Dyson imagined a universe in which alien civilizations harness the energy of the stars.
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Freeman Dyson
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Legendary physicist and big thinker Freeman Dyson died today at age
96 in New Jersey after a fall earlier this week, according to reports
from
Maine Public Radio and
The New York Times.
Dyson,
born in England in 1923, moved to the United States in 1947 and spent
most of his life as a professor or professor emeritus at the Princeton
University Institute for Advanced Study. Dyson first became widely known
for important work in the late 1940s on the interactions between light
and matter, then went on to have a remarkably wide-ranging career. He
published papers on the future of the universe, worked on ideas for a
nuclear-explosion-powered spacecraft that was never built, developed new
ideas in mathematics and philosophy, and imagined how humans of the far
future — as well as alien civilizations — might live and operate in
space.
"Dyson
generated revolutionary scientific insights, including calculations
bridging the quantum and human worlds. His contributions stem from his
work in numerous areas, including nuclear engineering, solid state
physics, ferromagnetism, astrophysics, biology and applied mathematics,"
the Institute for Advanced Study wrote in an
obituary for Dyson.
He described his own approach to science as driven by wide-ranging curiosity.
"I've always enjoyed what I was doing quite independently of whether it was important or not," Dyson
told The New York Times in 2009,
explaining why he never won a Nobel Prize like his colleague Richard
Feynman. "I think it's almost true without exception if you want to win a
Nobel Prize, you should have a long attention span, get ahold of some
deep and important problem, and stay with it for 10 years. That wasn't
my style."
Arguably, Dyson's most famous idea was the "
Dyson sphere,"
a hypothetical structure a civilization might build around a star to
enclose it and best harness its energy. The notion has made its way into
science fiction and astronomy as well. In recent years, some
astronomers have even speculated that a particular star in our galaxy
exhibiting odd dimming behavior might have an incomplete Dyson sphere,
an "alien megastructure," around it. (That idea, however, has since been
largely discredited in favor of another explanation,
as Live Science previously reported.)
Dyson was also known for his idiosyncratic views on
climate change,
notions that he largely publicized toward the end of the first decade
of the 21st century. While he did not dispute that human emissions were
causing Earth's climate to warm, he expressed frustration with the
tone in which the subject was discussed
at the time, as The New York Times reported in 2009. Dyson suggested
that other problems were more important and expressed doubts about some
techniques used by climate scientists to estimate the effects of future
warming.
He also argued that planting billions of trees,
genetically engineered to capture more carbon than existing trees, would
solve the problem. As of 2020, such genetically modified mega-forests
do not exist and the world has continued to experience increasingly
drastic effects from climate change.
Robert McNees, a physicist at Loyola University in Chicago,
memorialized Dyson on Twitter, pointing to Dyson's 1979 paper "Time Without End,"
published in the journal Reviews of Modern Physics. McNees called it "a real late-night-dorm-room-conversation of a paper."
In
that paper, Dyson argued that if the universe continues to spread out
forever and cool down, life might not die out as most physicists assume.
"Looking
at the past history of life," Dyson wrote, "we see it takes about [1
million] 10^6 years to evolve a new species, [10 million] 10^7 years to
evolve a genus, [100 million] 10^8 years to evolve a phylum and less
than [10 billion] 10^10 years to evolve all the way from the primaeval
slime to Homo sapiens. If life continues in this fashion in the future,
it is impossible to set any limit to the variety of physical forms that
life may assume. What changes could occur in the next 10^10 years to
rival the changes of the past?
"It is conceivable," Dyson
continued, "that in another 10^10 years, life could evolve away from
flesh and blood and become embodied in an interstellar black cloud or in
a sentient computer."
Dyson went on to write that life might
require warmth, liquid water and a reliable energy source to persist in a
cold universe, but only if consciousness is tied to the body.
"Since
I am a philosophical optimist, I assume … life is free to evolve into
whatever material embodiment best suits its purposes," he wrote.
Rafi Letzter
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