Freeman Dyson
Our Biotech Future
By Freeman Dyson
The New York Review of Books, July 19, 2007
Edited by Andy Ross
I predict that the domestication of
biotechnology will dominate our lives during the next fifty years at least as
much as the domestication of computers has dominated our lives during the
previous fifty years.
Domesticated biotechnology, once it gets into the hands of housewives and
children, will give us an explosion of diversity of new living creatures.
Designing genomes will be a personal thing, a new art form as creative as
painting or sculpture.
Few of the new creations will be masterpieces, but a great many will bring joy
to their creators and variety to our fauna and flora. The final step in the
domestication of biotechnology will be biotech games, designed like computer
games for children down to kindergarten age but played with real eggs and seeds
rather than with images on a screen.
Carl Woese is the world's greatest expert in the field of microbial taxonomy. He
discovered the large-scale structure of the tree of life. Before Woese, the tree
of life had two main branches called prokaryotes and eukaryotes, the prokaryotes
composed of cells without nuclei and the eukaryotes composed of cells with
nuclei. All kinds of plants and animals, including humans, belonged to the
eukaryote branch. The prokaryote branch contained only microbes. Woese
discovered that there are two fundamentally different kinds of prokaryotes,
which he called bacteria and archea. So he constructed a new tree of life with
three branches, bacteria, archea, and eukaryotes.
Woese presents evidence that Darwinian evolution does not go back to the
beginning of life. Woese is postulating a golden age of pre-Darwinian life, when
horizontal gene transfer was universal and separate species did not yet exist.
Life was then a community of cells of various kinds, sharing their genetic
information so that clever chemical tricks and catalytic processes invented by
one creature could be inherited by all of them. Evolution was a communal affair.
But then, one day, a cell resembling a primitive bacterium happened to find
itself one jump ahead of its neighbors in efficiency. That cell separated itself
from the community and refused to share. Its offspring became the first species
of bacteria. With their superior efficiency, the bacteria continued to prosper
and to evolve separately. Some millions of years later, another cell separated
itself from the community and became the ancestor of the archea. Some time after
that, a third cell separated itself and became the ancestor of the eukaryotes.
The Darwinian interlude has lasted for two or three billion years. It probably
slowed down the pace of evolution considerably. The basic biochemical machinery
of life had evolved rapidly during the few hundreds of millions of years of the
pre-Darwinian era, and changed very little in the next two billion years of
microbial evolution.
Now, after three billion years, the epoch of Darwinian evolution based on
competition between species ended about ten thousand years ago, when Homo
sapiens began to dominate and reorganize the biosphere. Since that time,
cultural evolution has replaced biological evolution as the main driving force
of change. Cultures spread by horizontal transfer of ideas more than by genetic
inheritance.
In the era of Open Source biology, the magic of genes will be available to
anyone with the skill and imagination to use it. The way will be open for
biotechnology to move into the mainstream of economic development, to help us
solve some of our urgent social problems and ameliorate the human condition all
over the earth.
A plant is a creature that uses the energy of sunlight to convert water and
carbon dioxide and other simple chemicals into roots and leaves and flowers. To
live, it needs to collect sunlight. But it uses sunlight with low efficiency.
Artificial solar collectors made of silicon can do much better. We can imagine
that in the future we may breed new crop plants that have leaves made of
silicon, converting sunlight into chemical energy with ten times the efficiency
of natural plants.
If the natural evolution of plants had been driven by the need for high
efficiency of utilization of sunlight, then the leaves of all plants would have
been black. Obviously plant evolution was driven by other needs, and in
particular by the need for protection against overheating. That is why it is
reasonable for plants in tropical climates to be green. But this logic does not
explain why plants in cold climates where sunlight is scarce are also green.
After we have explored this route to the end, when we have created new forests
of black-leaved plants that can use sunlight ten times more efficiently than
natural plants, we shall be confronted by a new set of environmental problems.
The twenty-first century will bring us powerful new tools of genetic engineering
with which to manipulate our farms and forests.
Green technology is based on biology, gray technology on physics and chemistry.
Roughly speaking, green technology is the technology that gave birth to village
communities ten thousand years ago, starting from the domestication of plants
and animals. Gray technology is the technology that gave birth to cities and
empires five thousand years later.
Within a few more decades, as the continued exploring of genomes gives us better
knowledge of the architecture of living creatures, we shall be able to design
new species of microbes and plants according to our needs. The way will then be
open for green technology to do more cheaply and more cleanly many of the things
that gray technology can do, and also to do many things that gray technology has
failed to do.
Many of the people who call themselves green are passionately opposed to green
technology. But in the end, if the technology is developed carefully and
deployed with sensitivity to human feelings, it is likely to be accepted by most
of the people who will be affected by it, just as the equally unnatural and
unfamiliar green technologies of milking cows and plowing soils and fermenting
grapes were accepted by our ancestors long ago.
My book
The Sun, the Genome, and the Internet (1999) describes a vision of green
technology enriching villages all over the world and halting the migration from
villages to megacities.
The
Sun, the Genome, and the Internet
By Freeman Dyson
Oxford University Press, 142 pages
From
the complete review's review:
We have always admired
Freeman Dyson highly. A talented scientist
with many interests, he has also managed to convey his interests and thoughts in
his thoughtful and accessible writing.
