Close all of the blinds and curtains in a room, then turn off all the lights. Move around the room, feeling your way through. Can you identify any of the objects in the room by touch? What can you say about the matter surrounding these objects?
Think of it as dark matter. Dark matter is a substance that is known to exist but is itself undetectable. It has mass and is believed to take up greater than 90% of the mass of the Universe.
Can you name any other substances which have mass and are invisible?
What methods can be used to detect the presence of these substances?
This activity was developed by Jacqueline Slay, Largo High School, Largo, MD