What Happens When a Planet Nears the Speed of Light Near a Black Hole?

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SUMMARY

This discussion centers on the behavior of a planet approaching a black hole at relativistic speeds. Participants clarify that while the gravitational force increases as the planet nears the black hole, the planet's speed asymptotically approaches but never reaches the speed of light (c). The concept of relativistic mass is addressed, emphasizing that it does not equate to gravitational mass. Additionally, the conversation highlights that kinetic energy is frame-dependent, and no explosion occurs when particles like neutrinos reach high speeds in particle accelerators, as they do not emit radiation after crossing the event horizon of a black hole.

PREREQUISITES
  • Understanding of general relativity and black hole physics
  • Familiarity with relativistic velocity and Lorentz transformations
  • Knowledge of kinetic energy and its frame dependence
  • Basic principles of particle physics and behavior of neutrinos
NEXT STEPS
  • Study the implications of general relativity on black hole dynamics
  • Learn about the relativistic velocity addition formula
  • Explore the behavior of particles in high-energy physics experiments, such as those conducted at CERN
  • Investigate the concept of event horizons and their effects on matter and energy
USEFUL FOR

Astrophysicists, physicists studying high-energy particle interactions, and anyone interested in the relativistic effects of gravity near black holes.

  • #61
CERN's SPS accelerator can accelerate protons to an energy of at most 7*10-8 J. From there the protons are transferred into the LHC, used to produce neutrinos, or used in one of the other experiments around SPS.
  • It can transfer these protons to the LHC, where they are accelerated to an energy of at most 1.0*10-6 J.
  • It can shoot these protons onto a fixed target, the collisions create some pions with an energy of at most 7*10-8 J. Energy is conserved - the pions can't have more energy than the protons used to make them. The pions then decay, among the decay products are neutrinos with an energy of at most 7*10-8 J - again, this limit is given by conservation of energy. "At most" because some energy will go into other particles produced in both processes.

The energy in the SPS is limited because the SPS must be able to keep the protons on their circular track using strong magnets. If you would try to increase the energy then the protons wouldn't stay in the beam pipe and more and crash into the outer wall, getting lost in the process.

The LHC can reach a higher energy than the SPS because it is larger and has stronger magnets. It could be used to create neutrinos at higher energy - but similar to the SPS, the neutrino energy could not exceed the proton energy, so you get at most 1.0*10-6 J (and usually much less). Stronger magnets might double that in the future, but it will stay a tiny energy in macroscopic terms.

Note that I didn't use speed values anywhere: You can find the corresponding speed for each energy, but in practice this doesn't matter. The energy is a more useful quantity, then you don't have to count digits in things like "0.999999995 times the speed of light".
 
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  • #62
Yes I have understood that the CERN energy transfer to the neutrinos is low : but it is enough to increase the neutrinos speed in the relativistic area. As explained before by jbriggs444 (point #52), the kinetic energy of the neutrinos, seen by the CERN is 1 trillion more than the neutrinos rest energy. So the coeffcient Gamma is equal to 1 trillion (around) and so I have calculated that the neutrinos speed (seen by the CERN frame) should be : v = 0, 99999…9995 c with 24 numbers 9 !
So it is very near to c
And I understand also that the neutrinos speed limitation comes only by the reduction of energy transfer from the CERN particle accelerator. Reasons are technical and cost, as explained by jbriggs444 (point #52).

If we take the hypothesis that we arrive to increase the accelearor particle power (like the Chinese are doing now) or find a technical way to increase the energy transfer to the neutrinos speed, the effect will be to increase more the neutrinos speed : there will be more 9 in the value of v, but the speed v will always be less than c. The only consequences of increasing the energy transfer between the particle accelerator and the neutrinos particles will be to increase their speed : there is nothing know today that will try to reduce the neutrinos speed, even if the energy seen by the CERN will increase a lot : no creation of new particles on the neutrinos level, or creation of radiation on the neutrinos level or other effects (or new theory not known) ?

I am still very surprised that if we find a way to increase the transfer of energy between a particle accelerator and a particle with no limit the only effect will be to only to increase its speed ? but is what today the science explains
If there is no limit for the transfer of energy from a particle accelerator to a particle, the energy of this particle seen by the CERN (for example) would be very very high : and nothing will happen on the particle level or on the CERN side : no explosion I understand this now but nothing will try to reduce this huge energy ? this is what is difficult for me to understand, even if it is well explained by all your remarks : thank you again for this !
The CERN will see a huge energy and that's it !
 
  • #63
Anyone for tennis?
 
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  • #64
John SpaceY said:
I am still very surprised that if we find a way to increase the transfer of energy between a particle accelerator and a particle with no limit the only effect will be to only to increase its speed ?
Why would anything else happen? As far as the neutrino is concerned, it is at rest. Adding a bit more energy to a particle we've accelerated can no more have a weird effect than adding the first bit of energy.
 
  • #65
John SpaceY said:
have understood that the CERN energy transfer to the neutrinos is low

John SpaceY said:
The CERN will see a huge energy and that's it !

You are contradicting yourself. You need to take a step back and think about what you are saying.

John SpaceY said:
If there is no limit for the transfer of energy from a particle accelerator to a particle

There is a limit; any accelerator can only transfer a limited amount of energy to any particle. In the case of CERN, that limit is ##10^{-6}## J.
 

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