English Culture

MARIO RITTER: Welcome to EXPLORATIONS in VOA Special English. I’m Mario Ritter. This week, we tell about one of the most recognizable objects in science fiction — the laser. It is one of the best examples of how technology can go from the science of the future to everyday use in a short period of time. Faith Lapidus and Steve Ember tell us about the history and many uses for the laser.
(MUSIC)FAITH LAPIDUS: Laser is short for Light Amplification by Stimulated Emission of Radiation. The idea behind lasers is complex. Just how complex? Consider that it took the mind of Albert Einstein to discover the physics behind the laser.
Theodore Maiman succeed in building the first working laser in nineteen sixty. Mr. Maiman worked at Hughes Research Laboratories in Malibu, California.
A laserfires a light beam. Before the laser, scientists developed a similar device: a maser which stands for Microwave Amplification by Stimulated Emission of Radiation. A maser is basically a microwave version of the laser. Microwaves are a form of electromagnetic radiation similar to, but shorter than, radio waves. The best-known use of masers is in highly accurate clocks.
In the nineteen fifties,researchers in the United States and Russia independently developed the technology that made both masers and lasers possible. Charles Townes was a professor at the Massachusetts Institute of Technology in Cambridge, Massachusetts. He and his students developed the first maser.
Russians Nicolay Basov and Aleksandr Prokhorov did their research in Moscow. Their work led to technology important to lasersand masers. The three men received the Nobel Prize in Physics in nineteen sixty-four.
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STEVE EMBER: The idea of a thin beam of light with deadly power came much earlier. By the end of the eighteen hundreds, the industrial revolution had shown that science could invent machines with almost magical powers. And some writers of the time were the first to imagine something like a laser.
Ineighteen ninety-eighty, H.G. Wells published a science fiction novel called “The War of the Worlds.” In it, he described creatures from the planet Mars that had technology far beyond anything on Earth. Among their weapons was what Wells called a “heat ray.” Listen to actor Orson Welles describe the weapon in a famous radio broadcast of “The War of the Worlds” from nineteen thirty-eight.
ORSONWELLES (as PROFESSOR PIERSON): “I shall refer to the mysterious weapon as a heat ray… It's my guess that in some way they are able to generate an intense heat in a chamber of practically absolute non-conductivity. This intense heat they project in a parallel beam against any object they choose, by means of a polished parabolic mirror of unknown composition, much as the mirror of a lighthouse projects abeam of light. That -- That is my conjecture of the origin of the heat ray.”
FAITH LAPIDUS: H.G. Wells’ description is not too far from the truth. All lasers have several things in common. They have a material that supplies electrons and a power source that lifts the energy level of those electrons. And, as Wells guessed, many lasers have mirrors that direct light.
Laser light is different fromdaylight or electric lights. It has one wavelength or color. Laser light is also highly organized. Light behaves like a wave and laser light launches in one orderly wave at a time from its source.
MARIO RITTER: You are listening to the VOA Special English program EXPLORATIONS.
STEVE EMBER: The physics of the laser may be complex. Still, it is just a story of how electrons interact with light.When a light particle, or photon, hits an electron, the electron jumps to a higher energy state. If another photon strikes one of these high-energy electrons, the electron releases two photons that travel together at the same wavelength. When this process is repeated enough, lots of organized, or coherent, photons are produced.
In Theodore Maiman’s first laser, a rod of man-made ruby supplied...