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定義
系の無秩序またはランダムさの度合いを測る熱力学的量で、ジュール毎ケルビン（J/K）で表される。
解説
The Second Law of Thermodynamics states that total entropy of an isolated system always increases over time. An ice cube melting in a warm room increases entropy as ordered crystal structure becomes disordered liquid. Entropy also underpins information theory: Claude Shannon borrowed the concept to quantify uncertainty in data, where 1 bit of entropy represents a 50/50 choice.
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