Professor Gauntlett gave the lectures for the General Relativity module for our physics course. Despite having learnt all this already, I still find myself sitting down and listening to him speak about physics! Easily one of the best, articulate and well-prepared lecturers I've ever come across!
Okay so iam a middle schooler and i want to study physics. I love to hear more about physics and life. This was the best lesson ever . I love this lesson.
This guy is a phenomenal teacher. This is the first time I have heard that the singularity inside a black hole is a singularity in time. He made the entire subject approachable and understandable to someone with little math and physics education.
I have my own theory that there is no such thing as a singularity. I think Black Holes are just giant neutron stars. They are full of neutrons and they can't collapse because time stands still. Without time - nothing can happen.
@@Bobby-fj8mk One would think that a person with such an interesting and important theory would sign their name and address to the revelation, so that the world's press could get in touch with them, to find out the details and the implications. Bobby?
I never would have had any understanding of what Hawking Radiation is had I not listened to this talk. Just one of many great nuggets free for the asking!
I know absolutely nothing about physics but I just recently started learning about black holes and now I’m hooked. Found this lecture and while this is definitely not my area of educational knowledge, I love how he explained things throughout. Made me feel a bit smarter after watching :)
i truly do not believe that anyone on the planet could take that lecture better than him......even though I'm off field here(dentist😅) i tend to have an interest in the topic and almost all of the lecture gave me an insight to what answers I've been looking for years .....hats off professor Jerome!!
One of the best lectures about black holes. Even though it is one of the toughest and mysterious stuff in physics, he did explain it in a very simple way. Thank you Professor for such a wonderful lecture.
@@calvinames8528 Yes Moose....but the psychological vacuum created by the material density of the conception in the Neoplatonic sense warps the physical dimension in accord with the ideal construction in the higher domain which renders any human measurement mute. Therefore the conceptual web of the human organism is tied down to a constraint of time and the associated curvature of this complex. Once this ideal realm is created it is perfectly possible for the human mind to get sucked into the vortex of its own creation, a type of a black hole. Therefore the ideal realm becomes reality. Or in other words, if you call a bagel sandwich a pizza then it taste like a pizza because it is now a pizza.
sorry but no... we did not obtain a picture of a black hole. we obtained a picture of the gases and material orbiting a black hole. NOT the actual hole itself. it is literally impossible to photograph a black hole in anyway other than images of it's surroundings. because a black hole doesn't itself emit anything we can photograph.
@Nemesis um... no armchair science please. magnetism, lol.... um.... no. and yes, time does exist and thus there is also space. and yes, they are relative.... because EVERYTHING is relative. literally.... EVERYTHING. hence the term.... "relativity". welcome to life in a 3 dimensional reality. but just for laughs... what do you call the "space" between two objects?
@Nemesis It is reletive only to those who measure it outside the black hole. Inside the black hole past, present and future probably exist in a higher dimension all together at the same one instant. Similar to The Nexus off star trek.
@Nemesis Wow, someone's trolling hard... Mr "other people are in Knindergarden" needs to learn the difference between "your/you're"... If you ever grow up, read up about 'scientific theory'... (I presume you liked your own posts, too...because that's what losers do.)
Just happened upon these lectures. Thank you for making them available to the public. Mr. Gauntletts presentation was incredibly good. Makes me wish I paid more attention in college.
Great talk, I learned a bit about hawking radiation, the tuesday analogy and essentially what the next big projects in cosmology might be. You get a glimpse of how things in science/physics are connected, the theories, how Newton wasn't invalidated but rather being a puzzle piece the next generation built upon. Then having relativity and quantum in parallel until we have more knowledge for the next theory. Then there are observations or experiments which are made by essentially spending money on detectors and accelerators. And with more advanced theories we as consumers get more powerful tools, spaceships, GPS, smartphones, that's the engineering benefit of it.
The experiment with the clip and the magnet at 23:00 left me genuinely shocked. I never actually thought of comparing the gravitational force of Earth with a magnet the size of my thumb. Like he said, it sounds like a simple, meaningless experiment. But it does show without question that gravity is by far weaker than we usually think.
If the effect of gravity is instantaneous, how does a gravitational waves work? The very nature of a wave suggests that it propagates from the source which means it takes time for the 'signal' to travel. I'm totally missing something.
From what I understand, in the lecture around the 12 min mark. The observations Newton made were an emergent property of the curvature of space-time. Newton was right to be suspicious about the observations he made, unfortunately he didn't have the scientific capability of making the types of measurements we can make today. The LIGO detectors are an incredibly advanced engineering and technology accomplishment. I sure wish I could get into the field of physics haha
'instantaneous' would still be limited by the speed of light though I think. I also know space-time itself doesn't have that speed limit, but I think any kind of wave would have that speed limit, which would still make it 'instant' since that the fastest speed information can travel. I think?
I heard from another lecture that they confirmed that light and gravity travels at around the same speed because of a star that was detected by Ligo and by observatories. Been binging so I can't remember which video.
At 16:30, what does he mean that positively charged matter will neutralize a black hole immediately? I have not heard of that. Unless of course theres some kind of interaction between the EM charge of the black hole and its event horizon and matter caught in the "vortex". (Term used very loosely)
is there a Computer Generated picture of only known or conjectured black holes of the universe ? any possibility of seeing the topographical display in toto ? as it exists at some/any known state? projected with or without "Spin" perhaps outlined in a red outer ring to represent them?
Most or all galaxies have a major black hole at their centers. So a map of all the galaxies is also a map of all the supermassive black holes. Google 'Hubble Ultra Deep Field' for the famous photograph.
The lecture basically covers how our understanding of the universe and its laws are moving forward..a fascinating topic like Black Holes which are so little known about and so many people talk about them as if they were physicists, makes me wanna punch them in the face when they do that by the way, and I see a lot of comments about lip-smacking and tongue clicking noises, is really your attention span that bad? is your mind really that feeble that you can be distracted from such an amazing topic, by noises we all make?
l mm m pååkåup pååkåup puh händige problem opinion å å ljusterö ljusterö och åkte hem honom att han är en fin fin p r och påverka medlemsstaternas å på påtp så n å vad ii å föri öl öl är håhåjaja tvivlar ejnån å kommentar sökbar ny nu nu och och och och åkp the ijj en jagpjj k att jag k jag och och vad lördag ljusterö och åkte åkte hem hem från jobbet ok ok vad lördag ö få pupjuouu å fy medlemsstaternas territorier upp e ok sovapu nui hos min mamma oj då å u
Perhaps my biggest peeve of all time: Einstein did not CONCLUDE that the speed of light was constant. He INTERPRETED the constant speed of light that physicists of the time kept observing.
@ around 11:25 he says imagine space is like a rubber sheet... the way i see it it's more like an infinite ocean and matter inside of it pushes/displaces the water around it just like when you enter a bath tub and water rises. The more massive an object is the stronger the gravity and the more spacetime is bent around it.
is graviton an elemental particle that is somehow responsible for the gravitational field or the geometric orientation of space time or is it a different quantum particle?
I've been sick so I put on some lectures to listen to while I rest, I fell asleep and the nextvideos opening theme came on. I think my heart stopped for a moment and sh*t myself...
I have many questions, but first, about the LIGO or interferometer specifically. Does the gravity wave manifest as a space or time distortion or is it a spacetime distortion? Does one arm see a length change or is the wavelength phase modulated or is there difference between looking at it either way over what is happening in the other arm? Is a gravity wave propagated as orthogonal space and time fields analogous to EM waves? Where can I find these answers?
