Blackbody Spectrum & Wien's Law
Change temperature and watch the blackbody curve, peak wavelength and glow colour of a hot object.
Drag the temperature handle (or use the slider). Hotter objects glow brighter and shift towards blue. Compare the Sun, a light bulb and your body.
About the Blackbody Spectrum & Wien's Law
Free blackbody spectrum & wien's law. Change temperature and watch the blackbody curve, peak wavelength and glow colour of a hot object. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for atomic & quantum, the blackbody spectrum & wien's law runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Change temperature and watch the blackbody curve, peak wavelength and glow colour of a hot object. Use it to explore atomic & quantum ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Blackbody Spectrum & Wien's Law
- Use the controls to change Temperature, Scale. The simulation reacts instantly.
- Pick an option such as Human 310 K, Bulb 2700 K, Sun 5772 K, Star 9000 K to switch modes or load an example.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Compare the human body (310 K) and the Sun.
- Raise the temperature to 9000 K.
- Switch to Same scale to see the brightness rise.
Key ideas you can learn
- Hot objects glow with a spectrum that depends only on temperature.
- Peak wavelength = 2.898 × 10⁶ nm·K ÷ T.
- Power radiated grows as T⁴.
- Hotter objects look bluer.
Where this is used in the real world
Astronomers use blackbody curves to measure star temperatures; thermal cameras and light bulbs rely on them.
Who is this simulation for?
Advanced high-school and university students in chemistry and physics, and curious learners who want to see how the atomic world behaves.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What is a blackbody?
An ideal object that absorbs all light and glows purely because of its temperature.
Why do hotter stars look blue?
Their peak wavelength is shorter, so more blue light is emitted.
Is the Blackbody Spectrum & Wien's Law free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Blackbody Spectrum & Wien's Law work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.