Question about thermal radiation

  • #1
Hello everybody,

I have a question about thermal radiation:
Imagine a body at a certain temperature T, in an environment with nothing around it. Theoretically, this body emits radiation according to its temperature (the maximum radiation is described by the Wien relation); If it emits, it must be losing energy in that process.
1) Does this body actually lose energy through this emission?
2) If so, to what extent does it lose energy? Will its temperature tend towards absolute zero?

Thank you.
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  • #2
The answer to both questions is yes.

Radiation is one of the three principal means of heat transfer.
  • #3
But it will only reach absolute zero under the conditions you described: ”with nothing around it”. (At least , I think it would).

In any real world conditions, it will only lose energy until it reaches equilibrium with its surroundings. And, since it cannot be in an environment where the ambiant temperature is absolute zero, it cannot reach that temperature.
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1. What is thermal radiation?

Thermal radiation is a type of electromagnetic radiation that is emitted by objects due to their temperature. It is also known as heat radiation or infrared radiation because it falls within the infrared region of the electromagnetic spectrum.

2. What causes thermal radiation?

Thermal radiation is caused by the movement of charged particles, such as electrons, within an object. As these particles move, they create electromagnetic waves that carry thermal energy and can travel through a vacuum.

3. How is thermal radiation measured?

Thermal radiation can be measured using a device called a thermal radiation detector or infrared thermometer. These devices detect the amount of infrared radiation emitted by an object and convert it into a temperature reading.

4. What are the applications of thermal radiation?

Thermal radiation has many practical applications, such as in thermal imaging cameras, which use infrared radiation to create images of objects based on their temperature. It is also used in industrial processes, such as heating and drying, and in medical treatments, such as laser therapy.

5. How does thermal radiation affect the Earth's climate?

Thermal radiation plays a crucial role in the Earth's climate by helping to regulate the planet's temperature. The Earth absorbs thermal radiation from the Sun and emits it back into the atmosphere, which helps to maintain a stable temperature for life to exist. However, human activities, such as the burning of fossil fuels, have increased the amount of greenhouse gases in the atmosphere, trapping more thermal radiation and causing global warming.

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