This small book, based on lectures given at the New York Public Library in 1997
again allow him to share his interesting thoughts with a wider audience.
Dyson is an admirable fellow, and this is an admirable book.
AR (2007) Indeed. He was a contemporary of Richard Feynman, and like him a pioneer of
quantum electrodynamics (he proved the equivalence of the three approaches taken
by the Nobelists Feynman, Schwinger, and Tomonaga). For some decades now he has
been at the institute in Princeton where Einstein and Gödel used to work.
Earlier, he was British, and even learned differential equations at school from
the same textbook by Piaggio that I used (but I had a new copy). Truly an
inspiring figure.
By Freeman Dyson
The New York Review of Books, June 12, 2008
Edited by Andy Ross
A Question of Balance: Weighing the Options on Global
Warming Policies
By William Nordhaus
Yale University Press, 234 pages
Global Warming: Looking Beyond Kyoto
Edited by Ernesto Zedillo
Yale Center for the Study of Globalization/Brookings Institution Press, 237
pages
There is a famous graph showing the fraction of carbon dioxide in
the atmosphere as it varies month by month and year by year. It gives us our
firmest and most accurate evidence of effects of human activities on our global
environment. The graph is generally known as the Keeling graph. Keeling measured
the carbon dioxide abundance in the atmosphere from 1958 until 2005.
The measurements have continued since 2005, and show an unbroken record of
rising carbon dioxide abundance extending over fifty years. The graph shows a
steady increase of carbon dioxide with time, beginning at 315 parts per million
in 1958 and reaching 385 parts per million in 2008. And it shows a regular
wiggle showing a yearly cycle of growth and decline of carbon dioxide levels.
The maximum happens each year in the Northern Hemisphere spring, the minimum in
the Northern Hemisphere fall.
The only plausible explanation of the annual wiggle and its variation with
latitude is that it is due to the seasonal growth and decay of annual vegetation
in temperate latitudes north and south. The asymmetry of the wiggle between
north and south is caused by the fact that the Northern Hemisphere has most of
the land area. The wiggle measures of the quantity of carbon absorbed from the
atmosphere each summer north and south by growing vegetation, and returned each
winter to the atmosphere by dying and decaying vegetation.
When we put together the evidence from the wiggles and the distribution of
vegetation over the earth, it turns out that about 8 percent of the carbon
dioxide in the atmosphere is absorbed by vegetation and returned to the
atmosphere every year. This means that the average lifetime of a molecule of
carbon dioxide in the atmosphere, before it is captured by vegetation and
afterward released, is about twelve years. This fact is of fundamental
importance to the long-range future of global warming. Neither of the books
under review mentions it.
William Nordhaus is a professional economist, and his book describes the
global-warming problem as an economist sees it. He is not concerned with the
science of global warming. He compares the effectiveness of various policies for
the allocation of economic resources in response. His conclusions are largely
independent of scientific details. He calculates aggregated expenditures and
costs and gains by running a computer model called DICE, Dynamic Integrated
Model of Climate and the Economy.
Each run of DICE takes as input a particular policy for allocating expenditures
year by year. The allocated resources are spent on subsidizing costly
technologies that reduce emissions of carbon dioxide, or placing a tax on
activities that produce carbon emissions. The climate model part of DICE
calculates the effect of the reduced emissions in reducing damage. The output of
DICE then tells us the resulting gains and losses of the world economy year by
year. Each run begins at the year 2005 and ends either at 2105 or 2205.
The practical unit of economic resources is a trillion inflation-adjusted
dollars. An inflation-adjusted dollar means a sum of money with the same
purchasing power as a real dollar in 2005. The difference in outcome between one
policy and another is typically several trillion dollars.
Nordhaus gives a summary of his results and their consequences. He believes that
the most important concern of any policy that aims to address climate change
should be how to set the most efficient "carbon price," which he defines as "the
market price or penalty that would be paid by those who use fossil fuels and
thereby generate CO2 emissions." He writes: "To a first approximation, raising
the price of carbon is a necessary and sufficient step for tackling global
warming."
Nordhaus examines five kinds of global-warming policy. The first kind is
business as usual, in which case, he estimates damages to the environment
amounting to some $23 trillion in current dollars by the year 2100. The second
kind is the "optimal policy," judged by Nordhaus to be the most cost-effective,
with a worldwide tax on carbon emissions adjusted each year to give the maximum
aggregate economic gain as calculated by DICE. The third kind is the Kyoto
Protocol, imposing fixed limits to the emissions of economically developed
countries only.
The fourth kind of policy is labeled "ambitious" proposals, with two versions
which Nordhaus calls "Stern" and "Gore." "Stern" is the policy advocated by the
Stern Review, an economic analysis sponsored by the British government. "Stern"
imposes draconian limits on emissions. "Gore" is a policy advocated by Al Gore,
with emissions reduced drastically but gradually, the reductions reaching 90
percent of current levels before the year 2050. The fifth and last kind is
called "low-cost backstop," a policy based on a hypothetical low-cost technology
for removing carbon dioxide from the atmosphere, or for producing energy without
carbon dioxide emission.
