We are condemned to an observer role in our own nightly dreams, which excludes any possibility of looking forward or backward in time


Let us consider a counterfactual history in which Szilard invents nuclear fission and realizes that a nuclear bomb could be made with a piece of glass, a metal object, and a battery arranged in a particular configuration. What happens next? Szilard becomes gravely concerned. He sees that his discovery must be kept secret at all costs. But how? His insight is bound to occur to others. He could talk to a few of his physicist friends, the ones most likely to stumble upon the idea, and try to persuade them not to publish anything on nuclear chain reactions or on any of the reasoning steps leading up to the dangerous discovery. (That is what Szilard did in actual history.)

Here Szilard faces a dilemma: either he doesn’t explain the dangerous discovery, but then he will not be effective in persuading many of his colleagues to stop publishing; or he tells them the reason for his concern, but then he spreads the dangerous knowledge further. Either way he is fighting a losing battle. The general advance of scientific knowledge will eventually make the dangerous insight more accessible. Soon, figuring out how to initiate a nuclear chain reaction with pieces of metal, glass, and electricity will no longer take genius but will be within reach of any STEM student with an inventive mindset.

The situation looks hopeless, but Szilard does not give up. He decides to take a friend into his confidence, a friend who is also the world’s most famous scientist—Albert Einstein. He successfully persuades Einstein of the danger (again following actual history). Now Szilard has the support of a man who can get him a hearing with any government. The two write a letter to President Franklin D. Roosevelt. After some committee wranglings and report-writing, the top levels of the U.S. government are eventually sufficiently convinced to be ready to take serious action.

What the U.S. government did, after having digested the information provided by Einstein and Szilard, […] was to launch the Manhattan Project in order to weaponize nuclear fission as quickly as possible. […]

But how would things have played out if there had been an easy way to make nukes? Maybe Szilard and Einstein could persuade the U.S. government to ban all research in nuclear physics (outside high-security government facilities)? […] Let us suppose that President Roosevelt could somehow mobilize enough political support to drive through a ban, and that the U.S. Supreme Court could somehow find a way of regarding it as constitutionally valid. We then confront an array of formidable practical difficulties. All university physics departments would have to be closed, and security checks initiated. A large number of faculty and students would be forced out. Intense speculations would swirl concerning the reason for all these heavy-handed measures. Groups of physics PhD students and faculty banned from their research field would sit around and speculate about what the secret danger might be. Some of them would figure it out. And among those who figured it out, some would feel compelled to use the knowledge to impress their colleagues; and those colleagues would want to tell yet others, to show they were in the know. Alternatively, somebody who opposed the ban would unilaterally decide to publish the secret, maybe in order to support their view that the ban is ineffective or that the benefits of publication outweigh the risks. […] Even if, by some miracle, the secret never leaked in the United States, scientists in other countries would independently discover it, thereby multiplying the sources from which it could spread. […]

An alternative approach would be to eliminate all glass, metal, or sources of electrical current. Given the ubiquity of these materials, such an undertaking would be extremely daunting. […] Metal use is almost synonymous with civilization, and would not be a realistic target for elimination. Glass production could be banned, and existing glass panes confiscated; but pieces of glass would remain scattered across the landscape for a long time. Batteries and magnets could be seized, though some people would have stashed away these materials before they could be collected by the authorities. […]

We now know that one cannot trigger a nuclear explosion with just a sheet of glass, some metal, and a battery. Making an atomic bomb requires several kilograms of fissile material, which is difficult to produce. We pulled out a grey ball that time. Yet with each act of invention, we reach into the urn anew.

Let us introduce the hypothesis that the urn of creativity contains at least one black ball. We can refer to this as the vulnerable world hypothesis . Intuitively, the hypothesis is that there is some level of technology at which civilization almost certainly gets destroyed unless quite extraordinary and historically unprecedented degrees of preventive policing and/or global governance are implemented.

{ Nick Bostrom | PDF }

related { Nick Bostrom on the Great Filter | PDF }

Have you grasped nothing of the reason why I am in the world?


In 1908, an asteroid measuring perhaps 90-190 meters across struck Siberia, damaging over 2,000 square kilometers of Russian forest – an area that measures larger than New York’s five boroughs. Scientists estimate that the energy of that explosion was about 1,000 times that of the atomic bomb the U.S. dropped on Hiroshima in 1945.

This is far from the only close call that humans have had with asteroids. In 2004, an asteroid big enough to have its own small moon narrowly missed the planet. In 2013, an asteroid struck the Russia countryside with many times the force of the Hiroshima bomb, and was widely captured on video.

And of course, it was an asteroid, smashing into the Earth with the force of more than billion Hiroshima bombs, which nixed the dinosaurs and allowed humans to take over the Earth in the first place. [Previously: The event appears to have hit all continents at the same time | more] […]

The probability that you’ll die from an asteroid may be surprisingly large – about the same probability as dying from a plane crash, according to research.

{ Washington Post | Continue reading }

everything is stooopid


Every 250m years the sun, with its entourage of planets, completes a circuit of the Milky Way. Its journey around its home galaxy, though, is no stately peregrination. Rather, its orbit oscillates up and down through the galactic disc. It passes through that disc, the place where most of the galaxy’s matter is concentrated, once every 30m years or so.

This fact has long interested Michael Rampino of New York University. He speculates that it could explain the mass extinctions, such as that of the dinosaurs and many other species 66m years ago, which life on Earth undergoes from time to time. Palaeontologists recognise five such humongous events, during each of which up to 90% of species have disappeared. But the fossil record is also littered with smaller but still significant blips in the continuity of life.

