Why Space Elevators Can't Mine Black Holes – Adam Brown

Adam Brown explains why the laws of physics forbid ropes strong enough to mine black holes, and why small black holes could be near-100%-efficient power plants.

• A solar-mass black hole left alone takes 10^55 times the current age of the universe to radiate away its energy via Hawking radiation.
• Proposed fix: dangle a rope near the event horizon to drag radiation away — effectively a black-hole space elevator — but material science kills it.
• Carbon nanotubes barely work for an Earth space elevator; they score ~10^-12 on the tensile-strength-to-mass ratio needed for a black hole rope — nowhere close.
• The speed of light sets a hard upper bound on tensile strength per unit mass (c²); a fundamental string from string theory saturates that bound but has zero leftover strength to carry any payload.
• Black hole temperature is inversely proportional to size, so smaller black holes radiate faster and are more useful as near-term energy sources.
• Chemical reactions extract ~1 part in 10 billion of MC²; nuclear fission ~1 part in 1,000; both are limited by baryon number conservation.
• Only gravity violates baryon number: throwing protons and neutrons into a small black hole converts their full rest mass into photons, gravitons, and neutrinos — approaching 100% MC² efficiency in principle.

2025-01-14 · Watch on YouTube