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The Largest Black Hole in the Known Universe

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Re: The Largest Black Hole in the Known Universe

#41
post #30

Well, I'm having a nice big existentialist crisis right now having being reminded of our place in the universe. I'm going to go pour myself a whiskey and hug my kids. G'night everybody.

Maybe a quote by David Deutsch will ease the pain:

"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."

Re: The Largest Black Hole in the Known Universe

#42
post #22

Here is the one thing that really keeps me awake at night: what if our science was the equivalent of a bunch of ants in a typical ant hill in anyone of our backyards, defining a mechanism or "method" through which they have explained for themselves the nature of the solar system? That's the one thing. And I can't shake it off.

dont let leorocky get you down. 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 afte…

This doesn't make me wrong about science, it's just that by then it will be will not have the data to figure out what happened. You can't see the other galaxies anymore. That's not a problem with science, that's a problem of insufficient data. It may be the case an intelligent could figure things out by looking at the evidence available to them within their finite, expanded universe. Space will still be expanding, there will still be red shift, there will still be gravity. And science will be the tool to use to figure this stuff out.

Re: The Largest Black Hole in the Known Universe

#43

Here is the one thing that really keeps me awake at night: what if our science was the equivalent of a bunch of ants in a typical ant hill in anyone of our backyards, defining a mechanism or "method" through which they have explained for themselves the nature of the solar system? That's the one thing. And I can't shake it off.

Well, for one thing we haven't found any other anthills and that's very weird. Other than that, just

      Stay Calm
         and
  Keep Doing Science
until you've scienced everything. The analogy with ants is weird, in that ants don't seem to be sentient and don't appear to have ant scientists that are trying to understand the mysteries of the universe. That makes it a bit hard to answer you on the level of the analogy, as such an answer would need to start with "assuming ants were sentient and had physicists, ...", from which point on the rest would be pure anthropocentric conjecture. We humans are a bit unique in that there are individuals who go "well I'm bored, guess I'll go observe the sun, moon and other bright discs in the night sky for decades and record their movements as precisely as I can, so that some other person, most probably of a race I've never seen from a place far beyond any horizon I've viewed, can read them centuries later and use them to come up with a heliocentric model of the solar system and from there on other mad toffs with nothing better to do could come up with the theory of gravity or something".

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.

Re: The Largest Black Hole in the Known Universe

#44
post #25

It not the complete list: http://en.wikipedia.org/wiki/List_of_most_massive_black_hole... 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-t…

I believe black holes can be treated as normal astronomical objects outside their event horizon. The weird singularity behavior only applies within the event horizons.

This is pretty much true. You could replace our sun with a black hole of the same mass, and nothing would change in terms of planet's orbits.

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.

Re: The Largest Black Hole in the Known Universe

#45

It's interesting that this has made it to HN! My research is on the dynamics of few body systems so I know OJ 287 well! One of the projects I've been wanting to work on but haven't gotten around to is about this system. As the article mentions, OJ 287 is strange because it is a blazar (which is very rare, since the outflow has to be pointed directly at us) and is in a binary (which is also rare), yet it also happens…

Its good to see more Astrophysicists using HN. I am very much interested in studying the workings of the cosmos, but I am not a professional degree holder in space science. I do freelance software development, but want to catch up with astrophysics too. Is it possible?

Re: The Largest Black Hole in the Known Universe

#46
post #41
post #30

Well, I'm having a nice big existentialist crisis right now having being reminded of our place in the universe. I'm going to go pour myself a whiskey and hug my kids. G'night everybody.

Maybe a quote by David Deutsch will ease the pain: "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 p…

A cow is still well within the realm of dimensions that a human mind can comprehend. You won't feel insignificant when looking at a cow because while bigger, it's not that much bigger. Apart from poisoning you when you eat it, or kicking you by mistake, it has relatively little influence or impact on you, your life, your fate, or indeed, the fate of the human race.

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.

Re: The Largest Black Hole in the Known Universe

#47
post #46
post #41

Earlier quoted context omitted.

Maybe a quote by David Deutsch will ease the pain: "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 p…

A cow is still well within the realm of dimensions that a human mind can comprehend. You won't feel insignificant when looking at a cow because while bigger, it's not that much bigger. Apart from poisoning you when you eat it, or kicking you by mistake, it has relatively little influence or impact on you, your life, your fate, or indeed, the fate of the human race. Now, if you had a cow the size of the earth, that ju…

For me, it is the opposite. If the world was small, I would be sad to be a part of a small un-awesome world. Looking at how big the world is makes me happy and excited.

The difference I guess comes from whether you see yourself as a part of the universe or as an observer separate from the rest of the world.

Re: The Largest Black Hole in the Known Universe

#48

Earlier quoted context omitted.

I looked it up! "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]" https://en.wikipedia.org/wiki/S2_%28star%29 Edit: wait that's not it, that…

Interesting tangent: when there's a binary star system that gets very close to this black hole, the three can interact in a way that one of the two stars falls in, while the other steals its gravitational potential and is ejected at extreme speed. There's a few "hypervelocity" rogue stars in the Milky Way, which were probably accelerated by the black hole. They're on escape trajectories leaving the galaxy. https://en…

Wow thank you for the second link. That was really interesting read.

Re: The Largest Black Hole in the Known Universe

#50
this smaller black hole should precess at 39°-per-orbit, and should inspiral in to the larger one in a timeframe of just a few thousand years!

So we are just incredible lucky to be here at this moment to have observed it? Fascinating.

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