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Science Newsfront

Last-minute news and notes to keep you up-to-date

By ARTHUR FISHER

NASA fights auto pollution

The big guns of aerospace technology are being enlisted in the battle against the major source of air pollution in this country—automobile exhaust. The mission: to reduce the one-quarter to one-half ton of carbon monoxide and hydrocarbons each car spews into the atmosphere in a year, as a result of incomplete fuel combustion. The battle plan: Develop a thermal reactor that would replace the standard exhaust manifold and serve as an afterburner. But such a reactor must withstand temperatures occasionally exceeding 2,000 degrees F, thermal shock from cold starts, and jarring vibrations—all problems routinely encountered in space exploration. Read the rest of this entry »

Not bad, this was published six months after the first laser was demonstrated.

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A True Light Amplifier

UNTIL now, no one has been able to take a light ray and amplify it thousands of times as we can with radio waves. Some attempts have been made using photomultiplier tubes and similar means, but the success has been limited and the amount of amplification possible by these methods small. Now, by modifying the Maser (see “The Amazing Masers” February, 1959 issue of Electronics Illustrated), Hughes Aircraft Company scientists have been able to produce an experimental light amplifier that treats light as if it were just a radio wave, which it really is. Read the rest of this entry »

Cutting wood with a beam of light

A new technique in woodworking may be on the way. The University of Michigan has developed a tool that cuts through maple and other hardwoods with bursts of light that act like the science-fiction writers’ disintegrating-ray gun. The experimental drill operates with a laser (light amplification by stimulated electron radiation) head that contains a coiled xenon flash tube and a ruby rod. It builds up intensely hot light pulses, focuses them through a lens to vaporize a hole in a block of wood instantly without leaving char. It’s not ready yet for the home workshop.

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The coming record revolution: digital discs

A laser “reads” the compact, no-wear disc to deliver superior hi-fi

By LEONARD FELDMAN

Tokyo, Japan

A Sony technician slipped a small disc into the slot of a player no larger than a portable cassette machine. I noticed the record’s shiny surface broke light into rainbow colors. Seconds later I was bathed in rich, wide-ranging stereo music that sounded better than anything I’d ever heard from discs or tapes.

Sony Corporation’s Dr. Toshi Doi, a leading digital-systems designer, explained that this was a true digital record: Information stored as number codes on its surface was being converted into music. Instead of grooves, this disc had an optical track “read” by a laser beam. I heard absolutely no surface noise or distortion and no pitch fluctuations from the spinning disc. Dynamic range, or the difference between the loudest and softest musical sounds, was awesome.
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Pointer
The Laser Pointer projects a visible bright red spot of light several hundred feet under normal lighting conditions-great for lecturers with slides. The $800 helium-neon laser has an output of 0.5 mW—not enough to harm eyes or body, says RMF Products, Box 413, Batavia, III., 60510.

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How Lasers Are Going to Work for You

The light fantastic is no longer a scientific curiosity: It’s now being used for just about everything from moon measuring to tire checking

By C. P. GILMORE / PS Consulting Editor, Science

At RCA’s David Sarnoff Laboratory in Princeton, N.J., Dr. Henry Kressel handed to me what appeared to be an odd-looking gold-colored bolt about three quarters of an inch long. The threaded part was ordinary enough. But a small block perhaps a quarter of an inch long and half that thick was built onto one side of its flat head. A wire from the head arched up and connected to the side of the block.

“That’s the laser,” he said, pointing to where the wire joined the block. “This metal block?” I asked.

He took the device, walked into a laboratory next door, put it under a powerful binocular microscope, and peered into the instrument as he adjusted it.
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Laser May Guide Space Ships
GREATLY amplified light beams may provide optical lane” navigation systems to guide planes or spaceships of the future, using a newly-developed material.
Scientists at the IBM Research Center, Yorktown, N. Y., have announced a laser (Light Amplification by Stimulated Emission of Radiation) that gives the first continuous beam of amplified light. It uses uranium ions in a cylindrical 1-1/2-in. crystal instead of the ruby in a previously-announced laser (see p. 94, Nov. ‘60 S&M). The earlier amplifier could transmit light only in widely-spaced pulses of about .001 second and needed about 500 times as much power as the uranium type. IBM says future refinements now depend on improved optical design rather than advances in materials research.

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PS Builds a LASER …and so can you

The incredible ruby ray is the hottest scientific discovery of the decade, but practical uses are still scarce. Here’s your chance to join the search

-June, 1960: Dr. T.H. Maiman, of the Hughes Aircraft Co., reports the development of the first successful ruby laser.
—November, 1964: Popular Science publishes plans for the first do-it-yourself ruby laser.

By Ronald M. Benrey

IT MAY sound like science fiction— but it’s really science fact: You can build a working ruby laser. It could be the most challenging—and rewarding— home-workshop project that you have ever tackled.

A ruby laser is a source of coherent light. All of the light waves in the pencil-thin, bright-red ruby laser beam are in phase—or in step—with each other. This extraordinary property of the laser beam—shared by no other light source—has spurred a world-wide search for practical uses.

Ordinary light sources—a light bulb, for example—generate incoherent light; the light waves are out of phase with each other.

Drop a pebble into a still pond, and the waves ripple out smoothly in all directions. This represents a single light wave from a light source. All light sources produce more than a single wave, however.

They act as if you dropped a handful of pebbles at once: You get a jumbled clutter of waves one on top of another. This clutter of waves is analogous to incoherent light.

Suppose, though, you dropped your handful of pebbles one pebble at a time, each in exactly the same spot in the pond. The waves would continuously radiate from that point. All of the wave crests would be in phase. This is coherent radiation.

A ruby laser generates a coherent light beam by a similar process. Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Inside the ruby laser rod—heart of the ruby laser—excited atoms are stimulated to emit light waves in phase with each other.
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