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philrainey
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is it true that the radiation a colder body radiates through a vacuum will never hit a hotter body and have its radiation energy absorped? Is the radiation simply one way from the hot body to the colder body?
philrainey said:is it true that the radiation a colder body radiates through a vacuum will never hit a hotter body and have its radiation energy absorped? Is the radiation simply one way from the hot body to the colder body?
russ_watters said:The wording of the first sentence is very unclear to me...
Are you asking about two bodies sitting near each other in space? The hot object will radiate toward the cold one, but both will radiate away into space. Depending on the specifics of the situation, the cold one may still have a net loss of energy. Ie, the planets in the solar system have lost energy and cooled over billions of years despite getting energy from the sun. They radiate away more than they receive.
Radiation is the emission of energy in the form of waves or particles. It can come from natural sources, such as the sun, or human-made sources, such as X-rays.
Radiation can have both beneficial and harmful effects on living organisms. Small doses can be used for medical purposes, such as X-rays for imaging, but high doses can damage cells and cause health problems.
The three main types of radiation are alpha, beta, and gamma. Alpha particles are the least penetrating and can be stopped by a sheet of paper, while beta particles can be stopped by a few millimeters of aluminum. Gamma rays are the most penetrating and require several inches of lead or concrete to shield.
Radiation is typically measured in units of absorbed dose, which is the amount of radiation energy absorbed by a material, and equivalent dose, which takes into account the type of radiation and its potential damage to living tissue. These measurements are usually expressed in units of gray (Gy) or sievert (Sv).
Some common ways to protect ourselves from radiation include maintaining a safe distance from sources, limiting exposure time, and using protective equipment, such as lead aprons or shielding. It is also important to follow safety guidelines and regulations set by authorities.