Since each policy put through DICE is allowed to run for one or two hundred
years, its economic effectiveness must be measured by an aggregated sum of gains
and losses over the whole duration of the run. The question is then how to
compare present-day gains and losses with gains and losses a hundred years in
the future. If we can save M dollars of damage caused by climate change in the
year 2110 by spending one dollar on reducing emissions in the year 2010, how
large must M be to make the spending worthwhile?
The conventional answer is to say that M must be larger than the expected return
in 2110 if the 2010 dollar were invested in the world economy for a hundred
years at an average rate of compound interest. The question then is how well
different strategies of dealing with global warming succeed in producing
long-term benefits that outweigh their present costs.
Nordhaus displays the results only for a discount rate of 4 percent. This is a
conservative number, based on an average of past experience in good and bad
times, assuming that the next hundred years will bring overall average growth
continuing at the same rate that we have experienced during the 20th century.
When the future costs and benefits are discounted at a rate of 4 percent per
year, the aggregated costs and benefits of a climate policy over the entire
future are finite. The costs and benefits beyond a hundred years make little
difference to the calculated aggregate. Nordhaus therefore takes the aggregate
benefit-minus-cost over the entire future as a measure of the net value of the
policy. He uses this single number, calculated with the DICE model of the world
economy, as a figure of merit to compare one policy with another.
The net values of the various policies as calculated by the DICE model are
calculated as differences from the business-as-usual model, without any emission
controls. A plus value means that the policy is better than business as usual, a
minus value that it is worse. The unit of value is $1 trillion, and the values
are specified to the nearest trillion. The net value of the optimal program, a
global carbon tax increasing gradually with time, is plus three. The Kyoto
Protocol has a value of plus one with US participation, zero without US
participation. The "Stern" policy has a value of minus 15, the "Gore" policy
minus 21, and "low-cost backstop" plus 17.
The main conclusion of the Nordhaus analysis is that the ambitious proposals,
"Stern" and "Gore," are disastrously expensive, the "low-cost backstop" is
enormously advantageous if it can be achieved, and the other policies including
business-as-usual and Kyoto are only moderately worse than the optimal policy.
The practical consequence is that we should:
— Avoid the ambitious proposals
— Develop the science and technology for a low-cost backstop
— Negotiate an international treaty coming close to the optimal policy
— Avoid making the Kyoto Protocol policy permanent
Nordhaus does not discuss the details of the "low-cost backstop" that might
provide a climate policy vastly more profitable than his optimum policy. He
avoids this subject because he is an economist and not a scientist. He does not
wish to question the pronouncements of the Intergovernmental Panel on Climate
Change, a group of hundreds of scientists appointed by the United Nations.
The Keeling graph shows us that every carbon dioxide molecule in the atmosphere
is incorporated in a plant within a time of the order of twelve years.
Therefore, if we can control what the plants do with the carbon, the fate of the
carbon in the atmosphere is in our hands. That is what Nordhaus meant when he
mentioned "genetically engineered carbon-eating trees" as a low-cost backstop to
global warming. I consider it likely that we shall have such trees within a few
decades.
Carbon-eating trees could convert most of the carbon that they absorb from the
atmosphere into some chemically stable form and bury it. Or they could convert
it into liquid fuels and other useful chemicals. Biotechnology is capable of
burying or transforming any molecule of carbon dioxide that comes into its
grasp. If one quarter of the world's forests were replanted with carbon-eating
varieties of the same species, the carbon dioxide in the atmosphere would be
reduced by half in about fifty years.
It is likely that biotechnology will dominate our lives and our economic
activities during the second half of the 21st century. Biotechnology could
spread wealth wherever there is land and air and water and sunlight. After we
have mastered biotechnology, some low-cost and environmentally benign backstop
to carbon emissions is likely to become a reality.
Global Warming is the record of a conference held at the Yale Center for the
Study of Globalization in 2005. The book consists of an introduction by Ernesto
Zedillo, who was chairman of the conference, and 14 chapters by speakers at the
conference. Among the speakers was William Nordhaus.
The Zedillo book covers a much wider range of topics and opinions than the
Nordhaus book. It includes a chapter by Richard Lindzen, professor of
atmospheric sciences at MIT, who does not deny the existence of global warming,
but considers the predictions of its harmful effects to be grossly exaggerated.
Answering Lindzen in the next chapter is Stefan Rahmstorf, professor of physics
of the oceans at Potsdam University in Germany. Rahmstorf sums up his opinion of
Lindzen's arguments in one sentence: "All this seems completely out of touch
with the world of climate science as I know it and, to be frank, simply
ludicrous."
In the history of science it has often happened that the majority was wrong and
refused to listen to a minority that later turned out to be right. The great
virtue of Nordhaus's economic analysis is that it remains valid whether the
majority view is right or wrong. Nordhaus's optimum policy takes both
possibilities into account.
The last five chapters of the Zedillo book are by writers from five of the
countries most concerned with the politics of global warming: Russia, Britain,
Canada, India, and China. Each of the five authors has been responsible for
giving technical advice to a government, and each of them gives us a statement
of that government's policy.
Howard Dalton, spokesman for the British government, says: "It is the firm view
of the United Kingdom that climate change constitutes a major threat to the
environment and human society, that urgent action is needed now across the world
to avert that threat, and that the developed world needs to show leadership in
tackling climate change."
