Black hole “billiards” may explain strange aspects of 2019 black hole merger

Simulations consistent with large masses, eccentric orbits, tilted spin axes of GW190521.

Read the whole story

 

[JerryLove]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

 

[appliance]

A "solar" system of black holes - not pleasant, I'm sure. Also, If a collapsing star isn't of sufficient mass to form a black hole, doesn't it form a neutron star? I'm at coloring book level with this stuff.

 

[Valgrus Thunderaxe]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Energy can be siphoned from a black hole with lasers.

EDIT: https://www.youtube.com/watch?v=ZevUW__aMZE

 

[fazman69]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Actually the 8 solar masses of energy are in the form of gravitational waves.

 

[LongTimeLurker629]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Energy can be siphoned from a black hole with lasers.

Link please? a quick google search didn't illuminate what you meant.

EDIT: thank you for your edit, and for anyone who doesn't want to watch the interesting 30m video, you siphon the kinetic energy from a spinning blackhole or a pair of orbiting blackholes. The idea is very ingenious and gets expanded a lot with corollaries for a galactic civilization evolution and some academic citations to boot (many form the author of the video).

 

[Tremelune]

A concept that is over my head is now orbiting a more complex concept.

 

[neil_w]

(adds "Black Hole Billiards" to list of album names)

 

[Wheels Of Confusion]

A system of black holes orbiting a giant black hole in a gas disk sounds like something straight out of Lensman sci-fi. So ridiculously over the top it's hard to think about it being real.

 

[Demosthenes642]

I'm continuously amazed at the LIGO/VIRGO data interpretation. It's like measuring the surf in Big Sur and being able to tell that a couple fishing boats banged into each other off the coast of Japan what their courses were and how big they were.

I do wonder what those accretion disks look like, they must get whipped up and fluffy with stars and black holes zipping in and out of the gas.

 

[JerryLove]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Actually the 8 solar masses of energy are in the form of gravitational waves.

Gravitational waves cause a loss of mass?

Mass-energy conversion is generally bi-directional (in theory at least)... mass converted to energy creates energy that could be converted to mass.

Since gravity itself is not created by the conversion of mass into energy, do you have a source I could look at to understand how gravitational waves *are* the result of mass-energy conversion?

If so, how is this energy immune to gravity (IOW, can escape)?

 

[Hapticz]

we're like Stanley Kubrick's primates discovering the sense and feel of a good club in hand, not quite as massive as a billion chunks of compacted chemistry, but there must be somewhere in our brains the capacity to 'discover' that which we will never touch or own.... (ohhh so frustrating indeed!)

maybe our curiosity will get us close enough to 'become one with that', and support the endless triumph of being 'human'....

 

[JerryLove]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Energy can be siphoned from a black hole with lasers.

EDIT: https://www.youtube.com/watch?v=ZevUW__aMZE

That's a slingshot; stealing inertia from a black hole. That does not actually pull any mass from within the event horizon.

 

[Hapticz]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Actually the 8 solar masses of energy are in the form of gravitational waves.

Gravitational waves cause a loss of mass?

Mass-energy conversion is generally bi-directional (in theory at least)... mass converted to energy creates energy that could be converted to mass.

Since gravity itself is not created by the conversion of mass into energy, do you have a source I could look at to understand how gravitational waves *are* the result of mass-energy conversion?

If so, how is this energy immune to gravity (IOW, can escape)?

i keep feeling the mass/energy dance is like a continuous 'pump', always enough to keep all things in balance (at infinite galactic/universe scale)

 

[AreWeThereYeti]

A system of black holes orbiting a giant black hole in a gas disk sounds like something straight out of Lensman sci-fi. So ridiculously over the top it's hard to think about it being real.

Yeah, I find that astronomy has actually gotten more interesting and cool since I was young. Black holes were a kind of "in theory, but we'll probably never see or encounter one" kind of thing. Now they are considered as a common outcome of stellar evolution, so common that the Milky Way probably has somewhere between 10 million and a billion black holes floating around!

You'd think that would make them boring, but they just keep getting more interesting. Not only are they a common thing that we can see all over the place, on the theory side they are becoming more and more central to the search for a theory of everything, since they are the best example of something that is both massive enough to warp space significantly and still exhibits significant quantum behavior, so they are the main thought laboratory for quantum gravity research.

