Read this aloud:
Since the 1960s, people have put lamps on their shelves with glowing blobs inside that drifted slowly up, then sank back down, over and over. Nobody pushed them. There was no motor inside. Today we're going to build our own blob machine with no plug at all, using things from the kitchen. Your job: figure out what makes the blobs go up, and what makes them come back down.
Jobs for one, two or three kids:
- Pourer: pours the water and oil.
- Dropper: adds the colouring and drops in the tablet pieces.
- Watcher: times the fizzing and says out loud what the blobs are doing.
One child? They do all three. Two? Pourer and Dropper swap halfway, and both watch.
In the full lesson PDF
- Bet (5 min)
- Hunt (20–30 min)
- Reveal (10 min)
- Act (10 min)
- The science, for grown-ups
- Questions they'll ask (and what to say)
- Make it easier, make it harder
- Go further
- Student sheet
Written for parents: no science background needed. US Letter, prints cleanly in black and white, with a kids’ sheet on its own page.