Fantastic lecture! Taking something so complex and making it so simple. Im quite earily in my space engineering studies and must say I did not know how the particles formed and collapsed in vacuum before. Thank you professor!
As Prof. Gauntlett mentioned different frequency of string would correspond to different particle, so are there infinite types of particle or we have a certain allowed frequency over the strings?
As I understand it, which is not much, the vibrations on the string are the equivalent of standing waves on a guitar or cello string. The possibilities are limited to whole number multiples of the fundamental (whole length) vibration of the string. Which is why there are only so many notes in an octave. The analogy turns to shit when one considers that a guitar or cello string can be of any length, but apparently vibrating quantum strings are constrained in what their lengths can be. If they weren't, there would be, as you note, an infinite number of possible particles. There are examples of an infinite series of particles, notably the photon, which has arbitrary values from ultra-long radio waves to blasts-through-concrete gamma rays. The fundamental weakness of the standing wave analogy is that it is just an analogy.
19:30 pretty cool that the star that passed the closest reached a vertex (point (0,0) on an x^2 parabola) almost exactly at year 2000. just coincidence but a pretty neat one.
A demonstration of the art of speaking at its best. Prof. Gauntlett has a superb command of his material, speaks beautifully and rationally, and does not invent arbitrary nonsenses to make his facts and his ideas, which he distinguishes well, fit into any arbitrary plan. A very fine and responsible teacher! He speaks the macro and quantum views being unconnected in the concepts we have achieved so far with elegance and precision from 47:33.
According to the knowledge we have of black holes, I do believe that black holes must be a single particle . However big or small , they couldn't be made up of many particles . They're one of the missing particles .
Excellent presentation. The animation of the stars orbiting the galactic black hole was amazing. I also liked how the presenter emphasized Newton's theories were not disproven so much as subsumed into the larger framework of General Relativity. This is one key aspect of scientific progression that is misunderstood by the general populace.
Went about 7 mins in to the video, read your comment, then bam it hit me. Great, now that is all I hear is some blah blah blah SMACK!, blah blah blah SMACK!
The opening theme is too loud. I've been following this channel for years, and I jump out of my skin every single time I play a video. Would someone do something about it, please? Thanks.
RUclips has this function called Auto-Play, where it'll automatically play the next video before you can alter the volume lower. The lecture volume is fine. The intro isn't. I do agree it's minorly cumbersome to have to manually lower the volume specifically for the first 6 seconds of every lecture video but then not have to adjust the volume after.
RUclips recommendation machine: Black holes lectures from the RI back to back to back (this is the third it gave me)...Scientifically super interesting, but I can't imagine a more...apocalyptic subject-related recommendation than that! :D
11:35 Here the idea that in GR gravity is understood as curvature of spacetime and not a force in Newtonian sense is explained by an analogy which assumes that gravity is a force in Newtonian sense :-)
I agree. That was sloppy. A clearer image is that everything moves in a straight line and that the space they travel in is curved. The straight line in curved space image makes the most sense to me.
john hanrahan anything can fall beyond the event horizon, the problem is nothing can get out unless it is going faster than the speed of light. This means that we can’t see anything fall past the event horizon, because the light can’t escape and travel to our eyes. Time stops relative to an outside viewer, but continues normally relative to anyone/thing beyond the event horizon. I hope this helps! -your friendly neighborhood physics major.
I have asked that question as well. All I got for an answer was some hand-waving and something about 'frame-dragging". I didn't understand it and I had the impression that the person telling me about it didn't either. The way I understand relativity is with vectors. As one approaches c, the frame rotates in space-time, such that the space dimensions appear to shrink while the time dimension appears to expand / dilate. This precedes Einstein and is known as the Fitzgerald contraction. (There is even a famous limerick about it.) At c, time's arrow becomes perpendicular to what it is to a remote observer. At the event horizon, time appears to stop, as seen by a remote observer. That is why black holes were originally referred to as "frozen stars". By analogy, rotating the time vector still further by passing through the event horizon should mean that time passes backward inside the event horizon. Since space-time curvature should continue to increase as one goes further into the black hole, so should the rate at which time elapses backward. As one nears the singularity, one also nears the origin of time, the Big Bang. Which is exactly what Hawking said about the Big Bang, that it resembled a black hole in reverse. This suggests to me, a complete layman who is not to be taken seriously in the least, that a black hole is a closed time-like loop. My speculation addresses why no theory explains the formation of supermassive black holes. My speculation is that the reason no theory of their formation makes sense, is that they never formed, that they are primordial. My speculation is that the Big Bang was neither symmetrical nor efficient. If Hawking's primordial singularity did not explode symmetrically but instead shattered, fragments of it could have become the supermassive black holes we see at the center of galaxies all over the universe. My authority for this speculation as well as my qualifications for making it, hover close to zero. In my defense, I have heard lectures by a genuine Berkeley faculty cosmologist. When I asked her about how supermassive black holes could have formed, she said no one knows. So why should I? Conversely, the Berkeley professor had some snarky remarks about her mother's mah jongg partners. To whom she had had to explain more than once that she was a cosmologist and not a cosmetologist. Fortunately I am too routinely disheveled to ever be suspected of cosmetology.
At about 32:40 in the video he says that the Gravity waves will hit one detector first and then hit the second detector 10 milliseconds later. This is only true if the gravity wave source is inline with the detectors (and not between them). In general the time between the detections will be from 0 to 10 milliseconds, and will depend on the direction the gravity waves come from. If for example the source creating the gravity waves is equal distance to both detectors, then the gravity waves will reach both detectors at the same time, and the time delay between the two detectors will be zero. This time can be used to tell the direction the gravity waves are coming from. This time will allow you to determine the angle between the gravity source and the line between the detectors. To get the direction in three dimensions you need a second angle, which you can get from a third detector. There is a third detector, named Virgo in Europe, that he did not mention. Maybe he gave the lecture before the third detector was working.
Which is one of the many reasons for building a network of LIGO detectors in space. The more of them you have, the narrower the error in the direction of the signal.
Recall that gravity is indistinguishable from acceleration. It's a heck of a lot easier to think about acceleration than curved space-time IMO. So, with the acceleration metaphor for gravity in mind, is the following an accurate description of events? Throw a ball up into the air. Our arm's muscle overcomes the ball's weight and gives the ball momentum relative to us. Up it flies. Gravity is not a force, so the ball does not "run out of momentum against the force of gravity and fall back to earth." Instead, is it exactly as if, standing on the earth, our 'floor' is pushing us ever faster upward and outward such that we are being accelerated at 9.8m/s^2, but the ball, not being pushed on by the earth, does not accelerate but rather continues moving uniformly just as it moved the instant it left our hand, with no further forces acting on it, until we, being further accelerated by our connection to the earth, observe the ball seeming to slow its rise, pause, and then change direction to "fall" back down to earth with what appears to us to be a 9.8m/s^2 acceleration. So it's not the ball falling to earth, it's us being accelerated until we overtake the ball's uniform motion. Weird. But okay.
Every time I hear about the incompatibility of quantum physics and general relativity I always start thinking about the same metal experiment: what happens if somebody begins to shrink or get bigger at a super fast speed, a speed which would make that one person infinite times smaller than a subatomic particle or infinite times bigger than the biggest galaxies, or even the entire universe, in a short given time of, let's say, few hours? I don't know how physics would work that out, nor if it is possible to write a formula to explain what I'm trying to say, nor if it makes any sense at all, but my intuition tells me that that person would ultimately end up finding herself in the exact same moment in time and space when and where her change of size began to happen. Help please!
In the curved sheet analogy the ball is already moving (in a straight line) before it hits the curve. The curve of spacetime is what causes the ball to change direction/go into orbit/accelerate etc as it takes the shortest/straightest path in that curve of spacetime (which is actually 3 dimensions of frictionless space and 1 dimension of time - spacetime, not the crude analogy of a 2D sheet). In general relativity, gravity is not a force, it is the curvature of spacetime. Any number of different forces could have been initially applied to that object to set it in motion in the first place (a push, an explosion, a collision etc etc). Spacetime is an almost impossible thing to visualise and any analogy is going to fail in some respect. The only true explanation is the mathematics.
Marcos, you are right, it all is irrational BS... The problem is that all physic is irrational BS... Literally... The whole physic is just fully abstract set of rules that has no connection to reality... Except one point... if you follow these abstractions carefully, you will see that they predict what you see in reality very closely.
@@turtle2720 please read my comment carefully... and you will see that I wrote "you will see that they predict what you see in reality very closely" - where they are abstract rules (laws) of physics... So yes, physics really helps us to build very interesting things (including devices)... but laws of physics (strictly speaking) are abstract. There are no physical entity in real World that represent laws of physics... So shortly speaking, yes, we do apply (abstract) physics to real World. In any case, I am glad that you found my comment... it probably means that you saw video... that is really cool video.
The lecturer says that black holes have only two properties - mass and spin. So what spins? As the core of a supernova collapses, its angular momentum should be conserved. As it shrinks it should spin faster and faster. When it contracts within its own event horizon, no angular momentum can escape as flying debris or orbiting gas, not even as radiation. As it shrinks further, the velocity of a point on its rotating surface should reach the speed of light. Whereupon it can spin no faster. So what happens? Is this what is meant by the laws of physics breaking down? I'm drowning here. Any help?
Not a physicist, but it seems that the rotation slows down due to gravity waves being emanated by the interactions of Inner and Outer event horizons in Kerr's solution (where the singularity itself is actually a 1D ring) - medium.com/starts-with-a-bang/ask-ethan-how-can-a-black-holes-singularity-spin-36d7bf94e1ee
@@dwightk.schrute8696 Thank you for throwing me that life preserver. But why does it have to be such a confusing and difficult life preserver? There are two event horizons? Can gravity waves escape through an event horizon? But seriously, thanks for the link. I will follow it now.
You were dreaming about what we might actually be doing. Pretty insightful. Our perception of the expansion or inflation of the universe would be exactly the same assuming we were collapsing in, rather than far out galaxies moving away. This would also serve to explain dark energy, or how 'empty' space, contains 99% of the energy within the cosmos. I'm convinced our current theories about the nature of our reality are exactly opposite the truth, and were too stubborn to retheorize these fundamental understandings, for fear of reprisal.
Actually, I am experiencing a different kind of lip smacking in the form of I have some fried chicken in front of me currently. It's "Lip smacking" goooo-ooooooooooodddd.
He says charged matter would neutralize the black hole so does that mean if we somehow got enough of it to a black hole we could then theoretically get it back to its previous star form or at least to a physically stable form?
Mass(in kilograms)=Charge squared(in Coulombs squared) x 10 to the power minus 7 divided by distance(between two charges in meters). Thus Newton's Law Of Universal Gravitation is absolutely equivalent to Coulomb's Law of electromagnetic attraction (or repulsion) and therefore gravity is identical with electromagnetism and quantum gravity is just electromagnetism of the quanta.
Newton's intuition (though he declined to hypothesize this) was that gravity attracts at near distances, and cohere, but at greater distances, both attracts and repels( that is both positive and negative charges are acted on at greater distance by gravity). Thus both positive and negative charges are subsumed in Newton's Law of Gravity ( "On the Shoulders of Giants" 2002 edition, page 1160).
But space time is isn't a sheet bend in / out of one specific horizontally direction.. it would be bend in all directions around a mass, so an object ( or objects ) would be prone to falling in all possible directions surrounding that specific mass.. ( black hole ) thus an object would normally stay perfectly stabilized ?
I understand that he doesn't mean to, and is probably not even aware of it, and being interested in the subject I really, genuinely tried to stay with him, but his constant lip smacking drove me away about half-way through. Please, whoever produces these lectures, please, please, please, make sure to mention this to future lecturers.
Grow some stamina in your brain, specifically in your ability to focus on the main matter at hand. You young people are such passive little snits who can't process any information unless it is cosmetically altered to fit into the tiny crevices in your weak brains. Who on earth would make a remark like this regarding a brilliant presentation on black holes, and get 34 likes? I don't even have to ask how old you are. I know. You are of that generation who couldn't cross the room to open a book to save your lives, and who have never spent more than a nanosecond wondering about anything -- no longer than it takes to google it. String theory describes the spineless spaghetti-like structure of your feeble little minds. May you disappear down into the dense uninformed information-free singularity of your own imploding brains.
Mary Kim Cool your damn jets, not every young person has a brain made of oatmeal and raisins. I appreciate the reasoning why you'd be so upset, but it's really not the best idea to meet ignorance with angry ranting, and it's definitely not smart to make blanket statements about entire groups of people you don't know anything about. Be more patient with people or you'll find they won't care what you have to say.
Is all the energy of a black hole collision carried away by gravitational waves, or are energy densities high enough to cause spontaneous particle production, or other types of radiation?
The zero-point energy emitted might be the origin of the discovered dark energy, which comprise 73% of the total mass of the universe. My surmise is that dark energy then condense into dark matter, which in turn condense into ordinary matter:hydrogen atoms, thus completing an eternal cosmic cycle of matter to energy, and energy to matter.
if you mean hawking radiation by "zero-point energy" this cannot be. Dark Matter and Dark Energy are not radiation, as any known form of radiation, that includes the one coming from a black hole, does not behave how they do. Dark Matter seems to only interact through gravity, not any other force. All forms of radiation interact with the electromagnatic field.
"my surmise" is bad phrasing. Dark matter and dark energy are theorized because physicist has a general idea of the amount of matter present in the entire universe and the gravitational behaviour suggest there are more "things" than just ordinary matter. Also, matter don't just disappear, you can follow how they evolve from compound to compound and matter to energy. This doesn't mean your theory is wrong though, just that physicist have their ducks in a row, and are most likely justified being puzzled or justified how they postulate ideas.
can we make a magnetic mono pole when we put a magnet in the event horizon. this is same analogy that the virtual particle will become ondinary matter in the absence of virtual pair.
Fascinating, thanks. Now is the Higgs Boson decoupled from a photon, at speed? Also, how is the quantum essence of space, a brane at the Planck scale, related to the Higgs?
At 53:30 I had to ask, 'Did Hawking account for the relative rate of time at the EH when trying to calculate how often (particles per local second per volume of space, or area of EH) such a real particle of a virtual pair, would 'form', or how 'fast' it would be traveling in its presumably random hemispherical direction away from the EH? Or how often it might 'encounter' another recently widowed particle? . Failure to ask these obvious(?) rhetorical questions, seems shortsighted on the part of all of these professors of this very theoretical domain.
Do most physicists agree that black holes have a sphere of super-dense mass within the event horizon and that the singularity point is simply its center of mass/gravity? Thx
Inverse of it is white hole so roger penrose was right yet the one is single and infinite. Every creation epic, or myth starts with motion then division I. E polarity (divergent, convergent), then rhythm precession etc all properties of black whole physics. So the energy within is the same. Black holes sound like a heartbeat when listened to. The EKG heartbeat monitor reads it in us. The spark of the ANU
I have no education beyond high school just curiosity. What I don’t visualize is how everything near it goes in the black hole downward but what if you were below the black hole would you have to go up to the surface to get pulled down? So if you’re not on the surface of the sheet you can’t fall in? And if you’re above the sheet you don’t fall in? I don’t know how to explain my confusion but I’m interested to know.
