Physics
Lightning is produced when

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

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Physics
Holography is a technique of

Recording a permanent three dimensional black and white photograph
Recording a permanent three dimensional photograph of a given single colour or a multicolour
Recording a permanent, sharp two diimensional black and white or multicolour photograph
Recording a permanent three dimensional multicolour photograph

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