Can you ask the professor how come the Telescope has an angular resolution of 25uAS (micro arc seconds) and the object is ~50uAS accross, that they get so much "detail" from about 4 pixles? And given the Signal to noise ratio of the data at arround one, how any of the can be regarded as science?
this image is a total FRAUD it is based on approximately 4 pixels worth of data that was "filtered" from what amounts to white noise using modeling that simply disregarded anything that was not the desired result...and as if that were not bad enough the data set its self is fraudulent because several of the radio telescopes involved were in use on other observations at the time and could NOT have been part of the array.
@@kevint1910 It's worse than that even. The paper they published states that the JCMT and PV telescopes (the ones that define the angular resolution) never even observed the calibration target at the same time! That means that they can't rely on the data at all, further reducing the data integrity. It makes me sad that people allow themselves to be hoodwinked by rubbish like this in modern science. 😞
My theory is all scientists and physicists and astronomers are wrong about black holes, black holes are depicted as a black pit when in reality it’s shape is a sphere( black orb) and not a hole!!!
If I had a science teacher like this I may have got past intro to science in high-school a.k.a past core curriculum, failed every year because teachers are all burnt out here in oregon
I think this helped me appreciate the challenge behind visually representing complicated observations. When I first saw the new picture I didn't get it, but I really can't imagine any other way you could cleanly display the new observations in a single image, but I also feel like I only got something out of it when I heard the explanation of what is going on.
+Justin Rus The image their showing of a black hole is in reality a plasmoid see the work of Winston Bostic or Brian J. Ford. Kristian Birkeland, and or the SAFIRE project for specifics.
It's complex because it's a lot of handwaving to disguise the fact that this isn't valid signal processing. If such algorithms existed to clarify a data stream suffering from under-sampling in comparison to the desired sampling rate for high fidelity reproduction, then cell phone calls wouldn't sound so lousy. And being linear data, as opposed to 2-dimensional data, cleaning up cell phone calls by this same method would be exceedingly cheap. Cheap enough to put multiple processors on EVERY cell-phone tower antenna for under $5/cellular antenna (and these things have costs in the $1000 range, and that doesn't even include the additional $1000s it costs to install the antenna ON the tower. Cell-tower technicians are extremely expensive).
Mike Merrifield knows how to explain difficult things. Very nice video. Brady what kind of software are you using for this video. Is it Zoom or are you using different software.
At 10:18, he says a black hole cannot have a magnetic field itself, because of the no hair theorem. However, it can have (a bit of) charge and it can have angular momentum, so wouldn't that cause it to have a magnetic dipole moment as well?
The no hair theorem says that black holes are completely characterized by mass, charge, and spin. That does not preclude a magnetic field, any more than it precludes an electric or gravitational field, because that field would be completely described by the charge and spin. If a black hole were to have a magnetic field, it would be aligned with the spin axis. Look up the Kerr-Newman metric.
@@michaelsommers2356 Yes I looked that up in combination with dipole, but didn't find a definitive statement. But then the video is wrong where it says that because of the no hair it cannot have a magnetic field itself, you confirm. I thought as much, since far away the dipole should behave the same whether the charged rotating mass has collapsed into a black hole or not, was my intuition.
You are right. And moreover, electric and magnetic fields are not invariants and can change depending on the observer. An electric field outside a purely charged black hole can be seen as a magnetic field by a moving observer.
@@landsgevaer Since any charge on a black hole will be very small, any magnetic field it creates will also be very small, and not significant on relevant scales. For practical purposes, it doesn't matter.
@@michaelsommers2356 Yes, I'm aware of that. But the prof didn't say it was practically irrelevant for this observed black hole, but that it was fundamentally impossible because not even magnetic field lines can escape from a black hole. So without meaning to bash an excellent educator, that is still wrong it seems.
Guys. Love the Chanell. This is NOT a PHOTO. It is an artistic rendering by computer. Higher resolution ? ! ? ! He just made more on his rendering. “We must be careful not to believe things simply because we want them to be true” Feynman
Algorithm: A set of instructions created to give a 'desired' outcome. Believe me I trust in science, but given the right algorithm, a binary data set of the magnitude gathered for this project could be manipulated to create an image of absolutely anything.
Sag A* is also more difficult to observe than M87 because it is more dynamic on shorter time scales. The gravitational time dilation is so extreme with the M87 black hole that the observed accreting material does not change much between observations. Sag A* is ~1/1000 the mass of the M87 black hole, so the shape/form of orbiting material can change quicker.
That was a new thing for me to learn about- no hair on a black hole. I never considered the fact that magnetic line can't emanate from within the black hole itself... so these field line outside of the black hole M-87, they are created by ... what?
0:20 OK thats much better I really wanna be able to observe a black hole up close ever since I was a kid ive always had this fascination with black holes I find them to be the most interesting objects in space.
Interesting, as usual, but it made me wonder. Polarization is a feature that can characterize any wave. Are gravitational waves polarized? Are we able to detect the polarization, or are our current generation of gravitational wave detectors too crude to detect it? Or are they sensitive enough but we need more of them?
