From what I understand, the word midnight is usually interpreted incorrectly. Midnight is written as 12am which would imply that it's in the morning. Therefore, it should be at the start of the day. On the other hand, both Dictionary.com and the Oxford Dictionary define it as twelve o'clock at night.
James Prescott Joule. The English physicist James Prescott Joule (1818-1889) proved that mechanical and thermal energies are interconvertible on a fixed basis, and thus he established the great principle of conservation of energy.
Medical Definition of joule. : a unit of work or energy equal to the work done by a force of one newton acting through a distance of one meter.