Comparing Temperature Scales

Three identical thermometers sit in a single bath, each using a different temperature scale. Because each scale is anchored at the ice‑melting point and the boiling‑water point, the readings are linked by a simple linear relationship. This lets students see how Celsius, Fahrenheit, Kelvin, Rankine and any user‑defined scale are mathematically connected.

Students can drag the dotted liquid level up or down (or use the arrow keys) to change the temperature. A menu lets them choose which scale appears on the middle thermometer, and two sliders let them set the ice and steam points for the custom scale. The graph updates in real time, showing straight‑line plots of the other scales against Celsius.

By interacting with the simulation, learners discover how scale conversion works, how slope and intercept represent degree size and ice point, and why absolute zero appears on Kelvin and Rankine. The activity reinforces concepts of linear functions, unit conversion, and basic thermodynamics.