Schwarzschild radius of an object is smaller than Planck length

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Discussion Overview

The discussion revolves around the implications of the Schwarzschild radius being smaller than the Planck length, particularly in the context of black holes potentially produced in particle accelerators like the LHC. Participants explore the relationship between mass, speed, and the Schwarzschild radius, as well as the limitations of current theories in addressing these scenarios.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant calculates that any mass greater than 9.375×107 kg has a Schwarzschild radius smaller than the Planck length and questions the implications for black holes with such small radii.
  • Another participant asserts that relativistic mass does not factor into general relativity when calculating the Schwarzschild radius, suggesting that the apparent mass of fast-moving particles is irrelevant.
  • A later reply indicates uncertainty about what happens to black holes with radii smaller than measurable lengths, noting the limitations of general relativity and quantum mechanics in addressing these extreme conditions.
  • Participants express that the concept of mass increasing with speed is often misunderstood and should be unlearned for a better understanding of relativity.
  • References to earlier threads are provided, indicating that the consensus remains that relativistic mass does not apply in this context.

Areas of Agreement / Disagreement

Participants generally agree that relativistic mass does not apply to the calculation of the Schwarzschild radius, but there is no consensus on the implications of black holes having radii smaller than the Planck length, and the discussion remains unresolved regarding the nature of such black holes.

Contextual Notes

The discussion highlights limitations in current theories, particularly the lack of a unified theory that reconciles general relativity and quantum mechanics at extreme scales. There are also unresolved questions regarding the implications of black holes with radii smaller than the smallest measurable length.

ColdheartedGod
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I had this idea when some people said that LHC can produce black hole. Based on the calculation of Schwarzschild Radius, any mass than 9.375×10^7 kg have a Schwarzschild radius smaller than the plank length. Particles inside LHC or other particle accelerator have clearly radii smaller than that.
what will happen to the black hole with smaller radius than the smallest measurable length?
On the other hand, mass moving at a high speed will undergo an increase of apparent mass, will that be counted as its actual mass when calculating the Schwarzschild radius in the case of particle accelerator?
 
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ColdheartedGod said:
On the other hand, mass moving at a high speed will undergo an increase of apparent mass, will that be counted as its actual mass when calculating the Schwarzschild radius in the case of particle accelerator?

This question gets asked a lot. The simple answer is "no". Relativistic mass has no relevance to GR.
 
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ColdheartedGod said:
what will happen to the black hole with smaller radius than the smallest measurable length?
No one knows.

We have a theory (general relativity) which tells us what happens with intense gravitational fields as long as the distances involved aren't too small. We have a theory (quantum mechanics) which tells us what happens at very small distances as long as the gravitational fields aren’t too strong. We’re still looking for a a unified theory that works with both very small distances and very strong gravitational fields.
On the other hand, mass moving at a high speed will undergo an increase of apparent mass, will that be counted as its actual mass when calculating the Schwarzschild radius in the case of particle accelerator?
No.
(This idea that mass increases with speed is very easily misunderstood; in fact it’s one of those things that you have to unlearn if you want to seriously understand relativity. We have many threads and an Insights article if you want to learn more about why).
 
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