All the books that I have seen about the science and economics of global
warming, including the two books under review, miss the main point. The main
point is religious rather than scientific. There is a worldwide secular religion
which we may call environmentalism, holding that we are stewards of the earth,
that despoiling the planet with waste products of our luxurious living is a sin,
and that the path of righteousness is to live as frugally as possible.
Environmentalism has replaced socialism as the leading secular religion. And the
ethics of environmentalism are fundamentally sound. Scientists and economists
that ruthless destruction of natural habitats is evil and careful preservation
of birds and butterflies is good. The worldwide community of environmentalists
holds the moral high ground. This is a religion that we can all share.
Unfortunately, some members of the environmental movement believe that global
warming is the greatest threat to the ecology of our planet. Much of the public
has come to believe that anyone who is skeptical about the dangers of global
warming is an enemy of the environment. The skeptics now have the difficult task
of convincing the public that the opposite is true. Many of the skeptics are
horrified to see the obsession with global warming distracting public attention
from what they see as more serious and more immediate dangers to the planet.
Global Warming as Mass Neurosis
By Bret Stephens
The Wall Street Journal, July 1, 2008
Edited by Andy Ross
Last week marked the 20th anniversary of the mass hysteria
phenomenon known as global warming.
Much of the science has since been discredited. NASA now confirms that the
hottest year on record in the continental 48 was not 1998, as previously
believed, but 1934, and that six of the 10 hottest years since 1880 antedate
1954. Data from 3,000 scientific robots in the world's oceans show there has
been slight cooling in the past five years.
The Arctic ice cap may be thinning, but the extent of Antarctic sea ice has been
expanding for years. At least as of February, last winter was the Northern
Hemisphere's coldest in decades. In May, German climate modelers reported in the
journal Nature that global warming is due for a decade-long vacation.
The place where discussions of global warming belong is in the realm of belief. I see three mutually compatible
explanations.
The first is as a vehicle of ideological convenience. Socialism may have failed
as an economic theory, but global warming alarmism is equally a rebuke to
capitalism. Take just about any other discredited leftist nostrum of yore and global warming
provides a justification.
A second explanation is theological. Surely it is no accident that the principal
catastrophe predicted by global warming alarmists is diluvian in nature. And
surely it is in keeping with this essentially religious outlook that the
"solutions" chiefly offered to global warming involve radical changes to
personal behavior. A light carbon footprint has become the 21st-century
equivalent of sexual abstinence.
Finally, there is a psychological explanation. Listen carefully to the global
warming alarmists, and the main theme that emerges is that what the developed
world needs is a large dose of penance. If you're inclined to believe that our
successes are undeserved and that prosperity is morally suspect, global warming
is nature's great come-uppance, affirming as nothing else our guilty conscience
for our worldly success.
William James distinguishes between healthy, life-affirming religion and the
"morbid-minded" religion of the sick-souled. Global warming is sick-souled
religion.
AR (2008)
A refreshingly forthright
opinion, and the William James invocation hits the spot. But the scientific details
are still troubling enough to be worth serious and ongoing debate.
By Kenneth Brower
The Atlantic, December 2010
Edited by Andy Ross
Freeman Dyson is an intellect whose true brilliance you
can grasp only if you can follow quantum electrodynamics. In 1958, Dyson
moved to California and joined Project Orion, a group of 40 scientists and
engineers working to build a spacecraft powered by nuclear bombs. The Orion
men believed that chemical rockets were too puny. Only nuclear power had
sufficient bang. From a hole at the center of a massive "pusher plate" at
the bottom of the craft, atom bombs would be dropped at intervals and
detonated. Via the pusher plate, the blasts would drive the ship heavenward
on a succession of blinding fireballs. Shock absorbers the size of grain
silos would cushion the cabin and crew, smoothing out the bumpiness of the
ride. Freeman calculated the velocity increments required to deposit the
Orion ship on various moons of Saturn and Jupiter.
Toward the end of
Project Orion, Dyson proposed a 240-million-ton ark with a pusher plate 90
miles in diameter and powered by hydrogen bombs. It was the smallest of a
class of 6,000-miles-per-second starships capable of crossing our solar
system in a month. His starship would be slow at first, with a
zero-to-6,000-mps time of 30 years, but then it would really get rolling.
Nuclear-pulse propulsion required that each nuclear bomb be packaged in
propellant that would transmit the necessary kick. For his starship, Dyson
proposed recycling the feces of the astronauts as propellant. Riding a
thermonuclear shit storm, his ark would carry several thousand colonists to
Alpha Centauri on a 150-year voyage.
Lecturing in London in 1972,
Dyson said, "It is generally considered that planets are important. Except
for Earth, they are not. Mars is waterless, and the others are, for various
reasons, basically inhospitable to man. It is generally considered that
beyond the sun's family of planets there is absolute emptiness extending for
light-years until you come to another star. In fact, it is likely that the
space around the solar system is populated by huge numbers of comets, small
worlds a few miles in diameter, rich in water and the other chemicals
essential to life." The comets contain everything we need except warmth and
air, he said, and predicted that bio-engineers would design trees that
function in airless space and thus make the comets habitable.
