Posthumous publication eliminating force as a fundamental concept in favor of hidden masses.

Hertz proves cathode rays pass through aluminum foils, demonstrating subatomic penetration.

Demonstrated cathode rays pass through thin aluminum and gold foils.

Proved radio waves undergo reflection, refraction, and travel at light speed c.

Hertz confirms Maxwellian electromagnetic waves and discovers the Photoelectric Effect.

Constructed LC spark transmitter and ring receiver, generating and detecting radio waves.

Discovered that ultraviolet light ejects electric charges from metal spark electrodes.

Initiated experimental investigations into spark gap electric discharge phenomena.