BLACK HOLE ELDERS COMMITTEE : They're now calling you the black hole that keeps on giving... do you even know what it means to be a black hole? You're supposed to take & swallow NOT give! M87 : it's my instant magnetism, it can be polarising
I find it sort of funny that the "Event Horizon Telescope" is not at all a telescope to see event horizons (of black holes, of course), even in a wider sense for "telescope". There seems to be a widespread notion that the EH is there where the BH is. Even when some account is given for infalling energy-matter to be slowed down and 'freezed' (or time-Zenoed?) at the EH, when "seen" from an "outer" observer, it's often still the notion of the EH surface "being there" and things getting 'freezed' as they fall onto it. All of this is a very pre-relativistic notion, and it is not consistent with GR. The EH, by its defining properties, does not affect the outer universe. Simply, future cones from the EH and the "inside" of the EH do not reach the "outer" universe. I want to stress, it is not that light or other things can't come out of it and yet the EH "is there", as a "hole which looks black". No, it is rather that the EH, as a spacetime geometrical configuration, is not present in any past cone of events of the outer universe. It does not affect the outer universe not just in the sense that it doesn't emit light, but also gravitationally (or better, geometrodynamically). If it did, it would violate causality. And it doesn't according to GR. GR is surprisingly raffinate and elegant in assuring causal consistency, as what is presented to the outer universe is never the EH, but rather always the proto-BH, that is the matter-energy undergoing gravitational collapse before the formation of the EH. It is in this sense that EHs are not there relative to any event of the outer universe, or that there are no EH in the visible universe. Now, in a paradoxical sense, a proto-BH physically looks just like a "mature" BH (aside from the non-negligible fact that the latter should not appear at all to the outer universe, if one thinks of it, which makes the look-alike totally non-sensical, as it is non-sensical to analyze how an EH "looks" from the outside -- it just doesn't) and proto-BHs is indeed what we are observing. But the theoretical conclusion is essential to the theoretical consistency, 'cause if we combine that the EH+inner of the BH does not affect the outer (by the geometry of causation represented by future cones), and also that it affects the outer (when indulging the pre-relativistic notion that it "is there"), e.g., determining the spacetime geometry "surrounding" the EH, and maybe in some thermodynamical and radiative sense, then we might be expected to produce inconsistencies from these premises. "Some" information loss might just be the tip of the iceberg here. If we instead realize that according to GR it is only and always the proto-BH that accounts for the entire causations by which the BH affects the outer universe, these inconsistencies have no possibility to occur, because, of course, the proto-BH is by definition within the outer universe and its causal structure. So, Wheeler can't hide his broken tea-cup behind the event horizon, the EH doesn't present a Bekenstein's temperature or entropy to the outer universe, and it doesn't cause the emission of Hawking's radiation. What "is there relative to" the outer universe and what affects it is always the entire mass-energy of the proto-BH, with its information, temperature and entropy, and its geometrodynamical effects on the surroundings, never hidden behind an EH. So, I think, EHT is one of those names we might keep for sake of conventions, well knowing they might be misleading when taken too literally. After all, I've been calling the phenomenon BH, even though it's not quite a hole, and it's not exactly black.
The jet of light that we see here is just the center of a much, much bigger electromagnetic tunnel that all galaxies count with - this electromagnetic tunnel is the medium that galaxies use to spread ENERGY-MASS to both sides so to keep on with the system and at the same time is the connection to a higger level so to connet with.
I really feel like this polarized light picture shows so brilliantly that blackholes are tunnels. Not spheres. I juxtappsed the polarized picture wuth drain swirls and looks pretty clear cut
Crazy to think that all these things, whether discovered or not, are just happening and gonging on all around us. And us humans are just trying to piece it together.
Dr. Tyson says that time is severely warped near a black hole and that if we fell into one we would see the universe end, our spaghettification notwithstanding. That makes me wonder: what does a black hole see from *its* point of view? Has the universe ended as far as it knows? Has it seen all of time play out and the heat death of the universe?
That method of visualizing magnetic fields has thin lines atop the base data is not unique to the EHT team, it's been used plenty in other studies of astronomical magnetic fields
That's the date the photons were collected, the publication date is just now. The first image was 2019 and if you look up Katie Bouman's lectures in 2019 you can hear a detailed explanation of the process in between that created the image from the data.
So, light is an electro-magnetic wave, and it bends in a strong gravitational field. Does that mean that magnetic fields are bent or compressed by a strong gravitational field. Do the magnetic field lines of the in-falling material get compressed by the gravity field of the black hole?
If its true, then magnetic field can overpower the pull of the black hole for some reason and shoot out other material with it without getting trapped to it???
Correct me if I'm wrong but isn't that image just a reconstruction and that there were several rejected "reconstructions"... This is touted as a "picture of a black hole" but it really doesn't seem to be anything like that.
It's a reconstructed picture of the accretion disk of the black hole, as you can't really take a picture or capture the light required to take a picture of a black hole, since a black hole by definition emits no light because no light can escape from it. Something a lot of people in the mainstream, outside of statistical or physics or even basic mathematical fields don't realize is that there are just absolutely mind-bogglingly intricate models and tests in order to verify these kinds of observations and "visual representations" of data. The scientific field at large applies such a sharp and aggressive knife to what is and is not STATISTICALLY verifiable that it is astronomically improbable if not impossible for misidentification or misrepresentation to take place.
Right next to the event horizon, you've got to be orbiting at close to the speed of light. Magnetic fields propagate at the speed of light, but when you're going at relativistic speeds, like when you're orbiting close to the event horizon, time is dilated. What is the effect of one on the other? I have no idea!
The faster you travel, the slower time gets, depending on your frame of reference. For an observer a safe distance away, watching something fall into a black hole (as in crossing the event horizon), they would see the infalling material become frozen in time. If you were to fall into a black hole (assuming for the moment you can do so intact), the 'outside' Universe would appear to freeze. You can think of yourself now as traveling at the speed of light through time, so your motion through space is much, much slower. There is always that balance between motion through space and motion through time.
@@mcarp555 Well, the "infalling" material would be shredded into component parts, then compounds, molecules, atoms, etc until photons reach the event horizon and add to it. Nothing actually "falls into" a black hole because gravity shreds everything into photons, many of which get blasted off as they get close, hence the beautiful imagery we see. What I was wondering is how the magnetic fields change within matter as you get closer to the event horizon and time starts to dilate, like how some models explaining things get red/blue shifted.
The video frequently mentions magnetic field lines but do they exist ? If I had a very small magnetic field detector would it show an increase when it crossed a magnetic field line ? The videos of the plasma above the sun seem to show some liner structure like field lines. However if field lines exist what is different where they exist to the space between them ?
No, field lines don't exist _per se._ Field lines are just a visualization of the local direction of the field. Suppose you're looking at a dry, sandy beach on a windy day. You see the grains of sand being picked up by the wind and moved around. If you took a photograph with a slow-ish shutter speed, you'd see the grains turn into streaks, and those streaks would indicate the field lines. In this case, the field is the velocity (speed and direction) of the wind. The statement in the video about field lines "not liking to be close together" comes with an implicit idea of scale. Think of contour lines on a map. Obviously, if you draw your contour lines at one-metre elevation intervals, they'll be much closer than if you drew then at ten-metre intervals. But whatever interval you choose, you'll find that the contour lines tend to be relatively far apart (relative to your interval), corresponding to the fact that, in most places, the ground doesn't slope steeply. The same is true of magnetic fields: you don't tend to get very steep gradients in magnetic fields, i.e., places with a strong magnetic field that are close to places with a much weaker magnetic field.
Very powerful magnetic fields were mentioned but how powerful? weaker, equal to or stronger than a magnetar for instance. Also of the modeling the magnetic fields that most resembled the data from M87 was the vertical magnetic fields, it would be interesting to know if that is at least partially responsible for the jets coming from the poles.
1-30 Gauss, or roughly twice to 60x Earth's field. On the one hand, this isn't very 'powerful' in terms of absolute field strength. We can exceed that easily. On the other hand though, the field is very large, and size really does matter here. A field of that strength stretching over such vast distances has a LOT of power behind it.
I wonder if it's actually true that magnetic field do not permeate and escape the black hole. Is it really the case that magnetic field lines do not pierce the black hole but they do bend around it's event horizon. If magnetism is somehow connected to gravity than it could make sense for the magnetic field to behave differently than we expect. Food for thought
They should send data to other teams around the world to allowe them to produce image with their alghorithms and in their supercumputers..to be all more objective
It is a complicated question! I can think of 4 answers: 1. You *can* think of a black hole as as point in space with some mass, which is packed into infinite density and no volume. With no volume, it also has no "shape". 2. But what we usually mean by _black hole_ is not just the point (or "singularity") but the sphere around it that nothing can escape, not even light or a magnetic field. This is a perfect sphere. (I forget whether the sphere is theorized to be "hairy" or "smooth". I'm not sure whether theoretical physicists agree on this.) The size of the sphere is the *Schwarzschild radius,* and its surface is the *event horizon.* 3. But that's not all. If the black hole is rotating - and they always are - the space around the sphere (or "spacetime") is distorted, not unlike spinning a spoon handle in a bowl of honey. Even if the handle doesn't change shape, the honey around it is distorted. This is gravitational *frame dragging,* and all rotating things do it, but it's particularly noticeable in black holes. So, due to this distortion of spacetime, I'm not sure how that would affect the shape you would perceive. 4. Finally, there's all the debris that is rotating around a black hole but hasn't fallen in. This is the *accretion disk* and, as the name implies, is roughly disk-shaped. The reason for the disk shape is the same as the disk shape of our solar system and our galaxy. Basically, any matter that rotates around the black hole but isn't in the same plane as the accretion disk will eventually have enough collisions with matter in the accretion disk that its momentum will be altered and it will join the disk. (And vice versa: the orbits of everything else in the accretion disk will be altered slightly as well. So the accretion disk can wobble around as new matter comes in, but it will remain disk-shaped.)
Magnetic fields are as fast as light and faster than gas and materials etc thats being pulled in, so its not the stuff that's doing that to the Magnetic field, its space, light and time and Magnetic thats feeding in to the black hole and not a stars plasma or debris from a planet etc, its space/Magnetic/light and time
Moving plasma. How gas splits into nuclei and electrons and when that flows the moving charges make a magnetic field. Similar phenomena power our sun's field.
Ha ha! I knew it from the start that the black hole would have a chaotic accretion disk and not that perfect fine disc with reflection like in Hollywood movie Interstelar. And I hated the initial interpretation of the picture.
