| Physicists have sometimes used the term "determinism" in a special way
that people such as Karl Popper and Stephen Hawking have called scientific determinism.
Popper insisted that the term "scientific" only be applied to statements that are falsifiable. Popper's book The Open Universe: An Argument For Indeterminism defines scientific
determinism as the claim that ...any event can be rationally predicted, with any desired degree of precision, if we are given
a sufficiently precise description of past events, together with all the laws of nature, a notion that Popper asserted was
both falsifiable and adequately falsified by modern scientific knowledge.
In his book, A Brief History of Time,
Hawking claims that predictability is required for "scientific determinism" (start of chapter 4). He defines "scientific
determinism" as meaning: "something that will happen in the future can be predicted."
Since many limitations on predictability are now known (for a partial list see: quantum indeterminacy), most people who argue for determinism do not argue in favor of a strong
version of scientific determinism. For example, a weaker type of determinism is one that only implies a unique, mechanical course
for the universe with future events being caused by past events.
Hawking admits that even the uncertainty principle
does not absolutely rule-out a kind of determinism "in principle", and says that quantum mechanics may very well allow the
universe to be deterministic. He wrote:
- "These quantum theories are deterministic in the sense that they give laws for the evolution of the wave with time. Thus if
one knows the wave at one time, one can calculate it at any other time. The unpredictable, random element comes in only when we
try to interpret the wave in terms of the positions and velocities of particles. But maybe this is our mistake: maybe there are
no positions and velocities, but only waves. It is just that we try to fit the waves to our preconceived ideas of positions and
velocities. The resulting mismatch is the cause of the apparent unpredictability." (conclusions section of A Brief History Of
Time)
See also:
|
