Two black holes

[quixata]

I have minimal idea about black holes.
While going through the posts on this subject, this question came into my mind.

Obviously, black holes are not static in the universe.
So, just like two celestial bodies colliding, two black holes may collide.
What might happen in such a case?

[wendy]

They join and become one. The new one has a radius equal to the sum of the two colliding black holes. The resulting surface is therefore the sum of squares of the radii, and therefore the resulting black hole is hotter.

This actually belongs in the 'relativity' section. which should be cosmology and relativity.

W

[Keiji]

This actually belongs in the 'relativity' section. which should be cosmology and relativity.

Moved :wink:

[Marek14]

One little correction - bigger black hole is COLDER, not hotter. Black holes get hotter as they shrink, thanks to Hawking quantum evaporation (particles escape more easily from smaller holes).

[wendy]

i was thinking that the surface area of a black hole behaves as a thermodynamic temperature, so the larger ought be hotter.

But then i don't intensely study that subject much past what is needed to make a weights and measure system for it (especially in ft/lb/s system).

[beehive]

online scam - [removed]

-beehive, nullspace spammer

(Edited by jinydu for better accuracy)

[Another IP address banned. Stupid spammers.]

[faranya]

Wouldn't black holes have different masses? If they did, couldn't parts of the black hole be torn apart, and possibly slungshot away from the point of collision farther into space? But of course, I have no theorys or formulas to support this, just a thought

[jinydu]

Wouldn't black holes have different masses? If they did, couldn't parts of the black hole be torn apart, and possibly slungshot away from the point of collision farther into space? But of course, I have no theorys or formulas to support this, just a thought

Sorry, but physics is all about formulas :wink:

[thigle]

sorry, but physics is NOT ALL about formulas. just jinidu likes to think that the way he likes it is the way it is by itself.
consider galileo, for exemple. and newton was at least half-alchemist. archimedes' heureka! was not due to formula, but due to his realization of relationship. einstein always thought without formulas & non-verbally. only when such meta-thoughts became clear and meaningful by themselves, THEN he started to verbalize them - i.e. formalization comes naturally after meaning is clear.
imagination is often enough for understanding physics. for ex., galileo's refutation of archimedes' theory that falling body is fast relatively to its weight was through thought-experiment: imagine throwing a half-cracked brick down from a tower. on its way, it splits. now both parts have half-weight. do they fall down at half-speed now?

i just cannot stand unprecise categorical statements.

[faranya]

Yes, but back to my statement about the black hole...could that happen?

[thigle]

actually, i think it was already stated down the thread: they join. so they're not "...torn apart, and possibly slungshot away from the point of collision farther into space...", but sucked together and slungshot INTO the point of collapse, not farther into space, but deeper into, or THROUGH space.
but the story is unclear about how do these objects behave at extreme possible parameters. it is an area of uncertainty. this is a qiestion of underlying assumptions on the nature of space - continuous or not ?

but then, i don't study blackholes, they just pop into my field of interest now & then...

[wendy]

two black holes would eventually become one, but it would be somewhat hotter, etc. Black Holes have some strange properties:

Were two black holes to join, their diameter would become combined, so a 2 mile black hole + 4 mile black hole = 6 miles.

The surface area is proportional to some thermodynamic thing, and this is in part what stops black holes gobbling things up straight away.

2 mile diam sphere has a surface area of 8 circ miles
4 miles diam sphere has a surface area of 32 circ miles

before joining, they have a surface area of 40 circ miles

after joining they have a surface area of 72 circ miles.

i am not exactly sure what this exactly means, but black holes tend to have accretion disks etc, and simply do not just gobble up whatever comes along.

[PWrong]

sorry, but physics is NOT ALL about formulas. just jinidu likes to think that the way he likes it is the way it is by itself.

If it's not all about formulas, it should be. What have you got against formulas anyway?

consider galileo, for exemple. and newton was at least half-alchemist.

He also invented calculus, which really is all about formulas. Alchemy was considered a proper science back then, and it led to a lot of developments in chemistry. Now of course, physics is the only real science, maths is an art, and chemists are obsolete thanks to Schrodinger's equation.

archimedes' heureka! was not due to formula, but due to his realization of relationship.

Do you mean this relationship?
B = pVg

einstein always thought without formulas & non-verbally. only when such meta-thoughts became clear and meaningful by themselves, THEN he started to verbalize them - i.e. formalization comes naturally after meaning is clear.

No, he used formulas. Otherwise he'd have no evidence for his ideas. Also relativity simply doesn't make sense without them. The maths in special relativity is surprisingly easy: just multiply everything by gamma. The hard part for everyone, including einstein, is understanding what's going on.

If they did, couldn't parts of the black hole be torn apart, and possibly slungshot away from the point of collision farther into space?

