16 Mar 2003 steve   » (Master)

Stephen Hawking Lecture Report

Susan and I drove down to Woodland Hills Friday to hear a public lecture by Stephen Hawking. He has been in Texas most of this month working with the new Mitchell Institute for Fundamental Physics at TAMU. The lecture was held at the outdoor Cynthia Woods Mitchell Pavillion (yes, the same Mitchells that paid for the TAMU physics institute).

The lecture, titled A Brane New World, gave a nice little introduction to M-theory, an offspring of string theory that attempts to unify Quantum Mechanics with General Relativity. It also covered the structure of the universe and why we seem to be able to perceive only 3 spatial dimensions when most modern theories of space-time say there should at least 10 spatial dimensions.

Having shown up early, we waited in line to get in for a half hour and then sat for about 45 minutes before the lecture started and observed the audience. There seemed to be three major groups represented: physics students and faculty, a contingent of wheelchair-bound disabled, and a spectrum of geeky regular folks like us. The place was packed and it's actually nice to realize there are enough people interested in a public lecture on science to pack a place like that.

Eventually, our wait was over and the lights went down. There followed a series of introductions including one by George and Cynthia Mitchell. George noted, among other things that, we should thank his wife Cynthia "'cause she owns the damn pavillion and gave me permission to hold Stephen's lecture here". After the last introduction left the stage empty, Hawking emerged from backstage, rolling much slower than I expected. I suspect the slower speed is required to give him time to operated the controls and steer. He made the entire 30 second trip to the microphone at center stage to the sound of a standing ovation and at least one enthusiastic shout of "GO HAWKING!" (at which Stephen showed a really big smile - something I've never seen him do in interviews).

An attendent showed up briefly to move Stephen's hand from the wheelchair controls back to his computer input paddle. He immediately began composing and seconds later said "Howdy!", much to the delight of his Texas audience. One thing you don't realize from seeing edited TV interviews is how long it takes for him to compose each sentence. He talks with a roughly 50% duty cycle. For each sentence he speaks, he spends about the same amount of time selecting words and building the sentence. This time is reduced somewhat when he is giving a public lecture because he has pre-composed much of his talk. Most of the time it appeared he merely needed to queue up the correct sentence or paragraph which took only 10-15 seconds of silence. But when he wanted to add a spontaneous statement or change something there was a more significant time delay.

The brief periods of silence punctating the lecture gave it a very unusual quality. I wonder if it was not unlike hearing R. Buckminster Fuller speak - he was also known for punctuating his public lectures with long periods of silence during which he would appear lost in thought.

The actual content of the lecture mostly consisted of describing M-Theory and the brane model of multi-dimensional space-time. The way the theory goes, there are 10 or 11 spatial dimensions but we see only three of them because most are curled up so small that we can't detect them. One of those extra dimensions, however, may be as much as 1cm in size and allows multiple 3-dimensional "branes", one of which is this thing we mistakenly call "the universe". The next brane along the way might have some other total different 3D "universe" on it. The interesting thing is that while most of physics is limited to the 3D branes, gravity can pass beyond into adjacent branes. If we were able to detect gravity from matter in an adjacent brane, it would appear to have the qualities of matter without being matter - dark matter. The term "shadow" was used to describe contents of adjacent branes. Shadow worlds, shadow civilizations, etc. Lots of good fodder for SF writers in there.

He pointed out a couple of ways in which these theories could be proven by observations of tiny black holes or other phenomena (and mentioned that he'd really like for one of those phenomena to be observed because, if it were, he'd probably get a Nobel prize. ;-)

Anytime I hear these modern, multi-dimensional space-time theories, I can't help thinking back to R. Buckminster Fuller, who believed in 12 dimensional space way before it was popular. Using only some string and a ping pong ball, Fuller concluded that there were four (not three) observable spatial dimensions, each composed of 3 lesser-dimensions that did not allow spatial movement but only tiny rotational movements (I've forgotten the term; "turbining"?). He believed that where we went wrong was in the arbitrary decision that spatial dimensions had to be at 90 degree angles to each other. In a Universe with 3 dimensions at 90 degree angles, he reasoned, a cube should be inherently stable - but it isn't. A tetrahedron is inherently stable, however, because it has four planes, each of which is in one of the four basic spatial dimensions. Unfortunately Fuller has almost joined Tesla in being so obsessed on by nuts that many scientists tend to discount his work these days. one has to wonder what a modern physicist like Hawking could do taking Fuller's 4D space as a starting point.

One of Hawking's descriptions of the structure of the real universe was a hyperspatial bubble. The bubble's surface is the 3D brane that we think of "the universe" but, in reality, it may simply be a side effect of all the hyper-dimensional fun going on inside the volume of the bubble. Everything we known may just be a reflection or shadow of reality. He noted that his is somewhat analogous to a hologram and explained that he was an expert on holograms because he had played one on Star Trek:TNG. This segued into a brief video clip from the Descent episode with Hawking, Newton, Einstein, and Mr. Data playing poker on the holodeck of the Enterprise.

He closed with a mention of the Large Hadron Collider Project and the hope that it could create artificial black holes that might help prove or disprove M-theory. It struct me as ironic that he was here in Texas, home of the ill-fated Super Conducting Super Collider, talking about the need for a giant collider. If it weren't for politics, we probably could have presented him with some home-grown Texas black holes (no doubt they'd have been twice as big as those puny European black holes).

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