Diagrams of black holes generally have to suppress two of the four spacetime dimensions; the resulting 2-D surface, warped by the presence of the entire black hole, represents everywhere that any "observer" (test particle) could be, and certain 1-D curves in that surface represents paths (trajectory) that are potentially traced out by a freely-falling test particle. Motion is constrained to the surface, so the test point is never "above" or "below" the surface. Spacetime is "bent" more and more the closer the test particle gets to the (usually drawn vertically) black hole's axis of symmetry. In recent years there has been an increasing appreciation that the traditional diagram of a black hole should not converge to a point at the so-called event horizon, but should leave room to continue the trajectory beyond that circle. Crossing the circle can be continued in a couple of ways, but I disagree with the description in the video. [In the following, I have to "get technical".] There is a phenomenon I described back in 1970 (at Rice U.) where an attempt to describe a "tachyon" with speed v/c > 1 results in all the same physics as for a tardyon with speed V/c < 1, where vV=c^2. At the same time, the signature of the metric tensor flips from (+−−−) to (−+−−), which means that right at the event horizon the time-like coordinate has become what started out as the radial spacelike coordinate and vice-versa. It is what is known as a coordinate singularity, but not a physical singularity. To correctly interpret events "inside" the event horizon, we must follow the trajectory as continuing "forward" along the local time-like coordinate. One way of visualizing this is to splice together the original spacetime with a reversed copy in an Einstein-Rosen bridge; another is to fully accept that the "manifold" has more than one coordinate "patch" and the physical objects (e.g. Riemann tensor and metric tensor) have to agree where the patches overlap. Roger Penrose is given credit for certain diagrams that are useful in doing this, and has used them to model the cosmos as a stack of half-bridges (funnels), which should have been connected continuously if the radius-time exchange had been taken into account properly. At this point of the development, topology (connectivity) may provide some interesting splicing options, and of course with every "point particle" accompanying a black hole, there are a lot of interactions instead of just the single-black-hole that we started with. As Jerome noted, besides the gravitation (scale of curvature) there need to be modified models for black holes to represent spin and charge (which was partly what Einstein had been working on late in his life). And of course quantum effects need to be dealt with, better than we have managed so far. Perhaps some of the work wasted on string theory could be recycled to integrate all these parts.
Lol, what @Doug Gwyn said. I think though, the laymen's answer you're looking for @Trulucy is that when we've had Black Holes demonstrated to us by using paper or like you said a sheet, that's actually demonstrating the mechanics/functions/"consequences" of a Black Hole, not it's structure or orientation. It's difficult to visualize, but from whatever angle or direction you're approaching the Black Hole... You aren't safe. Get close enough and for sure you will be going "in" whether you want to or not. It's fantastic you have a sense of wonder and curiosity about these types of things, never stop being curious and trying to figure things out. And don't feel bad about level of education or anything because after all.. This is LITERALLY astrophysics we are talking about haha. Even the PhDs don't have it all completely figured out.
Professor Gauntlett gave the lectures for the General Relativity module for our physics course. Despite having learnt all this already, I still find myself sitting down and listening to him speak about physics! Easily one of the best, articulate and well-prepared lecturers I've ever come across!
Okay so iam a middle schooler and i want to study physics. I love to hear more about physics and life. This was the best lesson ever . I love this lesson.
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Middle schooler, 🤣
Not alone.....
Keep learning. Maybe we'll be watching your lecture on this channel one day
This guy is a phenomenal teacher. This is the first time I have heard that the singularity inside a black hole is a singularity in time. He made the entire subject approachable and understandable to someone with little math and physics education.
I have my own theory that there is no such thing as a singularity.
I think Black Holes are just giant neutron stars.
They are full of neutrons and they can't collapse because time stands still.
Without time - nothing can happen.
@@Bobby-fj8mk
One would think that a person with such an interesting and important theory would sign their name and address to the revelation, so that the world's press could get in touch with them, to find out the details and the implications.
Bobby?
@@TheDavidlloydjones - who - me?
I never would have had any understanding of what Hawking Radiation is had I not listened to this talk. Just one of many great nuggets free for the asking!
Thank you so much for delineating these subjects and putting these in laymen's terms, enabling EVERYONE to grasp and understand
I know absolutely nothing about physics but I just recently started learning about black holes and now I’m hooked. Found this lecture and while this is definitely not my area of educational knowledge, I love how he explained things throughout. Made me feel a bit smarter after watching :)
i truly do not believe that anyone on the planet could take that lecture better than him......even though I'm off field here(dentist😅) i tend to have an interest in the topic and almost all of the lecture gave me an insight to what answers I've been looking for years .....hats off professor Jerome!!
One of the best lectures about black holes. Even though it is one of the toughest and mysterious stuff in physics, he did explain it in a very simple way. Thank you Professor for such a wonderful lecture.
What a fantastic speaker, so clear, so detailed, talk so well constructed, thank you for uploading
@@calvinames8528 ok
@@calvinames8528 am looking forward to your 1+ hour presentation
@@calvinames8528 Yes Moose....but the psychological vacuum created by the material density of the conception in the Neoplatonic sense warps the physical dimension in accord with the ideal construction in the higher domain which renders any human measurement mute. Therefore the conceptual web of the human organism is tied down to a constraint of time and the associated curvature of this complex. Once this ideal realm is created it is perfectly possible for the human mind to get sucked into the vortex of its own creation, a type of a black hole. Therefore the ideal realm becomes reality. Or in other words, if you call a bagel sandwich a pizza then it taste like a pizza because it is now a pizza.
@@booklover3959 Shit! That is EXACTLY what I was gonna say!
@@calvinames8528 who the fock are you
Found this in 2020. And since this lecture "we" have also obtained a photograph of a black hole.
sorry but no... we did not obtain a picture of a black hole. we obtained a picture of the gases and material orbiting a black hole. NOT the actual hole itself. it is literally impossible to photograph a black hole in anyway other than images of it's surroundings. because a black hole doesn't itself emit anything we can photograph.
@Nemesis um... no armchair science please. magnetism, lol.... um.... no. and yes, time does exist and thus there is also space. and yes, they are relative.... because EVERYTHING is relative. literally.... EVERYTHING. hence the term.... "relativity". welcome to life in a 3 dimensional reality.
but just for laughs... what do you call the "space" between two objects?
@Nemesis
It is reletive only to those who measure it outside the black hole.
Inside the black hole past, present and future probably exist in a higher dimension all together at the same one instant.
Similar to The Nexus off star trek.
@Nemesis Wow, someone's trolling hard...
Mr "other people are in Knindergarden" needs to learn the difference between "your/you're"...
If you ever grow up, read up about 'scientific theory'...
(I presume you liked your own posts, too...because that's what losers do.)
True
I live for the day when these videos will get 20,000,000 views instead of flashy music videos (which will be forgotten in a year or so)
That tutting after each sentence is doing my head in.
Thank you for giving that sound a name. Now I know what to call it.
Yes, it's a really bad habit and he needs to stop it.
@@Slarti I actually don't mind it. Call me weird, but I find it rather soothing.
Irritating lol.
I was wondering why the video had so many dislikes. Didn't even notice it.
Just happened upon these lectures. Thank you for making them available to the public. Mr. Gauntletts presentation was incredibly good. Makes me wish I paid more attention in college.
pourquoi?