Well, the "slingshot" effect does happen in Newtonian gravity. It's called a hyperbolic trajectory. I doubt a black hole could ever be ripped apart by another black hole, but maybe the event horizon would stretch or something. I guess you'd get a kind of ellipsoid surrounding the two black holes, from which light can't escape.

[thigle]

i didn't state anything against formulas. just that physics is not all about formulas. whether you or jinydu or whoever thinks that physics should be all about formulas, is not relevant to physics as it is. physics is a natural phenomenon.
galileo not only didn't invent calculus. what he did (re)invent, was telescope. which wasn't all about formulas.
if you think physics is today the only real science, then what is your conception of real ? math isn't art, it just shares certain of its attributes: it is heavily structurally coupled with art. but it's not art. if you state it is, you either overestimate physics, or don't realize art. alchemy was not considered proper science back then as it is not today, by the same regions of socius.
you ask if your formalization of relationship is what i mean ? no. i stated what you quoted. no more or less. please re-read it and think if your formula is a meaningful question or reply to the meaning of what you quote (starting 'archimedes...').
on einstein's thought: visual is hardly exclusively formulas, if they pass at all. and all i was trying to say, on the issues not concerning 2 black holes, is expressed well in einsteins words, from John Conway's net-posting, (which,btw, i think is contradictional or unprecise. he ain't getting his structural differential very much. einstein says play first then labor. conway says let's not play much or we might look silly and get nowhere, rather stick to naming and be effective. he's all about power and shit)

"
Here's a quote from Einstein about his "visual thinking."

"The psychical entities which seem to serve as elements in thought are certain signs and more or less clear images which can be 'voluntarily' reproduced and combined...The above mentioned elements are in my case of visual and some of muscular type. Conventional words or other signs have to be sought for laboriously only in a secondary stage, when the mentioned associative play is sufficiently established and can be reproduced at will." (quoted in Jan. 1985, Byte, p. 114).

Subject: REPOST: Re: Question Concerning Buddhism
Author: John Conway <conway@math.princeton.edu>
Date: Mar 2 19:54:14 1994
[Originally posted Wed Feb 9 22:09:58 1994]

I myself think names are pretty important things - in mathematics at least there is what I call the ju-ju principle : one gains power over an object by knowning its name. The power comes from the ability to "summon it up" to the mind quickly, and think and communicate about it efficiently.

So I think it is VERY important to name lots of things, and I spend a lot of time trying to ensure that the names I use will be suggestive ones, that help for instance to "summon up" the properties of the object just as easily as we summon it itself up.

But I don't think it's profitable to assert that we "must" name things before we can think about them, or even to discuss the meaning of such propositions at any length. Many positive advantages of names are clear, so we can advocate them without needing to explore what language" means, or what properties thought must or may have, or ... . [Especially because when we DO start wondering about such things, we often end up just agreeing that one of us uses some of these words in a slightly different way to another of us, rather than really learning anything useful about language, thought, or life!]

John Conway
"

on 2 black holes horizon, wouldn't it be rather like ellipsoid but with the part in the plane tangent to their contact slightly 'squeezed' ? i mean, what phase of 2blackholes-merge process does ellipsoid shape correspond to?

[PWrong]

galileo not only didn't invent calculus. what he did (re)invent, was telescope. which wasn't all about formulas.

Actually I meant Newton invented calculus. As for Galileo, you need a lot of maths to do astronomy.

if you think physics is today the only real science, then what is your conception of real ?

That was just a joke. Physicists always look down on other scientists, don't get too worked up about it.

math isn't art, it just shares certain of its attributes: it is heavily structurally coupled with art. but it's not art. if you state it is, you either overestimate physics, or don't realize art.

Maths is similar to art, because we do it mostly for personal satisfaction, not for any practical purpose. It also doesn't pay very well. At any rate, I think I act more like an art student than a science student.

alchemy was not considered proper science back then as it is not today, by the same regions of socius.

Today we know that you can't turn one element into another, at least not without nuclear physics. They didn't know that back then, so a lot scientists tried to turn things into gold. Alchemy is just chemistry, but with an impossible goal.

you ask if your formalization of relationship is what i mean ? no. i stated what you quoted. no more or less. please re-read it and think if your formula is a meaningful question or reply to the meaning of what you quote (starting 'archimedes...').

B = pVg is just a precise way of stating Archimedes's principle.
"When a body in completely or partially immersed in a fluid the fluid exerts an upward force on the body equal to the weight of the fluid displaced by the body."
That is, Buoyant force = density of fluid * volume of body * gravity
B= p V g

Maybe Archimedes didn't actually mention invent the formula, but so what? The formula and the relationship are the same statement, but the formula's just shorter and easier to use.

on 2 black holes horizon, wouldn't it be rather like ellipsoid but with the part in the plane tangent to their contact slightly 'squeezed' ? i mean, what phase of 2blackholes-merge process does ellipsoid shape correspond to?

