1. Plants need inputs to grow
2. Growing plants without soil
Week 3 - The environment has an effect on all living things
Week 4 - Chemical and Physical reactions
Week 5 - Introduction to Light
6. Energy
7. Growing Peas
8. Heat and Energy
9. Corn

Reflection / Refraction

But when that laser hits a mirror, it will reflect, just like a flashlight does, because the photons are bouncing off the surface of the mirror. Reflection is a property of light, where the photons bounce off the surface of the material it hits.

When you shine a laser into a piece of glass some of the photons will reflect, and some will travel through the glass. When the photons hit the glass, they start to travel through the glass instead of travelling through the air. Because glass and air are not the same, the photons change speed. Sometimes when they change speed, their direction also changes. This is called refraction, the change in direction as waves move from travelling through one material into a different material.

When lasers refract, they change direction. Refraction is often called the bending of light because of how this looks. Lasers can be created in any color, and all of the different colors reflect exactly the same. But when different color lasers refract, they do not behave the same. Different color lights travel in different types of waves, and this makes them change direction differently depending on the wavelength. Red has the longest wavelength and refracts the least, and violet has the shortest wavelength and refracts the most.

Better image of colored lasers refracting needed

When you think of light as a wave, think of it like an ocean wave. The amplitude of the wave is the distance from sea level to the top of the wave, which is called it’s crest. The distance from the crest of one wave to the crest of the next wave is its wavelength. And with light waves, just like with sea waves, the greater the amplitude of a wave then the more energy it is has.