Trivia Junction

A Compendium of trivia I find interesting
...for the curious

Is time driving you dizzy yet?

Feeling dizzy yet?

Most physicists accept the idea of time symmetry (at least in the context of things like Maxwell's equations). The same cannot be said of reverse causation, which goes farther by suggesting the future can influence the past.

“The tendency is to ignore it, to say it's just a fact of nature that time moves one way,” said Michael Ibison, a physicist at the University of Texas at Austin.

If reverse causation is real, it most likely occurs at the largely theoretical and unseen level of quantum mechanics, a place where subatomic particles with names like mesons and quarks interact in ways contrary to both classical physics and common sense.

To wit: Mesons exist simultaneously as both particles and waves until they are observed. But until they are observed, they don't exist.

“Anyone who thinks they can talk about quantum theory without feeling dizzy hasn't yet understood the first word about it,” said the late, great Danish physicist Niels Bohr who, incidentally, invented much of the theory.

“People know how to calculate with quantum mechanics, but that's not to say they know what it means,” agreed Sheehan. “Quantum mechanics is like poetry. The poem is right there, for everyone to see, but it has many different interpretations.”

Sheehan offers a couple of scenarios to ponder:

First, imagine a large boulder at the top of a hill. The boulder begins rolling downhill. Now freeze the action with the boulder midway along its descent. Call this the boulder's present. At this point in time, Sheehan says the boulder is being influenced both by its past (when it was atop the hill) and by its future (when it will come to rest at the bottom of the hill). The boulder's current position midway down the hill cannot happen without the effect of both the past and the future.

“The present is always a negotiation between the past and the future,” said Sheehan.

Or think about this: You're invited to a Saturday wedding. On Friday, you go to the barber for a haircut. As you sit in the chair, the future is influencing the present. The wedding hasn't happened. It may not happen at all. And yet its possibility changes what will be the past.

The best evidence for reverse causation – perhaps the only evidence, said Sheehan – comes from parapsychology, which investigates phenomena not explained by the known laws of science, such as telepathy, clairvoyance and psycho kinesis (the alleged ability to move matter with the mind).

Prior | Tell us what you think | Next

Add to Your Social Bookmarks: Del.icio.us Digg Furl Reddit Simpy Spurl Y! MyWeb - StumbleUpon