Damn fine showing. Bravo. The talk and Q and A were both excellent. I occasionally tend to get exasperated by some lecturers failure to address a point properly, sometimes leaving common misconceptions uncorrected. That never happened throughout. Splendid talk.
If a black hole keeps evaporating, then it’s total mass will decrease. At some point, the mass will dip below a value where the event horizon disappears and it stops being a black hole. Does it revert to a neutron star then?
The bigger black hole the lower density. It is so easy to imagine that our universe is an insides of some black hole. The light in our universe will travel forever the same way the light would travel in a black hole and never leave it. You will think your "universe" is infinite because it takes infinite time for your light to get to the edge of a black hole. The blackhole is the universe for inner creatures.
My question please : The future civilisations would love to huddle around a black hole and tap its gravity for energy, but how would we find them? Maybe due to our brilliant future tech and gravity scanners etc Chris Impey is by far my favourite physicist and explains so much in clear detail, thankyou
Hard to get my head around the density of a black hole. How does quantum field theory fit into the density. Neutron star = protons and neutrons all next to each other. What is the next level of density? All quarks (10 to minus 18 meters) jammed up? And next?
What a great talk! And I would have loved to ask Prof. Impey some questions, like: - why are the small (e.g., tennis ball-size) black holes not considered an option for dark matter? - is there a specific standard number for the size of a black hole compared to the size of the space around it which it affects or dominates? (I assume the large black hole in the center of the Milky Way affects only a small percentage of our galaxy?) Anyone?
>- why are the small (e.g., tennis ball-size) black holes not considered an option for dark matter? I think it's because we don't think that would have formed in the early universe. There are some other candidates which seem more likely.
Do most physicists agree that black holes are super dense spheres of mass (not unlike neutron stars, red dwarfs, etc) that have become dense and massive enough that their event horizon diameter exceeds the sphere’s diameter, going black (and that the sphere remains)?
Is a black hole a globe or a tube. It must be spherical because if not, we won't see it as always round. Therefore, isn't it more likely that if we fall in, it will be heading towards it's centre rather than into a tube which narrows to a singularity like what you said.
Yeah and another question. If protons had generally decayed by year 10e50 what would the future civilisation consist of? Or can we just assume they would re-replicate their bodies and machines out of energy at that point?
No he didn't which seems a bit strange given that we have found some black holes that are billions of times the mass of the sun very early in the universe such that stellar mass black holes couldn't feasibly accrete enough material to get that massive so early. He didn't mention the issue that small black holes have accreting matter given the vastness of space or even the difficulties related to finding intermediate mass black holes. He did mention the context that there is the question of which came first the first black holes or the galaxies but he only mentioned the idea that the first massive stars could have made black holes of hundreds of solar masses. He didn't explain why but from what I'm aware of those stars could have gotten so massive because there were no heavy elements with efficient cooling to enable matter fragmentation. However no mention was made of any of the variations of direct collapse theory that could result in black holes of thousands of solar masses.
It is counterintuitive to me that compressing matter into a black hole would somehow increase its gravitational pull. Assuming this is true, the amount of matter alone doesn't determine the amount of gravity it creates. For example, a proton inside a rather large star has some gravitational pull but if the star turns into a black hole, that same proton creates more gravity. How is that?
It’s not increasing the overall gravitational pull. Think about it this way, let’s say, a large ball has moderate effect on the fabric of space time creating the effect of gravity. Now, if you compress that large ball to an insanely small size, there is no change in the gravitational pull. However, because of how dense they are, the closer you get to the center of the large ball, the harder it would be to escape essentially tending towards infinity. So compressing matter doesn’t increase gravitational pull for an observer that’s at the same distance from the center. For the example you mentioned - You are assuming that the proton inside the star continues to be a proton inside a black hole, currently there isn’t a way to know that. Nobody knows what is the ‘stuff’ inside a black hole.
one question -Black Hole curve space and time .how deep is the curvature. does it extend till the end of space and time? how far is the fabric of space and time is stretched?
From theory, these are singularities. Of course, as the speaker stated a singularity is an indication that the theory is somewhat not complete. There should be a limit near the the center of the black hole where the general theory of relativity does not longer apply
I would like to ask a question: ive heard a theory where with time in large scales, light acoualy slows down. For instance, now we know speed of light as constant 300 000 km/s, but 1 bilion years ago it was faster (lets say 350 000 km/s), so my question is this: is this theory right? and if so was there a time where light was so fast it could escape Black hole?