Hi guys. I have an opinion I’d like to share with you, if you don’t mind. I think that these black holes are made of SUB COOLED SUPER FLUID. Non Newtonian subatomic particles smooshed into liquid metal or helium. No electrons because of too much gravity. Two main forces at play. Friction and gravity. Friction keeps the hole a liquid. Heat from friction in the event horizon heads toward the cool dense hole. Fire and ice literally. Absolute zero just about inside. It’s colder than space. Can only give off heat because of PRESSURE. ❤
I don't think the statement at 10:28 is correct. Black holes can have electric and magnetic fields of their own. Even outside a non rotating charged black hole, a stationary observer can see an electric field and moreover, in a different moving rest frame, that same electric field can be transformed into an electric and magnetic field. Outside a rotating charged black hole, I think there would be a magnetic field by the black hole. Since massive charged bodies are rare in our universe, the M87 black hole is probably uncharged with no EM field of its own.
The reason that this took so long was that systematic artifacts needed to be rigorously tested for. The explanation of how this was done makes up a decent amount of both papers. If two years of expert scrutiny didn't catch a problem then it must be a subtle issue indeed. Of course, it's always possible we just missed something. This is the first data on the cutting edge. It looks solid, but you can't rest on it, you need to make more observations. Hopefully we'll be proven right, possibly proven terribly wrong. So does science advance.
the matter falling towards it i.e. the accretion disk think of it like a clogged drain where no more stuff is able to fall in so it all bunches up in this case in alignment with angular momentum serving to counter gravity all that stuff has its own magnetic field which gets concentrated
If one traveled in a spaceship to a location near enough to M87 to observe it with the naked eye, wouldn't the accretion disk be far too bright to look at directly?
And intensely radioactive. But you could always put some filters on your craft. I mean the sun is too bright to look at in space but it's not hard to look at with thick enough sunglasses.
“Just for fun” I would love to know if a super massive, intergalactic Birkeland current, forming a charged plasma focus at the centre of a galaxy, would generate the same data. It’s basic electrical engineering that a perpendicular magnetic field is formed by a directional current flow. A straight line with a swirling magnetic field around it. I think what the Professor just said made me think the data doesn’t match an accretion disk phenomenon which some credit the magnetism to.
You wouldn't have the large gravitational field from the "charged plasma focus" you mention that we do observe from M87's black hole. It would have a measure more of a repulsive force effect on local stars. This is the opposite of what we see here.
So for any EM you can measure magnitude, wavelength and polarization. This sounds like very high dimensional data... How do you represent that data truly?
See our black hole playlist of videos: bit.ly/Black_Hole_Videos
Can you ask the professor how come the Telescope has an angular resolution of 25uAS (micro arc seconds) and the object is ~50uAS accross, that they get so much "detail" from about 4 pixles? And given the Signal to noise ratio of the data at arround one, how any of the can be regarded as science?
@@ZeroRyoko Yeah I also want that answer ;)
this image is a total FRAUD it is based on approximately 4 pixels worth of data that was "filtered" from what amounts to white noise using modeling that simply disregarded anything that was not the desired result...and as if that were not bad enough the data set its self is fraudulent because several of the radio telescopes involved were in use on other observations at the time and could NOT have been part of the array.
@@kevint1910 It's worse than that even. The paper they published states that the JCMT and PV telescopes (the ones that define the angular resolution) never even observed the calibration target at the same time! That means that they can't rely on the data at all, further reducing the data integrity. It makes me sad that people allow themselves to be hoodwinked by rubbish like this in modern science. 😞
My theory is all scientists and physicists and astronomers are wrong about black holes, black holes are depicted as a black pit when in reality it’s shape is a sphere( black orb) and not a hole!!!
Just want to say, Prof Mike has a fantastic sounding microphone, 10/10
It looks like it might just be the airpods mic
Whenever Mike Merrifield is back for a video I get a boost to my day. Wish he was my teacher 🙌
If I had a science teacher like this I may have got past intro to science in high-school a.k.a past core curriculum, failed every year because teachers are all burnt out here in oregon
While I too wish he were my teacher, I'm actually glad I wasn't his student. (because my younger self was awful)
He is your teacher 🙂.
Man I know!
Best on the channel now that the one bald guy retired.
I think this helped me appreciate the challenge behind visually representing complicated observations. When I first saw the new picture I didn't get it, but I really can't imagine any other way you could cleanly display the new observations in a single image, but I also feel like I only got something out of it when I heard the explanation of what is going on.
+Justin Rus The image their showing of a black hole is in reality a plasmoid see the work of Winston Bostic or Brian J. Ford. Kristian Birkeland, and or the SAFIRE project for specifics.
ok?
7:15 "No, I'm not going that way." -- M87*'s magnetic field and most toddlers.
"... the black hole that keeps on giving."
*Schwarzschild has left the chat*
1990s: Blackhole takes everything.
2021: Blackhole is the gift that keeps on giving.
*hawking radiation has entered the chat*
@@mastershooter64 I believe HawkingRadiation can only ever leave the chat ;-)
@@thereisaplace I guess a better one would be
*virtual particles have entered the chat*
*Hawking radiation has left the chat*
Kerr and einstein also left the chat
University of Notingham would be quite an experience for a grad student.
It's even a pretty sweet experience for those of us that just watch these videos tbh :)
Almost top 100 ranking in the world.
I live near there. It's pretty neat in general
Nottinghams great 😃
It's not. I study there.
This video gives fantastic context to the image. It really makes you appreciate how complex it is to visualize this information
It's complex because it's a lot of handwaving to disguise the fact that this isn't valid signal processing.
