A question about quarks and black holes

[Ignorantsmith12]

TL;DR Summary

If black holes can "spaghettify" objects that fall into them, and if pulling on quark pairs hard enough makes new quark/antiquark pairs, does that mean black holes can create quark/anti-quark pairs as atoms fall into them?

This question was not my idea. I heard it while watching a YouTube video hosted by a celebrity astrophysicist and a comedian. This astrophysicist answers the physics questions of his Patreon supporters, and one of the supporters asked him about the spaghettification of quarks. I'm paraphrasing here, but basically, the supporter wondered if the gravitational power of a black hole and strong nuclear force in quarks somehow reach an equilibrium since the strong nuclear force gets stronger the further quarks are yanked away from each other (credit to the supporter for using actual physics terminology in the question.)

The astrophysicist noted that pulling quarks apart hard enough creates new quarks using the energy pulling on them. His comedian co-host suggested that black holes could perhaps make infinite quarks this way. The astrophysicist admitted he had no rebuttal to this and would have to talk to some people.

So then, let me ask you this question. What happens to quarks as they fall into black holes? Can new quark/anti-quark pairs be made by a black hole's gravity?

 

[PeterDonis]

a YouTube video

Please give a specific reference. And please note that YouTube videos are not good sources for learning physics.

the strong nuclear force gets stronger the further quarks are yanked away from each other

Note that this is only true over short ranges, roughly the size of an atomic nucleus. If it were true over longer ranges, nuclear fusion reactions would be much easier to initiate than they are (and in the limit all of the matter in the universe would be neutronium).

Can new quark/anti-quark pairs be made by a black hole's gravity?

No. The "pulling apart" due to a black hole's tidal gravity adds no energy to objects and so cannot create any particle-antiparticle pairs. What is described as "pulling apart" is actually the spacetime geometry having enough curvature to disrupt the internal forces within objects.

I should note that there is a heuristic explanation of Hawking radiation that talks about virtual particle-antiparticle pairs being created by the tidal gravity of a black hole at its horizon. However, this is only a heuristic explanation and is not a good basis on which to generalize.

 

[PeroK]

This question was not my idea. I heard it while watching a YouTube video hosted by a celebrity astrophysicist and a comedian.

So, a quark, an electron and a neutrino walk into a bar ...

 

[Ignorantsmith12]

Please give a specific reference. And please note that YouTube videos are not good sources for learning physics...

As requested, It comes up 10 minutes and 26 seconds in.

By the way if the spacetime curvature of a blackhole can disrupt the strong nuclear force without providing energy for more quarks/antiquarks does that mean color confiment is violated?

 

[Vanadium 50]

So, a quark, an electron and a neutrino walk into a bar ...

Neon walks into a bar. The bartender says "We don't serve your filthy, stinking kind here!"

Neon doesn't react.

would be much easier to initiate

And fuel for fusion would be much harder to obtain.

To be honest, I don't follow the question. What happens to quark as they fall into a black hole? Same as happens to everything else - they stay there. Making new quarks? If I throw a brick into a black hole, I don't make new bricks, do I?

 

[Ignorantsmith12]

Neon walks into a bar. The bartender says "We don't serve your filthy, stinking kind here!"

Neon doesn't react.


And fuel for fusion would be much harder to obtain.

To be honest, I don't follow the question. What happens to quark as they fall into a black hole? Same as happens to everything else - they stay there. Making new quarks? If I throw a brick into a black hole, I don't make new bricks, do I?

To my understanding quarks must always be united with at least one other quark in sharp contrast to a brick, at the macro scale, which can be alone, and therefore if you try to separate two quarks with enough energy a quark/antiquark pair will be formed so no quark is alone. I also understand this is called color confinement.

Now if everything I said is untrue please tell me and I apologize. Otherwise the question, is how does the black hole pull quarks apart, without making new quarks, since it doesn't donate energy to make new quarks. Does it separate quarks at all?

