Physicists Question Heisenberg's Uncertainty Principle

Uncertainty principle expressed mathematically

In the development of quantum mechanics many claim that Heisenberg's principle of uncertainty embodied the strange personality of the quantum world. With Dirac's input and Schrodinger's equation the uncertainty principle acted as the foundation of this fairly new physics.

It states that the 'degree of certainty' of a measurement of a particles displacement would effect the 'degree of certainty' of the measurement of the particles momentum. In the expression above, the Greek symbol delta
is used to denote the 'degree of certainty'. The product of the delta(displacement) and the delta(momentum) must obey a rule which states that the product must have a value larger or equal to a constant. This constant is related to planks  constant and it is a well known one in quantum mechanics.

Recent research in the University of Toronto has found data implying that the principle may be too 'pessimistic', the disturbance on the system by measurements might be slightly more than what the researchers found. This does not invalidate that principle, it is merely an improvement due to more precise measuring equipment.

The team at Professor Aephraim Steinberg's quantum optics research group at U of T  used a weak enough measurement (which did not impose itself too greatly on the system of photons) on a pair of photons then measured it strongly to see the effect of the weak measurement on the system. They found that the disturbance was less than Heisenberg would have predicted. Many repeats of these experiments help validate the conclusion that the principle needs slightly adjusting for weaker measurements.

Maybe Heisenberg wasn't so certain about his principle aye..