Saturday, October 15, 2011

Stenger on Einstein causality

Physicist and skeptic (ie, atheist) Victor Stenger writes:
When you read, "Einstein proved that particles cannot go faster than the speed of light" you have to understand that this was not a consequence of the basic axioms of the theory of special relativity. To prove this he introduced an additional assumption now called the "principle of Einstein causality": cause must always precede effect. In that case, it then follows that we can't have superluminal motion.

Einstein causality certainly seems reasonable based on normal experience. Cause and effect are deeply embedded in our thinking, in both everyday life as well as virtually all of science. Causality is one of those commonsense notions, such as the world is flat, that hangs in there as a "self-evident truth" until some very bright person come along and says: "Maybe not." ...

In modern chemistry and physics today, no distinction is made between cause and effect on the atomic and subatomic scales. Time is completely reversible. A carbon atom and oxygen molecule will combine to give carbon dioxide and energy. You can just as well have energy plus carbon dioxide give a carbon atom and oxygen molecule. ...

Furthermore, many events on the quantum scale are described without even introducing cause and effect. For example, the theories that successfully describe atomic transitions and the decay of nuclei treat these phenomena as occurring spontaneously, without cause.

So, if confirmed, the reported result from CERN or any future observation of superluminal motion will not lead to the overthrow of Einstein's theory of relativity. Its significance will be to overthrow the distinction between cause and effect. At the worst, Einstein might be faulted for taking causality a little too seriously.

Finally, you might want to ponder what effect the demise of causality would have on the notion of God as the ultimate cause of all there is.
Stenger usually knows what he is talking about, but these comments are weird. Causality does apply at an atomic scale. Yes, chemical reactions are often reversible, but it still makes sense to say that some events help cause other events.

I hardly found any references to the "principle of Einstein causality". One was on Quantum Field Theory, where the whole point is to apply it on an atomic scale.

Stenger suggests that if neutrino experiments disprove causality, then they would also undermine God as the ultimate cause. Most physicists are betting that causality will not be disproved. So I guess that Stenger would have to say that God can be the ultimate cause after all.


  1. "these comments are weird"

    They are. Presumably, whatever he says about cause and effect, it will always be possible to ask what caused him to make such comments.

  2. ...what affected him so much as to cause such comments that effect us all ? ;-)