- How does a microwave oven heat up food even though it emits no thermal radiation?
- How does diffraction make a tree's shadow blurry?
- Light has no mass so it also has no energy according to Einstein, but how can sunlight warm the earth without energy?
- What is the color of the sun?
- Why doesn't the outside world appear blue even though so much light comes from the blue sky?
- Why is the sun cold in the winter?