A suggested way to think about Black (and white) Holes.., (in my worthless to you, opinion, ie "take no man's word for it"):- the concept of the BH is a Mathematical manifestation of Singularity, (which is not considered definable in the context of a particular locality), but in relation to the Observable Universe, it is a point positioning location near enough to the Center of Gravity at the same perspective vanishing point, objective location, apparently coordinated by the surroundings. (Using Einstein's gravity = curvature idea and Geometry) This is the Origin of the hypothesis that the sum-of-all-histories Universal Quantum Operator Fields Modulation Mechanism of probabilities, coordinates the sequences of Time Timing in Eternity-now, to define Singularity positioning as here-now-forever in Actuality, the Central Limit of Conception of quantization = coordination. WYSIWYG, eternal zero-infinite spacing/positioning potential possibilities, and probable sum-of-all-histories resonance imaging, of multi-phase superimposed frequency interference positioning. (Don't over-think it, this is the ultimate abstraction by dispassionate disassociation so (un)desired in Meditation, and mathematical (im)possibilities of disproof)
Another suggested way is blackholes do not exist. And we are being deceived with complicated theories that no one can understand and do not challenge fully for fear of ridicule. Bodies of water will always lay level until we are told 'gravity ' bends it around a giant ball.
So an observer falling into a black hole looking out would see the universe speed up infinitely? If so then is there some crossover point between the event horizon shrinking due to Hawking Radiation which is a slow process and the universe including the outer edge of the black hole speeding up the further you fall in? Ima call it frog's point if no one has thought of it before. (lol)
frognik79 I’m thinking about the same thing. I do NOT fall in any further. From the Universes POV, I’m frozen on the event horizon, until the end of time when the Hawking radiation evaporates me back to the universe. From my POV, it is an instant. I reach the black hole, the universe speeds up, and I bounce back right away.
Top notch lecture and Q & A. As a species we are brilliant, and yet what this shows us, is that we need to approach these questions with humility and gentle curiosity. Our vocabulary has not yet arrived at a level to describe the realities and phenomenon we observe. To paraphrase Socrates: "The only thing I know, is that I don't know anything". 2500 years have passed and it is still true. We have not as yet, ripped away the veil of awesome revelation from the secrets of the Universe. Perhaps we should be satisfied to gently peel away one layer of the "Cosmological Onion" at a time. And, the questions from the younger members of the audience, were equally as pertinent and brilliant as anyone else. Bravo and thank you Dr. Impey. Your lecture has quickened my dull mind once again.
Space is void yet the parrlce field, mass enegy you can not create of destroy. Dark Energy has an event horizon projection in particle field. Gravity waves are beyond light? Reacting to what?
Sometimes he was doing it so that he didn't have to just say 'no you're wrong you don't understand'. So he just talked about something related instead. Kind man
at 13. 30 the lady asked best question for a long time & Professor fudged the reply. correct answer is Man dose not know evolution of galaxy, gravity, structure of matter, which they use photon part to observe the space. with such a collection of ignorance and the vast distances they constantly create fiction and present it as fact. Ferydoon Shirazi. MG1
![Gunna - HIM ALL ALONG [Official Visualizer]](http://i.ytimg.com/vi/HiCxoDeo0hc/mqdefault.jpg)
I love that Impey takes the young peoples' questions just as seriously as the adults', doesn't even modulate his tone of voice.
What an amazing science speaker. Such an easy, smooth, layman explanation of such complex topic. Great Job.
Best presentation and Q & A I've seen yet. Thank you.
As a science enthusiast, I am thankful for the Royal Institution's dedication to providing great topics and scientists to us lay people. 😃
What a great Q&A to cap off a superb presentation.
Oratory skills: 10/10. Which makes mr Impey, along with his knowledge of the universe, genuinely interesting to listen to. Thank you.
Damn fine showing. Bravo. The talk and Q and A were both excellent.
I occasionally tend to get exasperated by some lecturers failure to address a point properly, sometimes leaving common misconceptions uncorrected. That never happened throughout.
Splendid talk.
I clicked on the lecture and thought I'd watch a few minutes but I've stayed for the coffee and cake.
If a black hole keeps evaporating, then it’s total mass will decrease. At some point, the mass will dip below a value where the event horizon disappears and it stops being a black hole. Does it revert to a neutron star then?
