Thermal radiation facts for kids
Thermal radiation is a special kind of radiation that everything gives off if it's warmer than its surroundings. You can feel it as heat or sometimes even see it as light. It's how heat transfer happens through invisible waves called electromagnetic radiation. The cool thing is, it doesn't need anything solid, liquid, or gas to travel through!
Thermal radiation can spread out in all directions, like the warmth from a campfire. Dark, dull surfaces are good at giving off this radiation, while bright, shiny surfaces don't give off as much. Things that are good at giving off thermal radiation are also good at soaking it up.
For example, when you stand near a fire, you feel warm even if the air around you is cold. That's thermal radiation from the fire reaching you. Another great example is the heat that travels all the way from the Sun to the Earth.
Warmer objects create more radiation, and the waves they send out are shorter. Most things on Earth are warm enough to make infrared radiation, which we feel as heat but can't see. But really hot things, like the glowing part of an incandescent light bulb, are so hot that their radiation includes visible light!
Cool Facts About Thermal Radiation
- Every single surface or object that is above absolute zero (which is super, super cold, like 0 K or -273°C) gives off heat.
- Objects that are good at sending out thermal radiation are also good at soaking it up.
- The other two main ways thermal energy moves are conduction (like heat through a metal spoon) and convection (like warm air rising). Both of these need matter to transfer energy.
- Something doesn't have to be "hot" to give off heat. It just needs to be warmer than what's around it.
- Special cameras called thermal imaging cameras can see the heat that objects radiate.
- When a room is full of people, it might feel warmer. That's because all the people are radiating thermal energy!
Related Topics
Images for kids
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Spectral response of two paints and a mirrored surface, in the visible and the infrared. From NASA.
See also
In Spanish: Radiación térmica para niños
