why is water reflective?
In: Physics
ELI5: if you’ve ever rubbed a balloon on your shirt and then held it close to your hair, you can see your hair get pulled towards the balloon without them even touching. This is because you took electrons from your shirt and put them on the balloon. When you hold the balloon near your hair, the electrons in the balloon pull on your hair because your hair also has electrons and nuclei. This is a good way to visualize how electric charges interact with each other. The “pull” is called an electric field. Light is made up of very tiny waves that pull up down up down as they travel, so when light waves hit a surface, they can feel the charges in the new material and decide to travel in one new direction. Since the light is traveling in the same direction to start, and since they all feel the new charge in the same way, they all decide to change direction at the same angle. The only time you can see reflections is when the surface is smooth because the light doesn’t scatter when it changes direction. Water is a liquid so its surface is smooth.
ELI10: Light travels as waves made of an electric field and magnetic field, and materials are made of atoms that have positive and negative charges (nucleus and electrons), so when light waves travel through air and hit the surface of a new material such as glass, the electric charges in the glass make the waves change direction. If the surface of the glass is smooth, the angle of incoming light matches the angle of reflected light, so you can see objects in your house. If the surface is rough, the reflected waves scatter in many directions so you can’t make out objects.
The surface of liquids are smooth. There might be ripples because of wind, but if you zoom in enough the atoms on the surface of the liquid look smooth. Water molecules have electrons and nuclei arranged differently than those in air, so the same thing happens as with glass and air.
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