• What is it? Thermal radiation is how energy is transferred using electromagnetic radiation.
• Special Power: Unlike other forms of heat transfer (like conduction & convection), it doesn't need a material to move through. It's like a superhero that doesn't need air to fly!
• Sun's Radiance: Think about it – the Sun's energy travels through a whopping 150 million km of the vacuum to give us that warm, sunny day!

Real-world Example: Ever stood outside on a sunny day? Even if it's cold out, the sun's rays can still make you feel warm. That’s thermal radiation in action!

• Thermal Motion: Atoms move around randomly due to heat. Inside these atoms are charged particles.
• Electromagnetic Radiation: When these charged particles speed up (or are accelerated), they emit electromagnetic radiation.

(For those super keen, there's even more info on page 401.)

Let's Do an Experiment! Ever wonder why some objects feel hotter than others?

• The Setup: Two tin cans (twins!). One painted matt black, the other shiny white.
• Heat 'em up: Fill them with equal amounts of hot water.
• Watch & Record: Place the thermometers in. Observe how the temperature changes over time.
• Graph Time: Plot a graph (cooling curve) to visualize the results.

Flip the Experiment!

• Start with cold water and warm them up with a radiant heater.