Physics
Wireless Power Transfer via Resonant Magnetic Coupling
Quick fact
Nikola Tesla demonstrated wireless power transmission over 100 years ago, but resonant systems remained largely a curiosity until the 21st century, when they were reinvented for practical charging devices.
Why this is interesting
You can charge your phone just by placing it on a pad—no wires, no plug. But how does electricity travel through the air, and why doesn’t it shock you?