Conclusion that it is impossible to know simultaneously the absolute exact position and the absolute exact speed of a particle such as an electron. The more precisely the position is known of a particle at a moment in time, the less precisely can its speed be determined. Conversely the more precisely the exact speed of a particle is known, the less precisely its position can be known. Werner P. Heisenberg, a German physicist, developed this principle from his work with quantum mechanics.
Some or all content above used with permission from J. H. Wittke.