مؤشر ليزر

They can wreck your eyes, and they can land you 14 years in jail for shining one at a police chopper. But where did they come from? When I was a freshman in college, I had a friend who spent more than $500 on a laser pointer powerful enough to reach the moon (and of course, devastate your vision). Combined with his penchant for downing cheap vodka, his fascination with this dangerous gadget was alarming: On the upside, though, he spent everything he had on the actual device and never amassed the money to buy a battery capable of actually powering the thing (I credit his poor financial decision-making for still having two working eyeballs today). I often wondered who and what made it possible for my alcoholic buddy to wield such a dangerous tool. They’ve been around in one form or another for a while, of course — the invention of lasers writ large can be traced all the way back to 1900, which was when famed German physicist Max Planck published a paper,%20Distribution%20Law.pdf) surmising that energy is made of individual units, which he called quanta . His theory would later inspire Albert Einstein, who became the first person to realize that light is made up of photons in 1905. Using this knowledge, Einstein proposed a theory called stimulated emission , a process by which electrons (previously known as the aforementioned quanta) can be stimulated to emanate light of a particular wavelength. This is the process that would eventually make lasers possible. Forty years later, Columbia University professor Charles Townes conceptualized a device that would come to be known as a maser (microwave amplification by stimulated emission of radiation) while sitting on a park bench in Washington. Based on Einstein’s stimulated emission theory, the device was able to amplify and even generate electromagnetic waves. A few years later, in 1957, Columbia University graduate student Gordon Gould scribbled the acronym LASER (light amplification by stimulated emission of radiation) and described the elements needed for constructing one in his notebook, which would eventually become the focus of a 30-year court battle for the patent rights to the device. Furthering the excitement surrounding laser pointers and the devices that utilized them, in 1986, Worlds of Wonder) released Lazer Tag . Much like every other form of laser gun game today, Lazer Tag included laser pointing toy guns and wearable vests that would acknowledge (i.e., flash and make some noise) when you were shot. Lazer Tag caused some controversy upon its release: Similar to the baseless accusations around modern gaming , many parents believed that Lazer Tag encouraged gun violence. While there was indeed at least one instance of bloodshed involving the game, it wasn’t on the part of an actual gamer: In 1987, a deputy shot and killed 19-year-old Leonard Falcon while he and three friends were playing Lazer Tag at an elementary school in Southern California, allegedly mistaking the toys for real guns. Some believe the negative publicity associated with the incident resulted in Worlds of Wonder’s dissolution the following year. Although many commercial pointers remained pretty chunky through the 1980s — just look at this 1987 Aerotech LS2R — in the 1990s, we started seeing more and more of the pen-like laser pointers, such as the Laserex Model LDP-300 Diode Laser Pointer (you can check out a whole assortment of 1990s laser pointers here if you’re feeling nostalgic). These days, laser pointers serve all kinds of purposes, including in educational and business presentations as eye-catching devices; in construction to help measure distances while working on large-scale projects; and at music festivals to ensure you have the wildest drug-induced experience of your life. In Beijing, ushers at theaters and other venues even use laser pointers to zap patrons on their cellphones during performances, a controversial (but effective) tactic considering the dangers these devices pose to your