COMMON QUESTIONS: *1. "Why does the evaporation speed up over time?"* The wavelength of the radiation is proportional to the black hole's radius, which means the frequency (and therefore the energy) of the radiation must be _inversely_ proportional to the radius. The smaller the radius, the more energetic the radiation and the faster the energy of the black hole goes down. In the last few nanoseconds when the black hole is microscopic, the energy release is absolutely enormous. *2. "What mechanism converts the curvature into particles?"* We don't actually know. To predict Hawking radiation, you have to use relativity and quantum together, which means you have to be _very_ careful. You need some kind of work-around for their incompatibility. Hawking's solution was to use a Bogoliubov transformation, which is non-local math tool. He was able to do his QFT calculations in two different patches of flat spacetime and then just connect them _through_ the curved spacetime of the black hole. It was a genius solution, but it also means there are questions we just can't answer at the moment. We need a deeper model that's consistent with both relativity and quantum before we can find those answers. *3. "Do we have experimental evidence for Hawking radiation?"* We do not. The Hawking radiation being emitted by black holes right now is too low energy to be detected. It's overpowered by all the other radio signals in the universe. All we have as support for it is how consistent it is with the rest of tested physics. The implications of Hawking radiation are also pretty compelling... and quite beautiful in my opinion. *4. "Since all mass curves spacetime, does all mass emit Hawking radiation?"* No. It's not the curved spacetime that's causing the Hawking radiation. It's specifically the event horizon. Since normal objects don't have an event horizon, they can't emit Hawking radiation.
Is hawking radiation basically the Unruh radiation you observe when hovering above the event horizon, but due to nonconstant spacetime curvature there's a residual effect even far away from the hole? If so, then hovering at fixed distance from a nonsingular mass you will observe the Unruh radiation that is analogous to the hawking radiation of a black hole with that mass. What exactly would be the difference between the two radiations and in what way does the event horizon make Hawking radiation special?
@@sarchlalaith8836 A 4-deminsional being would just look through that part of space either before the event horizon formed, or after it evaporated (if their 4-deminsional extent is that great. There's no reason to guess it is. My 3-dimensional existence doesn't allow me access to the 2-dimensional surface of the far side of the moon).
@@siquod no, Unruh radiation is the vacuum energy of empty space - virtual particles - that you would collide with as you fell into a back hole's gravitational well. Hawking radiation also comes from the vacuum but converts the mass of the black hole to radiation due to the event horizon altering the quantum field of the vacuum.
My favorite thing about you is that you take nothing from granted. A bunch of huge name physicists are like hawking radiation is real and you're like... But what about the huge issues in that boiled down explanation? Then you admit to your own shortcomings as an educator and add that you're learning like the rest of us. That's what makes your explanations rewarding. You went through hell to make sense of it so that everyone can. We need more people with your humility, intelligence, honesty, and work ethic. Thanks for what you do.
Models are not actually the stuff they are supposed to represent (hence models) So its always nonsensical to look at it through other aspects of what it is trying to represent. That's why models will always be nonsensical what we always need are once that are less nonsensical than the others hence more nonsense
Outstanding. I have already described Hawking radiation to my students using the common explanation you described earlier, and then I finished with "but these are really just lies to children." I explain that it is a model meant to simplify rather than provide an accurate explanation. Your model is far superior yet still explained in a way that students may grasp it. I will reference another one of your videos for those who would like an improved model!
@@ScienceAsylum The Papa Flammy _field_ is everywhere, but that's not the same thing. You could think of it as there being a probability at all points of PF being there. But a PF event can't be in more than one place at the same time, even when the excitation of the nearby fans is very high.
Wow, our school system would be so much better if every subject had master class tutorials by amazing teachers like you, who craft each lesson optimally, and actually take the time and effort to understand what it is they teach.
As a connoisseur of physics videos on RU-vid, this is by far the clearest, most instructive explanation of Hawking Radiation I've seen. Thank you. I know you inspire lots of young people, but letting you know you also inspire some of us older folks, too. Thank you for the great work you do!
Yup that's science for you :D. The more you learn, the more you are stunned by how much we 'already know' (or at least the scientists at the moment haha), it's pretty overwhelming. And even that gets overshadowed by how much we still don't know :P
You're not alone! Even the brilliant Richard Feynman once said, "My students don't understand quantum mechanics because I don't understand quantum mechanics." And "I think that I can safely say that nobody understands quantum mechanics." So, what chance have mere mortals like us got? The more we can understand, the better but it's clearly not realistic to expect to have a full understanding of quantum mechanics.
In my case, he teaches me enough so that I suspect that the usual "explanations" (which never make any sense to me) are wrong - and that a solution, which I now almost have a clue about, might be possible.