If such algorithms existed to clarify a data stream suffering from under-sampling in comparison to the desired sampling rate for high fidelity reproduction, then cell phone calls wouldn't sound so lousy. And being linear data, as opposed to 2-dimensional data, cleaning up cell phone calls by this same method would be exceedingly cheap. Cheap enough to put multiple processors on EVERY cell-phone tower antenna for under $5/cellular antenna (and these things have costs in the $1000 range, and that doesn't even include the additional $1000s it costs to install the antenna ON the tower. Cell-tower technicians are extremely expensive).
Mike Merrifield knows how to explain difficult things. Very nice video. Brady what kind of software are you using for this video. Is it Zoom or are you using different software.
wait a sec 2019 wasn't two years ...
oh nevermind :smile_with_a_tear:
Yeah, fast as lighting huh.
EXACTLY-
I kinda mist 2020 was there something?
??
At 10:18, he says a black hole cannot have a magnetic field itself, because of the no hair theorem. However, it can have (a bit of) charge and it can have angular momentum, so wouldn't that cause it to have a magnetic dipole moment as well?
The no hair theorem says that black holes are completely characterized by mass, charge, and spin. That does not preclude a magnetic field, any more than it precludes an electric or gravitational field, because that field would be completely described by the charge and spin. If a black hole were to have a magnetic field, it would be aligned with the spin axis. Look up the Kerr-Newman metric.
@@michaelsommers2356 Yes I looked that up in combination with dipole, but didn't find a definitive statement.
But then the video is wrong where it says that because of the no hair it cannot have a magnetic field itself, you confirm. I thought as much, since far away the dipole should behave the same whether the charged rotating mass has collapsed into a black hole or not, was my intuition.
You are right. And moreover, electric and magnetic fields are not invariants and can change depending on the observer. An electric field outside a purely charged black hole can be seen as a magnetic field by a moving observer.
@@landsgevaer Since any charge on a black hole will be very small, any magnetic field it creates will also be very small, and not significant on relevant scales. For practical purposes, it doesn't matter.
@@michaelsommers2356 Yes, I'm aware of that. But the prof didn't say it was practically irrelevant for this observed black hole, but that it was fundamentally impossible because not even magnetic field lines can escape from a black hole. So without meaning to bash an excellent educator, that is still wrong it seems.
Guys. Love the Chanell. This is NOT a PHOTO. It is an artistic rendering by computer.
Higher resolution ? ! ? ! He just made more on his rendering.
“We must be careful not to believe things simply because we want them to be true” Feynman
Algorithm: A set of instructions created to give a 'desired' outcome.
Believe me I trust in science, but given the right algorithm, a binary data set of the magnitude gathered for this project could be manipulated to create an image of absolutely anything.
Nice explanation Mike. I saw the new Image at Anton Petrov, but your explanation is much deeper. Keep up the great work.
black holes are so ridiculously cool 😭 i could learn about them all day and never get bored!!!
Only when one makes any progress the curiosity is sustained. Otherwise all gets in the cold bag.
Thank you to both of you for this excellent video!
Very nicely explained. Mike does a great job. Thank you!
Sag A* is also more difficult to observe than M87 because it is more dynamic on shorter time scales. The gravitational time dilation is so extreme with the M87 black hole that the observed accreting material does not change much between observations. Sag A* is ~1/1000 the mass of the M87 black hole, so the shape/form of orbiting material can change quicker.
Next Firefox logo?
I'm in love With Messier-87
I like that your visualization of the hole gives it height and not just width.
That was a new thing for me to learn about- no hair on a black hole. I never considered the fact that magnetic line can't emanate from within the black hole itself... so these field line outside of the black hole M-87, they are created by ... what?
The matter around it.
0:20 OK thats much better I really wanna be able to observe a black hole up close ever since I was a kid ive always had this fascination with black holes I find them to be the most interesting objects in space.
So since it is so far away, are we looking at and measuring a black hole as it was however many light years it is away from us?
I'm a bit surprised that the orange color being synthetic is not mentioned.
Could we have an emergency video on the Muon discovery that is rocking physics to its core, cheers!
Very humbling lisenting to the wonder of our space time , it's such a exciting time for sceintist.
black hole simulations and renderings thereof are surprisingly easy to make.
Sure would love a picture of our own cute monster
The legends are back
Interesting, as usual, but it made me wonder. Polarization is a feature that can characterize any wave. Are gravitational waves polarized? Are we able to detect the polarization, or are our current generation of gravitational wave detectors too crude to detect it? Or are they sensitive enough but we need more of them?
You gotta like because you went straight to the subject. Other people got dislikes because they took ten or so minutes to get to the point.
BLACK HOLE ELDERS COMMITTEE : They're now calling you the black hole that keeps on giving... do you even know what it means to be a black hole? You're supposed to take & swallow NOT give!
M87 : it's my instant magnetism, it can be polarising
??
This professor is a great speaker
Just love these videos; wish we can have these more regularly, please!!!
Scientists are trying their best, ok?
I find it sort of funny that the "Event Horizon Telescope" is not at all a telescope to see event horizons (of black holes, of course), even in a wider sense for "telescope".
There seems to be a widespread notion that the EH is there where the BH is. Even when some account is given for infalling energy-matter to be slowed down and 'freezed' (or time-Zenoed?) at the EH, when "seen" from an "outer" observer, it's often still the notion of the EH surface "being there" and things getting 'freezed' as they fall onto it.
All of this is a very pre-relativistic notion, and it is not consistent with GR.