And jets from stellar black holes may well be the source of the bizarre galactic filaments that we have recently become a lot more aware of: https://www.youtube.com/watch?v=h59uLPBcXgs

 

[Valgrus Thunderaxe]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Energy can be siphoned from a black hole with lasers.

EDIT: https://www.youtube.com/watch?v=ZevUW__aMZE

That's a slingshot; stealing inertia from a black hole. That does not actually pull any mass from within the event horizon.

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

 

[JerryLove]

A "solar" system of black holes - not pleasant, I'm sure. Also, If a collapsing star isn't of sufficient mass to form a black hole, doesn't it form a neutron star? I'm at coloring book level with this stuff.

It depends on what the actual mass of the star is.

Yes, some stars end up as neutron stars either because they were not large enough to begin with or because they lost too much mass in their death to form a black hole.

Others, like our sun, are not massive enough to form neutron stars. It will eventually collapse into a white dwarf that will, over trillions of years, cool to a black dwarf.

I believe under some conditions, a star can also blow into basic non-existance so that there's no clear remnant (Other than a rapidly expanding cloud). But don't quote me on that.

 

[JerryLove]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Energy can be siphoned from a black hole with lasers.

EDIT: https://www.youtube.com/watch?v=ZevUW__aMZE

That's a slingshot; stealing inertia from a black hole. That does not actually pull any mass from within the event horizon.

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

 

[Valgrus Thunderaxe]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Energy can be siphoned from a black hole with lasers.

EDIT: https://www.youtube.com/watch?v=ZevUW__aMZE

That's a slingshot; stealing inertia from a black hole. That does not actually pull any mass from within the event horizon.

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

That's correct, *if* indeed you could have a star consisting only of photons which isn't possible.

 

[JerryLove]

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

That's correct, *if* indeed you could have a star consisting only of photons which isn't possible.

It wouldn't be a star anymore but... why is it impossible? What law of physics prevents that many photons from being in that small a space?

Put another way: Convert the entire universe to photons and there's no gravity anywhere anymore?

 

[Valgrus Thunderaxe]

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

That's correct, *if* indeed you could have a star consisting only of photons which isn't possible.

It wouldn't be a star anymore but... why is it impossible? What law of physics prevents that many photons from being in that small a space?

I wasn't being clear. You're correct that photons lack mass, so any density of photons (a "star-like" configuration or otherwise) will also lack mass.

 

[LongTimeLurker629]

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

That's correct, *if* indeed you could have a star consisting only of photons which isn't possible.

It wouldn't be a star anymore but... why is it impossible? What law of physics prevents that many photons from being in that small a space?

I wasn't being clear. You're correct that photons lack mass, so any density of photons (a "star-like" configuration or otherwise) will also lack mass.

I always thought that gravitational lensing was because photons do have some mass... or is it just how spacetime is curved? wait, I'm no longer sure what mass actually is. Crap... back to wikipedia...

 

[Komarov]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Actually the 8 solar masses of energy are in the form of gravitational waves.

Gravitational waves cause a loss of mass?

Mass-energy conversion is generally bi-directional (in theory at least)... mass converted to energy creates energy that could be converted to mass.

Since gravity itself is not created by the conversion of mass into energy, do you have a source I could look at to understand how gravitational waves *are* the result of mass-energy conversion?

If so, how is this energy immune to gravity (IOW, can escape)?

The gravity waves form outside the event horizons of the black holes and move in all directions at the speed of light. They don't escape from inside the event horizon.

 

[JerryLove]

Gravitational waves cause a loss of mass?

Mass-energy conversion is generally bi-directional (in theory at least)... mass converted to energy creates energy that could be converted to mass.

Since gravity itself is not created by the conversion of mass into energy, do you have a source I could look at to understand how gravitational waves *are* the result of mass-energy conversion?

If so, how is this energy immune to gravity (IOW, can escape)?

The gravity waves form outside the event horizons of the black holes and move in all directions at the speed of light. They don't escape from inside the event horizon.

That goes back to my original question.

8 solar masses was lost. Where did that 8 solar masses reside prior to being lost? Did it reside inside the event horizon (meaning there's a way to reduce the mass of a black hole), or was it already outside the event horizon (an accretion disk for example), in which case "nothing to see here".