I am a professor in Micro and Nanosystems (basically applied physics), devouring your videos and learning new things, or at least new perspectives, in most of them. Keep up the great work! You inspire me to inspire others in my own teaching.
@@jamestheotherone742 very true. I think I just meant that it answered some questions that were puzzling me about hawking radiation in the first place.
I had the exact same thinking about why Hawking radiation could never be real. Thank you for explaining this important hole in my gap of understanding away, very grateful for finally "understanding" the elusive Hawking radiation through it's actual concept...for as far as that is possible for a novice in fifteen minutes. AWESOME
You probably lost the imaginary time dimensions: strings can't vibrate backward in time uniquely at the event horizon, not in other areas. Only there. There is no movement through time at the event horizon, but only spatial movement above the speed of light. Just time for some vibrations is going back at the event horizon, they might be split, and take energy from that split.
The thing I like about you is that you START where all the other videos on such topics LEAVE us with. You truly are a masterful explainer. Keep being awesome!
Who needs science when there are so many channels on RU-vid with horoscopes, paranormal, superstition, religion, conspiracy and tin-foil hats that also completely fail to answer everything. All we can hope for is that one day people will realise science has testability, repeatability, and logic as a backround; the others have nothing but faith at best.
8:48 200 years in the future: "Nick Lucid discovered the flowton in 2021, he solved one of the greatest mysteries of the universe, he would have won the Nobel prize.
I listened to it multiple times, and it doesn't sound like he ever accidentally said "flowton". all I ever hear was "photon". I can't hear a difference.
I watch a LOT of physics and cosmology videos and this is by far the best explanation of Hawking radiation I ever seen. Thank you for finally answering some of my lingering questions!
Glad I could help. A lot of research, thinking, and planning when into this video. I'm really proud of it, so it's nice to hear other people appreciating it 🙂
It’s pretty amazing what you can convey in less than 15 minutes. For years I’ve had the same questions you’ve had. The concept as it is usually explained just didn’t pass the sniff test. I recall watching a video featuring none other than Leonard Suskind who has made a large part of his reputation on black hole physics where he gave that same hand-waving explanation of virtual particles forming at the event horizon. It was immediately obvious that, if one of the virtual pair was trapped inside the event horizon, the black hole would not lose mass and evaporate. On another note, I believe that black holes are the key to unifying QFT and GR. They are enormous enough to conform to GR (their existence was predicted by GR years before any experimental evidence was available), yet they are essentially quantum objects having only three properties, mass, charge and angular momentum just like a fundamental particle. Thanks again for the refreshing approach. I always look forward to your posts.
It changed my whole view on black holes to because it wasn’t making sense to me how the mass just stopped being accessible. Then I realized mass can be converted into energy and that’s what happens over a REALLY long time
I will now forever see you with your arms over your head saying that line when ever I hear or say "CONSERVATION OF ENERGY SHALL NOT BE VIOLATED!" Thank you.
1:20 oh *SLAPS THE TABLE* finally someone said that this explanation is ridiculous, I mean Space Time did it too but what they said was a little too much for me
Yea didnt want to be the party pooper but Matt already explained why the particle version is just an "allowed approximation". Personally I always found it ridiculous because to me that would mean that the antiparticles should have negative mass, and even though there were not many experiment to measure their mass, so far it seems they have the expected normal value for it. (and just to be clear, even if antiparticles would have negative mass one should explain why would the anti particles be the ones which are preferencibly fall into the hole and why always the "normal" ones would escape. In case of a pair production it sounds 50-50 to me, which would mean that any negative mass falling into the hole would be canceld by the positive ones) So then the question, how can you add the mass of any normal particle or antiparticle to a black hole and still make it less massive?
@@CraftyF0X Now it might seem childish but to me it looks like that antiparticles reacts equally with even spinn bosons and in an opposite way with odd spin bosons, and since the gravity particle must have a spin=2 than antiparticles and normal particles should behave the same way with gravity. Also, if conservation of energy is a thing than all antiparticles must have a positive mass
Finally, a popular explanation of Hawking radiation that deals with the reality of quantum fields instead of virtual particle pairs! Thank you and well done. I'm a self-taught physics amateur who has studied some QFT in curved spacetime, but I've only received confused looks every time I've tried to explain this amazing prediction to friends. Next time I try to explain this topic I will recommend this video.
Wow, being obsessed with black holes, this is the first time EVER I finally grasped how Hawkings radiation should be possible. Thank you so much for your videos!
I discovered your channel when I was trying really hard to understand a very difficult concept (Tensors). Every single YT video I watched felt like the person was reading straight out of a textbook. You're the only RU-vidr who actually helps me not just understand but visualize difficult concepts. I get excited when a new video of yours pops up. Thank you for taking the time to explain things in a way that is easy and enjoyable to understand. You rock. By the way, cool shirt!
