Science Can Be Revised

Activities to try

1. 1

   The 'Best Idea So Far' machine: overturn a model with evidence

   Why it works: Revision is an evidence-driven mechanism: the old idea was the best explanation for the evidence people HAD, and when better evidence arrived science did not collapse — it upgraded and became stronger. The new model earns its place by accounting for the observations the old one could AND the ones it could not, while itself remaining a best-current explanation open to revision.

   1. Start with the accepted model: Earth sits still at the centre and everything circles it — note that at first it seems to work, so you accept it.
   2. Feed observations into the model one at a time from an evidence tray and judge for each whether the current model fits it or not: 'Mars sometimes loops backwards across the sky' (the geocentric model needs an awkward extra circle to cope), 'Through a telescope, Venus shows phases like the Moon' (a model with Venus circling Earth cannot fit the full set of phases), 'Through his telescope, Galileo saw four moons orbiting Jupiter, not Earth' (another mismatch with 'everything circles Earth').
   3. Watch mismatches accumulate until a REVISE option becomes available; choose to revise, swapping in the Sun-centred model.
   4. Re-test the revised Sun-centred model against each of these earlier observations and confirm that it now accounts for all three.
   5. Note that the Sun-centred model is itself a new best-current explanation — stronger because it fits more evidence, but still open to further revision, not a final perfect answer.
2. 2

   Interview a scientist who lived a revision

   Why it works: Changing your mind in the light of evidence is honest and is what science is for; this builds the affective sense that openness to revision is a strength, told from inside a real human change of view.

   1. Take the role of an interviewer and question a historical or expert figure at the moment an accepted worldview is crumbling (e.g. an astronomer as the geocentric picture breaks down).
   2. Challenge the figure: ask why they are changing a belief they once held, and what specific evidence turned them.
   3. Press for evidence, not just anecdote — ask 'what did you observe?' and 'why didn't the old idea fit?'
   4. Ask whether being shown to be mistaken means they failed, and listen to them explain why revising an idea in light of evidence is the point of science, not a defeat.
3. 3

   Gallery of overturned ideas

   Why it works: Revision is normal and recurring across all of science, not a one-off embarrassment in one field; the same old-idea -> breaking-evidence -> revised-idea pattern repeats.

   1. Move through examples of scientific revision: Earth-centred to Sun-centred models, fixed continents to plate tectonics, and spontaneous generation to the explanation that new organisms come from existing living organisms.
   2. For each exhibit, reveal in order: the old explanation, then the new evidence that broke it, then the revised explanation.
   3. Read for each a note on why the change strengthened science, and look for the common pattern across all three.