Yes, you're right. If they were close enough, you'd get a combined event horizon that was squeezed in the middle. But it's probably a lot more complicated than that. We're talking about a 3-body problem (the two black holes and a photon). Given an arbitrary photon, it's almost impossible to predict where it might end up.

[thigle]

alchemy's real goal was never to transmute lead to gold in the physical sense. it's goal was individuation, leading to transubstantiation - a transmutation of ordinary substance into light - a body of light as freed inherent nature was and is its real goal. the chemistry was just the formalism chosen to describe in analogies the psychophysical processes, which didn't have refined languague back then, (nor that they would today). you can think of it as chemistry, with an impossible goal, but then it's just very shallow (if any) understanding of alchemy. purely physical was never its exclusive domain.
my artist friend, again, i ain't got nothing against formulas. some i understand, some not, but I considered it always more useful to be able to think on the level before the formulas, where fuzziness and diffuse associativity take over. having clear and precise and concise formulas is cool, but that's just the tip of the whole creativity process.
but surely math & art are close family.

on 2 blackholes: down the process of their 'merging' or collapse, is there a moment from when they can be treated as 1 blackhole again ?

[houserichichi]

I think the science-is-math debate would be an excellent topic in its own right...

BUT back to the question at hand, a very simple google search provided this page. Nothing too deep but interesting nonetheless.

http://archive.ncsa.uiuc.edu/SCMS/DigLib/text/astro/Colliding-Black-Holes-Seidel.html

[jinydu]

At any rate, I think I act more like an art student than a science student.

Awww... How humble...

Not to be disrespectful to art, but you've done plenty of quality derivations on this board, some of which I wouldn't be able to do myself.

Certainly, my quantum chemistry professor would disagree strongly with what thigle has said. Quantum theory at least is a very rigorous science that is centered around Schrodinger's Equation and several other postulates. In is only through understanding the equations, and how to solve them, that one can fully correctly understand quantum theory.

[thigle]

i think if perfect synthetic scientist finds a way to convey his understanding of order, truth and of beauty, in a chosen medium(s) and skillfully enough, it can be considered in some cases as art. Leonardo was as much of artist as of scientist. jmho

and alchemy doesn't stop or limit itself to Planck scales. I truly believe that there might come a time when it is possible for humans to understand quantum dynamics intuitively, as cartesian space is intuitively understood today.

[PWrong]

Awww... How humble...

Not to be disrespectful to art, but you've done plenty of quality derivations on this board, some of which I wouldn't be able to do myself.

What I meant was, I tend to behave more like an arts student in person. But now I'm just stereotyping art students. I also tend to be more creative (with maths at least) than my friends, who are mostly doing science-engineering double degrees. I think of maths as more of a hobby than as part of my degree, and I just study what I feel like, instead of what's in the exam (which happens to be this friday). That's probably why I can solve 2nd year PDE's, but not basic linear algebra questions.

and alchemy doesn't stop or limit itself to Planck scales.

Alchemy doesn't really exist as a science anymore. The word itself is almost obselete.

I truly believe that there might come a time when it is possible for humans to understand quantum dynamics intuitively, as cartesian space is intuitively understood today.

Well, since the only correct interpretation of quantum mechanics is the mathematical one, the human race has a lot of hard work ahead of them. Have you seen the thread on the 4D Schrodinger's equation? That's what real quantum mechanics is like. We're really just trying to answer a very simple question, "does energy come in packets and levels, or is it continuous." You can find it out through experiment, or by solving the equation, but you can just figure it out through intuition.

[thigle]

pwrong: 'obsolete' . and btw, if you were acting like an art student, instead of just thinking you do, ( ), you surely would know alchemy better, and if not, you would know value of not knowing, and you would know what to do with it. in an artistic way. how to sublime your ignorance, how to transform lead to gold, your not knowing to inspiring revelations. but beware. no equations and shit ! just real transmutation. realm of art is indeterminate and open. precision is not indispensable. so alchemy... oh, no more offerings to not interested.

