**From:** Ben Goertzel (*ben@goertzel.org*)

**Date:** Wed Jun 12 2002 - 16:09:27 MDT

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Hi,

Most of my knowledge of the history of physics comes from reading works on

the history of science, not from talking to physicists.

My favorite philosophers of science are Paul Feyerabend and Imre Lakatos,

who were good friends but radically disagreed on the nature of scientific

progress.

My own take on Theories of Everything is given at the end of the newspaper

article

http://www.goertzel.org/benzine/StringTheoryEtc.htm

which has one of my favorite titles among all my journalistic offerings,

"In Search of the Universal Equation: String Theory, Subatomic Computing,

and Other Bold Attempts to Form a Unified Picture of the Submicroscopic

World of which our Universe is but a Shadow."

In there, I include a quote by superstring theorist John Schwarz: “the TOE

phrase is very misleading on several counts….. [And] it alienated many of

our physics colleagues, some of whom had serious doubts about the subject

anyway. Quite understandably, it gave them the impression that people who

work in this field are a very arrogant bunch. Actually, we are all very

charming and delightful.”

I also say, at the end of the article (most of which summarizes technical

physics stuff in a nontechnical way):

"So, let’s suppose the string theorists, or the universal computists, or

some other group finally achieves their end goal -- unifying quantum theory

and gravitation, creating one single equation, accounting in principle for

all phenomena in the universe. What happens then? Do the angels descend

from heaven, dancing and singing in the streets and on the rooftops, serving

out the wine in holy grails laminated with spinning black holes, bringing

peace on earth at long long last? More seriously: does science enter a

whole new era, where every phenomenon observed is analyzed in terms of the

one true equation?

"Well, parts of physics will surely be revolutionized. There will be new

technologies, maybe those we envision now like quantum gravity computers or

time travel machines, maybe other types of things we can hardly imagine now.

Perhaps, as some maverick theorists believe, new light will be shed on the

mysteries of biological processes like cell development.

"But no serious scientist really believes that such a “Theory of Everything”

(TOE) in principle will really be a theory of everything in practice. There

are a number of technical and conceptual points that will stop this from

happening.

"For one thing, if string theory or universal computation or some other

approach succeeds in making quantum theory and gravitation play nice

together, this still doesn’t explain why our universe is the way it is,

because it doesn’t explain what physicists call the “initial conditions” of

the universe: it only explains how things evolved from their starting-point.

This may seem a small technical point but it’s a big one in practice: there

may be many, many very different universes consistent with equations as

general as those of string theory.

"Next, we may find that one thing the “universal equation” binding quantum

theory and gravitation teaches us is that some very important things can’t

be explained or understood. Just as quantum theory has taught us that

particles don’t have definite states, the next wave of physics may open up

new kinds of indeterminacy and unknowability. We may wind up learning, in

ever more exquisite detail, why our own finite, macroscopic minds are not up

to the task of understanding the real world underlying the shadow-world they

’ve evolved to see.

"And this latter point ties in with the most serious problem with these

approaches to physics: the problem of intractable calculations. Right now,

the equations of string theory are so hard to solve that we can only really

understand them in very special cases. There is an assumption that the

mathematics of the next century will allow us to make more progress in this

regard. But to what extent will this really be true? Right now, we can’t

do explicit quantum theory calculations to understand proteins or neurons –

only very simple molecules. And we can’t do string theory calculations to

understand electrons and protons. To bring string theory to the next level,

we’ll have to be able to use it to understand electrons and protons, but

that may be as far as it goes – the elucidation of the implications of these

micromicromicro-level equations for macroscopic phenomena may remain too

difficult for mathematicians or computer-simulators to resolve for hundreds

or thousands of years, or even forever.

"It all comes down to Plato, and his parable of the cave [this metaphor was

introduced at the beginning of the article]. From studying these shadows on

the wall, we can’t really figure out what the birds and trees and squirrels

are. But we can learn more and more about them. We can make deeper and

deeper theories, some of them explaining the interaction of very small bits

of shadow, some of them explaining particular kinds of large shadow. It’s

vain to think we can fully understand reality, or even fully understand what

“reality” means. The very notion of “everything,” when taken seriously,

intrinsically goes beyond our understanding. The hubristic search to

understand everything is valuable insofar as it give us the passion to

understand more and more, but in more reflective moments, we have to

acknowledge, as Schwarz did in the quote given above, that we can’t really

capture the whole big universe in any little box -- not even a box composed

of the most sophisticated and fantastic equations."

-- ben g

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