Such a deep, clear, concise and simple to understand explanation. Fascinating.
Great talk, I learned a bit about hawking radiation, the tuesday analogy and essentially what the next big projects in cosmology might be.
You get a glimpse of how things in science/physics are connected, the theories, how Newton wasn't invalidated but rather being a puzzle piece the next generation built upon. Then having relativity and quantum in parallel until we have more knowledge for the next theory. Then there are observations or experiments which are made by essentially spending money on detectors and accelerators. And with more advanced theories we as consumers get more powerful tools, spaceships, GPS, smartphones, that's the engineering benefit of it.
That the LIGO detectors can even be built at all is amazing. That they actually work is even more amazing!
I love the way Professor Gauntlett kisses the brilliant words he has just uttered.
Thank you. I'm not a fan of that particular noise, like others, but you've changed my perspective, and now I can watch it.
Hahahahahahaha omg
Thank you. Glad to know it wasn't just me being over critical. I found this to be very distracting.
We need a compilation of it repeating non stop.
Lmao 😂👌x
Very nice lecture indeed. Captivating, pedagogical, nicely paced. Thanks.
Stunning lecture, and I really appreciate the professional coverage, a joy to watch. Thank you.
Harry Percival. EI8HVB stunning only for those that are ignorant!
Thanks!
Great lecture, he explained everything fantastically.
@@stalzemsty1669He eats Sugar Smacks for breakfast.
The experiment with the clip and the magnet at 23:00 left me genuinely shocked. I never actually thought of comparing the gravitational force of Earth with a magnet the size of my thumb. Like he said, it sounds like a simple, meaningless experiment. But it does show without question that gravity is by far weaker than we usually think.
Fantastic Lecture to listen to over a cup of tea ☕️! Professor is very eloquent. Thank you for the upload 👍
"T's" up
When not even one person giggled at “studying the motion of Uranus”
I did xD
they were all hoping no one would notice the klingons
I wish more people pronounced it as 'Ur-uh-ness' it sounds far more mysterious and ethereal. But nope, your anus.
@@noahwilliams2662 kling ons hahahahahahahaaaaa
I doubted my nerdiness b/c I laughed and no one else did.
A brilliant and concise lecture. Thank you for sharing it.
If the effect of gravity is instantaneous, how does a gravitational waves work? The very nature of a wave suggests that it propagates from the source which means it takes time for the 'signal' to travel. I'm totally missing something.
From what I understand, in the lecture around the 12 min mark. The observations Newton made were an emergent property of the curvature of space-time.
Newton was right to be suspicious about the observations he made, unfortunately he didn't have the scientific capability of making the types of measurements we can make today.
The LIGO detectors are an incredibly advanced engineering and technology accomplishment.
I sure wish I could get into the field of physics haha
'instantaneous' would still be limited by the speed of light though I think. I also know space-time itself doesn't have that speed limit, but I think any kind of wave would have that speed limit, which would still make it 'instant' since that the fastest speed information can travel. I think?
if sun disappeared now earth would still feel its gravity for 8,3 minutes
I heard from another lecture that they confirmed that light and gravity travels at around the same speed because of a star that was detected by Ligo and by observatories. Been binging so I can't remember which video.
I found this lecture to be lip smacking good.
-OK Internet- ha!
Great speaker, minus the lip smacking .....geeesh, horrible habit
Eli King Biting the lips, and lip smacking is a signs of uncertainty!
I was peacefully listening until I read this, now I cant help but notice it damnit
It's killing me
At 16:30, what does he mean that positively charged matter will neutralize a black hole immediately? I have not heard of that. Unless of course theres some kind of interaction between the EM charge of the black hole and its event horizon and matter caught in the "vortex". (Term used very loosely)
Literally, who would dislike a free University Lecture?! much less 600 people. wow
The most beautiful explanation about time singularity in the entire internet.
Which is not real is just fary tail so they have something to talk and get paid just brilliant instead of investing in something useful
@@kostadinkondev829Your grammar is absolutely atrocious. You shouldn't be critiquing.
That was an absolutely fantastic lecture. Very clear, very precise. Thank you.
Whattttttt????????????????????/
is there a Computer Generated picture of only known or conjectured black holes of the universe ? any possibility of seeing the topographical display in toto ? as it exists at some/any known state? projected with or without "Spin" perhaps outlined in a red outer ring to represent them?
Most or all galaxies have a major black hole at their centers. So a map of all the galaxies is also a map of all the supermassive black holes. Google 'Hubble Ultra Deep Field' for the famous photograph.
The lecture basically covers how our understanding of the universe and its laws are moving forward..a fascinating topic like Black Holes which are so little known about and so many people talk about them as if they were physicists, makes me wanna punch them in the face when they do that by the way, and I see a lot of comments about lip-smacking and tongue clicking noises, is really your attention span that bad? is your mind really that feeble that you can be distracted from such an amazing topic, by noises we all make?
Serious question, do you feel superior to those commenters?
@@836-e7g HAHAHAHA Yes I'm their god and I'll smite them all with my lightning for being such pretentious shmucks!!
Thank you for a fantastic lecture.
l mm m pååkåup pååkåup puh händige problem opinion å å ljusterö ljusterö och åkte hem honom att han är en fin fin p r och påverka medlemsstaternas å på påtp så n å vad ii å föri öl öl är håhåjaja tvivlar ejnån å kommentar sökbar ny nu nu och och och och åkp the ijj en jagpjj k att jag k jag och och vad lördag ljusterö och åkte åkte hem hem från jobbet ok ok vad lördag ö få pupjuouu å fy medlemsstaternas territorier upp e ok sovapu nui hos min mamma oj då å u
@@TheQuallsing ???
Perhaps my biggest peeve of all time: Einstein did not CONCLUDE that the speed of light was constant. He INTERPRETED the constant speed of light that physicists of the time kept observing.
@ around 11:25 he says imagine space is like a rubber sheet... the way i see it it's more like an infinite ocean and matter inside of it pushes/displaces the water around it just like when you enter a bath tub and water rises. The more massive an object is the stronger the gravity and the more spacetime is bent around it.
didn't even notice the lip smacking until I read the comments and even after that it didn't bother me!
udo dirkschneider I noticed it but it didn’t bother me. That’s just something some people do, including a lot of lecturers.
udo dirkschneider you weren't really listening then.
UDO: but his lip smacking is better than the "haaa.... haaa" uttered during pauses in between sentences by other speakers !!
I didn't notice either but after it was pointed out it was all I could hear lol
Polite and considerate people don't do that.
is graviton an elemental particle that is somehow responsible for the gravitational field or the geometric orientation of space time or is it a different quantum particle?
I've been sick so I put on some lectures to listen to while I rest, I fell asleep and the nextvideos opening theme came on. I think my heart stopped for a moment and sh*t myself...
We've made them less deafeningly loud recently. Sorry for the scare!
I have many questions, but first, about the LIGO or interferometer specifically. Does the gravity wave manifest as a space or time distortion or is it a spacetime distortion? Does one arm see a length change or is the wavelength phase modulated or is there difference between looking at it either way over what is happening in the other arm? Is a gravity wave propagated as orthogonal space and time fields analogous to EM waves? Where can I find these answers?
the most easy to understand explanation for me so far about how these things fundamentally works. Thank you Professor, great talks.
WOAH! Amazing demonstration! 29:09 Had no clue the interference was so sensitive... to a sound wave (moving the lasers right?). That was crazy.
Fantastic lecture! Taking something so complex and making it so simple. Im quite earily in my space engineering studies and must say I did not know how the particles formed and collapsed in vacuum before. Thank you professor!
