New & Timely
October 1969 Radio-Electronics

October 1969 Radio-Electronics [Table of Contents] Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Electronics, published 1930-1988. All copyrights hereby acknowledged.

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New & Timely

Readings Indicate Gravity Phenomena

Simultaneous readings on instruments 600 miles apart suggest a new phenomena - gravity waves - have been detected. Recordings were made near Chicago and College Park, Md. by Dr. Joseph Weber, a physicist, and his colleagues. The detectors for gravity waves are aluminum cylinders 5 feet long encircled with quartz piezo-electric crystals that generate electric pulses when the cylinders oscillate. The cylinders are cushioned against tremors originating in the earth.

According to relativity theory, the cylinders should oscillate as the gravity waves pass through the space-time continuum. The oscillation frequency is about 1660 Hz. in this experiment.

Further observations and confirmation of the discovery may help to resolve conflicting theories on the origin of the universe and the distribution of matter.

Magnetic 'Bubbles' Move in Rare Earths

Murray Hill, N.J.-A new technology involving magnetic "bubble" movement in crystalline materials is being studied at Bell Labs for use in logic, memory, switching and counting functions.

The magnetic bubbles, seen as light dots in the photo, are about 0.004 inch in diameter, and move through the magnetic material in which they are formed. The circuit pattern in the photo is etched on the surface of a thulium orthoferrite sheet, a rare-earth iron oxide, and signals applied to the circuit magnetically control the paths of the bubbles. The bubbles can also be directed with external magnetic fields.

Much smaller bubbles, the size of a few wavelengths of light, can also be manipulated, and may lead to memory densities of 1 million bits per square inch. In applications such as shift registers, data rates of 3 million bits per second have been demonstrated.

The presence or absence of the bubbles can be detected, they respond to each other's proximity (attracting or repelling) and can be combined or separated with no change in their size. Bell, who was granted a patent for the discovery, suggests "a computer on a slice" may become practical after more work is done with the technique.

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