YES! Just what Reeko likes to see - a kid interested in learning! Check
back here every week to see what the new Science Word of the Day is. Just
think, after a year of this you'll be a genius!
LEDs are a special diode that emit light when connected to a battery. Each
LED has a semi-conductor "chip" inside of it. When an electrical
voltage is applied, the electrons will only flow in one direction and when the jump
across the chip they are attracted to other positively charged particles.
When a negative and positive charge are combined a "quantum" of energy
is emitted in the form of a "photon" of light. The color of the
LED light that is emitted is a result of what the chip is made of (typically the
elements gallium, arsenic, and phosphorus).
We may be going through a memorial time in history right now. LEDs may soon
replace the regular lights (called incandescent lights) that Thomas Edison invented
100 years ago. If you pay attention you may notice that things such as LED
flashlights are beginning to become popular. Many traffic stoplights are now
built using LEDs (the LED stoplights are the bright ones that look like they're
made of many small light bulbs). LEDs are much more durable that incandescent
lights, they are brighter, they don't get as hot, and they use less battery power.
The light is a very bright, white light instead of the yellowish color we see with
regular light bulbs. And best of all - they last a LONG time!
A typical traffic stop light burns out once a year. LED stoplights are expected
to last up to 10 years!
Pay attention to the various types of lights around you and you'll begin to notice
more and more of these lights being replaced with LED lights. Car manufacturers
are beginning to use them in the brake lights of new cars. TV monitors are
starting to use LED lights. Neon signs are being replaced with LED signs.
Even the Jefferson Memorial in Washington D.C. is now lit with LED lights.
As the chips used in the lights become cheaper and scientists figure out easier
ways to build them, we'll see LEDs used more and more in place of ordinary light.