That's the one thing. And I can't shake it off.
There is nothing to shake off when it comes to science. If good science led us to wrong answers it is because of insufficient data, bad process, and human error. Science is the best tool we have ever created. Just look at your smartphone. The transistors in that thing are not individually visible with the human eye but you can post your selfies to snapchat just fine right? Right. Those transistors are measured in nanometers.
Stay Calm
and
Keep Doing Science
There is no reason to believe we will never ever find out some fundamental properties of the world, given enough time. If something exists, it can be interacted with and if it can be interacted with, it can be studied. If we can't interact with it ourselves, we'll make machines to interact with it. If we cannot make machines to interact with it, we'll study the results of other things interacting with it that we can observe. If it cannot be interacted with in any way via any method, its existence is largely a philosophical question.
It can be argued that we don't (and won't) have the absolute most simple, exact and perfect formulations for the rules of nature, but arguing whether those rules have a one true form and if there aren't equivalent ways to state them is again a largely philosophical question.
if the universe keeps expanding, eventually it will expand at the speed of light and everything that is not gravitationally locked with us (wich only includes the milky way and about 5 or so other galaixies) will be moving faster than the speed of light and will be impossible to observe in any way.
in a sense, it means leo is actually wrong. if an intelligent race comes into being after said event, it could be true that no amount of science will ever be able to show that the rest of the universe existed. that also means some other phenomenon may have occurred that will make us as just as useless at understanding what happened as ants are at knowing/exploring the stars.
that is, if certain theories about the expansion of the galaxy is true.
Of course, the ones in your backyard typically don't do that. Those are like boring human villages.
Are we sure that Einstein's law of gravity is the really 'correct' one or the 'last' one we will discover? Nope. Indeed, that doubt is part of why the article got so excited about using one black hole orbiting another one to "test" Einstein's law of gravity. We keep testing that law because we will learn something, either (1) something doesn't fit and we have to ditch the law or (2) the law fits and we gain more 'confidence' in the law.
You can look at it this way: The stuff we 'accept' now is what we have dreamed up and that has passed some apparently 'significant' (don't mean statistics here) tests and so far never really failed a test. Net, stuff 'accepted' at present is what appears to work so far.
But, in physics and cosmology, we have some issues that, at least intuitively, appear to be potential biggies: (1) What happened before the big bang? Can we get some clues from the data we have on what might have happened before the big bang -- some physicists have tried to look. (2) What's with this stuff about dark energy and dark matter? (3) Why does it appear that there is much more matter than anti-matter? (4) What's with neutrinos and how they 'change'? (5) What can we dig out of 'spooky action at a distance', that is, Einstein–Podolsky–Rosen (EPR) paradox?
So, maybe more progress understanding one of these biggies will cause us to ditch some of our currently 'accepted' results, look for, and maybe find some new results.
Could everything we have seen so far be just some light show put on just for our amusement? We can't say. So far, it appears that somehow mathematics works shockingly well; why? We don't know.
That there is a law of gravity that works as well as even Newton's might be seen as surprising. That is, why doesn't the 'law of gravity' change each 10 minutes? Well, some things do change 'randomly', and for them the only laws we have are probabilistic. Newton's law is not probabilistic because so far it appears to work the same yesterday, today, and tomorrow, that is, doesn't change. Or our science is what we have found that in some important sense doesn't change, e.g., we can 'reproduce' results. Why are such results possible? Not at all clear.
Even if what we are seeing is just some light show for our amusement, still we get some utility, e.g., via applications to engineering, etc. So, the Internet works because Maxwell's equations of electro-magnetism continue to work as they have for 100+ years now.
> And I can't shake it off.
Relax and enjoy the light show or whatever the heck it is. There's a lot to be amazed about, curious about, etc. And we really do make progress, astounding progress. E.g., we've made a lot of progress since I studied physics i college. The math I studied has been more stable!
On a related note, I never understood how a black hole (or frozen stars like the Russians call them) could potentially orbit or be swallowed by another black hole. If they "infinitely" deform space-time, shouldn't they be unable to move at all? If time stands still past the event horizon as they say and they also rip the space-time fabric so much, they shouldn't be able to "get out of the hole". This is just too mind-bogging for me I guess.
The image of a black hole "sucking" things in like a vacuum cleaner is hugely incorrect. I think this perception comes about from the funnel image we often see representing black holes.
But I greet the new legend about Russians that just born here!
The term "frozen star" has certainly been used for black holes. If you Google both terms you'll find an article from 1971 called "Introducing the black hole", by Ruffini and Wheeler, which mentions that term. (It doesn't say anything about Russian obscenities, though.)
TL;DR: blackhole mergers are really rare, because one often kicks the other out.
with that being said, it would seem to me that yes, black holes can move, our milky way is not stationary, and black holes have been known to have very fast rotation speeds.
The reason that OJ 287 has to be so massive in this model is because the orbit of the secondary black hole precesses so rapidly. For GR to give you that precession rate, you need a very, very massive black hole.
An alternative model I would like to explore is a three-body model for OJ 287. If this black hole binary is orbited by a tertiary black hole, the tertiary can also induce precession in the inner binary, so OJ 287 would not need to be so massive, which would make the triple model more plausible. It's unclear yet whether the triple dynamics can reproduce the observed lightcurve of OJ 287, though, so this is just an idea that's been on my to-do list for a year now. Let me know if you have any questions!