2:15 “As long as you understand two things; black holes and quantum fields” Nick, I’m gonna have to stop you there. Really though I love the explanation and it definitely opened up some good insights for me.
Yeah, it is a PITA having to limit myself to relativity and q.m. when I have a perfectly working TOE. It's a bit like doing calculus on an abacus. (I wish. Hope I live to see a working TOE that combines both space-time and quantum mechanics 🧐)
Imagine the crazy dynamics of a universe with nothing left but evaporating black holes, who now and then are "refilled" ever so slightly by the explosions of another nearby black hole at the end of its life. We have something like the Game of Life going on for real where each "cell" is dependent on the life cycle of its neighbors but over crazy time scales.
Yay....New Studio. The tone and pacing difference was noticeable. I like the slow pacing and sob, it lets me absorb stuff, the earlier pacing went by too fast and I had to re-watch it multiple times. I think you are still thinking about removing the humor, but this amount is always healthy. Keep growing, our best wished is with you.
Best explanation of Hawking radiation I’ve ever witnessed. The issues with the virtual particle picture is exactly why I never believed in Hawking radiation either... until now 😅
I'm a little uncomfortable in this new wing of the Asylum, but wanted to say thanks Nick! You have made me almost understand things I never thought I would at all.
This makes so much more sense to me than the original description. I always asked myself how the paired particle would mitigate some of energy from the black hole.
I really enjoyed the reiteration of the concept after all the key points were presented - some of your older videos lacked such a reiteration, and it really helps tie everything together and put a bow on your glorious knowledge packages :)
Saw this same topic on PBS Space-Time. Came away understanding that I didn't understand Hawking Radiation. Thank you for explaining it so well. Hey, you should be a teacher 😉
Thank you for teaching physics in such an understandable way, truly. I always have been fascinated by how our reality works, and extremely frustrated I couldn't understand so much of it. You are really a good teacher and I am so grateful for your work.
First time watched The science asylum in 2021 when i was in 8th standard -video was how solar panels works?(I wanted to make one lol) Through that Video curiosity grew however i wasn't able to make one. That wasy first time watching a edtuber.Thank you very much
This video is up there with the one about gravity being primarily caused by gradients in time as among my favorites. Your videos make me wish I had followed my interests in science and physics years ago when in high school. If only I’d had teachers like you back then....
I was just discussing this with my son today. I was explaining how it was all to do with virtual particles popping into existence at the event horizon. Thank you for proving to him that his dad doesn’t know anything useful about physics. 🤓 From now on he can watch your videos if he wants to know anything!
@@damanybrown5036 It depends on what you mean. The energy that used to comprise what was infalling light does. But the Hawking particles have none of the information of what was infalling particles.
Huh, so you can think of Hawking Radiation as the universe's method of self-correcting the blemishes in space-time that are black holes... that actually makes it way easier to digest.
Remember kids! Quantum particles are always, _always_ waves. No matter what. And also, didn't expect the wavelength size of Hawking Radiation to be that gigantic
Yes, the video did help me to understand this concept a little better. And you're right, the idea of such blemishes in spacetime being gradually smoothed out by the universe is beautiful and the unimaginable lengths of time this housekeeping involves is simply staggering.
Thank you very much for making this much needed explainer. Ever since I read " A brief history of time" I always had my own problems with this phenomenon.
Oh wow. I learned so much from this video. The event horizon particle explanation never sounded right to me because why wouldn't they get trapped in the black hole's gravity well? I never thought about "pinching" quantum fields. Hawking radiation makes so much sense now!
Thank you so much Nick...No wonder why Hawking picked the layman's terms, the logical explanation is nuanced. Approaching this from the wave perspective makes a lot more sense! As always please keep it up!
Thank you. I always thought the same things when I heard about Hawking Radiation (not buying the particles popping in and out at the event horizon and stealing from the black hole). This makes much more sense (it's still over my head...anything with Quantum in it, is over my head). 🤪
Earlier I had this confusion if virtual particles are just mathematical gimmicks used to solve equations how come they evaporate blackholes but after watching this video I think understand a bit more. They are virtual as long as there's nothing around! Thanks Nick.
This is really insightful, i wondered how a black hole would decay at the end of the known universe. Also helped me understand what the heck hawking was talking about. Great video overall 👍.
I laughed out loud twice during the course of this video. That is very uncommon for a physics video, and very uncommon for a goofy video, but you combine the two in a wizardly manner.
