Black Hole Elements?

[YT2095]

a Thought just occured to me (from a Chemists standpoint).

 

we know that Stars undergo Many atomic reactions, that convert hydrogen into helium and so on to even heavier elements such as Iron...

 

we`re taught that an atom has a nucleus with electrons in "Orbit" around it , and that most of the size of an atom is empty space.

 

now in a black hole, all this empty space is "taken away" and the electrons and protons and neutrons are all squished together by gravity into what`s called the singularity by.

 

I`m wondering if at some point between being an element as we know it to being part of the singularity, that New elements are being produced, even for a fraction of a second during this transition, elements heavier than say 103 Lawrencium (my ptoe doesn`t go any higher).

 

Thoughts?

[woelen]

The Pauli exclusion principle assures that we have elements, as we know them. This is the reason, why solids and liquids for instance are not compressed easily. The electrons and nuclei cannot be at the same location at the same time (very roughly speaking ), orbitals only can accomodate two electrons with opposite spin.

 

If the pressure on a solid is increased further and further, then at a certain point, the force, excerted on the electrons and nuclei becomes so high that it would break the Pauli exclusion principle. However, as that is not possible, another thing happens. The electrons and nuclei 'melt' together, forming neutrons. These neutrons occupy much less space and the matter can collapse incredibly (the density can increase by a factor of 10^10 or something like that). In fact, no new elements are formed, but the (neutral) atoms simply collapse, as soon as the back-force from the Pauli principle breaks. Of course, it might be that there are fractions of elements with partially collapsed nuclei and electron shells for a small moment of time, which may melt together to something which may be element-like, but this is just theoretical. Such entities quickly will 'melt' down with the remaining electrons.

 

Now, in the neutron star the same principle holds. Neutrons also satisfy the Pauli exclusion principle and it is this again, which assures that the neutron star does not collapse further. However, when the mass of the neutron star also exceeds a certain value, then the pressure becomes so high, that the Pauli exclusion principle cannot hold anymore. This causes the neutrons to 'melt' together and at this point there is no (known) particle anymore, which satisfies the Pauli principle. So, the collapse continues forever and the density grows to infinity.

[YT2095]

so there wouldn`t be a point where you had the nucleus with it`s heavy mass being bombarded by the faster moving electrons (very little mass) and making new elements then?

 

I was thinking along the lines of, since the nucleus has greater mass, it would travel a little slower towards the midle, and the electrons with much less could be "ripped off" quite easily and accelerate towards the middle faster, and along the way meet other nuclei (or nuclei cluster) and for a split second be a new element, a bit like a naturaly occuring Collider or Cyclotron.

 

just a thought

 

 

cheerz for the answer

[jdurg]

With the insanely high temperature present in and around the black hole, wouldn't it be logical to assume that the nuclei are free of electrons? (We all know that in the sun there are no electrons. It's all just a giant ball of plasma).

[YT2095]

(We all know that in the sun there are no electrons. It's all just a giant ball of plasma).

 

are you sure?

I don`t know the dynamics of a sun either, but I know it mostly hydrogen gas turning into other elements, they usualy die when they start producing Iron, and so they must have Electrons somewhere?

[Xyph]

There are electrons in the sun. Plasma contains electrons.

[woelen]

With the insanely high temperature present in and around the black hole, wouldn't it be logical to assume that the nuclei are free of electrons? (We all know that in the sun there are no electrons. It's all just a giant ball of plasma).

As someone else already stated, plasma contains electrons. The electrons are not bound to a specific atom (just as part of the electrons are free to move around through a metal). Still, the Pauli principle holds and the nuclei and electrons cannot occupy the same space. So, you can have a conductive plasma with a density of severals tens of grams per cubic centimeter, but at a certain gravitational pressure the Pauli contra-force collapses and the matter inside the star degenerates to a srt of neutrons.

[Borek]

With the insanely high temperature present in and around the black hole

 

No need for high temperatures, although they are very likely, especially in case of dense black holes. But black hole can have as low density as you like.

 

Black hole size is given by Schwartzschild radius -

 

r = 2Gm/c²

 

So for given mass you can calculate radius, then volume, and finally - if I am not mistaken - black hole density is given by

 

d = 3c⁶/(32 pi G³m²)

 

thus the higher mass of black hole, the lower its density.

 

c - light speed, G - gravitational constant, m - mass.

 

If the black hole density is low you can be inside even don't knowing about it, with a 'normal' temperature around. Black hole with the mass comparable to Milky Way (about 4*10⁴¹) have density of 0.5 g/m³ - not much.

 

Check out http://en.wikipedia.org/wiki/Supermassive_black_hole.

 

Best,

Borek

--

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[woelen]

What do you mean with 'density' for a black hole. To me, this concept hardly makes any sense, because near the Schwarzschild radius, you just have empty space and near the singularity you have very weird conditions. Indeed, if you were to fall inside a large black hole, then at first you would not notice, but the closer you fall towards the singularity, the more you're torn apart (the difference in gravitational pull between your feet and your head will become larger and larger, because your feet are somewhat closer to the singularity, assuming you are falling inwards with your feet 'below').

 

The concept of density, as you mention, isn't that 'average density' over the entire volume of the black hole?

[Borek]

What do you mean with 'density' for a black hole. To me, this concept hardly makes any sense, because near the Schwarzschild radius, you just have empty space and near the singularity you have very weird conditions.

 

As you asked at the end of your post - I was referring to the average density. For sure mass distribution isn't uniform, but in case of very large black hole you may be so far from the center that your surrounding can look just like in Solar system. In fact we can be already inside of the black hole not knowing about it.

 

Indeed, if you were to fall inside a large black hole, then at first you would not notice, but the closer you fall towards the singularity, the more you're torn apart (the difference in gravitational pull between your feet and your head will become larger and larger, because your feet are somewhat closer to the singularity, assuming you are falling inwards with your feet 'below').

 

I think these forces are called 'tidal' in Polish, no idea how they are called in English. However, once again it all depends on the black hole size - the smaller the black hole and the closer to the singularity you are, the larger tidal forces are. When you are far enough (but you can be already under 'event horizon' - if it is called this way in English) tidal forces will be too small to be noticed.

 

I was referring to density as I suppose jdurg idea of high temperatures starts with the assumption that black holes are 'extremal' in all aspects - high temperatures, high densities, high space curvature (sorry if it is not in English, I am translating Polish terms on the fly). That's not necessarily true, and - what is important - counterintuitively the larger the black hole, the more 'normal' are conditions below event horizon. What is going on at singularity is other thing.

 

Best,

Borek

--

Chemical calculators at www.chembuddy.com

pH calculation

concentration conversion

[woelen]

Indeed, I agree with you, situations just below the 'horizon' are not extreme at all.

 

I understand your word 'tidal' , I think it also is the English word, in Dutch it is called 'getijde'.