@At their narrowest points, calcium ion channels are less than a nanometre in diameter. This extreme smallness of the opening in the calcium ion channels has profound quantum mechanical implications. The narrowness of the channel restricts the lateral spatial dimension. Consequently, the lateral velocity is forced by the quantum uncertainty principle to become large. This causes the quantum cloud of possibilities associated with the calcium ion to fan out over an increasing area as it moves away from the tiny channel to the target region where the ion will be absorbed as a whole, or not absorbed at all, on some small triggering site.@