Measure Heat Dissipation and Predict Cooling with Python

Newton's law of cooling meets machine learning in your kitchen

High School Thermal Systems 2–3 weeks
Last reviewed: March 2026

Overview

Every piece of electronics on an aircraft — from cockpit displays to engine controllers — generates heat that must be managed. If a component overheats, it fails. Thermal engineers design cooling systems to keep everything within safe temperature limits, and the foundation of all their work is Newton's law of cooling: the rate of heat loss is proportional to the temperature difference between the object and its surroundings.

In this project, you'll run a simple kitchen experiment: heat up small samples of different materials (aluminum, steel, plastic, ceramic) and record how their temperature changes over time as they cool. Using a digital thermometer or thermocouple and a timer, you'll collect real experimental data that follows the exponential cooling curve. Then you'll use Python to fit the data to Newton's law and train a regression model that predicts cooling behavior.

This is the same physics that governs how an avionics computer cools in flight, how a rocket nozzle survives extreme temperatures, and how a spacecraft's thermal control system keeps components within operating limits. The difference is scale and complexity — but the fundamental principles you'll discover with a hot piece of metal and a thermometer are identical.

What You'll Learn

  • Conduct a controlled thermal experiment with multiple materials
  • Understand Newton's law of cooling and exponential decay
  • Use Python curve fitting (scipy.optimize.curve_fit) to extract physical parameters from data
  • Compare materials based on their thermal properties using measured data
  • Build a regression model that predicts cooling time from material properties

Step-by-Step Guide

1

Gather Materials and Equipment

Collect 3–4 small samples of different materials: a thick aluminum washer or bolt, a steel nut or bolt, a ceramic tile piece, and a thick plastic piece (HDPE or nylon). Each should be roughly the same size (2–3 cm across) so you're comparing material properties, not geometry.

You'll need a way to measure temperature: a digital cooking thermometer with a probe works well, or an infrared thermometer (point-and-shoot). For more precise readings, a K-type thermocouple with a USB reader (~$15 online) gives you digital data you can log directly. You'll also need a way to heat the samples safely: a pot of boiling water works perfectly.

2

Run the Cooling Experiment

Heat each sample by immersing it in boiling water for 3–5 minutes (so it reaches approximately 100 degC). Remove it with tongs, place it on a wooden cutting board (which acts as a poor conductor, minimizing heat loss through the bottom), and immediately start recording temperature readings every 15 seconds for 10–15 minutes.

Record the data in a notebook or spreadsheet: time (seconds) and temperature (degC). Also note the room temperature (ambient), which is the temperature the sample is cooling toward. Repeat each material at least twice for reproducibility. If readings are inconsistent, check whether airflow (drafts, AC vents) is affecting the experiment.

3

Plot and Understand the Cooling Curves

Load your data into Python and plot temperature vs. time for all materials on the same axes using matplotlib. You'll see classic exponential decay: rapid cooling at first (when the temperature difference is large) that gradually slows as the sample approaches room temperature.

Plot ln(T - T_ambient) vs. time — if Newton's law holds perfectly, this should be a straight line with slope equal to the negative cooling constant -k. The steeper the slope, the faster the material cools. Which material has the largest k? The smallest? How does this relate to the material's density and heat capacity?

4

Fit Newton's Law to the Data

Use scipy.optimize.curve_fit to fit the function T(t) = T_ambient + (T_initial - T_ambient) * exp(-k * t) to each material's cooling data. The function takes time as input and returns temperature, with k as the parameter to fit. Start with an initial guess of k=0.01.

Extract the best-fit k value for each material and compare. Create a bar chart of k values. The aluminum sample should cool fastest (high thermal conductivity spreads heat to the surface quickly), while plastic cools slowest (low conductivity traps heat inside). Discuss why this matters for aerospace: electronics housings are made of aluminum partly because it dissipates heat quickly.

5

Build a Predictive Model

Now create a regression model that predicts the cooling constant k from material properties. Look up the thermal conductivity, density, and specific heat capacity for each material. Even with just 3–4 data points, you can fit a simple relationship using scikit-learn's LinearRegression and see which property best predicts the cooling rate.

Predict: if you tested a copper sample (high conductivity, high density), what k value would your model predict? What about a wood sample (low conductivity, low density)? If possible, test one of these predictions experimentally to validate your model.

6

Present Your Findings

Create a summary with four key visualizations: (1) raw cooling curves for all materials, (2) linearized ln(T-T_amb) plots showing the straight-line fit, (3) bar chart of fitted cooling constants k, and (4) the regression model predictions vs. actual k values. Include photos of your experimental setup.

Discuss the connection to aerospace thermal management: explain how the same exponential cooling law governs how quickly an overheating avionics unit returns to normal temperature after a high-power computation phase, or how a spacecraft radiator panel dissipates heat into space. The physics is identical — what changes is the complexity of the geometry, the cooling mechanism (conduction, convection, radiation), and the consequences of getting it wrong.

Go Further

  • Add forced convection — repeat the experiment with a fan blowing on the sample and measure how air velocity changes the cooling constant
  • Test insulation — wrap samples in different insulating materials (fabric, foam, aluminum foil) and measure how insulation changes the cooling curve
  • Build a thermal model — use the lumped-capacitance method to predict the cooling curve from first principles and compare with your measured data
  • Measure radiation — paint one sample black and leave another shiny; compare cooling rates to see the effect of emissivity on radiative cooling