but the quantum mechanics question... realize it's a construct of human minds over open actuality of manifestation. you don't understand word-limits, so you think it is something, defined by its formalism. but no formalism covers its object fully, and the aspect of facticity of manifestation to which quantum mechanics and dynamics (so called quantum 'reality') corresponds goes on unceasingly irrelevant of your formulas. the formulas in schrodingers' thread are just that: representations. that of which they are representations of, that is present regardless of understanding formulas. images in mirror are not objects mirrored. and ok, forget intuition, you surely not use it often. but i'll be more blunt: quantum mechanics and dynamics, as well as anything other in the universe, is not hidden to direct perception of any sentient being who made his perception free of symbolization, stabilized in it, and familiarized with it.
do it and see directly the limits of representations through formalisms: beyond einstein's reduction of observer to position and speed lies physics which embraces its makers' presence in all its richness: consciousness is incorporated within its domain of inquiry as rightfully as the objectivized world is today. you can see, instead of just looking. that's also basic art skill. basic, the most primal and most fundamental artistic skill, is to learn to alter your perception. to the level of its liquefaction and evaporization. then next comes imagination. and then,...oh,no offerings to uninterested.

so what says the voice of a rose ? can you hear it without hearing ? can you see quantum dynamics ?

because admit this at least: knowing equations of hydrodynamics of water, its precise molecular composition, its whatever you can formalize, however far or close you go in your description, it won't tell you a shit about how is it to drink it.

so if you see instead of just looking, you would have no problem with the packet/wave duality. you cannot understand it, because you do not consider the act of understanding in your equations. that is the hidden variable.
i can see quantum dynamics. not on daily basis, but not so seldom as to forget its dancing beauty and ultramicroscopic finesse. and i feel just sadness for those who know so much and know so little. because 4 blinds touching different parts of an elephant, will all imagine an elephant differently. could they open eyes to see, they would no longer have to be indirect. as all you poor physicists locked up in virtual word of formulas.

some people (especially physicists) seem to forget very often that it is the world, that backs up their science, not the other way around. and also that it is them, making their science, that they are included, irrelevant of whether they like it believe it or not or whatever. it's the very fact of your presence.

[jinydu]

Once again, thigle, your post is hard to read.

But I will ask this:

If you think that understanding quantum phenomena is best done without mathematics, how would you, for instance, predict the colors in the emission spectrum of hydrogen gas?

[thigle]

it's a pity you fail to understand my languague (you miss its pattern). at least for me because i care. strange, i have no problem in verbal english communication. sure, it's not my native languague, but i speak fluently, fast and with huge nonconform vocabulary, and so i can always easily explain myself. is true that in written communication, i tend to diffuse too much.

but to your question:

what would you need such a thing for ? i am not interested primaly in tidbids. and note that understanding is perception of pattern, not power over a certain phenomenal field.

[thigle]

and a question for you: what do you consider most important ? most thought-provoking ? most relevant ? science ?

[Batman3]

When I hear words like, "Uranium 235 nucleus", I experience a feeling in the words not unlike those when I look at a flower or when I eat Ice-cream(the physical shape of the flower or ice-cream corrsponding to the letters). Of course the feeling is different. The flower is percieved in a visual sense, an ice-cream is percieved in a gustatory sense but the "uranium-235 nucleus"' experience is perceived in some kind of scary or religious sense. The heat between atheism(i.e. Communism) and presbyterianism(i.e. the U.S.A.) is a religious conflict and puts its self into the visual experience of the black and white letters referring to the "N-U-C-L-I-U-S".
Similarly with math concepts. They have implications for physics and so get a certain experience indirectly. But the more abstract they are the harder they are to relate to physics and thereby to religious conflict whether between atheism and theism or between Eastern Orthodoxy and Roman Catholism.
If we want to arrive at a 4d universe with experiences in side of it, instead of empty and blind concepts, it seems to me religious conflict may be the way to go. It may be unpleasant, but C'est La Vie.

[thigle]

what do you mean by religious conflict ? i understand religio as binding (like with ropes), so i understand your religious conflict most broadly as any kind of not-freedom. so religious conflict in sense of conflict of kinds of limitations ?

[jinydu]

and a question for you: what do you consider most important ? most thought-provoking ? most relevant ? science ?

What do I consider most important? In quantum mechancs, it is the Schrodinger equation:

i (h-bar) (partial psi)/(partial t) = (H-hat) psi

(please excuse the lack of proper symbols available on this board)

... and of course, the Born interpretation of the wavefunction.

[houserichichi]

I'm amazed by the standard model, as incomplete as it is. :wink:

[thigle]

houserichichi: what do you consider are the fundamental incompletenesses, or limits, of the standard model ?

jinydu: why do you consider that particular interpretation of the wavefunction so important ? are there other interpretations you're aware of, that you consider worth attention, or some that you find most provoking, you're most curious about, or wild about ?

anyone here into cognitive sciences ?

[houserichichi]

Well the Standard Model describes the fundamental forces of nature on a quantum scale. The glaring hole, then, is the lack of gravity...the SM is missing 1/4 of the forces it was created to describe. There's also the hole reserved for the Higgs particle, the one that gives the other particles mass. With the advent of new particle colliders on the horizon, however, things could be going for a spin...we might just see what we need to fill it up.