Black Hole Mergers and Multi-Messenger Astronomy - Sixty Symbols
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- Опубликовано: 26 сен 2024
- Professor Ed Copeland discusses latest happenings at LIGO - and how it is shedding light on mergers between Black Holes and Neutron Stars. More links and info below ↓ ↓ ↓
More Ed Copeland videos: bit.ly/EdCopeland
Previous LIGO video on gravitational waves doiscovery: • Gravitational Waves Di...
Fab Four: • Fab Four and Vacuum En...
LIGO: www.ligo.calte...
VIRGO: www.virgo-gw.eu
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I can never get enough of prof. Copeland's enthusiasm and he does such a great job at trying to explain complex matters to the masses.
The sign of a great teacher, is being able to explain things, to different students, in the way the student learns and understands. And he makes it exciting, bonus.
He's wrong though cause black holes and gravitational waves don't exist. Pure fantasy from heads like these .
@@garrysekelli6776 right on
@@garrysekelli6776 He's guessing, it's a theory he's working with. Great teachers can open your mind to new possibilities, I never take it as fact, because they don't know enough yet. But they can inspire others to think in new directions, even prove them wrong. I like to hear all ideas and theories.
@@spazmobot well that's a complete cop out. I mean like mate: either it's real or it isn't real. So what you are saying is that cause what this guy is saying is so revolution ary that we need to revamp our entire society.
I love listening to Professor Copeland explaining these things.
Always a pleasure.
Really wish I could find some extended lectures of his.
This has to be one of the longest, yet simplest, explanation of the most exciting new field of Science! I mean…I could’ve listened all day!
Really enjoy listening to Copeland explain.
Please tell him we want even more with him!
(that does NOT mean we want less of the other wonderful professors)
Professor Ed Copeland for the win my absolute favorite professor
Prof. Copeland is my personal favourite in the line-up for sixty symbols. They're all great, the bar is high. But it's just that I feel a little bit more humbled when, through your videos, I get the opportunity to sit down with this wise and calm professor.
Happy to see Proffesor Copeland again!
Never knew our man Ed was a collar up kinda guy. Thanks for yet another fascinating video!
Ed is the man bro
Collar up is the only way to rock a polo neck!
This is one of my favorite channels. I love how you can break these complex things down into simple language. I have learned so much about physics from watching you and some others, and I hope I can get around to learning the kinds of maths to understand this stuff better one day.
I could listen to Ed talk for hours and hours. I've listened to his previous interviews on this channel many many many times now. Having a new one to listen to, and on such an exciting topic, has made my whole week better.
I went to UoN and Ed was my lecturer for a couple of modules.
His voice is so soothing, it's dangerous for those early morning lectures. It was like being read the most fascinating bedtime story.
@@scottrobinson4611
Oh man that's luxurious and dangerous in double measure. I, not a morning person by any measure, would be utterly doomed.
17:07 the frequency signature (the particular sound) of an musical instrument can be recognized regardless of the amplitude of the signal, as long as it's at least partially above the noise floor. a violin and a trumpet playing the very same note are quite distinguishable from each other even at low SPL (different amplitudes for different harmonics).
to take it farther, even just by ear, we can recognize the voice of someone familiar to us if they're whispering or talking over a poor quality phone connection. w/ a lot of data missing, a pattern/ the voice signature can still be recognized. that's how i understand analyzing the faint gravitational wave signals.. :}
another great upload, thanks to everyone involved. truly enjoyable, wishing you all all the best.
i'm a musician and i can't believe i didnt make this comparison, thanks. though i'm a performer, not a sound engineer lol
Professor Copeland is such a great guy :) Always a joy to listen to.
I'm so glad that after watching these Sixty Symbols uploads for years they're popping out new stuff building on old stuff - it's like watching science in action!!! Who'd have thunk it?
On the Hubble tension at 16:10: "As long as you can pinpoint how far away the object is and the polarization of the light, then actually, the expansion rate of the universe will pop out. It will come out. It will be a direct measurement."
I wish Prof. Copeland could expand on that in a future video. I would love more information on how measuring the properties of these mergers can reveal the Hubble constant, and why this method is not constrained in the same way that the study of the CMB or supernovae would be.
I'm guessing how fast the universe is expanding will shift the light coming in, changing its wavelength. If you know the distance, you can measure the change in wavelength and determine the expansion required to result in that change.