 

[Veritas super omens]

At this early juncture in our ability to detect gravitational waves many events will be records of some kind or another. Still, this event stands out in a number of ways. Re photon mass, obviously photons must have mass or they would not be gravitationally lensed. Isn't their mass related to their wavelength?

 

[Hapticz]

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

That's correct, *if* indeed you could have a star consisting only of photons which isn't possible.

It wouldn't be a star anymore but... why is it impossible? What law of physics prevents that many photons from being in that small a space?

Put another way: Convert the entire universe to photons and there's no gravity anywhere anymore?

whew, that's a pretty tall order!

who's gonna do this , you and who else???

no disrespect intended, but imaginations have been known to yield some fantastic movies!

 

[JerryLove]

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

That's correct, *if* indeed you could have a star consisting only of photons which isn't possible.

It wouldn't be a star anymore but... why is it impossible? What law of physics prevents that many photons from being in that small a space?

I wasn't being clear. You're correct that photons lack mass, so any density of photons (a "star-like" configuration or otherwise) will also lack mass.

I always thought that gravitational lensing was because photons do have some mass... or is it just how spacetime is curved? wait, I'm no longer sure what mass actually is. Crap... back to wikipedia...

The last explanation I had (from relativity) was that a photon travels in a straight line, but the fabric of spacetime is curved by gravity. Similarly, an event horizon represented a point at which the curvature came back on itself (think of the inside of a sphere); such that there was no spacial path out (no direction represents "away" from the singularity at that point).

But I think that's been supplanted (or is attempting to be supplanted) about something with fields and field interactions... but my understnading of quantum is worse than my understanding of relativity.

 

[JerryLove]

It wouldn't be a star anymore but... why is it impossible? What law of physics prevents that many photons from being in that small a space?

Put another way: Convert the entire universe to photons and there's no gravity anywhere anymore?

whew, that's a pretty tall order!

who's gonna do this , you and who else???

no disrespect intended, but imaginations have been known to yield some fantastic movies!

It's a though experiment. It seems to be how most modern theories began, from relativity to thermodynamics.

I guess the same guy who invented Maxwell's demon and Shrodinger's cat.

 

[PhaseShifter]

The black holes merged to form a new, even larger black hole of about 142 solar masses, emitting the energetic equivalent of eight solar masses in the process

Was this mass not within the event horizon to begin with? Or is there a mechanism by which 8 solar masses can leave the event horizon rapidly?

I understand that these are very energetic; but I was of the impression that, other than hawking radiation (which doesn't technically *leave* the black hole) nothing returns to the universe from past the event horizon other than gravity.

Energy can be siphoned from a black hole with lasers.

EDIT: https://www.youtube.com/watch?v=ZevUW__aMZE

That's a slingshot; stealing inertia from a black hole. That does not actually pull any mass from within the event horizon.

What's the difference?

Mass is energy. A good chunk of the "mass" of baryons is just the kinetic energy of quarks and the strong force interactions between them.

A tiny but significant amount of "mass" in atomic nuclei is weak force interactions within the nuclei. That's how the whole "mass deficit=energy released" thing works.

A system of black holes is no different in that regard. As the black holes fall closer together, they trade gravitational potential for kinetic energy. As they orbit around one another, they trade kinetic energy for gravitational wave emissions. As energy eaves the system through gravitational waves, the "mass" of the entire system decreases, not the mass of either black hole.

I've seen theoretical processes for stealing rotational energy from a solitary black hole as well.

 

[rapster]

At this early juncture in our ability to detect gravitational waves many events will be records of some kind or another. Still, this event stands out in a number of ways. Re photon mass, obviously photons must have mass or they would not be gravitationally lensed. Isn't their mass related to their wavelength?

Photons are lensed because space(time) is curved, not because photons have mass.

 

[Iarvos]

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

That's correct, *if* indeed you could have a star consisting only of photons which isn't possible.

It wouldn't be a star anymore but... why is it impossible? What law of physics prevents that many photons from being in that small a space?

I wasn't being clear. You're correct that photons lack mass, so any density of photons (a "star-like" configuration or otherwise) will also lack mass.

