uncertainty
(noun)
A parameter that measures the dispersion of a range of measured values.
Examples of uncertainty in the following topics:
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The Uncertainty Principle
- The reasoning was derived from considering the uncertainty in both the position and the momentum of an object.
- Roughly, the uncertainty in the position of a particle is approximately equal to its wavelength (λ).
- The uncertainty in the momentum of the object follows from de Broglie's equation as h/λ.
- Therefore, to a first approximation the Heisenberg Uncertainty Principle gives that the product of these two uncertainties is on the order of Planck's constant (h).
- Doc Physics - Heisenberg Uncertainty Principle Derived and Explained - YouTube
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Exact Numbers
- There is a degree of uncertainty any time you measure something.
- For example, the weight of a particular sample is 0.825 g, but it may actually be 0.828 g or 0.821 g because there is inherent uncertainty involved.
- On the other hand, because exact numbers are not measured, they have no uncertainty and an infinite numbers of significant figures.
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Indeterminacy and Probability Distribution Maps
- This quantum uncertainty principle can also be expressed in terms of other variables.
- Therefore the units involved in quantum uncertainty are on the order of Planck's constant (found experimentally to be 6.6 x 10−34 J·s).
- Recall from the uncertainty principle that we cannot simultaneously know an electron's position and velocity—therefore we are unable to determine its trajectory.
- The uncertainty principle prevents us from knowing how the electron gets from one place to another, and so an orbit really does not exist as such.
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Tiffeneau-Demjanov Rearrangement
- This uncertainty can be removed by nitrous acid deamination of the corresponding 1º-aminoalcohols, as shown in the following equation.
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Conductors
- This separation is comparable with the energy uncertainty due to the Heisenberg uncertainty principle for reasonably long intervals of time.
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Accuracy, Precision, and Error
- All measurements are subject to error, which contributes to the uncertainty of the result.
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Microstates and Entropy
- The interpretation of entropy is the measure of uncertainty, which remains about a system after its observable macroscopic properties, such as temperature, pressure, and volume, have been taken into account.
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Significant Figures
- For example, it may not always be clear if a number like 1300 is precise to the nearest unit (and just happens coincidentally to be an exact multiple of a hundred) or if it is only shown to the nearest hundred due to rounding or uncertainty.
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Anomeric Forms of Monosaccharides
- Fischer's brilliant elucidation of the configuration of glucose did not remove all uncertainty concerning its structure.
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Acid-Base Reactions
- For both these groups, the reported pKa values extrapolated to water are approximate, and many have large uncertainties.