Heat can be transferred through radiation, convection, and conduction. Convection and conduction require matter, while radiation does not. Heat is transferred when hotter materials contact cooler ones, and this continues until they reach thermal equilibrium. Conduction occurs when faster-moving particles transfer energy to slower-moving ones, while convection occurs when particles with more thermal energy move faster and spread out, causing the material to become less dense. Radiation is a type of electromagnetic radiation that does not depend on particle interaction and can be absorbed by atoms, causing an increase in temperature.
Radiation, convection and conduction are three different ways heat can be transferred. Convection and conduction require matter to transfer heat. Radiation transfers heat through space in the form of energy, like waves. While these three heat transfer methods involve different principles, they can all be understood based on the physics of heat or thermal energy.
Matter is made up of particles, which interact with each other to transfer heat energy. When a hotter-temperature material contacts a lower-temperature material, heat flows from the hotter material to the colder one. This process will continue until the two materials are at the same temperature and have reached a state of thermal equilibrium.
In conduction, a hotter piece of matter contacts a cooler piece of matter, and heat flows from the hotter to the colder region. Heat is conducted because fast-moving particles of hotter matter transfer energy to cooler, slower-moving molecules of colder matter. A material’s ability to conduct heat depends on its molecular structure and texture. For example, metals are better conductors of heat than wood, and solids are better conductors of heat than liquids.
Convection transfers heat based on a different principle of particle motion. When particles possess a large amount of thermal energy, this energy causes them to move faster and spread out, making the material less dense. Particles in a cooler region have less energy and move slowly, leading to higher density. In fluids and gases, this principle causes the colder regions of the material to sink down, while the hotter regions rise up.
A stream is formed by the circulation of fluid or gas in this pattern. This is called convection current. In the atmosphere, for example, cold air sinks while warm air rises, producing circulation.
The third method of heat transfer, radiation, requires no matter and does not depend on particle interaction. An example is solar radiation. The sun’s heat reaches the earth despite traveling in the vacuum of space. In the case of radiation, thermal energy exists in the form of waves. It is a type of electromagnetic radiation, like visible light.
Atoms absorb the energy of radiation through their electrons, which use the energy to move to a higher level within the atom. This energy can be emitted again when the electron drops to its original level. The temperature of an object in the presence of radiation depends on how much energy it absorbs versus how much it emits, so an object that absorbs more energy than it emits will increase in temperature.
Protect your devices with Threat Protection by NordVPN