I always thought that gravitational lensing was because photons do have some mass... or is it just how spacetime is curved? wait, I'm no longer sure what mass actually is. Crap... back to wikipedia...

From my layman's perspective, light behaves in the same manner as any other objects when exposed to gravity, - there's a constant acceleration proportional to the mass of the gravitational source and inversely proportionate to the square of the distance from the source. Apparently there is no discontinuity as you approach zero, or even at zero. This is often stated instead as there being a force proportional to the mass of the object that the gravitational field is acting on, but that breaks down when you get to massless things such as light.

If we ever do find/create objects with negative mass it makes me wonder though if you then would need to have photons that also interacted with gravity negatively. The fact that the acceleration doesn't approach zero as the mass goes to zero doesn't seem to bode well for negative mass being a method for producing "anti-gravity". [/BaselessSpeculation]

 

[The_Motarp]

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

That's correct, *if* indeed you could have a star consisting only of photons which isn't possible.

It wouldn't be a star anymore but... why is it impossible? What law of physics prevents that many photons from being in that small a space?

I wasn't being clear. You're correct that photons lack mass, so any density of photons (a "star-like" configuration or otherwise) will also lack mass.

This is incorrect. While photons lack mass they still have energy, and will still cause distortion of spacetime. In fact, it is theorized that we could create tiny black holes called Kugelblitz black holes by shining a large number of very powerful and focussed lasers through a microscopic region of space.

 

[JerryLove]

That's a slingshot; stealing inertia from a black hole. That does not actually pull any mass from within the event horizon.

What's the difference?

Mass is energy. A good chunk of the "mass" of baryons is just the kinetic energy of quarks and the strong force interactions between them.

How much mass did Jupiter lose when Voyager used it as a slingshot?

The correct answer is "none". The transferrance of momentum does not inolve a change in mass.

Another question: how much mass does the Earth convert per-day into gravity? The correct answer is "none".

The mechanism by which that momentum is transferred is gravity. We know that gravity escapes black holes. So there's no violation of the event horizon there. Slingshotting something with momentum around a blackhole to trade momentum doesn't violate anything I'm aware of (but mass leaving the event horizon does).

There is a thermodynamics concern. If the laser can impart new energy and that energy did not come from somewhere (if momentum wasn't taken from the black hole because the photon is massless), then you've violated the first law of thermodynamics as best I can tell.

A tiny but significant amount of "mass" in atomic nuclei is weak force interactions within the nuclei. That's how the whole "mass deficit=energy released" thing works.

A system of black holes is no different in that regard. As the black holes fall closer together, they trade gravitational potential for kinetic energy. As they orbit around one another, they trade kinetic energy for gravitational wave emissions. As energy eaves the system through gravitational waves, the "mass" of the entire system decreases, not the mass of either black hole.

I've seen theoretical processes for stealing rotational energy from a solitary black hole as well.

So your statement is that there was 8 solar masses of potential energy and that potential energy was creating gravity (had mass)? And that potential energy became gravity waves (which don't have mass?) Or did I miss something?

If mass can be converted into a gravity wave, can a gravity wave be converted into mass? Seems to me there's a symmety rule that would require that.

 

[JerryLove]

Not quite. It would be if this was dealing with accelerating an object with mass around the BH. The interaction with the BH in this case is done strictly with light.

I'm not sure there is a difference. A photon has a mass of ~0, but are we saying that there's zero higgs interaction? If I turned an entire star into photons, and contained all those photons in a space the size of the star, there would be no gravity from that space? That feels counter-intuitive.

That's correct, *if* indeed you could have a star consisting only of photons which isn't possible.

It wouldn't be a star anymore but... why is it impossible? What law of physics prevents that many photons from being in that small a space?

I wasn't being clear. You're correct that photons lack mass, so any density of photons (a "star-like" configuration or otherwise) will also lack mass.

This is incorrect. While photons lack mass they still have energy, and will still cause distortion of spacetime. In fact, it is theorized that we could create tiny black holes called Kugelblitz black holes by shining a large number of very powerful and focussed lasers through a microscopic region of space.

Would the Kugelblitz black hole result in the photons converting back into matterr? Or would the photons convert to mass for some other reason thus causing it? Or do massless items have gravity?

