Heinrich Rudolf Hertz (German: [hɛʁʦ]; 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of electromagnetic waves theorized by James Clerk Maxwell's electromagnetic theory of light. Hertz proved the theory by engineering instruments to transmit and receive radio pulses using experimental procedures that ruled out all other known wireless phenomena. The scientific unit of frequency – cycles per second – was named the "hertz" in his honor.
Parallels occur when two planets are at the same declination, both in the north or south. They are considered to have the same effect as conjunctions. Contraparallels are when one star in the north and another in the south are at the same declination. They are considered to have the same effect as oppositions.