As Prof. Gauntlett mentioned different frequency of string would correspond to different particle, so are there infinite types of particle or we have a certain allowed frequency over the strings?
As I understand it, which is not much, the vibrations on the string are the equivalent of standing waves on a guitar or cello string. The possibilities are limited to whole number multiples of the fundamental (whole length) vibration of the string. Which is why there are only so many notes in an octave. The analogy turns to shit when one considers that a guitar or cello string can be of any length, but apparently vibrating quantum strings are constrained in what their lengths can be. If they weren't, there would be, as you note, an infinite number of possible particles. There are examples of an infinite series of particles, notably the photon, which has arbitrary values from ultra-long radio waves to blasts-through-concrete gamma rays. The fundamental weakness of the standing wave analogy is that it is just an analogy.
19:30 pretty cool that the star that passed the closest reached a vertex (point (0,0) on an x^2 parabola) almost exactly at year 2000. just coincidence but a pretty neat one.
No one cares
it might be stimulated.. who knows. :/ Some coincidences are too good to be true
A demonstration of the art of speaking at its best.
Prof. Gauntlett has a superb command of his material, speaks beautifully and rationally, and does not invent arbitrary nonsenses to make his facts and his ideas, which he distinguishes well, fit into any arbitrary plan.
A very fine and responsible teacher!
He speaks the macro and quantum views being unconnected in the concepts we have achieved so far with elegance and precision from 47:33.
I just closed my eyes and enjoyed the ambient utters.
You said (18:26) that Sagittarius A weighs 3-4 million sun masses. I've heard it is 3-4 billion sun masses. Did you mix up million and billion?
This was excellent. Thank you for offering it to us!
Excellent lecture about the black holes. Thank you professor.
According to the knowledge we have of black holes, I do believe that black holes must be a single particle . However big or small , they couldn't be made up of many particles . They're one of the missing particles .
Hmm
Gabe Cerrato singularity
Excellent description and very helpful understanding of the physics of black holes.
"Gravity, my old nemesis, you win again" - Zap Brannigan
Excellent presentation. The animation of the stars orbiting the galactic black hole was amazing. I also liked how the presenter emphasized Newton's theories were not disproven so much as subsumed into the larger framework of General Relativity. This is one key aspect of scientific progression that is misunderstood by the general populace.
Thank you *smack* for this wonderful presentation *smack* Professor :)
smack EXACTLY smack THANK YOU!
Went about 7 mins in to the video, read your comment, then bam it hit me. Great, now that is all I hear is some blah blah blah SMACK!, blah blah blah SMACK!
Jewdo Master 厂，
Sounded like he had 5 or 6 jolly ranchers in his mouth....
One of the very best RI-lectures.
The opening theme is too loud. I've been following this channel for years, and I jump out of my skin every single time I play a video. Would someone do something about it, please? Thanks.
RUclips has this function called Auto-Play, where it'll automatically play the next video before you can alter the volume lower. The lecture volume is fine. The intro isn't. I do agree it's minorly cumbersome to have to manually lower the volume specifically for the first 6 seconds of every lecture video but then not have to adjust the volume after.
Yes, that's what I meant: only the first few seconds when the logo is showing, otherwise I have nothing against the lecture volume as a whole.
Agreed!
agreed
yup
RUclips recommendation machine: Black holes lectures from the RI back to back to back (this is the third it gave me)...Scientifically super interesting, but I can't imagine a more...apocalyptic subject-related recommendation than that! :D
11:35 Here the idea that in GR gravity is understood as curvature of spacetime and not a force in Newtonian sense is explained by an analogy which assumes that gravity is a force in Newtonian sense :-)
I agree. That was sloppy. A clearer image is that everything moves in a straight line and that the space they travel in is curved. The straight line in curved space image makes the most sense to me.
If time stops passing at C, can anything fall beyond the event horizon?
If the speed of G=C at the event horizon, is it faster just beyond the EH?
john hanrahan anything can fall beyond the event horizon, the problem is nothing can get out unless it is going faster than the speed of light. This means that we can’t see anything fall past the event horizon, because the light can’t escape and travel to our eyes. Time stops relative to an outside viewer, but continues normally relative to anyone/thing beyond the event horizon.
I hope this helps!
-your friendly neighborhood physics major.
I have asked that question as well. All I got for an answer was some hand-waving and something about 'frame-dragging". I didn't understand it and I had the impression that the person telling me about it didn't either.
The way I understand relativity is with vectors. As one approaches c, the frame rotates in space-time, such that the space dimensions appear to shrink while the time dimension appears to expand / dilate. This precedes Einstein and is known as the Fitzgerald contraction. (There is even a famous limerick about it.) At c, time's arrow becomes perpendicular to what it is to a remote observer. At the event horizon, time appears to stop, as seen by a remote observer. That is why black holes were originally referred to as "frozen stars". By analogy, rotating the time vector still further by passing through the event horizon should mean that time passes backward inside the event horizon. Since space-time curvature should continue to increase as one goes further into the black hole, so should the rate at which time elapses backward.
As one nears the singularity, one also nears the origin of time, the Big Bang. Which is exactly what Hawking said about the Big Bang, that it resembled a black hole in reverse. This suggests to me, a complete layman who is not to be taken seriously in the least, that a black hole is a closed time-like loop.
My speculation addresses why no theory explains the formation of supermassive black holes. My speculation is that the reason no theory of their formation makes sense, is that they never formed, that they are primordial. My speculation is that the Big Bang was neither symmetrical nor efficient.
If Hawking's primordial singularity did not explode symmetrically but instead shattered, fragments of it could have become the supermassive black holes we see at the center of galaxies all over the universe. My authority for this speculation as well as my qualifications for making it, hover close to zero.
In my defense, I have heard lectures by a genuine Berkeley faculty cosmologist. When I asked her about how supermassive black holes could have formed, she said no one knows. So why should I?
Conversely, the Berkeley professor had some snarky remarks about her mother's mah jongg partners. To whom she had had to explain more than once that she was a cosmologist and not a cosmetologist. Fortunately I am too routinely disheveled to ever be suspected of cosmetology.
Fascinating talk, really brilliant new insights!
At about 32:40 in the video he says that the Gravity waves will hit one detector first and then hit the second detector 10 milliseconds later. This is only true if the gravity wave source is inline with the detectors (and not between them). In general the time between the detections will be from 0 to 10 milliseconds, and will depend on the direction the gravity waves come from. If for example the source creating the gravity waves is equal distance to both detectors, then the gravity waves will reach both detectors at the same time, and the time delay between the two detectors will be zero. This time can be used to tell the direction the gravity waves are coming from. This time will allow you to determine the angle between the gravity source and the line between the detectors. To get the direction in three dimensions you need a second angle, which you can get from a third detector. There is a third detector, named Virgo in Europe, that he did not mention. Maybe he gave the lecture before the third detector was working.
Which is one of the many reasons for building a network of LIGO detectors in space. The more of them you have, the narrower the error in the direction of the signal.
Recall that gravity is indistinguishable from acceleration. It's a heck of a lot easier to think about acceleration than curved space-time IMO. So, with the acceleration metaphor for gravity in mind, is the following an accurate description of events?
Throw a ball up into the air. Our arm's muscle overcomes the ball's weight and gives the ball momentum relative to us. Up it flies. Gravity is not a force, so the ball does not "run out of momentum against the force of gravity and fall back to earth." Instead, is it exactly as if, standing on the earth, our 'floor' is pushing us ever faster upward and outward such that we are being accelerated at 9.8m/s^2, but the ball, not being pushed on by the earth, does not accelerate but rather continues moving uniformly just as it moved the instant it left our hand, with no further forces acting on it, until we, being further accelerated by our connection to the earth, observe the ball seeming to slow its rise, pause, and then change direction to "fall" back down to earth with what appears to us to be a 9.8m/s^2 acceleration. So it's not the ball falling to earth, it's us being accelerated until we overtake the ball's uniform motion.