The EH, by its defining properties, does not affect the outer universe. Simply, future cones from the EH and the "inside" of the EH do not reach the "outer" universe. I want to stress, it is not that light or other things can't come out of it and yet the EH "is there", as a "hole which looks black". No, it is rather that the EH, as a spacetime geometrical configuration, is not present in any past cone of events of the outer universe. It does not affect the outer universe not just in the sense that it doesn't emit light, but also gravitationally (or better, geometrodynamically). If it did, it would violate causality. And it doesn't according to GR.
GR is surprisingly raffinate and elegant in assuring causal consistency, as what is presented to the outer universe is never the EH, but rather always the proto-BH, that is the matter-energy undergoing gravitational collapse before the formation of the EH. It is in this sense that EHs are not there relative to any event of the outer universe, or that there are no EH in the visible universe.
Now, in a paradoxical sense, a proto-BH physically looks just like a "mature" BH (aside from the non-negligible fact that the latter should not appear at all to the outer universe, if one thinks of it, which makes the look-alike totally non-sensical, as it is non-sensical to analyze how an EH "looks" from the outside -- it just doesn't) and proto-BHs is indeed what we are observing.
But the theoretical conclusion is essential to the theoretical consistency, 'cause if we combine that the EH+inner of the BH does not affect the outer (by the geometry of causation represented by future cones), and also that it affects the outer (when indulging the pre-relativistic notion that it "is there"), e.g., determining the spacetime geometry "surrounding" the EH, and maybe in some thermodynamical and radiative sense, then we might be expected to produce inconsistencies from these premises. "Some" information loss might just be the tip of the iceberg here.
If we instead realize that according to GR it is only and always the proto-BH that accounts for the entire causations by which the BH affects the outer universe, these inconsistencies have no possibility to occur, because, of course, the proto-BH is by definition within the outer universe and its causal structure.
So, Wheeler can't hide his broken tea-cup behind the event horizon, the EH doesn't present a Bekenstein's temperature or entropy to the outer universe, and it doesn't cause the emission of Hawking's radiation. What "is there relative to" the outer universe and what affects it is always the entire mass-energy of the proto-BH, with its information, temperature and entropy, and its geometrodynamical effects on the surroundings, never hidden behind an EH.
So, I think, EHT is one of those names we might keep for sake of conventions, well knowing they might be misleading when taken too literally. After all, I've been calling the phenomenon BH, even though it's not quite a hole, and it's not exactly black.
This is sooo coool
I've so much more to learn about Magnetism
Off topic: The professor's audio is fantastic for true wireless buds. Is the sound coming from that source?
Anyone know what brand that is?
I don't think there's anything more satisfying than his British accent saying "polarization information"
Merrifield is the best!
Never get rid of the bloopers
Why isn’t the view on M87 not blocked in the same was as it is blocked on the center of the Milky way? Wouldn’t there also be ‚rubble’ around M78?
Is it certain at what angle that black hole rotates relative to our point of view?
Really ought to say it's an artists impression up front, not doing so detracts from the incredible achievement in acquiring the data.
I just assume now since most pictures of galaxies are artist impressions or c.g. over the real pixelated satellite images...
You got to do something to get general public interested. Once they are interested they don't care that it's an artist impression.
The jet of light that we see here is just the center of a much, much bigger electromagnetic tunnel that all galaxies count with - this electromagnetic tunnel is the medium that galaxies use to spread ENERGY-MASS to both sides so to keep on with the system and at the same time is the connection to a higger level so to connet with.
I really feel like this polarized light picture shows so brilliantly that blackholes are tunnels. Not spheres.
I juxtappsed the polarized picture wuth drain swirls and looks pretty clear cut
Crazy to think that all these things, whether discovered or not, are just happening and gonging on all around us. And us humans are just trying to piece it together.
When light or magnetism oscillates, what causes it to travel? Why doesn't it just as oscillate in place???
This is the gift that keeps on giving🍄
Dr. Tyson says that time is severely warped near a black hole and that if we fell into one we would see the universe end, our spaghettification notwithstanding. That makes me wonder: what does a black hole see from *its* point of view? Has the universe ended as far as it knows? Has it seen all of time play out and the heat death of the universe?
Such an articulate explanation!
Great explanation. Thanks prof mike!
Please unravel "Faraday rotation thing" at 13:46
That method of visualizing magnetic fields has thin lines atop the base data is not unique to the EHT team, it's been used plenty in other studies of astronomical magnetic fields
Where is the footage of the stars revolving around Sagittarius A from? Looks awesome
How does the black hole looks from the other side?
Brady always has the best videos!
April 11th, 2017 was when this paper was published. That was 4 years ago and we are just now getting this. What else are we four years behind on?
That's the date the photons were collected, the publication date is just now. The first image was 2019 and if you look up Katie Bouman's lectures in 2019 you can hear a detailed explanation of the process in between that created the image from the data.
So, light is an electro-magnetic wave, and it bends in a strong gravitational field. Does that mean that magnetic fields are bent or compressed by a strong gravitational field. Do the magnetic field lines of the in-falling material get compressed by the gravity field of the black hole?
If its true, then magnetic field can overpower the pull of the black hole for some reason and shoot out other material with it without getting trapped to it???
Correct me if I'm wrong but isn't that image just a reconstruction and that there were several rejected "reconstructions"... This is touted as a "picture of a black hole" but it really doesn't seem to be anything like that.