In
2007, Dyson said that genetic engineering "will give us an explosion of
diversity of new living creatures … New lineages will proliferate to replace
those that monoculture farming and deforestation have destroyed. Designing
genomes will be a personal thing, a new art form as creative as painting or
sculpture." Dyson misjudged the deliberation with which Darwinian evolution
shapes organisms, assuring the world of plants and animals that make sense
in their respective biomes.
In 2008, Dyson reviewed two books on
global warming and wrote, "There is a worldwide secular religion ... of
environmentalists" who have "adopted as an article of faith the belief that
global warming is the greatest threat to the ecology of our planet." This is
a tragic mistake, he says. Dyson often suggests that science is on his side,
but on the question of global warming, the world's climatologists and
scientific institutions are almost unanimously arrayed against him.
Dyson does not deny that the world is getting warmer. He argues that melting
ice and the resulting sea-level rise is no cause for alarm. He says that the
release of increasing volumes of carbon dioxide into the atmosphere is a
good thing, as it makes plants grow better. The planet is warming mainly in
places that are cold, and at night rather than during the day, so the
phenomenon is making the climate more even.
Plants do grow better
with increases in carbon dioxide. If a plant's survival depended only on its
metabolism, then increased CO2 in the atmosphere might be a good thing. But
plants grow in ecosystems, where they are sustained by complex webs of
interdependency with fungi, microbes, animals, and other plants. Much of
this mutually dependent life is adapted to narrow temperature and rainfall
regimes, and these biomes are collapsing everywhere.
Plants do not
grow better when deprived of water. Climatologists, hydrologists, foresters,
and water managers are nearly unanimous in their conviction that what we are
seeing now is climate change, the anthropogenic kind, a consequence of too
much CO2 and other greenhouse gases. The planet is getting hotter. The
warming is most pronounced in cold places. Temperature differentials at
different latitudes and altitudes are a prime driver of planetary weather.
Weather patterns are full of consequence for all life everywhere.
Freeman Dyson is a national and international treasure. His career
demonstrates how a Nobel-caliber mind can fertilize many fields. Ted Taylor,
the chief of Project Orion, says that what distinguished Dyson was that
"he's able to see more interconnections between more things than almost
anybody. He sees the interrelationships, whether it's in some microscopic
physical process or in a big complicated machine like Orion."
AR Perhaps
some of Freeman's ideas are past their best-before date.
By Freeman Dyson
The New York Review of Books, March 10, 2011
Edited by Andy Ross
The Information: A History, a Theory, a Flood
By James
Gleick
Pantheon, 526 pages
The central dogma of information theory is that meaning is irrelevant.
Information is an abstract concept, which can be embodied equally well in
human speech or in writing or in drumbeats. All that is needed to transfer
information from one language to another is a coding system.
Samuel
Morse the invented Morse code in 1844. His code used short and long pulses
of electric current to represent letters of the alphabet. For a hundred
years after the electric telegraph, engineers invented and developed other
communication systems without any need for higher mathematics.
Claude
Shannon supplied the theory to understand all of these systems together. In
1948 he published a paper with the title "A Mathematical Theory of
Communication" that became the founding document for the modern science of
information.
In 1965, Gordon Moore stated Moore's Law, which said
that the price of electronic components would decrease and their numbers
would increase by a factor of two every eighteen months. Since then, the
price has decreased and the numbers have increased by a factor of a billion
(30 doublings, 45 years).
The purpose of the hardware is to store and
process information. Storage is memory and processing is computing. The
price of memory and computing decreased and the available amount of memory
and computing increased by a factor of a hundred every decade. The flood of
hardware became a flood of information.
In 1949, Shannon drew up a
table of the various stores of memory that then existed. The biggest memory
in his table was the U.S. Library of Congress, which he estimated to contain
one hundred trillion bits of information. That was a guess at the sum total
of recorded human knowledge. Today a disk drive for that much information
costs about a thousand dollars.
The consequences of the information
flood are not all bad. Wikipedia was started in 2001 by Jimmy Wales, who
hoped that the combination of volunteer writers with open source code would
cause a revolution. The rate of growth of Wikipedia exceeded his wildest
dreams. Within ten years it has become the biggest storehouse of information
on the planet.
The information flood has also brought enormous
benefits to science. In fact, science is not a collection of truths but a
continuing exploration of mysteries. Even physics is still full of
mysteries. We do not know how much of Shannon's theory of information will
remain valid when quantum devices replace classical electric circuits as the
carriers of information.
Twenty-first-century science is dominated by
huge databases. The information flood has made it easy and cheap to build
databases. One example is the collection of genome sequences of living
creatures belonging to various species from microbes to humans.
In
the twentieth century, genomes of humans and other species were laboriously
decoded and translated into sequences of letters in computer memories. The
first human genome took fifteen years to decode and cost about a billion
dollars. Now a human genome can be decoded in a few weeks and costs a few
thousand dollars.
In astronomy, telescopes and spacecraft have
evolved slowly, but cameras and optical data processors have evolved fast.
Modern sky-survey projects collect data from huge areas of sky and produce
databases with accurate information about billions of objects. Big databases
have caused similar revolutions in other sciences such as biochemistry and
ecology.
The explosive growth of information in human society is a
part of the slower growth of ordered structures in the evolution of life.
Organisms and ecosystems embody increasing amounts of information. The
evolution of life is a part of the evolution of the universe. In the living
and in the nonliving world, we see evidence of increasing order and
increasing information.
