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Science & the scientific method

Science isn't a pile of facts — it's a procedure for turning a hunch into something you can trust. Observe, guess, test, repeat.

The loop

  1. Observe — notice something. The bathwater goes cold faster on a windy day.
  2. Question — why? Does moving air really cool water faster?
  3. Hypothesis — a testable guess: “water under a fan loses heat faster than still water.”
  4. Predict — if that's true, then a cup by a fan should drop, say, 5 °C in the time the control drops 2 °C.
  5. Experiment — two identical cups, same starting temperature, one fan. Measure.
  6. Analyse — did the numbers match the prediction? By how much? Could chance explain it?
  7. Conclude & repeat — support it, tweak it, or throw it out. Then someone else tries to reproduce it.

The one rule that makes it science

A hypothesis has to be falsifiable — there must be a possible result that would prove it wrong. “Invisible dragons that leave no trace” isn't science, because nothing could ever contradict it.

Why the controls and the repeats

A control is the version where you change nothing — it tells you what would have happened anyway. Variables come in three jobs: the one you change (independent), the one you measure (dependent), and the many you hold fixed (controlled). And you repeat because one measurement could be a fluke; patterns that survive repetition are the ones worth believing.

Hypothesis → theory → law

  • A hypothesis is a single testable claim.
  • A theory is a big, well-tested explanation that ties many observations together — evolution, relativity, plate tectonics. “Just a theory” gets this exactly backwards: in science a theory is about as solid as it gets.
  • A law describes what happens, usually as an equation (F = ma); a theory explains why.

Where the math comes in

Measurement turns “hotter” into a number with units and an uncertainty. Statistics tells you whether a difference is real or just noise. Graphs reveal the shape of a relationship. Every claim in this physics section started as somebody's hypothesis and earned its place by surviving this loop — often for centuries.