a universe and that universe is expanding faster and faster, then where is a place to measure movement from? Where is a place that is 'still'?

@russell_js

3 ай бұрын

The observer comes into play here. You as an observer experience it as “standing still”. This is how I understand it from Einstein talking about the moving train. I might be wrong here, but that’s my understanding of it.

Time travel is possible. The video came out 60 seconds ago and it already had 16 likes

@Thomas-gk42

6 ай бұрын

That's the proof 😅

Black holes REE The fact that they "burp" and flare with periodicity after large amounts of material shows that they behave very similarly behind the event horizon as they do outside. Of course they're going to have a rotation, how close the majority of the mass is to becoming a singularity will determine how strongly that rotation will affect objects gravitationally. Things such as neutron stars that get drawn in have a lot less chance of getting "spaghettified" and will create a higher density area in the mass circling the theoretical singularity, this creates a system that will push matter into an elliptical orbit. If something is recently drawn in, it will become subject to the elliptical and possibly even form other high density masses within

You hinted at but missed an extremely important concept: Novikov self-consistency principle In a superdeterministic system, Novikov is absolutely guaranteed. It's a direct consequence from the axioms. In fact, it's a direct analytic synthesis from the superdeterministic axioms.

That's why I love that show sliders it was the same time same day but different outcomes in the parallel worlds I would love to see that program back

I didn’t come from the future but would like to go back in time to ask my uncle a question. He taught mathematics to school children in Alaska so he was fairly unavailable to me in Missouri. But he one time said his favorite theory was the second law of thermodynamics. At the time (probably 1980’s) I didn’t think to ask him why and thought I could look it up. But then I tried to find information that would be for non-math types, well I only took college algebra. But I have not found a possible reason till now if it is related to time travel as you mention. And I assume the second law relates to entropy? So if you have a reference book about the second law that would be readable for a person such as me please reply! Thanks! I love your talks and not just because of your accent. 😂

I love how Sabine implies that time travelers from the future wouldn't know who the sponsor is. ( By the way, I bought the book. ) Because if they did, I'd mean that closed time-pike curves on macroscopic scale only bring you back where you started, confining you to a region of space-time where you cannot influence anything beyond your original light cone, the one from before your jump. 🤷🏼‍♂️

A thought experiment about time travel and quanten theory: Let’s say I have Schrödinger’s cat in the box *and* a time machine. The mechanism that kills the cat (or not) activates at a point in time A. I then open the box at point C in time, and find a dead cat. I don’t like that, and use my time machine. But I can only go back to point B in time, between point A and C (for whatever reason). According to Quantenmechanik, the cat is in a superposition, both alive and dead, until the box is opened for the first time. Because I used my time machine, I open the box (again) for the first time; that means there is (again) a 50% chance that the cat is alive (despite that the mechanism in the box had already triggered before I arrive, at point A)! Addendum I: If I go back to point B, but then simply sit on a chair and wait for my past version to enter the room (“hello past me”, “hello future me”) and open the box, also past me has (again) a 50% chance to find a live cat. It doesn’t matter, after all, who opens the box. Addendum II: Even if I fly to the other side of the planet, use my time machine there, and immediately hide there in a wardrobe in the cellar, my past version has a 50% chance. In other words, the classic time travel trope about being careful not to change the past ist totally unrealistic; you can’t be more careful than to hide in a wardrobe in a cellar on the other side of the planet. Addendum III: Of course that assumes that my knowledge about what I found the first time in the box, before I traveled back in time, does not already count as measurement that collapses the wave function. But that depends a lot on how time travel would actually work. And might prove/disprove the many-world-interpretation?

Time travel for something on the scale of people is not possible and even trying could get very messy. But, like you said Sabine, small/quantum may be possible. Something like manipulating bits on a computer chip, or changing or implanting memories in people from the past may just be possible. And in theory it would not require the power of a sun to do. But the computing power to do such calculations will not exist in our lifetime, if ever. A Very thought provoking subject Sabine.