Interstellar and science

 from copilot:

Yes—absolutely. A planet could orbit a black hole closely enough and fast enough for strong relativistic effects to be important. Whether it can do so without being destroyed depends primarily on the black hole’s mass and the orbital radius.

Here’s how it works.

1. Relativistic effects come from speed and gravity

Two main relativistic effects are relevant:

1. Special relativistic time dilation – from moving at a significant fraction of the speed of light.
   
2. Gravitational time dilation – from being deep in a strong gravitational field.
   

Near a black hole, both can be extreme.

2. How close can something orbit a black hole?

There is a minimum stable orbit called the ISCO (Innermost Stable Circular Orbit).

For a non-rotating (Schwarzschild) black hole:

• ISCO = 3× the Schwarzschild radius
  
• Orbital speed there ≈ 0.5c
  

For a rapidly rotating (Kerr) black hole:

• ISCO can be much closer
  
• Orbital speeds can exceed 0.9c
  

At these speeds and gravitational depths, relativistic effects are enormous.

3. Could a planet survive there?

This depends critically on the black hole’s mass.

❌ Stellar-mass black hole (≈ 5–20 solar masses)

• Tidal forces near the ISCO are catastrophic
  
• A planet would be torn apart into a debris disk
  
• No survivable orbit
  

✅ Supermassive black hole (millions–billions of solar masses)

• Event horizon is huge
  
• Tidal forces near the ISCO are much weaker
  
• A planet could survive intact
  

👉 Counterintuitively, bigger black holes are gentler near the horizon.

4. How strong could the relativistic effects be?

For a planet orbiting close to the ISCO of a supermassive black hole:

• Time dilation:
• 1 hour on the planet could equal days, years, or more far away
  
• Orbital velocity:
• 30–90% of the speed of light
  
• Gravitational redshift:
• Light leaving the planet would be strongly redshifted
  
• Frame dragging (if the black hole spins):
• Space itself is pulled along with the orbit
  

This is not science fiction—these are direct predictions of general relativity.

5. Realistic caveats

While physically possible, such a planet would face challenges:

• Intense radiation from accretion disks
  
• Long-term orbital stability issues
  
• Difficulty forming naturally (it might be captured)
  

But nothing in physics forbids it.

6. Famous example

The idea was popularized in Interstellar:

• Planet Miller’s Planet
  
• Orbits a rapidly rotating supermassive black hole
  
• Time dilation ratio ≈ 1 hour = 7 years
  
• While dramatized, the scenario is theoretically plausible
  

Bottom line

✅ Yes, a planet can orbit close enough to a black hole to experience strong relativistic effects
✅ This requires a supermassive, likely rapidly spinning black hole
❌ It is not survivable near stellar-mass black holes

If you’d like, I can:

• Show the math behind time dilation
  
• Compare rotating vs non-rotating black holes
  
• Explore habitability implications
  
• Break down what Interstellar got right vs wrong
  

Just tell me where you want to go next.