The uncertainty principle of Heisenberg states that it is actually impossible to
make a measurement to better than a finite degree of accuracy
If DE, Dx and Dp represent the smallest
uncertainty with which the energy, position and momentum of a particle can be measured and
Dt the smallest uncertainty in the time of measurement,
then:
where h is the Planck constant (6.6x10-34 Js).
According to the
wave mechanical model of Schroedinger a particle has both wave and particle properties described by . This model is complex but simply states that we
cannot fix the position of a particle (as in classical Physics) but can only predict the probability of
it being at a given point at a certain time. It could therefore be anywhere, but is in fact more
likely to be at one place than another. The square of the amplitude of the wave associated with
a particle at a given point in space and time is proportional to the probability of the particle being
at that point.
Further consideration of this subject is beyond the scope of this text, but it
is hoped that this very brief introduction has been sufficient to demonstrate the uncertainty of
Physics on a nuclear level. Remember that all the world around us is composed of waves, even
ourselves.
As you read this, there is only a probability that you are there at
all!