Zhi Nuo's tortoise is an image in Zeno's paradox. It applied for running 100 meters ahead of schedule on the grounds of physical disadvantage, and was finally caught up by Achilles and killed. This paradox reveals some misunderstandings and contradictions in people's cognition of time, speed and distance.
Laplace demon is a hypothetical intelligent creature, which can infer the past and the future. This hypothesis was first put forward by the French mathematician Laplace. He believes that if an intelligent creature knows the exact position and momentum of each atom in the universe, it can instantly calculate the past and future of the universe with Newton's concise formula.
Maxwell's demon is a creature imagined by British physicist Maxwell. It can use its own speed and energy to control the behavior of a single molecule. This hypothesis was originally intended to explain the irrationality of the second law of thermodynamics, but it was later proved to be correct and became one of the basic principles in quantum mechanics.
Schrodinger's cat is a thought experiment put forward by Austrian physicist Schrodinger, which discusses the measurement problem in quantum mechanics. In this experiment, a cat was kept in a closed room with a bottle of poison and a device containing radioactive nuclei. If the nucleus decays, the device will start, release the toxin and kill the cat. However, without observation, the state of this nucleus is unknown, so the state of the cat is also unknown.