## The Planck Time

The big bang theory also runs into a fundamental limitation during the first 10 to the negative 43rd power seconds after the initial big bang. This time is called the Planck time and arises from quantum mechanics.

Quantum mechanics essentially predicts that for anything smaller than a certain scale, uncertainty is more applicable than Newtonian determinism. We can therefore predict or measure the path of a planet or a baseball, but we can only estimate probabilities for an electron. Subatomic particles are much smaller than Planck's scale, so uncertainty dominates. This lack of prediction or measurement capability of their paths results not from bad instruments or techniques but from a limitation of nature.

Quantum mechanics essentially predicts that for anything smaller than a certain scale, uncertainty is more applicable than Newtonian determinism. We can therefore predict or measure the path of a planet or a baseball, but we can only estimate probabilities for an electron. Subatomic particles are much smaller than Planck's scale, so uncertainty dominates. This lack of prediction or measurement capability of their paths results not from bad instruments or techniques but from a limitation of nature.