Laser Light
Laser light is a beam where all the light waves move together in one color and one direction.
A flashlight scatters light in all directions, like water splashing out of a bowl. A laser lines up all its waves on the same path, like water pouring in one stream into a glass. Every wave moves in step, aimed at the same spot.
Explaining laser light by grade level
Normal light spreads out in every color, like a flashlight. A laser is different. All its light moves the same way in one straight line. That is why a laser beam stays thin and bright, even far away.
Projects that explore laser light
Because a laser beam moves in one color and one direction, each photon carries the same wavelength of energy. When you aim red, green, and blue laser pointers at a solar cell, the red laser delivers the most power overall. Colored glass filters fail to block the beam significantly because the laser's single-wavelength light does not contain the mix of wavelengths that a broadband filter is designed to separate.
Laser light waves all travel in the same direction, which makes them ideal for revealing how light behaves as a wave. Shine a laser pointer through two narrow slits cut in cardboard and the spreading waves overlap on the other side. As a result, they interfere with each other — combining in some spots and canceling in others. The screen shows a pattern of alternating bright and dark bands that is three to four times wider than the single-slit result, proving that the synchronized waves can add or cancel depending on their alignment.