Flickering Lights Science Fair Experiment


To conduct a simple experiment to understand the flickering effect of an LED bulb.

Materials required:

  1. A radio or any other device with an LED light. Or an LED bulb.


  1. Switch on the LED bulb.
  2. Stand around 4 to 10 feet away from the bulb and observe the light.
  3. Give a Bronx cheer. That is, make sound by blowing air through your lips and vibrating them. Observe how the LED light flickers.
  4. Try shaking you head very fast and see if the LED light is flickering.
  5. Do the Bronx cheer while looking at an incandescent light bulb and see if there is any flickering.

Scientific explanation:

Even though an LED light bulb seems to give out light constantly when it is turned on, it actually flickers on and off sixty times a second. However this is so fast that your eye usually can’t notice when the bulb goes off. Hence you see it as continuous light. However when you do the Bronx cheer, your entire body vibrates and your eyes see the LED bulb from different angles. Hence the flickering is noticed as the image of the bulb falls at different points on your retina instead of at the same point. An incandescent bulb does not flash on and off and gives a steady glow throughout the time it is kept on. Therefore this flickering effect does not come into play when you give a Bronx cheer looking at an incandescent lamp.