What we believe but cannot prove..

[Guest guest]

http://www.npr.org/templates/story/story.php?storyId=5254203

 

Thinkers Lay Out the Beliefs They Can't Prove

 

Our day-to-day beliefs often come from established theories, but what

about beliefs based on theories in progress? A new book asks literary

and scientific thinkers about what they believe but cannot prove.

 

Guest:

 

John Brockman, editor, What We Believe But Cannot Prove: Today's

Leading Thinkers in Science in the Age of Certainty; author and

literary agent; publisher and editor of Edge.org

 

Richard Dawkins, evolutionary biologist; professor of the public

understanding of science at Oxford University; author of many books

about science and evolution, including The Selfish Gene and most

recently, The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution.

 

Alison Gopnik, professor of psychology at the University of

California, Berkeley; her books include The Scientist in the Crib

 

Paul Steinhardt, theoretical physicist; Albert Einstein professor of

science at Princeton University

 

Excerpt: What We Believe but Cannot Prove

by John Brockman

 

Read from the first chapter of What We Believe but Cannot Prove:

Today's Leading Thinkers on Science in the Age of Certainty

 

Martin Rees

 

Sir Martin Rees is a professor of cosmology and astrophysics and the

master of Trinity College at the University of Cambridge. He holds

the honorary title of Astronomer Royal and is also a visiting

professor at Imperial College London and Leicester University. He is

the author of several books, including Just Six Numbers, Our Cosmic

Habitat, and Our Final Hour.

 

I believe that intelligent life may presently be unique to our Earth

but has the potential to spread throughout the galaxy and beyond it --

indeed, the emergence of complexity could be near its beginning. If

the searches conducted by SETI (the Search for Extra-Terrestrial

Intelligence) continue to come up with nothing, that would not render

life a cosmic sideshow; indeed, it would be a boost to our self-

esteem. Terrestrial life and its fate would be seen as a matter of

cosmic significance. Even if intelligence is now unique to Earth,

there's enough time ahead for it to permeate at least this galaxy and

evolve into a teeming complexity far beyond what we can conceive.

 

There's an unthinking tendency to imagine that humans will be around

in 6 billion years to watch the sun flare up and die. But the forms

of life and intelligence that have by then emerged will surely be as

different from us as we are from a bacterium. That conclusion would

follow even if future evolution proceeded at the rate at which new

species have emerged over the past 3.5 or 4 billion years. But

posthuman evolution (whether of organic species or artifacts) will

proceed far faster than the changes that led to human emergence,

because it will be intelligently directed rather than the gradual

outcome of Darwinian natural selection. Changes will drastically

accelerate in the present century -- through intentional genetic

modifications, targeted drugs, perhaps even silicon implants in the

brain. Humanity may not persist as a single species for longer than a

few more centuries, especially if communities have by then become

established away from Earth.

 

But a few centuries is still just a millionth of the sun's future

lifetime -- and the universe probably has a much longer future. The

remote future is squarely in the realm of science fiction. Advanced

intelligences billions of years hence might even create new

universes. Perhaps they'll be able to choose what physical laws

prevail in their creations. Perhaps these beings could achieve the

computational ability to simulate a universe as complex as the one we

perceive ourselves to be in.

 

My belief may remain unprovable for billions of years. It could be

falsified sooner -- for instance, we or our immediate posthuman

descendants may develop theories that reveal inherent limits to

complexity. But it's a substitute for religious belief, and I hope

it's true.

 

Ray Kurzweil

 

Ray Kurzweil is an inventor, entrepreneur, and principal developer of

(among a host of other inventions) the first print-to-speech reading

machine for the blind, the first text-to-speech synthesizer, the

first CCD flat-bed scanner, and the first commercially marketed large-

vocabulary speech recognition system. Recipient of the National Medal

of Technology among many other honors, he is the author of several

books, including The Singularity Is Near: When Humans Transcend

Biology.

 

We will find ways to circumvent the speed of light as a limit on the

communication of information.

 

We are expanding our computers and communication systems both

inwardly and outwardly. Our chips' features are ever smaller, while

we deploy increasing amounts of matter and energy for computation and

communication. (For example, we're making a larger number of chips

each year.) In one or two decades, we will progress from two-

dimensional chips to three-dimensional self-organizing circuits built

out of molecules. Ultimately we will approach the limits of matter

and energy to support computation and communication.

 

As we approach an asymptote in our ability to expand inwardly (that

is, using finer features), computation will continue to expand

outwardly, using materials readily available on Earth, such as

carbon. But we will eventually reach the limits of our planet's

resources and will expand outwardly to the rest of the solar system

and beyond.

 

How quickly will we be able to do this? We could send tiny self-

replicating robots at close to the speed of light, along with

electromagnetic transmissions containing the needed software. These

nanobots could then colonize faraway planets.

 

At this point, we run up against a seemingly intractable limit: the

speed of light. Although a billion feet per second may seem fast, the

universe extends over such vast distances that this appears to

represent a fundamental limit on how quickly an advanced civilization

(such as we hope to become) can spread its influence.

 

There are suggestions, however, that this limit is not as immutable

as it may appear. Physicists Steve Lamoreaux and Justin Torgerson of

the Los Alamos National Laboratory have analyzed data from an old

natural nuclear reactor that 2 billion years ago produced a fission

reaction lasting several hundred thousand years in what is now West

Africa. Analyzing radioactive isotopes left over from the reactor and

comparing them with isotopes from similar nuclear reactions today,

they determined that the physics constant a (alpha, also called the

fine structure constant), which determines the strength of the

electromagnetic force, apparently has changed since 2 billion years

ago. The speed of light is inversely proportional to a, and both have

been considered unchangeable constants. Alpha appears to have

decreased by 4.5 parts out of 108. If confirmed, this would imply

that the speed of light has increased. There are other studies with

similar suggestions, and there is a tabletop experiment now under way

at Cambridge University to test our ability to engineer a small

change in the speed of light.

 

Of course, these results will need to be carefully verified. If they

are true, it may hold great importance for the future of our

civilization. If the speed of light has increased, it has presumably

done so not just because of the passage of time but because certain

conditions have changed. . . .

 

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