One Old Light bulb 800L-900L_TEKS_review

You flip the light switch and hear a crisp pop! The room remains dark, which can mean only one thing. It is time to replace the light bulb.

“Mom, I am getting a new bulb out of the closet,” you announce to your mother.

“Let it cool down,” your mother calls back.

She knows you have changed many light bulbs over the last few years. You learned long ago that light bulbs get really hot when they are on.

Imagine a light bulb that seems to last forever. A typical incandescent bulb may only last a few years but there is one bulb in a California firehouse that has broken all the records.  It has been illuminating light for over 100 years.  In fact, it has been burning bright since 1901. The bulb supports the phrase, “they don’t make them like they used to.” But do they? The answer to that is a little complicated.

Until just a few years ago, most light bulbs that were sold were similar to the one in the firehouse. This type of light bulb is called an incandescent bulb. These bulbs emit light as electricity is passed through a carbon filament.

As electrical current passes through the filament, it gets really hot and emits light. You can clearly see the filament in the centennial bulb pictured.

Electric current enters the light bulb, passes through the filament, and then travels back out. This loop through the light bulb completes the circuit,  allowing the bulb to light. When the filament in a bulb breaks, it opens the circuit and electric current will not move. 

These old bulbs had much thicker filaments than more modern bulbs. This thick filament is what has kept this bulb burning so long.

The problem with this type of light bulb though is it produces a lot of heat. Things that emit light also emit heat and these old bulbs produce a lot more heat than light.

That’s why newer bulbs are made with thinner filaments. This is also why it’s important to let the bulb cool off before you try to replace it.

Producing more heat than light wastes energy and electricity. Older light bulbs used 90% of their energy to produce heat so to conserve electricity, new light bulbs were developed that were more efficient. Many people now are replacing their light bulbs with another new version of the light bulb: LED bulbs. LED, is short for Light Emitting Diode. These bulbs are very efficient and extremely long lasting because they do not over heat and burn out as incandescent bulbs do. By using LED bulbs, families conserve energy and save a lot of money.

As you open the closet door, you see the box of bulbs. You carefully remove one from the box and return to your room. Your mother has brought the step stool for you to stand on. You check the old bulb to make sure it has cooled enough to touch, unscrew the old bulb and replace it with the new bulb.