On this day in physics: 23 February 1927, Werner Heisenberg writes a letter to his colleague Wolfgang Pauli, describing his infamous Heisenberg Uncertainty Principle.
Word of the day- Heisenberg Uncertainty Principle- A big dog. One of the biggest principles in quantum mechanics. So, as scientists, especially scientists who have done any type of real lab work, think that we have a really good handle on the ability to measure things. And, even if our scale is only good to a tenth of a pound, it is possible to build something good enough to measure down to the exact amount of weight? Right? Wrong. There are limits to what we can measure, and that's evident from the Heisenberg Uncertainty Principle. What this principle says is that at the most microscopic measurements, the uncertainty of the position multiplied by the uncertainty of momentum must be greater to or equal to a constant which we call h-bar divided by 2 (5.272859 × 10-35 m2*kg/s). Now, this might seem like a crazily small number, and for human scales, it's totally not affecting our life at all, but at the quantum scale, there is a limit to your ability to measure. So, on any measurement that you take, there is going to be some amount of uncertainty, example, your bathroom scale is probably good to about one hundredth of a pound, which means, plus or minus .01 lbs, the measurement is reliable. This is called the "uncertainty" of the measurement. What this means at quantum scales? The more precise you know the position, the less precise you'll know the momentum, and if you choose to have a high level of precision on the momentum, the higher the uncertainty of the position. And there is no way to "burn the candle at both ends" here. You cannot know the momentum and position of something with exact certainty. Sorry friends.
There is a great joke about this: Heisenberg is driving his car down the road, and he gets pulled over by a police officer for speeding. The officer walks to Heisenberg's car, and asks him "Do you know how fast you were going?", and Heisenberg says 'No, but I know exactly where I am!'. Get it? Because..you know..uncertainty....anyways....
Quote of the Day: "What we observe is not nature itself, but nature exposed to our method of questioning." -Werner Heisenberg
Keywords: Heisenberg, Uncertainty, Principle, Position, Velocity, Momentum, h-bar.