That's one of the ways we measure the expansion rate today. We use type 1A supernovae, which always explode when they reach the same critical mass, so they can be used as a so-called "standard candle" throughout the universe because they are believed to always explode with the same luminosity (I read somewhere recently that there may be outliers in that data, but we can ignore that for now). We use that in combination with redshift to get one value for the Hubble constant.
My naïve understanding of the way we would perform this measurement with gravitational waves would be to derive the original energy of the collision, then measure that against the energy received to understand distance from us. Beyond that, every popular explanation I've read has been too hand-wavy to get anything meaningful out of it.
The way I interpret Prof. Copeland's words at 15:53 is that there is something intrinsic in that data that is not in the supernova data that could give a definitive answer, and that's what I'd really like to dig into. At 15:53, he says that the supernova and CMB data "rely on you understanding the cosmology of the system". And I totally get that for the CMB -- our understanding of the Hubble constant relies on our understanding on the CMB. I'm less sure why that is for supernova data, but regardless, I'd love to understand why all of the necessary data is self-contained in the gravitational wave signal.
@@tedsword there is still a chance the expansion is not uniform over time and or space. It was only 2 years ago that the accepted shape of our heliosphere changed (dramatically)!
My confusion is not about /why/ they are measuring it -- I'm sure that telescope time has been proposed with the James Webb Space Telescope, as well, to measure the Hubble constant, as well.
My confusion is that Prof. Copeland seemed to indicate that there is something about the gravitational wave signal that doesn't have a dependency on "the cosmology of the system", as he put it. But I don't see how the study of cepheid variables, type 1A supernovae, and other techniques to derive the Hubble constant have a dependency, either. I don't know what makes the gravitational waves technique more special.
I could listen to Professor Copeland for hours ...popped collar and all. ;)
This is what science is about. The way the professor humbly accepts that his theory is out based on new data, and is not married to an idea but knows to look at things in a factual way, is what we need more of in our society today.
true!
Well, you know, that's just the universe's opinion on the matter... ;-)
/s
I love listening to Ed talk about stuff. The twinkle in the eye when he's excited about something, it's so charming.
Sixty Symbols is one of the very best science news here on RUclips.
I do love it when you've been rewatching sixty symbols videos for the umpteenth times and a new one pops up 😊.
I love prof. Copeland. Literally love the man.
Always a pleasure to see prof Copeland
Excellent interview and very insightful questioning. Well done.
Professor Copeland is my favorite on this channel, I can listen to him for hours!
Tis guy is truly incredible. Wish I'd have had a single Prof like that.
this is my favoritest physicks professor
I can't pass up a video with Professor Copeland in the thumbnail.
Yeah!
the person in the thumbnail is the biggest deciding factor of whether or not I'll be clicking on the video in question
false.
I'm a simple man, I see Ed Copeland on the thumbnail, I click.
I really appreciate follow up videos like this. When the first detection took place, all the talk was about how this would open up the field of gravitational astronomy. It's so interesting to see now how it is starting to contribute to the field 🙏
Copeland has such a calmness. It has always struck me as a lovely presence.
3:01 "the lesbians bounce off the mirrors"
Sometimes I feel that the engineers and experimentalists don't receive enough credit.
Theorists gather more attention because is easier to make headlines.
*No credit besides salary. But isn´t that in most of society?
Ed! Glad you guys a posting again
Would love a video going over how another Hubble constant measurement pops out of these multimessenger measurements.
I think that Dr. Copeland is one of my favorite academics to listen to. When I hear him explain a topic, it makes me wish I had gone into theoretical cosmology so I could have collaborated with him.
Just an extra thing to add to the theories of formation, crucially we can measure how misaligned the spins are. If you imagine the BHs have a spin vector pointing up out of its axis of rotation, and similarly for the total angular momentum of the orbit, the angle between these vectors (tilt) can be measured using the LIGO data. We generally measure quantities that are dependent on tilt, not tilt itself because it's very difficult to directly measure. Misalignment and magnitude of the spins are important characteristics of different formation channels as they are called.
17:07 "How can we infer so much from such a tiny signal?" Thanks for asking this question!!
absolutely phenomenal work, amazing explanation
Great stuff!
Is there actually any explanation for even the minuscule 1.7s second difference in arrival time of the electromagnetic and gravitational waves?
Assuming the light was slower than the gravitational waves (because I don’t think they explicitly said so) I’d say smth like interstellar dust slowing down the X-rays. Space isn’t a perfect vacuum so it’ll slow the light down a little bit like any other medium.
