@CRDrost afaik the best astronomical observation/ measurement of black holes so far, other than LIGO, is a bunch of wobbling stars near the center of the milky way galaxy... announced not too long ago...
You always see these black spots in the simulations showing where the black holes "are," but if they're surrounded by radiating gas clouds I think it would make things look super-interesting and even pretty. I have a sneaking suspicion that if we actually get to look at a black hole it'll look nothing like those early simulations due to all of this infalling light and matter and stuff...
I'm also interested in the x-ray stuff because presumably it gets redshifted into some sort of rainbow trail as it comes from further and further down. :D
Hughes cautions that scientists are only just learning to understand this new language—the warbling that codes for spin could be inaudible if both black holes spin the same way. “There are homonyms,” he said, laughing. “Two sources can say different things but sound exactly the same.”
I don't know exactly because my university was really strong in condensed matter (TU Delft), I didn't get to do much work with computational astrophysics visualizations. :(
user54412
@EmilioPisanty The PRL paper seems to have a very clean picture of a waveform
@Danu I was working as a colloid scientist, and we were looking at depletion flocculation of emulsions and suspensions by the sort of polysaccharides used as thickeners in food.
@ChrisWhite Doh, of course. Now I look more carefully their paper says:
Using the fits to numerical simulations of binary black hole mergers in [92,93], we provide estimates of the mass and spin of the final black hole, the total energy radiated in gravitational waves, and the peak gravitational-wave luminosity
@CRDrost it possible that black holes "rarely" swallow stuff or are caught in that act and that usually stuff is just "circulating/ orbiting nearby"...?
@vzn: I don't know. I guess another way to ask that question is, "is it possible that there are a lot of invisible black holes in interstellar space where there's not very much to accrete?" and the answer is probably "yes, if they're small enough that we haven't really seen them."
Any black hole with a certain size will have a radius outside the event horizon where there are no stable orbits, so you expect to be able to see stuff which falls in because it comes too close.
@CRDrost what was your masters on? seems like its either pass/ fail, thats the main thing... perfect is the enemy of the good...
@CRDrost another (contrarian) idea (afaik not contradicting any observations/ theory) is that black holes are mostly at center of galaxies, holding them together & rarely seen alone outside of them.
another interesting related question is "how many galaxies do not have black holes at center, and how are they different from ones that do?"
@vzn: I wrote a thesis about a vibration-modulated electron transport junction which did not seem to be generating, in my simulations, the normal vibrational "sidebands" you'd see from quantum mechanics. This made it very interesting as those vibrations could be weakly measured via transport but were protected from otherwise entangling.
Then after my thesis I stayed on for half a year to try and turn it into a paper. During that I discovered a crucial flaw in the thesis -- the thing which everybody uses to measure electrical properties was, in my case, not the right thing to look at for those measurements anymore.
If you look at the right thing you find out that actually there are these sidebands and the whole system is far more boring.
@CRDrost agreed over long periods stuff is falling into black holes (basically how they form in 1st place), but the question is, how often? all stellar objects have lifecycles...
Recently,and my browser and configuration have not changed, hardly any maths formulas are exhibited in the question. Sometimes there is not even a red phrase about an error...nothing to indicate that the formula or symbol is missing. Has the site changed its rendering or something?
And th...
J. Heefner (LIGO CalTech, d. Apr 2012), R. Schilling (Max-Planck-Institut, d. May 2015) and C.V. Torres (U.Texas Rio Grande Valley, d. March 2015) were given posthumous authorship credits.
@hubot The point of that tip is that wanting to understand a certain idea will motivate you. The entire purpose is lost if someone else tells you what idea to understand.
@dmckee As one of my profs used to point out, everyone keeps saying supernovae are the most luminous things in the universe, but BH mergers in fact emit 1000 times more power in gravitational waves.
@JohnRennie Oops. You are right. Gravity waves are very different. The contexts are very different. Is there a gravity wave in space, separate from gravitational waves? (not the fluid mechanics gravity wave....)
If someone were to write a self QA explaining thermodynamic "potentials" starting from statistical mechanics, and explaining the meaning of exact and inexact differentials etc. from a someone mathematical perspective, I'd drop a bounty on it.
The hype of the announcement last night caused me to dreamt about millimetre gravitational waves (as said in the dream).
After waking up, I then translate this into the usual language used to describe the gravitational wave spectrum (i.e. in units of time) and I got femtosecond gravitational waves
However I am not sure if there are any sources that can potentially produce that, whether they can in principle be detected (because it is oscillating too fast) and whether they can actually be produced (since the GW detected by LIGO is from black holes that are already travelling at near 0.5c
How to prove this rigoriously by experiment or prove it with other mechanics law but without the chain rule?
Also please explain what this is term by term since i don't quite understand what this seem to be simple formula is.
If I still cannot googled up some answers, or calculated something >c (thus showing they are impossible to be produced) for my curiosity, I am going to write that millimetre gravitational wave question later on the PSE
but for now I have 10 mins before I must go to a symposium in my uni
@0celo7 Well, as you may recall, curvature does determine the sum of the internal angles of a triangle, for example, so this flatness already says that triangles have the usual 180°.
Recently,and my browser and configuration have not changed, hardly any maths formulas are exhibited in the question. Sometimes there is not even a red phrase about an error...nothing to indicate that the formula or symbol is missing. Has the site changed its rendering or something?
And th...
How to prove this rigoriously by experiment or prove it with other mechanics law but without the chain rule?
Also please explain what this is term by term since i don't quite understand what this seem to be simple formula is.