Weird. But okay.
Every time I hear about the incompatibility of quantum physics and general relativity I always start thinking about the same metal experiment: what happens if somebody begins to shrink or get bigger at a super fast speed, a speed which would make that one person infinite times smaller than a subatomic particle or infinite times bigger than the biggest galaxies, or even the entire universe, in a short given time of, let's say, few hours? I don't know how physics would work that out, nor if it is possible to write a formula to explain what I'm trying to say, nor if it makes any sense at all, but my intuition tells me that that person would ultimately end up finding herself in the exact same moment in time and space when and where her change of size began to happen. Help please!
But the ball goes around the curved sheet because of gravitational force in the first place...so what causes the objects to move in curved spacetime?
In the curved sheet analogy the ball is already moving (in a straight line) before it hits the curve. The curve of spacetime is what causes the ball to change direction/go into orbit/accelerate etc as it takes the shortest/straightest path in that curve of spacetime (which is actually 3 dimensions of frictionless space and 1 dimension of time - spacetime, not the crude analogy of a 2D sheet). In general relativity, gravity is not a force, it is the curvature of spacetime. Any number of different forces could have been initially applied to that object to set it in motion in the first place (a push, an explosion, a collision etc etc). Spacetime is an almost impossible thing to visualise and any analogy is going to fail in some respect. The only true explanation is the mathematics.
Amit Mondal ..INERTIA!!
Marcos, you are right, it all is irrational BS... The problem is that all physic is irrational BS... Literally... The whole physic is just fully abstract set of rules that has no connection to reality... Except one point... if you follow these abstractions carefully, you will see that they predict what you see in reality very closely.
@@vasylshcherban4825 If physics doesn't apply to the real world then I wonder what device you used to write your comment :)
@@turtle2720 please read my comment carefully... and you will see that I wrote "you will see that they predict what you see in reality very closely" - where they are abstract rules (laws) of physics...
So yes, physics really helps us to build very interesting things (including devices)... but laws of physics (strictly speaking) are abstract. There are no physical entity in real World that represent laws of physics...
So shortly speaking, yes, we do apply (abstract) physics to real World.
In any case, I am glad that you found my comment... it probably means that you saw video... that is really cool video.
The lecturer says that black holes have only two properties - mass and spin. So what spins? As the core of a supernova collapses, its angular momentum should be conserved. As it shrinks it should spin faster and faster. When it contracts within its own event horizon, no angular momentum can escape as flying debris or orbiting gas, not even as radiation. As it shrinks further, the velocity of a point on its rotating surface should reach the speed of light. Whereupon it can spin no faster. So what happens? Is this what is meant by the laws of physics breaking down? I'm drowning here. Any help?
Not a physicist, but it seems that the rotation slows down due to gravity waves being emanated by the interactions of Inner and Outer event horizons in Kerr's solution (where the singularity itself is actually a 1D ring) - medium.com/starts-with-a-bang/ask-ethan-how-can-a-black-holes-singularity-spin-36d7bf94e1ee
@@dwightk.schrute8696 Thank you for throwing me that life preserver. But why does it have to be such a confusing and difficult life preserver? There are two event horizons? Can gravity waves escape through an event horizon? But seriously, thanks for the link. I will follow it now.
My daughter was genuinely being born as I was listening to this. 8 lbs 10 ounces gotta love wireless headphones
Wow. This might genuinely be the best endorsement we have ever received.
SO WHERE WERE YOU??
Holding my wifes hand as she pushed lol
That is one big baby. Condolences to your wife. Congratulations to you both.
Happy birthday baby
Beautiful lecture ... Overwhelming ... Humbling ...
Really
I fell asleep listening to this and had awesome scifi dreams about traveling through black holes!
You were dreaming about what we might actually be doing. Pretty insightful. Our perception of the expansion or inflation of the universe would be exactly the same assuming we were collapsing in, rather than far out galaxies moving away. This would also serve to explain dark energy, or how 'empty' space, contains 99% of the energy within the cosmos. I'm convinced our current theories about the nature of our reality are exactly opposite the truth, and were too stubborn to retheorize these fundamental understandings, for fear of reprisal.
Great lecture, just leaves me with more questions !!!
It's not lip smacking he's blowing kisses to me while I listen.
Ya'll just jealous.
Trust me - even if every word of this is true, not one soul on this earth is jealous.
@@chuckschillingvideos Cleaver girl
Actually, I am experiencing a different kind of lip smacking in the form of I have some fried chicken in front of me currently. It's "Lip smacking" goooo-ooooooooooodddd.
He says charged matter would neutralize the black hole so does that mean if we somehow got enough of it to a black hole we could then theoretically get it back to its previous star form or at least to a physically stable form?
Neutalize the electric charge of the BH, not netralize the BH itself.
Mass(in kilograms)=Charge squared(in Coulombs squared) x 10 to the power minus 7 divided by distance(between two charges in meters). Thus Newton's Law Of Universal Gravitation is absolutely equivalent to Coulomb's Law of electromagnetic attraction (or repulsion) and therefore gravity is identical with electromagnetism and quantum gravity is just electromagnetism of the quanta.
Electric charge comes in positive and negative varieties though, so its definitely different.
Newton's intuition (though he declined to hypothesize this) was that gravity attracts at near distances, and cohere, but at greater distances, both attracts and repels( that is both positive and negative charges are acted on at greater distance by gravity). Thus both positive and negative charges are subsumed in Newton's Law of Gravity ( "On the Shoulders of Giants" 2002 edition, page 1160).
@Reckless Abandon You can derive the equation from the S.I. units equivalence of 1 coulomb = 1 joule / 1 volt.
But space time is isn't a sheet bend in / out of one specific horizontally direction..
it would be bend in all directions around a mass, so an object ( or objects )
would be prone to falling in all possible directions surrounding that specific mass..
( black hole )
thus an object would normally stay perfectly stabilized ?
I understand that he doesn't mean to, and is probably not even aware of it, and being interested in the subject I really, genuinely tried to stay with him, but his constant lip smacking drove me away about half-way through. Please, whoever produces these lectures, please, please, please, make sure to mention this to future lecturers.
rolmfao
Fuckn sook
I thought it was just me but yes it's really off putting. I hope he's aware of it tut tut tut
Grow some stamina in your brain, specifically in your ability to focus on the main matter at hand. You young people are such passive little snits who can't process any information unless it is cosmetically altered to fit into the tiny crevices in your weak brains. Who on earth would make a remark like this regarding a brilliant presentation on black holes, and get 34 likes? I don't even have to ask how old you are. I know. You are of that generation who couldn't cross the room to open a book to save your lives, and who have never spent more than a nanosecond wondering about anything -- no longer than it takes to google it. String theory describes the spineless spaghetti-like structure of your feeble little minds. May you disappear down into the dense uninformed information-free singularity of your own imploding brains.
Mary Kim Cool your damn jets, not every young person has a brain made of oatmeal and raisins. I appreciate the reasoning why you'd be so upset, but it's really not the best idea to meet ignorance with angry ranting, and it's definitely not smart to make blanket statements about entire groups of people you don't know anything about. Be more patient with people or you'll find they won't care what you have to say.
Is all the energy of a black hole collision carried away by gravitational waves, or are energy densities high enough to cause spontaneous particle production, or other types of radiation?