When two neutron stars merge, they throw off neutronium in an excretion disk, which then decompresses and splits into heavy nuclei. Maybe it's the time it takes to form nuclei and electrons from throw-off neutronium.
My understanding is that it's a difference in when they're emitted. Different phases of the mergers are producing the electromagnetic and the gravitational waves, since the gravitational waves are produced leading up to the two objects actually making contact, but the light is (presumably) produced most brightly at the actual moment of contact.
maybe the gravitatioal waves got slowed down due to all the matter in their path bending space-time?
Beautiful visualization of how LIGO works!
Great video. Questions If you are on a planet that's let's say 2 light years away from 2 merging black holes. And say you do survive the radiation and all that, what would the gravity wave be like when it passes by?
Love Prof Copeland
Fantastic explanation. Inspirational!
I find it impossible not to love Prof. Copeland (I'm not trying mind you).
This video left me wondering: do gravitational waves get "red shifted"?
I missed Ed. Very glad to see him back.
Ed is the man.
I'm waiting patiently for the video about Bradyons.
Gosh! This is so amazing! When he explains it, he makes it look so simple.
Thank you for what you do.
What a wonderful man. Brilliant.
Interesting way of thinking about the relationship of strong gravity and small black holes. I read somewhere that the forces will be so weak for supermassive black holes that you won't even feel anything noticeable when you pass the event horizon.
Amazing! I always love the way he explains things. I could've listened for hours
Bradyons just means slow particles, I.E not travelling at C, meaning they have a real, positive mass, as opposed to tachyons, which have an imaginary mass and thus cannot travel below C. All stars are bradyon stars in that they're made of matter that is not travelling at C.
This is breathtakingly fascinating. Thank you for sharing this with us!
Mind blowing, seriously mind blowing.
Great video as always, fascinating stuff ! Video explaining the engineering behind LIGO would be amazing !
With three (or more) synchronized observatories, we would be able to triangulate the spatial origin of each event, right? This could be compared to the direction of the X-ray burst.
Yes. This is exactly what happened with the event in 2017 they referenced with the gamma ray burst coupled with gravitational waves. Three detectors triangulated a position and Fermi detected the gamma rays 1.7 s later.
@@jeffk8019 Ah, I see.. I thought the third one became operational only recently.
These presentations are superb well done
This dude is like the Bob Ross of physics. He always seems like a really wholesome guy.
yessss haha great comparison. both people could walk you through these super complex things in simple steps, until before you know it you’ve painted a fishpond or measured spacetime distortions.
Actually, if Bob Ross had lived, he would have developed enough to include space-time distortions in his paintings! I think he was already getting there...
I Need a prof Copeland in my life. I can listen hours to this man.
Awesome. I get graced with a fantastic sixty symbols video.
Guys, can you do something about the sound volume on future videos, please? I watch RUclips on my laptop and for softer-spoken interviewees it is sometimes hard to hear them, even at my max volume. A pity since Prof. Copeland has interesting things to convey.
Thank you, thank you, thank you!
Ed Copeland is always a delight to listen to but this one really felt special to me. The way he talks about an observation contradicting his own hypothesis that he was quite fond of with a smile and a laugh really shows the beauty and warm humanity of science.
He had worked, with others, hard on a hypothesis and a framework about some stuff and he was proud and excited about it. When there is date that contradicts it he faces it with a smile and excitement about new directions to take his research.
Today skepticism about science is on the rise but if more people spent more time listening to actual scientists like Copeland and less times listening to hate filled conspiracies on Facebook they might actually see the warm humanity and care that scientists put into their work.
Such a soft-spoken gentleman.
Very clear and sort of easy to follow. Well done stuff.
Great questions and answers! Thank you.
As I've gotten older, I've noticed a really weird thing. I'm getting....jealous...of people just being born.
Imagine...
I was born mid-70's and in JUST MY ONE LIFETIME, we've gone from launching the Voyager probes to contemplating and working towards an actual moon base. My mind just weeps at what is going to come once I've gone. AND I'm GOING TO MISS OUT ON ALL OF IT!!! -_-
Thanks for the amazing video, as always :)
Great answers and great questions, as always.
I love how the audio of the merger sounds like a bubble popping. It seems intuitively appropriate.
Wonderful video.
