Black Hole Mergers and Multi-Messenger Astronomy - Sixty Symbols 

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.

Really wish I could find some extended lectures of his.

true!

Well, you know, that's just the universe's opinion on the matter... ;-) /s

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.

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

Ed is the man bro

Collar up is the only way to rock a polo neck!

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.

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?

Theorists gather more attention because is easier to make headlines.

*No credit besides salary. But isn´t that in most of society?

Mr. Ed, your ability to explain these incredibly complex ideas sets you apart. While maybe not to Feinman’s level but close!!

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.

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.

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...

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 RU-vid 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"

The destructive interference prevents the energy transfer before it can occur.