[katieHaylor (OP)]

David asks:

Would a black hole be made up of sub-atomic particles we have not yet detected, or made up of dark matter, which we have not yet detected?

What do you think?

[Bill S]

Possibly, normal matter/energy in an abnormal state.

Wait for it! Someone's going to say: "What is normal?".

[jeffreyH]

What is a black hole?

[evan_au]

A black hole is made up of anything that has mass and/or energy.

Would a black hole be made up of sub-atomic particles we have not yet detected, or made up of dark matter, which we have not yet detected?

Both of these sound like they would have mass, so yes.
It is also made up of normal matter and light, which also have mass and/or energy.

However, what form it takes when it reaches the central singularity, we can't say, because that is shrouded by the event horizon.

[jarvisss]

When I will be 60, before my death I want to jump in the rocket and fly into the black hole.

[Bill S]

Hi Jarvisss, welcome.

You might think differently when you are 59.

[jeffreyH]

I would hazard a guess that you would be dead before you reached your destination.

[Halc]

I would hazard a guess that you would be dead before you reached your destination.

Only the little ones kill you before you get there.  One can cross the event horizon of a big one without even noticing.  OK, it will still kill you soon enough, but a similar death to being spun at a fatal RPM, which isn't the sort of way I'd choose to go out given a choice.

Answer to the OP then:  It would then be made of you!  You are what you eat.

[PmbPhy]

David asks:

Would a black hole be made up of sub-atomic particles we have not yet detected, or made up of dark matter, which we have not yet detected?

What do you think?

Any kind of matter which falls toward a black hole gets stuck just outside the event horizon and never passes it. That's why they used to be called "frozen stars." The matter at the center is of an unknown makeup since any kind of matter gets compressed, first so that everything becomes neutrons and then compressed further. To know more requires a yet unknown quantum theory of gravity.

[guest45734]

David asks:

Would a black hole be made up of sub-atomic particles we have not yet detected, or made up of dark matter, which we have not yet detected?

What do you think?

Any kind of matter which falls toward a black hole gets stuck just outside the event horizon and never passes it. That's why they used to be called "frozen stars." The matter at the center is of an unknown makeup since any kind of matter gets compressed, first so that everything becomes neutrons and then compressed further. To know more requires a yet unknown quantum theory of gravity.

Are you taking the piss, in what universe does matter get stuck outside the event horizon of a black hole. Do you have a citation?

Regards the matter inside a BH, the laws of thermodynamics "ALWAYS" apply. If matter is compressed inside a BH its going to get very very hot eventually breaking down to fundamental particles etc etc.

[PmbPhy]

Are you taking the piss, in what universe does matter get stuck outside the event horizon of a black hole. Do you have a citation?

Yes. See: https://en.wikipedia.org/wiki/Black_hole#Gravitational_collapse

Even though the collapse takes a finite amount of time from the reference frame of infalling matter, a distant observer would see the infalling material slow and halt just above the event horizon, due to gravitational time dilation. Light from the collapsing material takes longer and longer to reach the observer, with the light emitted just before the event horizon forms delayed an infinite amount of time. Thus the external observer never sees the formation of the event horizon; instead, the collapsing material seems to become dimmer and increasingly red-shifted, eventually fading away.

The derivation for the speed of light in a gravitational field is on my website at:
http://www.newenglandphysics.org/physics_world/gr/c_in_gfield.htm

The same thing applies to all matter because all matter is slower than light.
See Eq 10.

[Bill S]

Any kind of matter which falls toward a black hole gets stuck just outside the event horizon and never passes it.

Even though the collapse takes a finite amount of time from the reference frame of infalling matter, a distant observer would see the infalling material slow and halt just above the event horizon, due to gravitational time dilation.

While your quote is apparently accurate in the RF of the distant observer; would it not be true that in its own RF, the infalling matter not only reaches, but crosses the event horizon?

[Bill S]

Could this be nothing more than a recurrence of Zeno’s paradox?  If we consider the situation from the point of view of the outside observer as an example of asymptotic decay, in which the infalling object is not simply stuck for ever in the same state, but is gradually vanishing, with its progress being recorded by an asymptotic curve, then, in theory, it would never actually vanish (although it would be red-shifted beyond the visible spectrum), but in reality, like Zeno’s arrow, it would come to a conclusion.  In other words, it would vanish.  Maybe, this is the simplest explanation.         

[guest45734]

Any kind of matter which falls toward a black hole gets stuck just outside the event horizon and never passes it.

Even though the collapse takes a finite amount of time from the reference frame of infalling matter, a distant observer would see the infalling material slow and halt just above the event horizon, due to gravitational time dilation.

While your quote is apparently accurate in the RF of the distant observer; would it not be true that in its own RF, the infalling matter not only reaches, but crosses the event horizon?

You will notice Peter answered  "YES" to my question are you taking the piss. Obviously if matter is accelerated towards the event horizon it will pass on towards the centre of the BH unless of course the object suddenly decelerates. What is observed and what is happening is all relative, to an outside observer of our universe time does not exist, it only exists in our reference frame.

Quoting the wiki link
"Oppenheimer and his co-authors interpreted the singularity at the boundary of the Schwarzschild radius as indicating that this was the boundary of a bubble in which time stopped. This is a valid point of view for external observers, but not for infalling observers. Because of this property, the collapsed stars were called "frozen stars", because an outside observer would see the surface of the star frozen in time at the instant where its collapse takes it to the Schwarzschild radius.[31] "

Time emerges from entanglement as might gravity according to some authors.

[evan_au]

the infalling object ... is gradually vanishing

The infalling object is traveling at something like 30% of the speed of light by the time it reaches the event horizon (or would have reached it, if it continued coasting along at this same leisurely speed).

The light of the infalling object is snuffed out in microseconds, by being red-shifted into oblivion.
You may be able to see it a few microseconds longer if you set off an atomic bomb at the right moment - the gamma rays would be red-shifted into the visible range for an instant...

[PmbPhy]

While your quote is apparently accurate in the RF of the distant observer; would it not be true that in its own RF, the infalling matter not only reaches, but crosses the event horizon?

Absolutely!

[Butch]

A black hole can be made up of very normal matter, it depends on the size of the black hole. The super massive black hole thought to be at the center of the milky way should have an average mass density about the same as water on Earth. All bodies have a Schwarzchild radius, in those that are not black holes this radius is smaller than that of the body itself.

[Butch]

The same thing applies to all matter because all matter is slower than light.
See Eq 10.

Only in reference to the observer, a object traveling faster than c relative to the observer, could not be observed, referenced to the object itself it would not be moving at all. Many are mislead by the idea that the gravity of a black hole rips objects asunder. This is not known, time and space dilation becomes very tricky ground to tread upon.

[PmbPhy]

A black hole can be made up of very normal matter, it depends on the size of the black hole. The super massive black hole thought to be at the center of the milky way should have an average mass density about the same as water on Earth.

All of that is wrong. Where did you get that idea from?

[guest45734]

The super massive black hole thought to be at the center of the milky way should have an average mass density about the same as water on Earth.

There are more than one black hole in our milkyway https://www.telegraph.co.uk/science/2018/04/04/tens-thousands-black-holes-exist-center-milky-way-scientists/ and more than meets the eye in our universe http://hubblesite.org/explore_astronomy/black_holes/encyc_mod3_q7.html