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  • Ten years ago, I wrote a book which I entitled

  • "Our Final Century?" Question mark.

  • My publishers cut out the question mark. (Laughter)

  • The American publishers changed our title

  • to "Our Final Hour."

  • Americans like instant gratification and the reverse.

  • (Laughter)

  • And my theme was this:

  • Our Earth has existed for 45 million centuries,

  • but this one is special

  • it's the first where one species, ours,

  • has the planet's future in its hands.

  • Over nearly all of Earth's history,

  • threats have come from nature

  • disease, earthquakes, asteroids and so forth

  • but from now on, the worst dangers come from us.

  • And it's now not just the nuclear threat;

  • in our interconnected world,

  • network breakdowns can cascade globally;

  • air travel can spread pandemics worldwide within days;

  • and social media can spread panic and rumor

  • literally at the speed of light.

  • We fret too much about minor hazards

  • improbable air crashes, carcinogens in food,

  • low radiation doses, and so forth

  • but we and our political masters

  • are in denial about catastrophic scenarios.

  • The worst have thankfully not yet happened.

  • Indeed, they probably won't.

  • But if an event is potentially devastating,

  • it's worth paying a substantial premium

  • to safeguard against it, even if it's unlikely,

  • just as we take out fire insurance on our house.

  • And as science offers greater power and promise,

  • the downside gets scarier too.

  • We get ever more vulnerable.

  • Within a few decades,

  • millions will have the capability

  • to misuse rapidly advancing biotech,

  • just as they misuse cybertech today.

  • Freeman Dyson, in a TED Talk,

  • foresaw that children will design and create new organisms

  • just as routinely as his generation played with chemistry sets.

  • Well, this may be on the science fiction fringe,

  • but were even part of his scenario to come about,

  • our ecology and even our species

  • would surely not survive long unscathed.

  • For instance, there are some eco-extremists

  • who think that it would be better for the planet,

  • for Gaia, if there were far fewer humans.

  • What happens when such people have mastered

  • synthetic biology techniques

  • that will be widespread by 2050?

  • And by then, other science fiction nightmares

  • may transition to reality:

  • dumb robots going rogue,

  • or a network that develops a mind of its own

  • threatens us all.

  • Well, can we guard against such risks by regulation?

  • We must surely try, but these enterprises

  • are so competitive, so globalized,

  • and so driven by commercial pressure,

  • that anything that can be done will be done somewhere,

  • whatever the regulations say.

  • It's like the drug lawswe try to regulate, but can't.

  • And the global village will have its village idiots,

  • and they'll have a global range.

  • So as I said in my book,

  • we'll have a bumpy ride through this century.

  • There may be setbacks to our society

  • indeed, a 50 percent chance of a severe setback.

  • But are there conceivable events

  • that could be even worse,

  • events that could snuff out all life?

  • When a new particle accelerator came online,

  • some people anxiously asked,

  • could it destroy the Earth or, even worse,

  • rip apart the fabric of space?

  • Well luckily, reassurance could be offered.

  • I and others pointed out that nature

  • has done the same experiments

  • zillions of times already,

  • via cosmic ray collisions.

  • But scientists should surely be precautionary

  • about experiments that generate conditions

  • without precedent in the natural world.

  • Biologists should avoid release of potentially devastating

  • genetically modified pathogens.

  • And by the way, our special aversion

  • to the risk of truly existential disasters

  • depends on a philosophical and ethical question,

  • and it's this:

  • Consider two scenarios.

  • Scenario A wipes out 90 percent of humanity.

  • Scenario B wipes out 100 percent.

  • How much worse is B than A?

  • Some would say 10 percent worse.

  • The body count is 10 percent higher.

  • But I claim that B is incomparably worse.

  • As an astronomer, I can't believe

  • that humans are the end of the story.

  • It is five billion years before the sun flares up,

  • and the universe may go on forever,

  • so post-human evolution,

  • here on Earth and far beyond,

  • could be as prolonged as the Darwinian process

  • that's led to us, and even more wonderful.

  • And indeed, future evolution will happen much faster,

  • on a technological timescale,

  • not a natural selection timescale.

  • So we surely, in view of those immense stakes,

  • shouldn't accept even a one in a billion risk

  • that human extinction would foreclose

  • this immense potential.

  • Some scenarios that have been envisaged

  • may indeed be science fiction,

  • but others may be disquietingly real.

  • It's an important maxim that the unfamiliar

  • is not the same as the improbable,

  • and in fact, that's why we at Cambridge University

  • are setting up a center to study how to mitigate

  • these existential risks.

  • It seems it's worthwhile just for a few people

  • to think about these potential disasters.

  • And we need all the help we can get from others,

  • because we are stewards of a precious

  • pale blue dot in a vast cosmos,

  • a planet with 50 million centuries ahead of it.

  • And so let's not jeopardize that future.

  • And I'd like to finish with a quote

  • from a great scientist called Peter Medawar.

  • I quote, "The bells that toll for mankind

  • are like the bells of Alpine cattle.

  • They are attached to our own necks,

  • and it must be our fault if they do not make

  • a tuneful and melodious sound."

  • Thank you very much.

  • (Applause)

Ten years ago, I wrote a book which I entitled

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B2 UK TED worse surely science fiction percent scenario

【TED】Martin Rees: Can we prevent the end of the world? (Martin Rees: Can we prevent the end of the world?)

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    CUChou posted on 2014/12/15
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