Yes, ALL bodies above absolute zero radiate. Warmer bodies just radiate more, so the NET for the colder body is that it absorbs more radiation than it sends out but that doesn't mean that it doesn't send any out.Alan Tomalty said:Assuming no conduction and no convection will a colder body be able to send photons to a hotter body while the hotter body is sending photons to t. We all know that an equilibrium will result with a temperature somewhere between the two bodies but do the photons emitted by the cooler body ever end up in the hotter body?
The short answer is "yes". Some of the thermal radiation from the cool body will be absorbed by the hot body.Alan Tomalty said:We all know that an equilibrium will result with a temperature somewhere between the two bodies but do the photons emitted by the cooler body ever end up in the hotter body?
Alan Tomalty said:Assuming no conduction and no convection will a colder body be able to send photons to a hotter body while the hotter body is sending photons to t. We all know that an equilibrium will result with a temperature somewhere between the two bodies but do the photons emitted by the cooler body ever end up in the hotter body?
It doesn't, because...Alan Tomalty said:How does the cool body know when to stop sending photons to the hot body?
At equilibrium the amount of energy flowing in each direction is the same. If there were any imbalance, then the object receiving more energy would warm up slightly, increasing the rate at which it radiated energy and reducing the imbalance. (As an aside, thinking in terms of photons instead of the intensity of the electromagnetic radiation just complicates the problem - photons aren't what you think they are)At equilbrium are each of them still continually sending photons to each other? Is each photon from the cool body at a lesser energy level than each one from the hot body?
They don't. They end up with the same temperature.I don't understand how the 2 bodies end up with the same energy
Alan Tomalty said:Assuming no conduction and no convection will a colder body be able to send photons to a hotter body while the hotter body is sending photons to t. We all know that an equilibrium will result with a temperature somewhere between the two bodies but do the photons emitted by the cooler body ever end up in the hotter body?
Yes, this phenomenon is known as thermal radiation. All objects with a temperature above absolute zero (0 Kelvin) emit thermal radiation, regardless of their temperature relative to other objects.
This occurs because of the nature of thermal radiation. Photons are constantly being emitted and absorbed by all objects, and the rate of emission is dependent on the temperature of the object. Colder objects emit photons at a lower rate than hotter objects, but they still emit them.
No, it does not. While it may seem counterintuitive, the second law of thermodynamics only applies to closed systems. In an open system, such as our universe, energy can be exchanged between objects, and colder objects can transfer energy to hotter ones through thermal radiation.
Thermal radiation is used in a variety of practical applications, such as thermography (thermal imaging), industrial processes, and even cooking. In thermography, colder objects appear as darker areas because they emit fewer photons, while hotter objects appear as brighter areas. In industrial processes, thermal radiation can be used to heat or cool objects, and in cooking, thermal radiation is responsible for browning and cooking food.
Yes, this is possible. When colder objects transfer energy to hotter objects through thermal radiation, the hotter objects can absorb this energy and become even hotter. However, the amount of energy transferred is dependent on the temperature difference between the two objects, so the colder object cannot make the hotter object infinitely hotter.