Laser

In 1960, Theodore Maiman at Hughes Research Labs won the race to build the first working laser using a ruby crystal, but Gordon Gould coined the term "laser" and sketched the fundamental designs in his 1957 notebooks. What followed was a 30-year patent battle—one of the most contentious in scientific history—with Gould finally winning crucial patents in the 1980s and earning millions. The irony? Most scientists initially dismissed lasers as "a solution looking for a problem," with one Nobel laureate calling them a "scientific curiosity with no practical applications."

Albert Einstein predicted stimulated emission—the fundamental principle behind lasers—in 1917, four decades before anyone built one. He was exploring how atoms and light interact at the quantum level, never imagining his theoretical work would lead to barcode scanners and laser eye surgery. This might be Einstein's most transformative but least celebrated contribution, affecting billions of daily transactions and medical procedures worldwide.

Unlike ordinary light that spreads in all directions with mixed wavelengths, laser light is coherent—all waves march in lockstep with the same wavelength and phase. This is why a laser pointer stays focused across a room while a flashlight diffuses, and why lasers can concentrate enough energy to cut steel or perform delicate retinal surgery. The same property lets fiber-optic cables carry your video call thousands of miles without the signal degrading into noise.

Early military funding for lasers focused on developing "death ray" weapons, but the technology's killer apps turned out to be remarkably peaceful. Every CD, DVD, and Blu-ray player reads data using laser light, making lasers the delivery mechanism for most entertainment consumed from the 1980s through 2010s. Today, lasers enable everything from barcode scanners (saving retail workers from pricing every item by hand) to LIDAR systems that help self-driving cars "see" their surroundings in three dimensions.

LASIK eye surgery reshapes your cornea with a laser guided by a computer to micron-level precision, completing in minutes what previously required invasive surgery and weeks of recovery. But lasers have transformed medicine far beyond vision correction—they remove tumors, break up kidney stones, perform delicate brain surgery, and even activate specific neurons in living brains for neuroscience research. The reason? Lasers deliver energy with unprecedented spatial and temporal precision, targeting problem areas while leaving surrounding tissue unharmed.

When you stream a video or video chat across continents, your data rides on laser pulses flashing through fiber-optic cables at the speed of light. A single fiber can carry 178 terabits per second—enough bandwidth to simultaneously stream 178 million high-definition videos. Without lasers, the internet as we know it couldn't exist; traditional electrical signals over copper wires can't carry information fast enough or far enough to support modern global communications.