It's a reconstructed picture of the accretion disk of the black hole, as you can't really take a picture or capture the light required to take a picture of a black hole, since a black hole by definition emits no light because no light can escape from it.
Something a lot of people in the mainstream, outside of statistical or physics or even basic mathematical fields don't realize is that there are just absolutely mind-bogglingly intricate models and tests in order to verify these kinds of observations and "visual representations" of data. The scientific field at large applies such a sharp and aggressive knife to what is and is not STATISTICALLY verifiable that it is astronomically improbable if not impossible for misidentification or misrepresentation to take place.
@@connorspangler510 fair enough, but is it a "picture"?... I'm gonna say no.
@@Mmouse_ who said it was a literal photograph?
@@connorspangler510 no one... But it is touted as that, and a lot of people think it is.
@Mary Terwiliger what conspiracy? That's how this image was formed.
Professor Mike Merrifield live in Harry Potter's room.
But he has a cool porthole with a view from his space ship though :)
Would it be possible to directly detect hawking radiation with the data?
Right next to the event horizon, you've got to be orbiting at close to the speed of light. Magnetic fields propagate at the speed of light, but when you're going at relativistic speeds, like when you're orbiting close to the event horizon, time is dilated.
What is the effect of one on the other? I have no idea!
The faster you travel, the slower time gets, depending on your frame of reference. For an observer a safe distance away, watching something fall into a black hole (as in crossing the event horizon), they would see the infalling material become frozen in time. If you were to fall into a black hole (assuming for the moment you can do so intact), the 'outside' Universe would appear to freeze.
You can think of yourself now as traveling at the speed of light through time, so your motion through space is much, much slower. There is always that balance between motion through space and motion through time.
@@mcarp555 Well, the "infalling" material would be shredded into component parts, then compounds, molecules, atoms, etc until photons reach the event horizon and add to it. Nothing actually "falls into" a black hole because gravity shreds everything into photons, many of which get blasted off as they get close, hence the beautiful imagery we see.
What I was wondering is how the magnetic fields change within matter as you get closer to the event horizon and time starts to dilate, like how some models explaining things get red/blue shifted.
I would imagine that this image is why keeping the wave front data not as much as for the first image. Thanks folks!
I had a feeling that image was fake at some level, now I know it was just an artist's depiction placed upon it
Would love to see what's in that DIY manual... :)
Wait, 10:30 - I learned that a black hole can have a charge, and wouldn't a charged black hole also produce a magnetic field?
The video frequently mentions magnetic field lines but do they exist ? If I had a very small magnetic field detector would it show an increase when it crossed a magnetic field line ? The videos of the plasma above the sun seem to show some liner structure like field lines. However if field lines exist what is different where they exist to the space between them ?
No, field lines don't exist _per se._ Field lines are just a visualization of the local direction of the field. Suppose you're looking at a dry, sandy beach on a windy day. You see the grains of sand being picked up by the wind and moved around. If you took a photograph with a slow-ish shutter speed, you'd see the grains turn into streaks, and those streaks would indicate the field lines. In this case, the field is the velocity (speed and direction) of the wind.
The statement in the video about field lines "not liking to be close together" comes with an implicit idea of scale. Think of contour lines on a map. Obviously, if you draw your contour lines at one-metre elevation intervals, they'll be much closer than if you drew then at ten-metre intervals. But whatever interval you choose, you'll find that the contour lines tend to be relatively far apart (relative to your interval), corresponding to the fact that, in most places, the ground doesn't slope steeply. The same is true of magnetic fields: you don't tend to get very steep gradients in magnetic fields, i.e., places with a strong magnetic field that are close to places with a much weaker magnetic field.
Very powerful magnetic fields were mentioned but how powerful? weaker, equal to or stronger than a magnetar for instance. Also of the modeling the magnetic fields that most resembled the data from M87 was the vertical magnetic fields, it would be interesting to know if that is at least partially responsible for the jets coming from the poles.
1-30 Gauss, or roughly twice to 60x Earth's field.
On the one hand, this isn't very 'powerful' in terms of absolute field strength. We can exceed that easily. On the other hand though, the field is very large, and size really does matter here. A field of that strength stretching over such vast distances has a LOT of power behind it.
If I had professors like this guy I might have actually made it through college. Oh well, Im still doing well for myself even without a degree.
that’s great Edward
College these days is a total scam.
false.
6:06 I think he mixed up the toroidal and radial ones?
I wonder if it's actually true that magnetic field do not permeate and escape the black hole.
Is it really the case that magnetic field lines do not pierce the black hole but they do bend around it's event horizon.
If magnetism is somehow connected to gravity than it could make sense for the magnetic field to behave differently than we expect.
Food for thought
If nothing can escape the black hole, how can the particles shoot out of it
They should send data to other teams around the world to allowe them to produce image with their alghorithms and in their supercumputers..to be all more objective
what about the black hole in the center of the milky way :3
10:19 (magnetic lines can’t emerge from a black hole)
But then how can a black hole still a have charge?
Forgive my ignorance but what is the shape of a black hole? Is it a disk or an orb or a cone - or something else?
It is a complicated question! I can think of 4 answers:
1. You *can* think of a black hole as as point in space with some mass, which is packed into infinite density and no volume. With no volume, it also has no "shape".