 

[Ibix]

To my understanding quarks must always be united with at least one other quark in sharp contrast to a brick, at the macro scale, which can be alone, and therefore if you try to separate two quarks with enough energy a quark/antiquark pair will be formed so no quark is alone. I also understand this is called color confinement.

Now if everything I said is untrue please tell me and I apologize. Otherwise the question, is how does the black hole pull quarks apart, without making new quarks, since it doesn't donate energy to make new quarks. Does it separate quarks at all?

I think the intended question is, if some colour-neutral particle like a proton approaches a black hole singularity and the tidal forces grow without bound, are the quarks pulled far enough apart to start creating particles out of the strong force.

I suspect that the answer is that it doesn't happen until very close to the singularity so there isn't much time to open any distance between them, and we don't really expect GR to be accurate in that regime anyway. So we'll get back to you when we have a theory of quantum gravity.

 

[PeterDonis]

if the spacetime curvature of a blackhole can disrupt the strong nuclear force

We don't know for sure that it can. The heuristic model of tidal gravity "pulling apart" things assumes internal forces like those between atoms in an ordinary object, which are electromagnetic, not the strong nuclear force.

does that mean color confiment is violated?

Tidal gravity as we currently understand it would not violate color confinement, no. But for a full analysis of a scenario where tidal gravity is significant on the scale of an atomic nucleus, we might well need a theory of quantum gravity, which we don't currently have.

 

[PeterDonis]

To my understanding quarks must always be united with at least one other quark in sharp contrast to a brick, at the macro scale, which can be alone, and therefore if you try to separate two quarks with enough energy a quark/antiquark pair will be formed so no quark is alone. I also understand this is called color confinement.

This is true under ordinary conditions, but the question being asked is whether very strong tidal gravity, such as would be present deep inside a black hole, could overcome this.

 

[PeterDonis]

pulling quarks apart

It is also worth noting that this heuristic model treats quarks as though they were particles with definite positions that could be "pulled apart", which is, to say the least, questionable.

 

[PeterDonis]

As requested

Please note that this is a pop science video and is not a good source for learning actual science. The question you are asking is a valid one if properly framed (something like "would strong tidal gravity add energy to a hadron such that color confinement could be violated"), but as already noted, the heuristic model used in the video to frame the question is not.

 

[Vanadium 50]

This question is essentially the same as "If I bring a bar magnet near a black hole and the south pole falls in, am I left with a pure north pole?".

The answer in both cases us "no".

 

[Nugatory]

Now if everything I said is untrue please tell me and I apologize. Otherwise the question, is how does the black hole pull quarks apart, without making new quarks, since it doesn't donate energy to make new quarks. Does it separate quarks at all?

Several things about that NdGT video:
a) It's entertainment, not real physics. Repeat this to yourself several times, then take a look at the Hawking paper I link below to see what the real thing would look like, then resolve to stop taking these videos seriously.
b) Trying to reason about the behavior of quantum particles in the vicinity of a black hole is a fairly dubious endeavor (unless you're working at the Stephen Hawking level). GR is a classical theory in which things have positions and the tidal forces that tend to pull macroscopic objects apart are calculated from the positions of opposite ends of the object. Your pair of quarks, however, is a quantum system in which there is no notion of force or position - it doesn't work to think about the pair of quarks as two little teeny solid objects tied together by some force.
c) He is not talking about what happens at the event horizon, he is talking about very near to singularity, where the curvature invariants increase without bound so in principle we can get an arbitrary large tidal force applied to arbitrarily close particles. For any remotely realistic black hole, the tidal forces across a meson-sized object at the horizon are totally insignificant, which is how @Vanadium 50 can compare an infalling meson with an infalling brick.
d) What he actually says is that he doesn't know what happens very near the singularity. This is a fairly non-controversial position; if we take the math of GR's Schwarzschild solution at face value we get ever greater forces at ever smaller scales as we get arbitrarily close to the singularity, but only because we're using GR's classical, as opposed to quantum, model of spacetime at distance scales so small that we cannot ignore quantum effects. What we actually expect is that some not yet discovered physics will come into play.