Minute Physics is at it again: science in under 10 seconds. 9.99s videos are enough to get a broad image and to understand some phenomenons. You only need to check more if you need more info.
Microwaves are electromagnetic waves that can cook our food. They are low energy waves that can heat up matter, but they have a wavelengths bigger than the crystals of glass and thus they cannot escape the oven:
There is no dark side of the Moon. There is, in fact, a side that we do not see, but it has all the cycles of day/night that every revolving cosmic object has. We do not see that side because the Moon orbits around the Earth in the same time it rotates around its axis:
The sky is blue due to the fact that the blue light gets scattered more into the atmosphere than the other colors: