Owen Densmore
2010-04-29 16:47:07 UTC
Yet another interesting article from the economist.
---- OwenI am an iPad, resistance is futile!
A QUANTUM CALCULATION
Apr 22nd 2010
A physicist argues that information is at the root of everything
DECODING REALITY: THE UNIVERSE AS QUANTUM INFORMATION. By Vlatko
Vedral. OXFORD UNIVERSITY PRESS; 256 PAGES; $29.95 AND GBP16.99. Buy
from Amazon.com[1], Amazon.co.uk[2]
ONE of the most elusive goals in modern physics has turned out to be
the creation of a grand unified theory combining general relativity and
quantum mechanics, the two pillars of 20th-century physics. General
relativity deals with gravity and time and space; quantum mechanics
with the microscopic workings of matter. Both are incredibly successful
in their own domains, but they are inconsistent with one another.
For decades physicists have tried to put the two together. At the heart
of the quest lies the question, of what is the universe made? Is it
atoms of matter, as most people learned in school? Or some sort of
energy? String theory, currently a popular idea, holds that the
universe is made up of tiny vibrating strings. Other equally esoteric
candidates abound. Indeed, cynics claim that there are as many grand
unified theories as there are theoretical physicists attempting
unification.
Now Vlatko Vedral, an Oxford physicist, examines the claim that bits of
information are the universe's basic units, and the universe as a whole
is a giant quantum computer. He argues that all of reality can be
explained if readers accept that information is at the root of
everything.
So what is information? Mr Vedral's notion of information is not the
somewhat fuzzy concept most people have of it, but a precise
mathematical definition that owes itself to Claude Shannon, an American
mathematician considered to be the father of "information theory".
Shannon worked at Bell Labs, at the time the research arm of AT&T,
a telephone giant, and in the 1940s became interested in how much
information could be sent over a noisy telephone connection. This led
him to calculate that the information content of any event was
proportional to the logarithm of its inverse probability of occurrence.
(Unlike many popular-science books that eschew equations, Mr Vedral
includes a couple and tries his best to explain them to the reader.)
What does the equation mean? As Mr Vedral points out, it says that an
unexpected, infrequent event contains much more information than a more
regular happening.
Once he has defined information, Mr Vedral proceeds to show how
information theory can be applied to biology, physics, economics,
sociology and philosophy. These are the most interesting parts of the
book. Of particular note is the chapter on placing bets. Mr Vedral
gives a good description of how Shannon's information theory can be
applied to winning at blackjack or in buying shares (Shannon and his
friends made fortunes in Las Vegas as well as on the stockmarket). And
his exposition of climate change and how to outwit the CIA make
entertaining reading. One quibble: Mr Vedral often digresses from the
point at hand, so the overall effect tends to be a bit meandering.
Mr Vedral's professional interests lie in quantum computing and quantum
information science, which use the laws of quantum mechanics
respectively to build powerful computers and render codes unbreakable.
There is a lot of discussion of both, which is very welcome because
there are not many popular science books that cover these relatively
young fields. Quantum computers, as Mr Vedral points out, "are not a
distant dream". Though still rudimentary, "they can solve some
important problems for us that conventional computers cannot."
Unusually for a physicist, Mr Vedral spends a fair bit of time talking
about religious views, such as how God created the universe. He asks
whether something can come out of nothing. Throughout the ages
philosophers and theologians have debated this question with respect to
Judeo-Christian faiths, in which dogma holds that the world was created
from the void, CREATION EX NIHILO. Others side with King Lear who tells
Cordelia that "Nothing can come of nothing." Mr Vedral makes a
persuasive argument for a third option: information can be created out
of nothing.
-----
[1] http://www.amazon.com/exec/obidos/ASIN/0199237697/theeconomists-20
[2]
http://www.amazon.co.uk/exec/obidos/ASIN/0199237697/economistshop-21
See this article with graphics and related items at http://www.economist.com/culture/displaystory.cfm?story_id=15949137
Apr 22nd 2010
A physicist argues that information is at the root of everything
DECODING REALITY: THE UNIVERSE AS QUANTUM INFORMATION. By Vlatko
Vedral. OXFORD UNIVERSITY PRESS; 256 PAGES; $29.95 AND GBP16.99. Buy
from Amazon.com[1], Amazon.co.uk[2]
ONE of the most elusive goals in modern physics has turned out to be
the creation of a grand unified theory combining general relativity and
quantum mechanics, the two pillars of 20th-century physics. General
relativity deals with gravity and time and space; quantum mechanics
with the microscopic workings of matter. Both are incredibly successful
in their own domains, but they are inconsistent with one another.
For decades physicists have tried to put the two together. At the heart
of the quest lies the question, of what is the universe made? Is it
atoms of matter, as most people learned in school? Or some sort of
energy? String theory, currently a popular idea, holds that the
universe is made up of tiny vibrating strings. Other equally esoteric
candidates abound. Indeed, cynics claim that there are as many grand
unified theories as there are theoretical physicists attempting
unification.
Now Vlatko Vedral, an Oxford physicist, examines the claim that bits of
information are the universe's basic units, and the universe as a whole
is a giant quantum computer. He argues that all of reality can be
explained if readers accept that information is at the root of
everything.
So what is information? Mr Vedral's notion of information is not the
somewhat fuzzy concept most people have of it, but a precise
mathematical definition that owes itself to Claude Shannon, an American
mathematician considered to be the father of "information theory".
Shannon worked at Bell Labs, at the time the research arm of AT&T,
a telephone giant, and in the 1940s became interested in how much
information could be sent over a noisy telephone connection. This led
him to calculate that the information content of any event was
proportional to the logarithm of its inverse probability of occurrence.
(Unlike many popular-science books that eschew equations, Mr Vedral
includes a couple and tries his best to explain them to the reader.)
What does the equation mean? As Mr Vedral points out, it says that an
unexpected, infrequent event contains much more information than a more
regular happening.
Once he has defined information, Mr Vedral proceeds to show how
information theory can be applied to biology, physics, economics,
sociology and philosophy. These are the most interesting parts of the
book. Of particular note is the chapter on placing bets. Mr Vedral
gives a good description of how Shannon's information theory can be
applied to winning at blackjack or in buying shares (Shannon and his
friends made fortunes in Las Vegas as well as on the stockmarket). And
his exposition of climate change and how to outwit the CIA make
entertaining reading. One quibble: Mr Vedral often digresses from the
point at hand, so the overall effect tends to be a bit meandering.
Mr Vedral's professional interests lie in quantum computing and quantum
information science, which use the laws of quantum mechanics
respectively to build powerful computers and render codes unbreakable.
There is a lot of discussion of both, which is very welcome because
there are not many popular science books that cover these relatively
young fields. Quantum computers, as Mr Vedral points out, "are not a
distant dream". Though still rudimentary, "they can solve some
important problems for us that conventional computers cannot."
Unusually for a physicist, Mr Vedral spends a fair bit of time talking
about religious views, such as how God created the universe. He asks
whether something can come out of nothing. Throughout the ages
philosophers and theologians have debated this question with respect to
Judeo-Christian faiths, in which dogma holds that the world was created
from the void, CREATION EX NIHILO. Others side with King Lear who tells
Cordelia that "Nothing can come of nothing." Mr Vedral makes a
persuasive argument for a third option: information can be created out
of nothing.
-----
[1] http://www.amazon.com/exec/obidos/ASIN/0199237697/theeconomists-20
[2]
http://www.amazon.co.uk/exec/obidos/ASIN/0199237697/economistshop-21
See this article with graphics and related items at http://www.economist.com/culture/displaystory.cfm?story_id=15949137