Peering Through the Gates of Time

[David Morris]

http://www.nytimes.com/2002/03/12/science/physical/12WHEE.html

In one corner is Dr. John Archibald Wheeler, 90, professor emeritus of 
physics at Princeton and the University of Texas, armed with a battery of 
hearing aids, fistfuls of colored chalk, unfailing courtesy, a poet's flair 
for metaphor, an indomitable sense of duty and the company of a ghost army 
of great thinkers.

In the other is a "great smoky dragon," which is how Dr. Wheeler refers 
sometimes to one of the supreme mysteries of nature. That is the ability, 
according to the quantum mechanic laws that govern subatomic affairs, of a 
particle like an electron to exist in a murky state of possibility — to be 
anywhere, everywhere or nowhere at all — until clicked into substantiality 
by a laboratory detector or an eyeball.

Dr. Wheeler suspects that this quantum uncertainty, as it is more commonly 
known, is the key to understanding why anything exists at all, how 
something, the universe with its laws, can come from nothing. Or as he likes 
to put it in the phrase that he has adopted as his mantra: "How come the 
quantum? How come existence?"

Standing by the window in his third-floor office in Princeton's Jadwin Hall 
recently, Dr. Wheeler pointed out at the budding trees and the green domes 
of the astronomy building in the distance. "We're all hypnotized into 
thinking there's something out there," he said.

[...]

The black hole "teaches us that space can be crumpled like a piece of paper 
into an infinitesimal dot, that time can be extinguished like a blown-out 
flame, and that the laws of physics that we regard as `sacred,' as 
immutable, are anything but," he later said in his 1998 autobiography, 
"Geons, Black Holes & Quantum Foam: A Life in Physics," written with Dr. 
Kenneth Ford, a former student and the retired director of the American 
Institute of Physics.

Moreover, Dr. Wheeler preached, the breakdown of physics could not be sealed 
away in a distant dead star. He pointed out that even space and time had to 
pay their dues to the uncertainty principle. When viewed on very small 
scales or in the compressed throes of the Big Bang, what looked so smooth 
and continuous, like an ocean from an airplane, would become discontinuous, 
dissolving like a dry sand castle into a mess of unconnected points and worm 
holes that Dr. Wheeler dubbed "quantum foam."

In a sense, black holes, or "gates of time," as he later called them, were 
everywhere, under our fingernails, courtesy of the uncertainty principle, 
and thus so was the issue of where the laws of physics came from.

[...]

Back in his office Dr. Wheeler busied himself at the blackboard with a 
diagram that is emblematic of quantum weirdness, and of his hope for 
constructing the universe and its laws "higgledy-piggledy," as he likes to 
call it, out of nothing.

It is called double slit experiment. In it an electron or any other particle 
flies toward a screen with a pair of slits. Past the screen is a physicist 
with a choice of two experiments. One will show that the electron was a 
particle and passed through one or another slit; the other will show that it 
was a wave and passed through both slits, producing an interference pattern. 
The electron will turn out to be one or the other depending on the 
experimenter's choice.

That was weird enough, but in 1978 Dr. Wheeler pointed out that the 
experimenter could wait until after the electron would have passed the slits 
before deciding which detector to employ and thus whether it had been a 
particle or wave. In effect, in this "delayed choice" experiment, the 
physicists would be participating in creating the past.

In a 1993 paper Dr. Wheeler likened such a particle to a "great smoky 
dragon," whose tail was at the entrance slits of the chamber and its teeth 
at the detector, but in between — before it had been "registered" in some 
detector as a phenomenon — was just a cloud, smoky probability.

Perhaps the past itself is such a smoky dragon awaiting our perception.




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