Glowing Light Ray in a Bottle

Super cool glow bottle that let you see light rays!

What you'll need

• Regularly shaped transparent bottle with cap
  

• Plenty of water
  

• Highlighter pen
  

• Laser
  

Instructions

1. Fill the transparent bottle full with water.

2. Take off the cap (or bottom) of the highlighter. Using tweezers, carefully take out the tube containing fluorescent ink.

3. Place the ink-tube into the water. Gently squeeze the ink tube using forceps to better leach out the ink into the water.

4. Tighten the lid. Invert the bottle several times to ensure even mix. Shine the laser from different angles of the bottle in a dark room and watch the light rays reflect and refract!

Hey, what's happening?

Laser light can be seen as a "solid ray" in a medium like this

. Fluorescent ink molecules absorb the high energy light, making their electrons hop up an energy level. The electrons soon drop down the energy level, releasing energy in the form of visible electromagnetic waves! That's why fluorescent ink appears unusually bright, especially when they get that extra concentrated energy from lasers! In other media such as a slightly-cloudy milk-water mixture, the laser beam could also be seen, though not so bright. This is caused by the photons scattering off the milk "particles" in all directions, and a fraction of the photons go into our eyes.