Context
You can hit stop at 3:15
Reflection Nebula Definition you need to know: A cloud of gas and dust that shines by reflecting the light of nearby stars.
Emission Nebula Definition you need to know: Glowing clouds of interstellar gas has been excited by a nearby energy source.
Magnets.... have a North Pole and A South Pole, a Positive and a Negative. This is because of things called ions. When you steal ions away it changes the way they work. An Emission Nebula has had these ions taken away making it so the gas gets "crazy" and moves away or toward certain things.