 

[PhaseShifter]

At this early juncture in our ability to detect gravitational waves many events will be records of some kind or another. Still, this event stands out in a number of ways. Re photon mass, obviously photons must have mass or they would not be gravitationally lensed. Isn't their mass related to their wavelength?

It depends on what you mean by mass.

They certainly don't require any rest mass, and the assumption "no mass=no gravitational interaction" is false even in Newtonian mechanics, where the acceleration due to gravity is independent of the mass (or lack thereof) of any object being accelerated by the gravitational field.

While it's true that there's a mass dependence for the force on an object in a gravitational field, there's also a mass dependence for the acceleration in terms of the force (F=ma), and when you combine the equations those dependencies cancel one another exactly.

You can certainly make the argument that photons in motion have energy and therefore mass due to mass-energy equivalence, but saying they must have mass to be affected by gravity is fallacy.

 

[Voix des Airs]

Gravitational waves cause a loss of mass?

Mass-energy conversion is generally bi-directional (in theory at least)... mass converted to energy creates energy that could be converted to mass.

Since gravity itself is not created by the conversion of mass into energy, do you have a source I could look at to understand how gravitational waves *are* the result of mass-energy conversion?

If so, how is this energy immune to gravity (IOW, can escape)?

The gravity waves form outside the event horizons of the black holes and move in all directions at the speed of light. They don't escape from inside the event horizon.

That goes back to my original question.

8 solar masses was lost. Where did that 8 solar masses reside prior to being lost? Did it reside inside the event horizon (meaning there's a way to reduce the mass of a black hole), or was it already outside the event horizon (an accretion disk for example), in which case "nothing to see here".

I'll try to find and add a reasonably readable link - if I can find one - to this post later if I get a chance but the source of "mass" in a black hole is space-time curvature itself (there actually isn't just one way to define the mass of a black hole but the usual way is as mass equivalence as determined a very long way away (technically, at infinity) from the black hole). In General Relativity (and Black Holes are creatures of GR so at least for now it's all we've got) it isn't really correct to think of a Black Hole like a classical object with some mass at the center causing the gravity. In the case of black holes, it's probably best to (by analogy) think of a black hole as being not the hole at the center of a whirlpool but the whirlpool itself. The way that this is often stated is that a black hole's mass is everywhere. So don't think of a black hole as some mass concentrated at the center and the gravity somehow getting out. The spacetime curvature is all there is.

Also, remember that mass-energy equivalence means literally that. Whatever they are - if they are anything beyond just energy being a mathematical property which must be locally conserved for purely mathematical reasons - in other words, energy may not be a thing in itself but just a thing we define because it is useful to describe things) mass and energy are the same thing.

Lastly, someone above mentioned this... Gravity doesn't pull on things. Photons are affected by spacetime curvature because they are traveling on what passes for straight lines in curved spacetime (called geodesics). Just like on the surface of a sphere, there is literally no such thing as a straight on line a curved surface - a straight line would have to leave the surface of the sphere. Since photons can't leave spacetime and spacetime is curved by mass/energy/momentum then a photon's path will curve just like an airplane following the curve of the Earth as it flies.

 

[JerryLove]

It depends on what you mean by mass.

They certainly don't require any rest mass, and the assumption "no mass=no gravitational interaction" is false even in Newtonian mechanics, where the acceleration due to gravity is independent of the mass (or lack thereof) of any object being accelerated by the gravitational field.

While it's true that there's a mass dependence for the force on an object in a gravitational field, there's also a mass dependence for the acceleration in terms of the force (F=ma), and when you combine the equations they cancel one another exactly.

You can certainly make the argument that photons in motion have energy and therefore mass due to mass-energy equivalence, but saying they must have mass to be affected by gravity is fallacy.

I'm not who that was to, but based on the "firing a laser around a black hole" assertion, I have to conclude that photons can exchange energy (via gravity) with an object (a black hole) in order to preserve concervation of energy.

For the photon to gain it, the black hole must lose it, or else it's "new".

All of which makes me think "mass doens't mean what many of us think it means".

 

[JerryLove]

I'll try to find and add a reasonably readable link - if I can find one - to this post later if I get a chance but the source of "mass" in a black hole is space-time curvature itself (there actually isn't just one way to define the mass of a black hole but the usual way is as mass equivalence as determined a very long way away (technically, at infinity) from the black hole). In General Relativity (and Black Holes are creatures of GR so at least for now it's all we've got) it isn't really correct to think of a Black Hole like a classical object with some mass at the center causing the gravity. In the case of black holes, it's probably best to (by analogy) think of a black hole as being not the hole at the center of a whirlpool but the whirlpool itself. The way that this is often stated is that a black hole's mass is everywhere. SO don't think of a black hole as some mass concentrated at the center and the gravity somehow getting out. The spacetime curvature is all there is.

OK. But we started with mass, yes?

So if I have 100 solar masses of whirlpool, and I didn't put 100 solar masses of mass and energy into it to make that, then there's "new" mass (or so it seems from your analogy). That would seem to be a problem.

Also, remember that mass-energy equivalence means literally that. Whatever they are - if they are anything beyond just energy being a mathematical property which must be locally conserved for purely mathematical reasons - in other words, energy may not be a thing in itself but just a thing we define because it is useful to describe things) mass and energy are the same thing.

That's my understanding. Massenergy that interacts with the higgs field cannot move a C and is called "mass". Massenergy that does not interact with the higgs field is called "energy" and can only move a C.

Lastly, someone above mentioned this... Gravity doesn't pull on things. Photons are affected by spacetime curvature because they are traveling on what passes for straight lines in curved spacetime (called geodesics). Just like on the surface of a sphere, there is literally no such thing as a straight line a curved surface - a straight line would have to leave the surface of the sphere. Since photons can't leave spacetime and spacetime is curved by mass/energy/momentum then a photon's path will curve just like an airplane following the curve of the Earth as it flies.

I believe am the person who mentioned that.

Though it also turn out that gravity has a speed (specifically: gravity travels at c); and I *think* quantum is trying to move us to an understanding of a "gravity field" more than Einstein's curved spacetime; but I'm way above my paygrade here.

 

[Shiratori]

Dave "Cinzano Bianco" Lister strikes again.

 

[Voix des Airs]

I'll try to find and add a reasonably readable link - if I can find one - to this post later if I get a chance but the source of "mass" in a black hole is space-time curvature itself (there actually isn't just one way to define the mass of a black hole but the usual way is as mass equivalence as determined a very long way away (technically, at infinity) from the black hole). In General Relativity (and Black Holes are creatures of GR so at least for now it's all we've got) it isn't really correct to think of a Black Hole like a classical object with some mass at the center causing the gravity. In the case of black holes, it's probably best to (by analogy) think of a black hole as being not the hole at the center of a whirlpool but the whirlpool itself. The way that this is often stated is that a black hole's mass is everywhere. SO don't think of a black hole as some mass concentrated at the center and the gravity somehow getting out. The spacetime curvature is all there is.

OK. But we started with mass, yes?

So if I have 100 solar masses of whirlpool, and I didn't put 100 solar masses of mass and energy into it to make that, then there's "new" mass (or so it seems from your analogy). That would seem to be a problem.

Also, remember that mass-energy equivalence means literally that. Whatever they are - if they are anything beyond just energy being a mathematical property which must be locally conserved for purely mathematical reasons - in other words, energy may not be a thing in itself but just a thing we define because it is useful to describe things) mass and energy are the same thing.

That's my understanding. Massenergy that interacts with the higgs field cannot move a C and is called "mass". Massenergy that does not interact with the higgs field is called "energy" and can only move a C.

Lastly, someone above mentioned this... Gravity doesn't pull on things. Photons are affected by spacetime curvature because they are traveling on what passes for straight lines in curved spacetime (called geodesics). Just like on the surface of a sphere, there is literally no such thing as a straight line a curved surface - a straight line would have to leave the surface of the sphere. Since photons can't leave spacetime and spacetime is curved by mass/energy/momentum then a photon's path will curve just like an airplane following the curve of the Earth as it flies.

I believe am the person who mentioned that.

Though it also turn out that gravity has a speed (specifically: gravity travels at c); and I *think* quantum is trying to move us to an understanding of a "gravity field" more than Einstein's curved spacetime; but I'm way above my paygrade here.

I promise to reply to this later. I've got a thing right now...