Question

what is the difference between error and uncertainty

Answer 1

Uncertainty, in quantum mechanics at least, is a theoretical maximum precision you can know the location of a particle while simultaneously knowing the momentum of the particle. The basic form, mathematically is that the uncertainty in momentum is inversely proportional to the uncertainty in position. \[\Delta p = \frac{h}{2 \Delta x}\]An expression for energy and time can be derived from this that essentially has the same basic shape. But the important thing to remember is that this is a physical law, if you know the momentum with 100% accuracy, you don't know anything at all about the particle's position.

Error, is a result of the accuracy and precision of our measuring devices. For example on a ruler with a minimum spacing of 1mm between ticks, has an error of plus or minus 0.5 mm.

In general during an experiment, the error in a measurement is half of the accuracy of your measuring device, and you can improve the error by getting more accurate devices. In quantum mechanics however, no increase in accuracy will help you to overcome the uncertainty principal.

Answer 2

sorry, that equation should be an inequality: \[\Delta p \ge \frac{\hbar}{2 \Delta x}\]

Answer 3

tanks

Answer 4

Don't forget, you can thank whoever helps you by clicking the good answer button, its sort of an incentive for people to keep helping

Answer 5

I think the original question is not about quantum mechanichs but metrology:
* Error refers to the disagreement between a measurement and the true or accepted value.
* Uncertainty of a measured value is an interval around that value such that any repetition of the measurement will produce a new result that lies within this interval.

Here is a good link:
http://scidiv.bellevuecollege.edu/Physics/Measure%26sigfigs/B-Acc-Prec-Unc.html

An example: if the actual temperature is 50 degrees and your termometer says 51, then there is an error of 1 degree. Usually, in the termometer manual it reads how accurate the termometer is. For example, it might read that the accuracy is +/- 2 degrees. Than means that if you get a reading of 51 degrees, the actual temperature lies between 49 and 53 degrees. So you have some uncertainty in your measured value.

Answer 6

@linjaaho- tnxs. dats the real deal!!!