Does the bus match?
Match builds confidence. A mismatch makes us look again.
A 120 km bus ride
A model says: “The bus keeps 60 km/h, so 120 km takes 2 hours.” The bus actually arrives after 2 h 30 min.
What should we do?
What this lesson covers
The idea
When predictions match observations, confidence in the underlying science grows; when they fail to match, scientists re-examine their assumptions, models or measurements.
A 120 km bus ride
A model says: “The bus keeps 60 km/h, so 120 km takes 2 hours.” The bus actually arrives after 2 h 30 min.
What should we do?
- Ignore what really happened
- Look again at our assumptions, model and measurements
- Say all of science is wrong
Prediction vs reality
Compare the prediction with what happened. Then re-examine what could be wrong.
Match or re-examine
When predictions match observations, confidence in the underlying science grows. When they do not, scientists re-examine their assumptions, models or measurements.
The mismatch did not destroy the model. It showed which assumption to repair. After adding the stops, the prediction matched.
- We re-examined | Result
- Measurement (the clock) | fine
- Model (the 60 km/h speed) | fine
- Assumption (non-stop trip) | wrong: there were stops
Notes
When predictions match observations, confidence grows. When they do not, scientists re-examine their assumptions, models or measurements.
Check yourself
A prediction matches the observation. What happens to our confidence in the science behind it?
A prediction does not match the observation. What do scientists do?
In the bus ride, which assumption caused the mismatch?
The model predicted 2 h. The bus took 2 h 30 min. By how many minutes did the prediction miss?
Answer: 30 min
2 h 30 min − 2 h = 30 min. Three stops of 10 min explain it.
- It grows — correct. Yes. Repeated matches build confidence.
- It drops to zero. A match is good news for the idea.
- Nothing can change it. Confidence grows with matching evidence.
- Hide the observation. Scientists trust careful observations.
- Re-examine their assumptions, models or measurements — correct. Yes. One of them may need to change.
- Stop doing science. A mismatch is a chance to learn.
- That the bus moves at 60 km/h while it runs. The bus did keep about 60 km/h.
- That the trip is non-stop — correct. Yes. Three stops of 10 minutes added 30 minutes.
- That the road is 120 km long. The distance was right.