A step beyond a black hole?

In summary: Summary:: In summary, iron doesn't create energy because its binding energy per nucleon is higher than other elements.
  • #1
LightningInAJar
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TL;DR Summary
Anything beyond iron?
I know black holes are stars that fuse together elements until they reach iron which doesn't radiate energy to counterbalance the gravity, but do any stars fuse elements heavier than iron that would once again give off energy prior to it imploding?

By the way, why doesn't iron creation create radiation?
 
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  • #2
LightningInAJar said:
Summary:: Anything beyond iron?

I know black holes are stars that fuse together elements until they reach iron which doesn't radiate energy to counterbalance the gravity
This is incorrect. A black hole is a region of spacetime from which light cannot escape.

Regarding fusing of elements: Iron has the highest binding energy per nucleon. It would not be energetically favorable to fusion it to heavier elements.
 
  • #3
As Orodruin says, a black hole is not just a star that's stopped fusing. That leads to a (super)nova and some larger stars collapse into black holes, but a black hole is very different from a star.

All sorts of heavy elements get produced in supernovae. I'm sure they get produced in tiny quantities in during normal operation, but it's an energy absorber not a producer so the process isn't self-sustaining. That's why you don't see iron-burning stars - it's the fusion equivalent of trying to light ashes.

As to why iron doesn't produce energy, the binding energy per nucleon changes as the atomic mass rises. It first increases, meaning that one helium atom needs slightly more energy to separate it into four nucleons than two deuterium atoms do. So two deuterium atoms combining into one helium leaves a bit of energy over.

But that stops at iron, and then the trend reverses. Very heavy elements need less energy to separate into components than smaller ones, so combining smaller atoms costs energy. Splitting large atoms into smaller ones (down to iron) releases energy - which is nuclear fission.

The underlying reason for the differences in binding energy is the balance between the strong force holding the nucleus together and increasing amounts of electrostatic repulsion between the increasing number of protons.
 
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  • #4
LightningInAJar said:
Summary:: Anything beyond iron?

I know black holes are stars that fuse together elements until they reach iron which doesn't radiate energy to counterbalance the gravity
You have a very bad habit of starting threads with "I know that" followed by something totally false. These are bad starts. Please stop this.
 
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  • #5
LightningInAJar said:
Summary:: Anything beyond iron?

By the way, why doesn't iron creation create radiation?
It does in some cases, for example the decay of Ni-56 to Fe-56.

Before you can understand the nuclear reactions involved in stellar evolution and collapse you will need a better understanding of the most important nuclear processes: fusion, fission, alpha and beta decay - you might start by searching for "binding energy curve" and "decay chain".

As this thread is based on a misunderstanding that has been addressed, it is closed.
 
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1. What is a black hole and how is it formed?

A black hole is a region in space where the gravitational pull is so strong that nothing, including light, can escape from it. It is formed when a massive star dies and its core collapses under its own gravity.

2. Can anything escape from a black hole?

No, once something enters the event horizon of a black hole, it cannot escape. The gravitational pull is too strong for anything to overcome.

3. What is a singularity and how is it related to a black hole?

A singularity is a point in space where the laws of physics break down. It is believed that the center of a black hole is a singularity, where the gravitational pull is infinite and the laws of physics as we know them do not apply.

4. Is there anything beyond a black hole?

It is currently unknown what lies beyond the event horizon of a black hole. Some theories suggest that there may be a parallel universe or a white hole on the other side, but this is still a topic of debate among scientists.

5. Can a black hole be destroyed?

No, a black hole cannot be destroyed. It will continue to exist as long as there is mass and energy within it. However, it is possible for a black hole to lose mass over time through a process called Hawking radiation.

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