The thing about astronomy is that it changes quickly, but not that quickly. The timescale for major changes in our knowledge of astronomy is perhaps ~10 years or so (that's usually how long it takes a big problem to be solved), so it's not as though it's something you need to keep on top of every day or every week. (Unless you're a professional astronomer and want to be aware of all the new papers coming out.) As a consequence of this, textbooks are a good place to start for background. There are tons, but Carroll & Ostlie is a good general introduction to all aspects of modern astrophysics. Each chapter also has general and technical references so you know where to go to learn more about any subjects that you find interesting.
For discussions of current problems in astronomy, the journal Annual Reviews in Astronomy & Astrophysics is a good place to start. Current articles are paywalled, but most of them appear on arxiv.org, so you can search for them there. They contain summaries of all the recent research on a particular problem. If you're interested in learned more about that particular problem, they're a good place to start because they'll point you to all the important papers on the subject.
Another good resource is ADS. You can search for papers here: http://adsabs.harvard.edu/default_service.html You can search for specific papers, or just search for papers with a particular keyword in the abstract or title. There's a handy feature that lets you sort by citations so that you can easily find the most influential papers.
Finally, you can find the newest papers here: http://arxiv.org/list/astro-ph/new About ~50 new papers appear here every weekday. It's a lot to keep up with even if you're a professional, but it can be useful to skim the titles every now and again and see what looks interesting. The introduction to astronomy papers usually acts as a sort of mini-review article. It'll review the problem that the paper is examining and will reference other papers that have looked at this problem. So from reading introductions you can get some background on the problem and the ways that astronomers have been trying to solve it -- and it's a lot shorter than a full review article!
Some of the problems may seem somewhat opaque if you don't have the necessary physics background, but not all of them are, so don't get discouraged! Or if that inspires you to learn more physics, so much the better!
I have no other knowledge, but just from the information in your comment, can we test the low prior assumption?
Would this bh still have been identifiable as the most massive known, if it did not have both of the following characteristics?
- blazar, pointed directly at us (makes it noticeable)
- binary, (makes it measurable at such a massive scale)
I was a little disappointed that the article ended with speculation though. Given the title, I was expecting something more concrete. But I guess I should be grateful that the author didn't feel the need to sensationalise the truth for the sake of narrative (like so many reporters do these days).
I think StartsWithABang is an excellent read: entertaining iand informative. One of the few blog-type-things I follow anymore.
In case anyone's curious: The double-quote is an arc-second. When measuring angles, a single quote is an arc-minute, which is 1/60th of a degree. An arc-second is, of course, 1/60th of an arc-minute. Rifle accuracy is measured in minutes of arc, with 1' being about an inch diameter circle at 100 meters. Proxima Centauri has a parallax of about 0.8".
To give you an idea of how far away Proxima Centauri is, we can scale everything down. A light-year is about 63,240 AU. A mile is 63,360 inches. So if Terra was an inch from Sol, Proxima Centauri would be about 4 miles away. The parallax from Proxima Centauri is the same as if you looked at an object 4 miles away, then moved your head 2 inches laterally. That's 0.8 arc-seconds. That's the second-closest star to us.
https://en.wikipedia.org/wiki/Parsec
https://en.wikipedia.org/wiki/Hipparcos
https://en.wikipedia.org/wiki/Gaia_%28spacecraft%29
This is the lowest rung of the "cosmic distance ladder":
https://en.wikipedia.org/wiki/Cosmic_distance_ladder
https://terrytao.wordpress.com/2010/10/10/the-cosmic-distanc...
"Given a recent estimate of 4.3 million solar masses for the
mass of Sagittarius A* and S2's close approach, this makes
S2 the fastest known ballistic orbit, reaching speeds
exceeding 5000 km/s (11,000,000 mph) or 1.67~% of the speed
of light and acceleration of about 1.5 m/s2 or almost
one-sixth of Earth's surface gravity.[7]"
Edit: wait that's not it, that's S0-2, but you're talking about S14/S0-16:
https://en.wikipedia.org/wiki/Sagittarius_A*#Central_black_h...
From those parameters, its perihelion speed would be about 8,200 km/s (2.7% c), using the classical approximation.
https://en.wikipedia.org/wiki/Perihelion#Mathematical_formul...
https://en.wikipedia.org/wiki/Stellar_kinematics#Hyperveloci...
"In the Sun, radiation pressure is still quite small when compared to the gas pressure. In the heaviest non-degenerate stars, radiation pressure is the dominant pressure component"
"Some people get depressed when they find out how huge the universe is. They feel tiny and insignificant and think that nothing matters in this world.
That makes no more sense than getting depressed when you find out that cows are bigger than you. What is the big deal about bigness? A cow is much bigger than you, but it is a ridiculous animal and you are a valuable person. You know it’s a cow. It doesn’t know anything. it just stands there eating grass (grass!) and mooing. And if it were bigger, that would only make it more ridiculous."
Now, if you had a cow the size of the earth, that just sits there and eats cosmic grass, and could blow up earth and wipe out the human race with one of its farts, then suddenly the cow is rather more significant than it was before - if only because of its possible influence on you.
Finally, if the said cow is in fact not just an object but the very substrate that you exist in, and its so big that you can't even begin to imagine how big it is, and it is filled with inhuman processes that could wipe humanity out at any moment from now to infinity, then a solid sense of insignificance seems perfectly warranted.
Also, helps to remind me of how cosmically tiny the problems of building my SaaS product really are.
http://www.nasa.gov/images/content/136063main_bm4_high.jpg
Then to get an astronomically bigger picture of just how small we all are, I start getting dizzy at even the thought.
So we are just incredible lucky to be here at this moment to have observed it? Fascinating.
Is this black hole pair likely to be two galactic cores that collided, and captured each other due to some sort of inelastic interaction (maybe ejecting stars out?) and their surrounding galactic matter got eaten up due to basically the three-body problem?