This man is so kind and so intelligent
The bigger black hole the lower density. It is so easy to imagine that our universe is an insides of some black hole. The light in our universe will travel forever the same way the light would travel in a black hole and never leave it. You will think your "universe" is infinite because it takes infinite time for your light to get to the edge of a black hole. The blackhole is the universe for inner creatures.
My question please :
The future civilisations would love to huddle around a black hole and tap its gravity for energy, but how would we find them?
Maybe due to our brilliant future tech and gravity scanners etc
Chris Impey is by far my favourite physicist and explains so much in clear detail, thankyou
Hard to get my head around the density of a black hole. How does quantum field theory fit into the density. Neutron star = protons and neutrons all next to each other. What is the next level of density? All quarks (10 to minus 18 meters) jammed up? And next?
What a great talk! And I would have loved to ask Prof. Impey some questions, like:
- why are the small (e.g., tennis ball-size) black holes not considered an option for dark matter?
- is there a specific standard number for the size of a black hole compared to the size of the space around it which it affects or dominates? (I assume the large black hole in the center of the Milky Way affects only a small percentage of our galaxy?)
Anyone?
>- why are the small (e.g., tennis ball-size) black holes not considered an option for dark matter?
I think it's because we don't think that would have formed in the early universe. There are some other candidates which seem more likely.
I guest they will evaporate very quickly due to Hawkins radiation
Part 2 answer:There's no specific standard number for the size of black hole. Its size can be from zero to infinity.
11:36 Very good question...
Do most physicists agree that black holes are super dense spheres of mass (not unlike neutron stars, red dwarfs, etc) that have become dense and massive enough that their event horizon diameter exceeds the sphere’s diameter, going black (and that the sphere remains)?
Is a black hole a globe or a tube. It must be spherical because if not, we won't see it as always round.
Therefore, isn't it more likely that if we fall in, it will be heading towards it's centre rather than into a tube which narrows to a singularity like what you said.
Yeah and another question. If protons had generally decayed by year 10e50 what would the future civilisation consist of? Or can we just assume they would re-replicate their bodies and machines out of energy at that point?
Great video thank u for sharing
I need to watch the talk.... Did he mention the theory of direct collapse black holes?
No he didn't which seems a bit strange given that we have found some black holes that are billions of times the mass of the sun very early in the universe such that stellar mass black holes couldn't feasibly accrete enough material to get that massive so early. He didn't mention the issue that small black holes have accreting matter given the vastness of space or even the difficulties related to finding intermediate mass black holes.
He did mention the context that there is the question of which came first the first black holes or the galaxies but he only mentioned the idea that the first massive stars could have made black holes of hundreds of solar masses. He didn't explain why but from what I'm aware of those stars could have gotten so massive because there were no heavy elements with efficient cooling to enable matter fragmentation.
However no mention was made of any of the variations of direct collapse theory that could result in black holes of thousands of solar masses.
It is counterintuitive to me that compressing matter into a black hole would somehow increase its gravitational pull. Assuming this is true, the amount of matter alone doesn't determine the amount of gravity it creates. For example, a proton inside a rather large star has some gravitational pull but if the star turns into a black hole, that same proton creates more gravity. How is that?
It’s not increasing the overall gravitational pull. Think about it this way, let’s say, a large ball has moderate effect on the fabric of space time creating the effect of gravity. Now, if you compress that large ball to an insanely small size, there is no change in the gravitational pull. However, because of how dense they are, the closer you get to the center of the large ball, the harder it would be to escape essentially tending towards infinity. So compressing matter doesn’t increase gravitational pull for an observer that’s at the same distance from the center.
For the example you mentioned - You are assuming that the proton inside the star continues to be a proton inside a black hole, currently there isn’t a way to know that. Nobody knows what is the ‘stuff’ inside a black hole.
@@VikasTiwari-TheIrritatedTrack Thank you Vikas, that was very nicely explained! That was an answer I was searching for for years!
one question -Black Hole curve space and time .how deep is the curvature. does it extend till the end of space and time? how far is the fabric of space and time is stretched?
From theory, these are singularities. Of course, as the speaker stated a singularity is an indication that the theory is somewhat not complete. There should be a limit near the the center of the black hole where the general theory of relativity does not longer apply
I would like to ask a question: ive heard a theory where with time in large scales, light acoualy slows down. For instance, now we know speed of light as constant 300 000 km/s, but 1 bilion years ago it was faster (lets say 350 000 km/s), so my question is this: is this theory right? and if so was there a time where light was so fast it could escape Black hole?