I recall hearing bits and pieces of your explanation before, but this video is the first time they were pulled together into a comprehensible form (still fuzzy around the edges though, but that's quantum weirdness for you!). Thanks for better nonsense!! 🤣 Bar-keep ... another round of Cool-aid.
Nick, this is a masterpiece. Science communication has come a long long way since the 1970’s. I still blame Hawking for telling the story using words he knew would be misleading, yet technically correct. Even today, the story at the beginning of the vid is repeated constantly. I also think the work Hawking and Penrose were doing was so advanced that an ‘old school’ particle physicist at that time would not get it. His ‘story’ was as much for physicists as the general public, imho. The confirmation of Bell’s Inequalities was about concurrent with this work, iirc, so there were still a lot of physicists that still believed in particles as little balls of stuff instead of excitations in quantum fields. Best explanation video possible, for as broad an audience possible.
Nah, your explanation didn’t help. You just gave us a different analogy without explaining it. So it’s like pinching the quantum field like you pinch a vibrating string. Ok, so it’s LIKE that, but what is it really?
Wow -- thanks for explaining Quantum Field Theory by way of Hawking radiation. This makes a lot more sense of things that bothered me with other poorly explained quantum theories.
Yes, this very much helped me understand Hawking Radiation a lot more, and a better way of describing black holes in general. I also laughed a couple times which is rare lately, thank you for that.
Been so annoyed of the inaccurate antiparticle explanation for so long, this is a welcoming relief. Very nicely explained. Thank you. Why must others continue to confuse us with explanations that breaks the laws of physics.
7:34 Why does antimatter travel back in time? How is that even possible? Or is it just a mathematical tool and doesn't really mean anything goes back in tume?
Man this makes so much more sense, virtual particles should be called virtual wavelengths, yeah it´s the same thing bcs of wave-particle duality but as pointed out it lead to so much more confusion and spreading of misingformation
Thank you so much. This is such a good channel. It removes all the "woo" associated with physics concepts that's present on basically every other RU-vid channel. The virtual particle explanation has always set off my BS detector.
Thank You!!!! You helped me realize that the object collapsing is not the black hole. If dense enough, the spacetime around the object IS the black hole! Big difference!
thats the part still doesnt make sense. the one thing he didnt mention was the singularity at the center of the black hole. when a massive star collapses, its gravity crushes its core into an infinitely tiny and infinitely dense point with zero volume. the event horizon is the area thats close enough to the singularity that the gravity is strong enough to trap in light.
Broke: Building a Dyson swarm around a star to harvest its sunlight. Woke: Building a Dyson swarm around a supermassive black hole to harvest its Hawking radiation.
@@nerobernardino88 the bomb idea sounds better to me. You just need to find a small one and then use a gravity tractor to throw it agains the enemy planet. If it is the right size and right velocity it will immediately get to the center of the planet, and then it will eat it from the inside I guess.
@@javiej Well, that wasn't what I had in mind. My idea was the simpler build a shell of mirrors, good fucking mirrors and them slam some energy into the big ball of death, close the last mirror and let it accumulate energy through the very complex ways shit works near a black hole.
I keep thinking I understand this, trying to explain it well enough so I can properly articulate a related question I came up with, and realizing I didn't really absorb it all. This is the third time I'm watching it and I'm realizing just how much complicated information you managed to fit into a short video while also making it engaging and easy to follow. I didn't even realize how nuanced this was the first time I watched it because you made it seem so simple and almost effortless to explain. It takes real talent to take something complicated and make it simple without making it _overly_ simple, and to make it look almost effortless is even more impressive. And then making it engaging too! The quality of your videos overall has improved a lot ever since you started doing RU-vid full-time (not that weren't quite good even before that) and this video in particularly really impresses me. I like it almost as much as your video on how SR fixed electromagnetism (that's still my absolute favorite as it made electromagnetism as a concept suddenly make a zillion times more sense than my textbook did) but this one is a close second. Keep up the great work Nick! Looking forward to your next video. :)
Dear Prof. Lucid, Would you be amenable to devoting an episode to Ludwig Boltzmann? ( his life or theories or anything of great general interest about the man). My thanks in advance and, I must say, Science Asylum is my Number One/ All Time Favorite RU-vid channel😊 It's my "Go To" channel. Art, Southampton.
That helped me not only understand Hawking Radiation better, but also quantum fields and virtual particles. I always feel like understanding of these concepts for me is always a slow, additive process for me, with small insights building up over time into actual revelations. I'm tempted to call it an accretion, but...yeah. Anyway, great video!
Thank you! Very well done. It always bothered me how people used matter/antimatter pairs as an explanation without explaining why the black hole allways ate the antimatter! Found an explanation a year ago and it mostly flew over my head. This, this was good stuff!
