Understanding Energy Transfer: Thermodynamics in an Insulated Box Scenario

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SUMMARY

The discussion centers on the thermodynamic implications of an insulated box containing a refrigerator with its door open. When energy is pumped into the system, such as through the refrigerator, the temperature inside the box increases due to the input of heat energy. However, the concept of laser cooling introduces a counterintuitive scenario where energy is added, yet the system cools down. This occurs because the laser light scatters, removing energy from the atoms, thus resulting in a net energy removal from the system. The discussion concludes that while laser cooling can lower temperatures at the atomic level, the overall energy dynamics still adhere to the laws of thermodynamics.

PREREQUISITES
  • Understanding of basic thermodynamics principles
  • Familiarity with the concept of energy transfer
  • Knowledge of laser cooling techniques
  • Basic grasp of quantum physics and atomic behavior
NEXT STEPS
  • Research "thermodynamics of insulated systems" for deeper insights
  • Explore "laser cooling techniques and applications" in quantum physics
  • Study the "Raman effect" and its relation to energy transfer
  • Investigate "energy conservation in thermodynamic systems" for broader understanding
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This discussion is beneficial for physics students, thermodynamics researchers, and professionals in quantum mechanics who seek to understand the complexities of energy transfer in insulated systems and the implications of laser cooling.

cragar
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I once was asked a question about this scenario.
Let's say we have an insulated box with a refrigerator in it.
Now the fridge is plugged in from outside. The box is perfectly insulated.
The door of the fridge is open. What happens to the temperate inside the box.
their is air in the fridge. I was told that the temperature of the box will go up because we are pumping energy into it.
But then I thought of laser cooling. When laser cooling happens we shoot photons into
a cloud of atoms and they Doppler shift the light an absorb them and slow down.
We pumped energy into that system and it cooled down.
Is it always true that if I pump energy into a system that it will heat up.
 
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Yes, it is always true that if you pump heat energy in (or input electrical energy and immediately convert it to heat), it will heat up. That's basically the definition of "heat up".
 
ok but in laser cooling we pump in energy and it cools down.
 
If you cool something, something else must heat up. Laser cooling is mostly used to cool at atom level. I don't find it plausible that this is some kind of optical trapping of the atoms - forcing them to stop viberating. Laser cooling is however mostly used in quantum physics so I can't help you further regarding what heats up if the atoms cools down. At least the laser equipment itself heats up - that for sure :-)

Vidar
 
In laser cooling, the laser light gets scattered and leaves the system with higher energy than the light that entered. So there is no net pumping of energy but energy removal.
 
so the light gets absorbed and then remitted with more energy so it took energy away from the atom. is this similar to the Raman effect.
 
If you ran the laser cooler in an opaque box, where the photons could not leave,
the inside of the box would heat up as well.
 

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