We don't know for sure but at the moment we have no reason to believe this idea is correct.
A suggested way to think about Black (and white) Holes.., (in my worthless to you, opinion, ie "take no man's word for it"):-
the concept of the BH is a Mathematical manifestation of Singularity, (which is not considered definable in the context of a particular locality), but in relation to the Observable Universe, it is a point positioning location near enough to the Center of Gravity at the same perspective vanishing point, objective location, apparently coordinated by the surroundings. (Using Einstein's gravity = curvature idea and Geometry)
This is the Origin of the hypothesis that the sum-of-all-histories Universal Quantum Operator Fields Modulation Mechanism of probabilities, coordinates the sequences of Time Timing in Eternity-now, to define Singularity positioning as here-now-forever in Actuality, the Central Limit of Conception of quantization = coordination.
WYSIWYG, eternal zero-infinite spacing/positioning potential possibilities, and probable sum-of-all-histories resonance imaging, of multi-phase superimposed frequency interference positioning. (Don't over-think it, this is the ultimate abstraction by dispassionate disassociation so (un)desired in Meditation, and mathematical (im)possibilities of disproof)
Another suggested way is blackholes do not exist. And we are being deceived with complicated theories that no one can understand and do not challenge fully for fear of ridicule. Bodies of water will always lay level until we are told 'gravity ' bends it around a giant ball.
He reminds me of Bob Lazar, and I can hear his English accent through his American one.
Quantum physics in reality.
Splitting imagine of professor Lawrence from Texas.
So an observer falling into a black hole looking out would see the universe speed up infinitely?
If so then is there some crossover point between the event horizon shrinking due to Hawking Radiation which is a slow process and the universe including the outer edge of the black hole speeding up the further you fall in?
Ima call it frog's point if no one has thought of it before. (lol)
frognik79 I’m thinking about the same thing. I do NOT fall in any further. From the Universes POV, I’m frozen on the event horizon, until the end of time when the Hawking radiation evaporates me back to the universe.
From my POV, it is an instant. I reach the black hole, the universe speeds up, and I bounce back right away.
What is are dimensions of a black hole
Is it not possible that stellar- mass black holes (dark stars) could be significantly different from super and ultra massive black holes?
Top notch lecture and Q & A. As a species we are brilliant, and yet what this shows us, is that we need to approach these questions with humility and gentle curiosity. Our vocabulary has not yet arrived at a level to describe the realities and phenomenon we observe. To paraphrase Socrates: "The only thing I know, is that I don't know anything". 2500 years have passed and it is still true. We have not as yet, ripped away the veil of awesome revelation from the secrets of the Universe. Perhaps we should be satisfied to gently peel away one layer of the "Cosmological Onion" at a time. And, the questions from the younger members of the audience, were equally as pertinent and brilliant as anyone else. Bravo and thank you Dr. Impey. Your lecture has quickened my dull mind once again.
Bank about the great attractor, it's a black hole that that has swallowed it's own galaxies!
Black holes are not the vacuum cleaners of the universe, they pretty much behaves like a normal start beyond the horizont.
Just as Newton was corrected ... I'm sure this guy will be corrected 300 years from now
Space is void yet the parrlce field, mass enegy you can not create of destroy. Dark Energy has an event horizon projection in particle field. Gravity waves are beyond light? Reacting to what?
Science.
Sir how can can we define time in respect to earth and space
u must b fun at parties
jokes on u pal I don't get invited to parties
It's also possible to meet up with a Klingon and steal some dilithium crystals from his warp drive....
My guess is that worm holes are from the collapse of one blackhole containing all the matter in the universe.
feel like he misunderstood most questions he got and answered a different one.
I actually think that he answered most of the questions very well, which cleared some of my misunderstanings too.
Sometimes he was doing it so that he didn't have to just say 'no you're wrong you don't understand'. So he just talked about something related instead. Kind man
at 13. 30 the lady asked best question for a long time & Professor fudged the reply. correct answer is Man dose not know evolution of galaxy, gravity, structure of matter, which they use photon part to observe the space. with such a collection of ignorance and the vast distances they constantly create fiction and present it as fact. Ferydoon Shirazi. MG1
Electric charge is involved gravity, wake up scientist.
English have well defined rules on how to put words together, wake up dyslectic!