1. Einstein showed that light travels in bundles called quanta, which are at
the heart of the light-emitting diode. When electrons in a semiconductor-based diode move from one side to another, they shift to a less excited state, releasing energy in the form of photons. Channel these, and you get a bright, long-lasting light source.
2. In 1917 Einstein demonstrated that when a photon comes into contact with an atom, it can trigger a chain-reaction release of additional photons from
local atoms. This phenomenon provided the theoretical basis for the laser. Without lasers, the data in Web pages would trudge along copper telephone lines instead of sprinting through fiber optics.
3. Einstein´s special theory of relativity shows that seconds tick by slower for satellites because they´re moving so much faster than ground receivers. Meanwhile, the general theory of relativity, which Einstein finalized in 1916, says that the decrease in gravitational pull at altitude speeds the flow of time for satellites. To keep GPS accurate, engineers adjust the satellites´ internal clocks.
4. The unexpected financier showed that water molecules bouncing around like pinballs caused the seemingly random motion of pollen in water. Derivations of those equations also describe the fluctuations of a stock´s price.
5. A common kind of smoke detector contains the radioactive element americium 241, which decays according to E=mc2. Radiation from the breakdown ionizes air molecules to create a smoke-sensitive electric field. In a world without smoke detectors, musicians constantly pass out drunk, drop lit cigarettes, and set their homes ablaze.
6. Devoid of even the cinematic notion of the laser, George Lucas must arm the characters in his epic films with guns.
7. Yes, Einstein has touched the lives of even couch potatoes. Remote controls rely on infrared LEDs.
8. Apparent canals observed on Mars led imaginations to run wild: water,
life . . . beavers.
9. Sunlight kicks electrons in photovoltaic panels out of their orbits; channeling the electrons generates power.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.