Comments by "EebstertheGreat" (@EebstertheGreat) on "The Most Misunderstood Concept in Physics" video.

  1. I worry about what the people you questioned will take away from these moments. Charitably, they will have questions about thermodynamics that they will look up online. More likely, they will take away that the Sun provides a fundamentally different type of energy, which we can use, and which we then convert to "useless energy." The Sun is hotter than the Earth. That's really all that this is about. The Sun is the hot side of the Carnot engine, and we are the cold side. Energy doesn't "change" as it goes through an engine. Energy is just a quantity, and it remains constant (which is its whole point). Solar radiation is thermal--it is as spread out as radiation can get. It is the least "ordered" sort of radiation, one might say. But we can use it because the Sun shines brighter on the Earth than the Earth shines on the Sun. The Earth-Sun system is not in equilibrium. If we ignore the rest of the universe, it will eventually reach thermodynamic equilibrium as all energy is exchanged for thermal energy and everything in the Solar System reaches the same temperature. If you expand your horizons to the whole universe, that is heat death. Nothing changes, because everything is already in equilibrium.
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