What is meant by thermal radiation?

Question

What is meant by thermal radiation?

Answer 1

Blackbody radiation is meant. Every body will emit radiation with a frequency distribution that depends on it's temperature. This happens due to random rearrangement of thermal energy in the object to photons, which then go everywhich way....

Objects at room temperature will radiate in the IR (infrared) range. Around 5000 K (the temperature of the sun) visible light will carry most of the radiated energy, and at higher temperatures UV (ultraviolet) radiation will carry most of the radiated energy.

Answer 2

The release of heat from a body by infared radiation.

Answer 3

Thermal radiation is mostly infrared light. Any object above absolute zero will radiate infrared light. Imagine a rock baking in the sun all day. After the sun sets the rock still retains all that energy and radiates it in the form of infrared light. Most of this escapes into space but because of all the c**p we're putting in the atmosphere an increasing amount of that IR light is reflected back to the earth (the greenhouse effect).