Not related to the video, I love the new channel icon
Thank you for this channel and the wonderful content. There is so much garbage and BS out there. 60 symbols gives me hope in humanity when they show the great work that's being done. Again, thank you.
At one point I was interested in what people believe when they talk about flat earth. Just to understand their view point. But the garbage I got recommended on RUclips was immense later on. I got rid of it by ignoring them for a while, so it doesn’t look like there is so much false theories going around.
@@Questerer if you watch something that you don't want more of in your recomendations, just go to history and remove every video related to the subject, it clears up a lot :)
@@tinyderppotato5410 I didn't know that was possible. Thanks for the reccomendation.
@@Questerer you can also click on the 3 dots next to a recommended video and choose "not interested"
At 22:00 a journal editor was quoted as saying the Beatles made only "limited contributions to cosmology." I would argue that the Beatles song "Across the Universe" is a significant contribution.
Words are flowing out like endless rain into a paper cup
They slither wildly as they slip away across the universe
Pools of sorrow, waves of joy are drifting through my opened mind
Possessing and caressing me
14:24 Despite the merged event horizons, you can actually tell by the still perturbating (perturberating ?) lensing, that even though
the event horizons have already become one, the orbits around each other's center is still happening
for at least 6 or 7 more orbits, but after that settles, there's no more, which means that the cores have now made contact.
this then allows for actually telling the size of the cores.
Now if there were also other types of detection on this particular event, which would maybe show an expression or
outburst of high gamma particles, or a plasma stream starting to go outward, that would have been nice too.
These could then be played simultaneously, with the timing synchronized by their center motion timing.
If only that video cut was a little longer., because even at the end of it there was still motion in the lensing.
It must be a truly exciting time to be an astronomer/astro-physicist
Does this suggest that once we develop sufficiently sensitive detectors, there will be infinitely many signals detected? I'm imagining a constant white noise of low amplitude gravitational waves, with ocasional, or maybe periodic, higher amplitude events.
Incredible stuff
Isn't the radius of the proton more like 1e-15 m so 1e-13 cm rather than 1e-18? Other than that, very cool video, as always!
I noticed that too, I think the professor got mixed up with units!
you're right
3:41 _"The distortion that we expect to arrive from these gravitational waves, which just to remind you, have typically come from a pair of BH which have been orbiting each other a billion years ago, coalesce together; it's been travelling for a billion years at the speed of light; passed through the detector; it distorts the detector by 10ᐨ²¹ cm. The size of a proton is 10ᐨ¹⁸ cm. This is a thousand times less than the radius of a proton."_
Wikipedia says:"2 different studies found the radius of the proton to be 0.833 fm, with an uncertainty of ±0.010 fm"
femtometer = a unit of length equal to 10ᐨ¹⁵ meters
0.8 fm = 0.8 x 10ᐨ¹⁵ m ≈ 1 x 10ᐨ¹⁵ m
to convert 1 m to centimeters we multiply by 100
=> 100 x 10ᐨ¹⁵ m = 10ᐨ¹³ cm
8:05 The x-rays that arrived 'late' had sleight bends to them by gravity source, except for
the ones that were from the source adding a sleight bending to them increasing their
path length by 510.000 over the distance of 300.000.000 LY.
The greater the frequency of the detection method the less bending, unlike light,
which may also have been capturable a few minutes or even hours later,
dependant on the amount of bending added.
It would be neat to have a full dataset on a phenomenon, ranging from gravitic to gamma, to light, to radio, etc.
The more there is the less speculation and less "I wish we had .as well"
9:06 You were right expecting that the different detection methods yield different ATA's., except
that the difference was really small for x-ray vs. gravitic, but did you also check for gravitic vs. light ?
Hubble constant:
Cepheid:73.4
Background: 67.4...
Grav waves:54.5 ...
Cosmologiests: 😱
Thank you, for all science and explanations of said science!
I never quite got how the mirror displacement measure isn't canceled by the light also conforming to spacetime bending, ie the mirror and light inside the spectrometer arm should deviate the same, so no net difference.
I haven't done the calculation myself, but it's probably not too hard, at least in a weak-field approximation, to calculate how the phase of the light wave at the detector changes depending on the current stretching or contracting of the space along the arm. They then probably work backwards from that to get the gravitational wave amplitude.
The 'trick' here is that the light doesn't behave that way. If gravitational waves just changed 'distance' there'd be no way for them to interact at all, they'd be totally undetectable. Fortunately for us their warping of space affects some things but not others. (This is amusingly known as the 'Sticky Bead Argument') Roughly stated, the mirrors notice the change but the light between them doesn't.
its not the mirror that is effected it is the length of the legs/arms, the observatory is JUST continuously measuring the change in their length.