2. But what we usually mean by _black hole_ is not just the point (or "singularity") but the sphere around it that nothing can escape, not even light or a magnetic field. This is a perfect sphere. (I forget whether the sphere is theorized to be "hairy" or "smooth". I'm not sure whether theoretical physicists agree on this.) The size of the sphere is the *Schwarzschild radius,* and its surface is the *event horizon.*
3. But that's not all. If the black hole is rotating - and they always are - the space around the sphere (or "spacetime") is distorted, not unlike spinning a spoon handle in a bowl of honey. Even if the handle doesn't change shape, the honey around it is distorted. This is gravitational *frame dragging,* and all rotating things do it, but it's particularly noticeable in black holes. So, due to this distortion of spacetime, I'm not sure how that would affect the shape you would perceive.
4. Finally, there's all the debris that is rotating around a black hole but hasn't fallen in. This is the *accretion disk* and, as the name implies, is roughly disk-shaped. The reason for the disk shape is the same as the disk shape of our solar system and our galaxy. Basically, any matter that rotates around the black hole but isn't in the same plane as the accretion disk will eventually have enough collisions with matter in the accretion disk that its momentum will be altered and it will join the disk. (And vice versa: the orbits of everything else in the accretion disk will be altered slightly as well. So the accretion disk can wobble around as new matter comes in, but it will remain disk-shaped.)
Is the matter now defining the strong magnetic field or is de strong magnetic field controlling the matter? You can,t have both!
The biggest question I have is how many times the professor has hit his head on that slanted ceiling.
Magnetic fields are as fast as light and faster than gas and materials etc thats being pulled in, so its not the stuff that's doing that to the Magnetic field, its space, light and time and Magnetic thats feeding in to the black hole and not a stars plasma or debris from a planet etc, its space/Magnetic/light and time
Beavering away! Stealing that.
It's a standard expression in English. There's nothing to steal.
To get up close to the black hole and see it like that image, you'd have to be a radio octopus.
aren't there petabytes of data to process?
I like his Nike Jumper
Where do the magnetic fields come from?
Moving plasma. How gas splits into nuclei and electrons and when that flows the moving charges make a magnetic field. Similar phenomena power our sun's field.
Ha ha!
I knew it from the start that the black hole would have a chaotic accretion disk and not that perfect fine disc with reflection like in Hollywood movie Interstelar.
And I hated the initial interpretation of the picture.
Hi guys. I have an opinion I’d like to share with you, if you don’t mind. I think that these black holes are made of SUB COOLED SUPER FLUID. Non Newtonian subatomic particles smooshed into liquid metal or helium. No electrons because of too much gravity. Two main forces at play. Friction and gravity. Friction keeps the hole a liquid. Heat from friction in the event horizon heads toward the cool dense hole. Fire and ice literally. Absolute zero just about inside. It’s colder than space. Can only give off heat because of PRESSURE. ❤
I don't think the statement at 10:28 is correct. Black holes can have electric and magnetic fields of their own. Even outside a non rotating charged black hole, a stationary observer can see an electric field and moreover, in a different moving rest frame, that same electric field can be transformed into an electric and magnetic field.
Outside a rotating charged black hole, I think there would be a magnetic field by the black hole.
Since massive charged bodies are rare in our universe, the M87 black hole is probably uncharged with no EM field of its own.
Professor, are the north/south poles moving??? Are we far more into the geomagnetic shift than science is telling us???
I hope this helps reduce the cost of prime beef.
okay so how do we know this is not artefacts due to post-processing?
Not explained in the video so you'll have to read the paper.
You'll have to take the scientists at their word...
The reason that this took so long was that systematic artifacts needed to be rigorously tested for. The explanation of how this was done makes up a decent amount of both papers. If two years of expert scrutiny didn't catch a problem then it must be a subtle issue indeed.
Of course, it's always possible we just missed something. This is the first data on the cutting edge. It looks solid, but you can't rest on it, you need to make more observations. Hopefully we'll be proven right, possibly proven terribly wrong. So does science advance.
explain polarization
If magnetic fields do no work, how can they exert pressure?
My guess is that the black hole is rotating and that can do work.
Sooo... what is producing the magnetic fields???
the matter falling towards it i.e. the accretion disk think of it like a clogged drain where no more stuff is able to fall in so it all bunches up in this case in alignment with angular momentum serving to counter gravity all that stuff has its own magnetic field which gets concentrated
If one traveled in a spaceship to a location near enough to M87 to observe it with the naked eye, wouldn't the accretion disk be far too bright to look at directly?
And intensely radioactive. But you could always put some filters on your craft. I mean the sun is too bright to look at in space but it's not hard to look at with thick enough sunglasses.
“Just for fun” I would love to know if a super massive, intergalactic Birkeland current, forming a charged plasma focus at the centre of a galaxy, would generate the same data. It’s basic electrical engineering that a perpendicular magnetic field is formed by a directional current flow. A straight line with a swirling magnetic field around it. I think what the Professor just said made me think the data doesn’t match an accretion disk phenomenon which some credit the magnetism to.
You wouldn't have the large gravitational field from the "charged plasma focus" you mention that we do observe from M87's black hole. It would have a measure more of a repulsive force effect on local stars. This is the opposite of what we see here.
They could’ve simplified all that over complicated mathematical model by a formula that shows the surface area of a donut 🍩!
So for any EM you can measure magnitude, wavelength and polarization. This sounds like very high dimensional data... How do you represent that data truly?
Sixty symbols my favorite
That is some thick paper that it’s printed on 👀