Many hypotheses have been put forward to explain these extinctions (and the events may, of course, not all have the same explanation). The two that have most support are collisions between Earth and an asteroid or comet, and extended periods of massive volcanic activity. Dr Rampino observed some time ago that cometary collisions might be triggered by gravitational disruptions of the Oort cloud, a repository of comets in the outermost part of the solar system. That would send a rain of them into the part of space occupied by Earth. This has come to be known as the Shiva hypothesis, after the Hindu god of destruction. […]

In his latest paper, Dr Rampino speculates that the real culprit may be not stars, but dark matter—and that this might explain the volcanism as well.

{ The Economist | Continue reading }

‘Everybody has a plan until they get punched in the face.’ —Mike Tyson


The asteroid landed in the ocean and would have caused megatsunamis, for which evidence has been found in several locations in the Caribbean and eastern United States—marine sand in locations that were then inland, and vegetation debris and terrestrial rocks in marine sediments dated to the time of the impact. […]

The asteroid landed in a bed of gypsum (calcium sulfate), which would have produced a vast sulfur dioxide aerosol. This would have further reduced the sunlight reaching the Earth’s surface and then precipitated as acid rain, killing vegetation, plankton, and organisms that build shells from calcium carbonate (coccolithophores and molluscs). […]

The impact may also have produced acid rain, depending on what type of rock the asteroid struck. However, recent research suggests this effect was relatively minor, lasting for approximately 12 years. […]

Such an impact would have inhibited photosynthesis by creating a dust cloud that blocked sunlight for up to a year, and by injecting sulfuric acid aerosols into the stratosphere, which might have reduced sunlight reaching the Earth’s surface by 10–20%. It has been argued that it would take at least ten years for such aerosols to dissipate, which would account for the extinction of plants and phytoplankton, and of organisms dependent on them (including predatory animals as well as herbivores). […]

The event appears to have hit all continents at the same time. […]

The event eliminated a vast number of species. Based on marine fossils, it is estimated that 75% or more of all species were wiped out by the K–Pg extinction. In terrestrial ecosystems all animals weighing more than a kilo disappeared.

The most well-known victims are the non-avian dinosaurs. […]

The fact that the extinctions occur at the same time as the Chicxulub asteroid impact strongly supports the impact hypothesis of extinction. […]

The Chicxulub crater is more than 180 kilometres (110 mi) in diameter and 20 km (12 mi) in depth, making the feature one of the largest confirmed impact structures on Earth; the impacting bolide that formed the crater was at least 10 km (6 mi) in diameter. […] Researchers dated rock and ash samples from the impact to roughly 66 million years ago. […]

Some scientists maintain the extinction was caused or exacerbated by other factors, such as volcanic eruptions, climate change, or sea level change, separately or together.

{ The Cretaceous–Paleogene (K–Pg) extinction event | Chicxulub crater }

related { Plants survive better through mass extinctions than animals }

related { Rising Sea Levels Are Already Making Miami’s Floods Worse }

related { 12 ways researchers think human civilisation is most likely to end }

The irreparability of the past


The world’s population is burning through the planet’s resources at such a reckless rate – about 28 per cent more last year - it will eventually cause environmental havoc, said the Worldwatch Institute, a US think-tank.

In its annual State of the World 2010 report, it warned any gains from government action on climate change could be wiped out by the cult of consumption and greed unless changes in our lifestyle were made.

Consumerism had become a “powerful driver” for increasing demand for resources and consequent production of waste, with governments, including the British, too readily wanting to promoted it as necessary for job creation and economic well-being.

More than £2.8 trillion of stimulus packages had been poured into economies to pull the world out of the global recession, it found, with only a small amount into green measures.

But the think tank warned that without a “wholesale transformation” of cultural patterns the world would not be able to “prevent the collapse of human civilisation”.

The think tank found that over the past decade consumption of goods and services had risen by 28 per cent — with the world digging up the equivalent of 112 Empire State Buildings of material every day.

The average American consumes more than his or her weight in products each day.

{ Guardian | Continue reading }

There’s a last time for everything


The cataclysmic extinctions that scoured Earth 200 million years ago might have been easier to trigger than expected, with potentially troubling contemporary implications.

Rather than 600,000 years of volcanic activity choking Earth’s atmosphere with carbon dioxide, just a few thousand years apparently sufficed to raise ocean temperatures so potent greenhouse gases trapped in seafloor mud came bubbling up.

Much of everything alive on Earth was soon wiped out. Another half-million years of vulcanism were just icing on the cake. The immediate question: What lessons, if any, can be drawn?

{ Wired | Continue reading }

Aladdin won’t be the only one on the carpet


Science knows approximately how, and when, our Earth will end. In about five billion years the sun will run out of hydrogen, which will upset its self-regulating equilibrium; in its death-throes it will swell, and this planet will vaporize. Before that, we can expect, at unpredictable intervals measured in tens of millions of years, bombardment by dangerously large meteors or comets. Any one of these impacts could be catastrophic enough to destroy all life, as the one that killed the dinosaurs 65 million years ago nearly did. In the nearer future, it is pretty likely that human life will become extinct – the fate of almost all species that have ever lived.

{ Richard Dawkins/Washington Post | Continue reading }

artwork { Dan Holdsworth, Blackout 08, 2010 }