Great information
Great Video
He has one of the best unintentional asmr voices
Great discussion!
Such a great job to have
More Ed. Nuff said!
I really love the acapella science video on LIGO
20:03 At LIGO they create raw data by measuring gravitional differences.
This is filtered, so only the usable part remains using high powered data crunching computers.
The timing difference in the both data streams gives an angle at which this overlap occurs.
That means that with such an overlap you know can plot a line towards the phenomenon from Earth.
The scrubbed data can then be interpreted with the variations, and now you know of large masses in motion
with the vibrations showing an orbit, which correlates with the freqency of those deviations.
They are orbitting, but also their mass sizes, their speed, their distance from one another.
Then you let the thing play out, and from the motion you can now re-create a 3D model,
which accurately shows both objects in motion, despite both's event horizons.
When this data is merged with other types of detection and synchronized, you can then also
tell the size of the event horizon, and by overlaying the trajectories of the objects you can also
see motion through the lensing effects, that may occur just that bit longer than the sensitivity
of the gravimetrics have reached their limit and thus tell you the physical dimension or at least
get a close approximation of such, with greater detail than current gravimetrics allow.
This all then is achieved through Multi-Messenger Astronomy which combines or cooperates
in such a fashion that all possible data that can be collected also is collected, emphasis is,
and also is collimated into one single data source, which subsequently tells a whole
lot more than just a single data source about said phenomenon.
Once the full array of data collectors (telescopes) are in play you'd ahve more than enough
data to make very intricate conclusions on just about anything happening in the Universe,
after watching a few events, which then harden as predictions either get proven or disproven
upon repeated observation. That is explorative astrophysics at it's very finest.
The description of receiving a "chirp" and then correlating/comparing it to templates sounds a lot like how modern radars work, so the principle makes sense. But in this case, the signal levels involved are staggeringly minute!
Can gravitational waves pass through a black hole, or are they swallowed?
If they pass, would this not mean, that within the BH can be produced gravitational waves which leave the BH and thus pass information to the outside of the event horizon?
Especially in large black holes this would technically possible, since they do not spaghettify.
please someone answer this question it's awesome!
@@nmarbletoe8210 I once found an answer somewhere, stating that no, they don't pass through the black hole. Which is explicable, since the amplitude of the gravitational wave is always very small compared to the huge gravity of the BH.
I don't remember the details, whether it is reflected or absorbed. But maybe the wave behaves similar to a water wave encountering a vertical pole in the water. The pole surface might be corresponding to the event hotizon.
@@rex_rabbit Cool cool cool! A photon can't fall into a black hole if it's wavelength is bigger than the hole's radius! So I read.
Maybe it's the same with grav waves. They get absorbed if their wavelength is smaller than the diameter of the hole, other wise they refract.
And if they the wavelength is much much longer than the diameter, they basically pass by the hole little effect since the refraction gets smoothed out.
@@nmarbletoe8210 Nevertheless, keep in mind that photons are attracted by gravitation, while gravity waves are not.
@@rex_rabbit Actually I'd expect that they would both follow null geodesics... idk
Isn't that (LIGO) the same setup as the old Michaelson-Morely experiment?
14:38 If a black hole has significant spin, it's the result of a large scale merger,
since that merger itself preserves some of the motion in the spin, with a high degree of certainty.
If it has little, it probably never merged with something similar sized.
The spin is the result of two objects similar in size and mass, that orbit each other before merger.
If no such orbit happens, it means that the object it merges with simply crashed close to the center,
and leaves very little spin.
Basically guaranteed spin is similar sized black holes merging after orbiting around a common center
outside of both black hole's event horizons.
Joke.
Two black holes merge to create a new bigger black hole.
What did they do when I tried to peek ? They closed their event horizons saying "u-p-erv."
don't understand it all but I love it
Misheard 11:55 and thought Prof Copeland said "merged into it, yeeeten by it".
(So burned in on neuron rom now, ready and loaded to use if the conversational opportunity presents itself. "Oh no they got Yeeeten!")
More Copeland plzzzzzzzzz
What a nice guy Mr Copeland, and he know his physics!
When bh’s collide, is the information in the mass loss from the coalesced bh’s encoded in the gw’s?