A quantum fluctuation is a temporary, random change in the amount of energy at a specific point in space. According to the Heisenberg Uncertainty Principle, it is impossible to know both the exact energy and the exact time of a system simultaneously. This “fuzziness” allows the universe to briefly “borrow” energy from nothing, as long as it is paid back almost instantly. You can see these fluctuations in action by placing two metal plates extremely close together. The fluctuations outside the plates are stronger than those inside, creating a tiny pressure that pushes the plates together. This is known as the Casmir Effect. Also, near the edge of a black hole, these fluctuations can cause one virtual particle to fall in while the other escapes, causing the black hole to slowly evaporate.
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