Physics
The first law of thermodynamics is simply the case of

The law of conservation of energy
The law of heat exchange
Newton's law of cooling
Charle's law

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Physics
Lightning is produced when

Water vapour produces electricity in the clouds
Clouds strike against impurities in air and the friction burns up these impurities
Similar charges of electricity rush towards each other and then get repelled
Strong opposite charges in different clouds break down the resistance offered by the intervening air

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