"Fascinating"
"It's coming at us!"
"Fascinating"
"Run!!!"
"Fascinating"
"You're being sucked into it!!!"
"Fascinatiiiiiiiiiinnnnng"
Two quick questions: Can particles take up the exact same space and how "sharply" is the event horizon defined?
No.
The zero-point energy emitted might be the origin of the discovered dark energy, which comprise 73% of the total mass of the universe. My surmise is that dark energy then condense into dark matter, which in turn condense into ordinary matter:hydrogen atoms, thus completing an eternal cosmic cycle of matter to energy, and energy to matter.
if you mean hawking radiation by "zero-point energy" this cannot be. Dark Matter and Dark Energy are not radiation, as any known form of radiation, that includes the one coming from a black hole, does not behave how they do. Dark Matter seems to only interact through gravity, not any other force. All forms of radiation interact with the electromagnatic field.
"my surmise" is bad phrasing. Dark matter and dark energy are theorized because physicist has a general idea of the amount of matter present in the entire universe and the gravitational behaviour suggest there are more "things" than just ordinary matter. Also, matter don't just disappear, you can follow how they evolve from compound to compound and matter to energy. This doesn't mean your theory is wrong though, just that physicist have their ducks in a row, and are most likely justified being puzzled or justified how they postulate ideas.
Maybe there is no dark matter/energy
can we make a magnetic mono pole when we put a magnet in the event horizon. this is same analogy that the virtual particle will become ondinary matter in the absence of virtual pair.
Brilliant.
Amazing lecture, and some great analogies to help understand what's going on. Brilliant
Its sad to see how Einsteins now disproved theories are still producing such artifice.
Fascinating, thanks. Now is the Higgs Boson decoupled from a photon, at speed? Also, how is the quantum essence of space, a brane at the Planck scale, related to the Higgs?
My theory is that all matter and space comes from SPACE ITSELF .
Fake! Does that make sense? How can you prove scientifically that something came from nothing? Is that even science?
@@ingodwetrustgachatuber2747 silence. Religion is what is not even science.
14:12 Really? What reason was there for the double smack?
For some reason, I imagine Ed Bassmaster giving this lecture. Would ya just look at it?! *cackle*
Extremely clear and comprehensible presentation.
New drinking game! Take a shot for every lip smack
The guy is obviously handicapped. What a dilemma. Excellent information but unshareable. Because this guy a lip smacking fiend.
I tried your game. By the fercond somonnn aye wass clooooooo-MARFT!! 🤪🤪🤪
Just curious, if the ball on a rubber mat interpretation of gravity is right, what is space time made up of?
Gravitons? (quanta)
It is not right. It is a loose analogy.
I fell asleep to Vsauce and ended up here....
I fell asleep to a video of AI learning to play the dinosaur game
oh yeah, I've seen that one!
At 53:30 I had to ask, 'Did Hawking account for the relative rate of time at the EH when trying to calculate how often (particles per local second per volume of space, or area of EH) such a real particle of a virtual pair, would 'form', or how 'fast' it would be traveling in its presumably random hemispherical direction away from the EH? Or how often it might 'encounter' another recently widowed particle?
. Failure to ask these obvious(?) rhetorical questions, seems shortsighted on the part of all of these professors of this very theoretical domain.
This dude clicking his tongue is almost as bad as someone scratching a chalkboard...
Absolutely brilliant, very clear and patient explanation!
I find your conception of our universe quite bizzare.
Do most physicists agree that black holes have a sphere of super-dense mass within the event horizon and that the singularity point is simply its center of mass/gravity? Thx
sanjuansteve I believe they don’t. After passing through a certain threshold there is no matter as we know it. So there is nothing inside a sphere.
Inverse of it is white hole so roger penrose was right yet the one is single and infinite.
Every creation epic, or myth starts with motion then division I. E polarity (divergent, convergent), then rhythm precession etc all properties of black whole physics. So the energy within is the same.
Black holes sound like a heartbeat when listened to.
The EKG heartbeat monitor reads it in us. The spark of the ANU
Lecture: Season 1-7 of Game of Thrones
Lip smacking: Season 8
I have no education beyond high school just curiosity. What I don’t visualize is how everything near it goes in the black hole downward but what if you were below the black hole would you have to go up to the surface to get pulled down? So if you’re not on the surface of the sheet you can’t fall in? And if you’re above the sheet you don’t fall in? I don’t know how to explain my confusion but I’m interested to know.
Diagrams of black holes generally have to suppress two of the four spacetime dimensions; the resulting 2-D surface, warped by the presence of the entire black hole, represents everywhere that any "observer" (test particle) could be, and certain 1-D curves in that surface represents paths (trajectory) that are potentially traced out by a freely-falling test particle. Motion is constrained to the surface, so the test point is never "above" or "below" the surface. Spacetime is "bent" more and more the closer the test particle gets to the (usually drawn vertically) black hole's axis of symmetry. In recent years there has been an increasing appreciation that the traditional diagram of a black hole should not converge to a point at the so-called event horizon, but should leave room to continue the trajectory beyond that circle. Crossing the circle can be continued in a couple of ways, but I disagree with the description in the video. [In the following, I have to "get technical".] There is a phenomenon I described back in 1970 (at Rice U.) where an attempt to describe a "tachyon" with speed v/c > 1 results in all the same physics as for a tardyon with speed V/c < 1, where vV=c^2. At the same time, the signature of the metric tensor flips from (+−−−) to (−+−−), which means that right at the event horizon the time-like coordinate has become what started out as the radial spacelike coordinate and vice-versa. It is what is known as a coordinate singularity, but not a physical singularity. To correctly interpret events "inside" the event horizon, we must follow the trajectory as continuing "forward" along the local time-like coordinate. One way of visualizing this is to splice together the original spacetime with a reversed copy in an Einstein-Rosen bridge; another is to fully accept that the "manifold" has more than one coordinate "patch" and the physical objects (e.g. Riemann tensor and metric tensor) have to agree where the patches overlap. Roger Penrose is given credit for certain diagrams that are useful in doing this, and has used them to model the cosmos as a stack of half-bridges (funnels), which should have been connected continuously if the radius-time exchange had been taken into account properly. At this point of the development, topology (connectivity) may provide some interesting splicing options, and of course with every "point particle" accompanying a black hole, there are a lot of interactions instead of just the single-black-hole that we started with. As Jerome noted, besides the gravitation (scale of curvature) there need to be modified models for black holes to represent spin and charge (which was partly what Einstein had been working on late in his life). And of course quantum effects need to be dealt with, better than we have managed so far. Perhaps some of the work wasted on string theory could be recycled to integrate all these parts.
Lol, what @Doug Gwyn said. I think though, the laymen's answer you're looking for @Trulucy is that when we've had Black Holes demonstrated to us by using paper or like you said a sheet, that's actually demonstrating the mechanics/functions/"consequences" of a Black Hole, not it's structure or orientation. It's difficult to visualize, but from whatever angle or direction you're approaching the Black Hole... You aren't safe. Get close enough and for sure you will be going "in" whether you want to or not.
It's fantastic you have a sense of wonder and curiosity about these types of things, never stop being curious and trying to figure things out. And don't feel bad about level of education or anything because after all.. This is LITERALLY astrophysics we are talking about haha. Even the PhDs don't have it all completely figured out.
he really needs to sort out that tutting tick, proper baked my noodle
Jack Kessler
I am watching this on a 2009 iMac 27". There is no lip-smacking / tutting sound. Check your source.
we need more captivating nerds like jerome