Nineteenth-century scientists and
philosophers believed in the heat death. Lord Kelvin predicted that the flow
of heat from warmer to cooler objects will result in a decrease of
temperature differences everywhere, until all temperatures ultimately become
equal. Life will disappear.
We now know that the heat death is a
myth. We now know that gravitation reverses the usual relation between
energy and temperature. In the domain of astronomy, when heat flows from
hotter to cooler objects, the hot objects get hotter and the cool objects
get cooler. There is no heat death. Information and order can continue to
grow for billions of years in the future.
The vision of the future as
an infinite playground, with an unending supply of information, is a
glorious vision for scientists. It is less attractive to other people, who
may not welcome a future spent drowning in an unending flood of information.
By Freeman Dyson
The New York Review of Books, July 14, 2011
Edited by Andy Ross
Quantum Man: Richard Feynman's Life in Science
By Lawrence M. Krauss
Norton, 350 pages
Richard Feynman visualized the world with pictures rather than with
equations. Other physicists describe the laws of nature with equations.
Feynman skipped the equations and wrote down the solutions directly, using
his pictures as a guide. Skipping the equations was his greatest
contribution to science.
Feynman had the idea that the world has two
layers, a classical layer and a quantum layer. Classical means that things
are ordinary. Quantum means that things are weird. We live in the classical
layer. The pictures that Feynman invented to describe the world are
classical pictures of objects moving in the classical layer. Each picture
represents a possible history of the classical layer. But the real world of
atoms and particles belongs to the quantum layer, which we cannot touch
directly.
The primary difference between the classical layer and the
quantum layer is that the classical layer deals with facts and the quantum
layer deals with probabilities. In situations where classical laws are
valid, we can predict the future by observing the past. In situations where
quantum laws are valid, we can observe the past but we cannot predict the
future. The Feynman pictures only allow us to calculate the probabilities
that various alternative futures may happen.
The quantum layer is
related to the classical layer in two ways. First, the state of the quantum
layer is a combination of every possible history of the classical layer
leading up to that state. Each possible classical history is given a quantum
amplitude. Second, the quantum amplitude is obtained from the picture of
that classical history by following a simple set of rules. The rules are
pictorial. The hard part is to add up the sum over histories correctly.
Feynman showed that this view of the quantum world allows an exact
description of quantum processes in situations where earlier versions of
quantum theory had broken down.
Feynman tried to find new laws of
nature, but the result of his efforts was in the end to consolidate the
existing laws in a new structure. He said nature tells us that both the
quantum world and the classical world exist and are real. We do not
understand precisely how they fit together.
Feynman avoided disputes
about priority in science by following a simple rule:
"Always give the
bastards more credit than they deserve."
By Freeman Dyson
The New York Review of Books, December 22, 2011
Thinking, Fast and Slow
By Daniel Kahneman
In 1955, when Daniel Kahneman was 21, he was a lieutenant in the Israeli
Defense Forces. He was given the job of setting up a new interview system
for the entire army. The purpose was to evaluate each freshly drafted
recruit and put him or her into the appropriate slot in the war machine.
Kahneman had a degree in psychology and had read a book by Paul Meehl, who
found overwhelming evidence that predictions based on simple statistical
scoring were generally more accurate than predictions based on expert
judgment.
Kahneman improved the Israeli army interviewing system. The
interviewers were required to ask a standard list of factual questions about
the life and work of each recruit. The answers were then converted into
numerical scores, and the scores were inserted into formulas measuring the
aptitude of the recruit for the various army jobs. The results showed the
new system to be much better than the old. Statistics work better than
expert intuition.
Cognitive illusions are the main theme of his book.
A cognitive illusion is a false belief that we intuitively accept as true.
The illusion of validity is a false belief in the reliability of our own
judgment. The interviewers sincerely believed that they could predict the
performance of recruits after talking with them for fifteen minutes.
Availability bias is
a biased judgment based on a memory that happens to be quickly available. It
does not wait to examine a bigger sample of less cogent memories.
Another theme of his book is the existence in our brains of two
independent systems for organizing knowledge. Kahneman calls them System One
and System Two:
— System One is amazingly fast. Intuition is the name we give to judgments based on the quick action of System One. The memories that are most accessible are those associated with strong emotions. The resulting judgments are often wrong, but in the world of the jungle it is safer to be wrong and quick than to be right and slow.
— System Two is the slow process of forming judgments based on conscious thinking and critical examination of evidence. It appraises the actions of System One. It lefts us correct mistakes and revise opinions. It probably evolved more recently than System One After we became human, System Two enabled us to create art and culture.
System One is much more vulnerable to
illusions, but System Two is not immune to them.
Kahneman is a psychologist who won a Nobel Prize for economics. His great
achievement was to turn psychology into a quantitative science. He subjected our
mental processes to precise measurement and exact calculation, by
studying in detail how we deal with dollars and cents. By making psychology
quantitative, he incidentally achieved a powerful new understanding of
economics.
The endowment effect is our tendency to value an object
more highly when we own it than when someone else owns it. It demolishes the
central dogma of classical economics that in a free market, buyers and
sellers will agree on a price that both sides regard as fair. The endowment effect gives stability to our lives and
institutions. Stability is good when a society is peaceful and prosperous
but evil when a society is poor and oppressed.
