Sciencespeaking topic
Why you have to reapply sunscreen every two hours: the UV filter isn't 'used up' on your skin, it's broken down by light. Why does the protection eat itself over time?
— avobenzone photostability
practice with this topic
Set the timer (5-30 min), take 20 seconds of prep if you like, start talking. Jot your thoughts onto the sticky-note board.
similar topics
- What did Vesalius change in medicine by dissecting cadavers himself and correcting Galen's anatomical errors in On the Fabric of the Human Body?
- Optimism bias: why do we think bad things always happen to someone else? Why do we systematically underestimate our own risks?
- The problem of induction: how can we know the sun will rise tomorrow just because it has risen every day so far? Do past observations guarantee anything about the future, or is it just habit?
- Why was it so surprising when Rutherford's gold foil experiment revealed that the atom is mostly empty space with a dense nucleus?
- The argument between Einstein and Bohr over quantum mechanics shows that great science can run on personal stubbornness as much as evidence.