Alexander Graham Bell and Charles Sumner Tainter demonstrate the photophone, a device in which a mirrored silver disc is made to vibrate by speech from a speaking tube. Light reflected off the disc is captured in a parabolic dish and focused onto a selenium cell, where variations in the reflected light are converted into the electrical signals that are carried to headphones. The laser disc and CD of the seventies will work on a remarkably similar principle.
Guglielmo Marconi is granted a patent for a system of tuned coupled circuits that allow simultaneous radio transmissions on different frequencies, allowing adjacent stations to operate without interfering with one another. (UK patent 7777)
The first film screening in Hawaii is held.
In an article in the April 26th Look magazine, “Deac” Aylesworth predicts that radio is “doomed” and that television will overtake it within three years.
International Business Machines (IBM) sends out a press release regarding its IBM 7030, otherwise known are the Stretch supercomputer. “The $10-million-and-up class computers are the world’s fastest and most powerful. They are similar to the STRETCH computer which IBM is now completing for the Atomic Energy Commission at Los Alamos, New Mexico. IBM will now contract with business firms and government agencies to build STRETCH type computers. They can complete 100 billion computations in a day. The new machines are seventy-five times faster than the large-scale IBM 704 computer.”
The NASA Ranger 4 spacecraft crashes into the Moon after sixty-four hours of flight. The probe’s mission is to rough-land a seismometer capsule on the Moon, to collect gamma-ray data in flight, to study the radar reflectivity of the lunar surface, and to continue testing the Ranger program for development of lunar and interplanetary spacecraft.
Tandy introduces the TRS-80 Model 4 computer, featuring a 4MHz Zilog Z80A processor, 16KB RAM, a cassette interface, a keyboard, and an 80×24 text 12-inch monochrome monitor. Price: US$1,000 or US$2,000 with 64KB RAM and two 180KB 5.25-inch floppy drives
In Pripet, Russia, the fourth reactor of the Chernobyl nuclear power plant explodes in the world’s worst civil nuclear catastrophe, sending a cloud of radioactive dust into the atmosphere over Europe. Radioactive fallout will result in the evacuation and relocation of over 336,000 people. Fifty-six people die in the explosion, and thirty-one people, most of whom are firemen, are killed immediately following the explosion. Several thousand more people in the immediate region will die from radiation-caused disease. Visit the oOfficial UN Chernobyl site
The anime series Dragon Ball Z premieres in Japan and Hong Kong on Fuji Television at 7:00pm with the episode “Arrival of Raditz / The New Threat.” The series will run for 291 episodes until January 31, 1996. It is based on the twenty-six volume manga series of the same name.
The Space Shuttle Columbia is launched on the second German sponsored D-2 Spacelab Mission. Eighty-eight experiments will be conducted before the shuttle returns on May 6th, covering a broad range of disciplines. Two hundred forty tadpoles and two hundred-forty fish larvae are carried aboard the shuttle to test how they will adjust to weightlessness in space, but most of the specimens will die in orbit. During the mission, specialist Dr. Bernard Harris will set up the first intravenous line in space, injecting payload specialist Hans Schlegel with saline as part of a study on replacing body fluids lost during weightlessness. This mission will bring the shuttle program’s cumulative flight time to one year.