We know that our
judgments are heavily biased by inherited illusions. Kahneman hopes to
change our behavior by changing our vocabulary. If the names he invented for
various common biases and illusions become part of our everyday vocabulary,
the illusions may lose their power to deceive us.
Sigmund Freud was a
dominating figure in the field of psychology for the first half of the
twentieth century. Freud is literary while Kahneman is scientific. The great
contribution of Kahneman was to make psychology an experimental science,
with results that could be repeated and verified.
William James
published his classic work, The Varieties of Religious Experience, in 1902.
James listens to people describing their experiences. He studies the minds
of his witnesses from the inside rather than from the outside.
Freud
and James were artists and not scientists. Admirers of Freud and James may
hope for the time when they stand together with Kahneman as
three great explorers of the human psyche.
Freeman Dyson
The New York Review of Books, April 5, 2012
Science is only a small part of human capability. We gain knowledge of our
place in the universe not only from science but also from history, art, and
literature. Science is a creative interaction of observation with
imagination. Imagination by itself can still enlarge our vision when
observation fails.
There is good reason to pay more attention to
scientific experts than to amateurs, so long as science is based on
experiments. Only trained experts can do experiments with the care and
precision that experiments demand. Expert experimenters are not infallible,
but they are less fallible than amateurs. Experiments give orthodox beliefs
a solid basis. An experimental basis exists for the established disciplines
of physics and chemistry and biology. However, some parts of physics are
less secure than others, because the experts in physics are divided into
experimenters and theorists.
The fringe of physics is not a sharp
boundary with truth on one side and fantasy on the other. All of science is
uncertain and subject to revision. The glory of science is to imagine more
than we can prove. The fringe is the unexplored territory where truth and
fantasy are not yet disentangled.
Freeman Dyson
The New York Review of Books, November 8, 2012
Edited by Andy Ross
Why Does the World Exist?
By Jim Holt
Jim Holt offers a portrait gallery of leading modern philosophers. He
visited each of them in turn and asked: "Why is there something rather than
nothing?" He reports their reactions and describes their habits and
personalities. The philosophers are more interesting than the philosophy.
According to Holt, the two most influential philosophers of the
twentieth century were Martin Heidegger and Ludwig Wittgenstein, Heidegger
supreme in continental Europe, Wittgenstein in the English-speaking world.
Heidegger was one of the founders of existentialism, but lost his
credibility in 1933 when he became a member of the Nazi Party.
Existentialism continued to flourish in France after it faded in Germany.
Wittgenstein wrote very little, and everything that he wrote was simple
and clear. The only book that he published during his lifetime was Tractatus
Logico-Philosophicus, published in England with a long introduction by
Bertrand Russell in 1922. I was given a copy as a prize in high school. I
read it through in one night, in an ecstasy of adolescent enthusiasm. It
said that philosophy is concerned with logic and the correct use of
language. All speculations outside this limited area are mysticism.
Holt: "Wittgenstein was brave and ascetic, Heidegger treacherous and vain."
Wittgenstein narrowed the scope of philosophy by excluding ethics and
aesthetics. During World War II, he served as a hospital orderly taking care
of patients. When I arrived at Cambridge University in 1946, Wittgenstein
had just returned. I held him in the highest respect and was delighted to
find him living in a room above mine on the same staircase. I frequently met
him on the stairs. Finally I ventured to speak to him. I told him I had
enjoyed reading the Tractatus, and I asked him whether he still held the
same views. He remained silent for a long time and then said, "Which
newspaper do you represent?"
Wittgenstein disliked female students
attending his lectures. If a woman appeared in the audience, he would remain
standing silent until she left the room. Fifty years later, walking through
a churchyard, I came by chance upon his tombstone. On the stone was written
the single word, WITTGENSTEIN. He was a tortured soul, the last survivor of
a family with a tragic history, living a lonely life among strangers, trying
until the end to express the inexpressible.
The philosophers that
Holt interviewed wander over a wide landscape. I lump them into two groups,
one obsessed with matter and the other obsessed with mind. For the
materialists, the question of existence concerns physics. For the
Platonists, the question concerns psychology.
The most impressive of
the Platonists is John Leslie. Plato imagined that we live in a cave, seeing
only shadows cast on the wall. The real objects outside the cave are ideas,
and all the things that we perceive inside are imperfect images of ideas.
Leslie understands that this is a poetic fantasy. He once calculated the
probable future duration of the human species, basing his argument on the
Copernican principle. Leslie said this should apply to our position in time
as well as to our position in space, so we should expect the future duration
of our species to be not much longer than its past. Since our species
originated about a hundred thousand years ago, we should expect it to become
extinct about a hundred thousand years from now.
David Deutsch is a
physicist who uses physics as a basis for philosophical speculation. He
likes the multiverse interpretation of quantum mechanics invented by
Hugh
Everett. According to Everett and Deutsch, the multiverse contains a
universe for every combination of choices. Each universe is constantly
splitting into many alternative universes, and the alternatives are
recombining when they arrive at the same final state by different routes.
The multiverse is a huge network of possible histories diverging and
reconverging as time goes on. The "spooky action at a distance" that
Einstein disliked is the result of universes recombining in unexpected ways.
