Notes concerning “Energy harvesting”

• Long distance radio 02020-07-17 (19 minutes)
• Minimal cost computer 02020-10-23 (updated 02020-12-01) (12 minutes)
• Geomagnetic energy harvesting is barely feasible at near-kilometer scales 02020-11-24 (3 minutes)
• Lava time capsule 02020-11-24 (8 minutes)