alt Hacker NewsHeat is the graveyard of energy. Everything that uses energy, or is energy, is actually just energy on it's way to the graveyard.
The energy of the universe is a pool of water a top a cliff. Water running off this cliff is used to do stuff (work), and the pool at the bottom is heat.
The "heat death of the universe" is referring to this water fall running dry, and all the energy being in this useless pool of "heat".
Do thermophotovoltaic cells operate on different kind of heat?
Is it impossible to convert heat into other forms of energy without "consuming" materials like in the case of steam, geothermal or even the ones that need a cold body to utilize thermoelectric effect.