The Invisible Blanket
Prove that air really takes up space.
What this lesson covers
Why it matters
Air looks like nothing, but push an upturned glass straight down into water and the water can't get in — something is already in there.
Predict first
Push an empty upturned glass straight down into a tub of water. What happens to the water inside the glass?
Air is real matter — it takes up space and has mass. In the upturned-glass experiment, the trapped air keeps the water out, proving air occupies space.
- It barely rises — air in the glass blocks it — correct
- It fills the glass completely
- It turns into air
What you do
Put the experiment steps in order to show that air takes up space.
Check yourself
Why couldn't the water rise into the upturned glass?
The trapped air takes up the space, so water can't enter until the air escapes.
When you tilted the glass, bubbles escaped because…
Tilting lets the trapped air bubble out, and water fills the space it leaves.
- Air already filled the space inside — correct
- Water is too heavy to rise
- The glass was wet inside
- the air left and water took its place — correct
- the water turned into air
- new air was created