Comments by "Liam" (@1495978707) on "The Most Misunderstood Concept in Physics" video.

20:10 It’s more simple than you explain. Like you said earlier, the energy present is constant, but the temperature was high, and that means low entropy. That’s the same reason the sun is a source of energy that has low entropy, it’s far hotter than earth. And space is far cooler than earth. So the earth is literally acting as a heat engine extracting work from the hot reservoir of the sun and cold reservoir of space. Gravity does matter though, because it has a tendency to decrease entropy, because it makes things less spread out
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20:30 Wrong. Uniform spreading of the matter of the universe is only unlikely because of the influence of gravity. Uniformity is otherwise the most likely configuration, as you should know about ideal gases. The increase in universal entropy came with the cohesion of matter, as total energy in a closed system is constant, so there would be no reason for matter to stick together (a low entropy state) without universal entropy increasing by at least as much
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9:10 While all of those losses are present, the biggest reason that efficiency was poor early on is that they didn’t realize what Carnot did, which was that you can stop adding heat and let the heat convert into work, and save a lot of your energy. Steam locomotives have two levers for what we might think of as “throttle”, and that is the steam outlet valve, and the timing lever, which determined what fraction of the cycle the steam port was open in the cylinder. Decreasing this fraction allows for mor efficient operation, but can only really be done at speed. So, they’d have the timing lever on full open when starting, and use the steam outlet valve as the throttle, but once at speed, transition to having the outlet always maxed out and vary the timing lever. This way, you can get the necessary massive torque for starting, but also switch to a sort of economy mode once at speed
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