According to Deutsch, each of us exists in the multiverse as a crowd of
creatures, traveling together through time along closely related histories,
splitting and recombining constantly.
Multiverse models are
fashionable in cosmology. Alex Vilenkin has multiple universes disconnected
and widely separated from each other. Each arises out of nothing by quantum
tunneling. Universes spring into existence with precisely zero total energy,
the positive energy of matter being equal and opposite to the negative
energy of gravitation.
Opinions vary widely concerning the proper
limits of science. For me, the multiverse is philosophy and not science.
Science is about facts that can be tested. I see no way of testing
hypotheses of the multiverse. Philosophy is about ideas that can be imagined
and stories that can be told. The multiverse has its place in philosophy and
in literature.
My favorite version of the multiverse is a story told
by the philosopher Olaf Stapledon. His 1937 novel Star Maker describes his
vision of the multiverse. The narrator travels through space visiting alien
civilizations from the past and the future, his mind merging with some of
their inhabitants. Finally, this "cosmical mind" encounters the Star Maker,
an "eternal and absolute spirit" who has created all of these worlds in a
succession of experiments. As each experiment fails he learns how to design
the next one better. Our own universe comes somewhere in the middle. Its
flaws will bring it to a tragic end.
For most of the twenty-five
centuries since written history began, philosophers were important. Two
groups of philosophers, Confucius and Lao Tse in China, and Socrates, Plato,
and Aristotle in Greece, were dominant figures in the cultures of Asia and
Europe for two thousand years.
In more recent centuries, philosophers
were still leaders of human destiny. Descartes and Montesquieu in France,
Spinoza in Holland, Hobbes and Locke in England, Hegel and Nietzsche in
Germany, set their stamp on the divergent styles of nations as nationalism
became the driving force in the history of Europe.
Compared with the
giants of the past, the philosophers of the twentieth and twenty-first
centuries are a sorry bunch of dwarfs. They are historically insignificant.
Until the nineteenth century, science was called natural philosophy. The
word "scientist" was invented in 1833 by William Whewell, a Cambridge
philosopher who became master of Trinity College and put his name on the
building where Wittgenstein and I lived in 1946.
Philosophy shrank
when it became detached from religion and from literature. The latest
masterpieces written by a philosopher were probably Friedrich Nietzsche's
Thus Spoke Zarathustra in 1885 and Beyond Good and Evil in 1886.
Dyson on quantum gravity and LIGO
AR Masterful. How can one disagree with him?
Freeman Dyson
The New York Review of Books, August 15, 2013
Edited by Andy Ross
Robert Oppenheimer was at the center of important events four times in his
life. In 1926 he was at Göttingen, where his teacher Max Born was one of the
leaders of the quantum revolution. In 1929 he was at Berkeley, where his
friend Ernest Lawrence was building the first cyclotron. In 1943 he was at
Los Alamos building the first nuclear weapons. In 1947 he was in Washington
as chairman of the General Advisory Committee of the United States Atomic
Energy Commission. In each case, he rose to the occasion.
Black holes
were the outstanding mystery of Oppenheimer’s life. In 1939 Oppenheimer
published with his student Hartland Snyder a paper inventing the concept of
black holes. They proved that every star significantly more massive than the
sun must end its life as a black hole, and deduced that black holes must
exist as real objects in the sky around us. Einstein never accepted this
consequence of his theory. Oppenheimer did. As a direct result, we now know
that black holes have played and are playing a decisive part in the
evolution of the universe. The mystery is Oppenheimer's failure to grasp the
importance of his own discovery.
Oppenheimer considered his
excursions into bomb-making and nuclear politics to be temporary
interruptions. I talked with him about bombs in 1958, when as director of
the Institute for Advanced Study in Princeton he grudgingly gave me
permission to work on a project in California aimed at building a spaceship
powered by nuclear bombs.
A few years later, when I was chairman of
the Federation of American Scientists, we learned that Oppenheimer had flown
to Paris in 1951 to persuade General Eisenhower, then in command of American
forces in Europe, that the United States Army needed tactical nuclear
weapons to defend Western Europe against a Soviet invasion. Oppenheimer: "To
understand why I advocated tactical weapons, you would have to see the Air
Force war plan that we had then. That was the God-damnedest thing I ever
saw. It was a mindless obliteration of cities and populations. Anything,
even a major ground war fought with nuclear weapons, was better than that."
Oppenheimer was caught in a battle between the Army and the Air Force.
The Army wanted small bombs to destroy invading armies. The Air Force wanted
big bombs to destroy whole countries. The Army wanted fission bombs and the
Air Force wanted hydrogen bombs. Oppenheimer was on the side of the Army.
The Air Force took its revenge by helping to drive Oppenheimer out of the
government. But in the end, both the Air Force and the Army got all the
bombs that they wanted.
Oppenheimer never regretted his role as the
chief architect of the bomb. He protested vigorously in 1964 about a play
portraying him as a tragic hero regretting his actions. The play was mostly
based on the security hearings of 1954. Oppenheimer said in a public
statement about the hearings: "The whole damn thing was a farce, and these
people are trying to make a tragedy out of it."
The real tragedy of
Oppenheimer's life was not the loss of his security clearance but his
failure to be a great scientist.
