The Great Filter

An advanced civilization passes through eight stages:

  1. A congenial star system
  2. Reproductive molecules
  3. Simple single-cell life
  4. Complex single-cell life
  5. Sexual reproduction
  6. Multicellular life
  7. Tool-using animals with big brains
  8. Colonization explosion

Now, we haven’t observed any intelligent extraterrestrials. That implies that at least one of these steps is very improbable, a “filter” that prevents life from colonizing space.

We’re on step 7. If the filter is among steps 1-6, then we’re not likely to meet any neighbors — something prevents most life forms from getting as far as we have. If the filter is in step 8, then it appears some catastrophe must strike us soon. Our future, it seems, must be either lonely or ruinous.

“The larger the remaining filter we face, the more carefully humanity should try to avoid negative scenarios,” writes George Mason University economist Robin Hanson. “Our main data point, the Great Silence, would be telling us that at least one of these scenarios [e.g., nuclear war, ecological collapse] is much more probable than it otherwise looks.”

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Future Tense

When he wasn’t inventing logarithms, John Napier took a keen interest in military affairs. In 1596 he composed a list of war machines that “by the grace of God and worke of expert craftsmen” he hoped to produce “for defence of this Iland.” These included a piece of artillery that could “clear a field of four miles circumference of all living creatures exceeding a foot of height,” a chariot like “a moving mouth of mettle” that would “scatter destruction on all sides,” and “devises of sayling under water, with divers and other strategems for harming of the enemyes.”

No one knows whether Napier built his machines, but by World War I they were certainly realities — he had foreseen the machine gun, the tank, and the submarine.

| Oddities · Science & Math · Technology

Quiet!

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Charles Babbage hated organ grinders. Calling them the worst of the “thousand nuisances” that made it “impossible for the householder to enjoy any quiet,” he claimed that such “instruments of torture” had cost him a quarter of his working life. At one point he tallied 165 “nuisances” in 90 days.

“It is difficult to estimate the misery inflicted upon thousands of persons,” he wrote, “and the absolute pecuniary penalty imposed upon multitudes of intellectual workers by the loss of their time, destroyed by organ-grinders and other similar nuisances.”

He spent £170 on a soundproof room in his Cheyne Row house to protect him from “vile yellow Italians”; it didn’t work. When a magistrate asked if he really believed that listening to a hand organ could impair a man’s brain, he replied, “Certainly not, for the obvious reason that no man having a brain ever listened to street musicians.”

Sadly, he was as much renowned for this crusade as for his scientific accomplishments — his 1871 obituary in the London Times notes that he lived to be almost 80 “in spite of organ-grinding persecutions.”

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Conflict of Interest

Eric Temple Bell led two lives. By day he was a mathematician at Caltech; by night he wrote science fiction as John Taine.

By a happy chance the two personalities met in 1951, when the Pasadena Star-News asked Taine to review Bell’s book Mathematics, Queen and Servant of Science.

Not one to lose an opportunity, he accepted. “The last flap of the jacket says Bell ‘is perhaps mathematics’ greatest interpreter,'” Taine wrote. “Knowing the author well, the reviewer agrees.”

| Literature · Science & Math

Charged Words

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On the night of Sept. 2, 1859, an enormous solar flare produced brilliant auroras around the world. Newspapers and ships’ logs reported striking displays throughout the United States, Europe, Japan, and Australia; Bostonians could read by their light at 1 a.m.

At the height of the storm, a curious conversation took place between two New England telegraph operators:

Boston: Please cut off your battery, and let us see if we cannot work with the auroral current alone.

Portland, Maine: I have done so. Will you do the same?

Boston: I have cut my battery off and connected the line with the earth. We are working with the current from the Aurora Borealis alone. How do you receive my writing?

Portland: Very well indeed. Much better than with the batteries on. There is much less variation in the current, and the magnets work steadier. Suppose we continue to work so until the Aurora subsides?

Boston: Agreed. Are you ready for business?

Portland: Yes; go ahead.

They carried on in this way for two hours, the storm inducing enough current in the lines to support their transmissions. It marked the first conclusive link between auroral activity and electricity.

(Thanks, Michael.)

| Oddities · Science & Math

The Will Rogers Phenomenon

Will Rogers allegedly said, “When the Okies left Oklahoma and moved to California, they raised the average intelligence level in both states.”

He was joking, but the effect is possible in principle. Consider two sets:

A = {1, 2, 3, 4}
B = {5, 6, 7, 8, 9}

If we move 5 to set A, the mean of both sets increases.

This produces a somewhat paradoxical effect when doctors find a better way to detect illness. Relatively healthy people are moved from the “well” category to the “ill” category, and the average health of both populations improves even before treatment takes place.

| Science & Math

The Visby Lenses

In 1997, three scientists examined 10 rock crystal lenses discovered in a Viking grave on Sweden’s Gotland Island. Made in the 12th century, the lenses had been thought to be simple ornaments, but examination showed they had been crafted with the ideal focusing lens shape 500 years before Descartes could calculate it mathematically.

“It seems that the elliptical lens design was invented much earlier that we thought and then the knowledge was lost,” researcher Olaf Schmidt told the BBC. Scientists speculate that the lenses were used to start fires or perhaps even to form a crude telescope.

Who made them? Not Vikings — probably a group of craftsmen in Byzantium or Eastern Europe, possibly even a single talented artisan. Whoever it was, he knew even more about applied optics than scientists at the time.

| Oddities · Science & Math

Infinite Egress

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Leinbach had discovered a proof that there really is no death. It is beyond question, he had declared, that not only at the moment of drowning, but at all the moments of death of any nature, one lives over again his past life with a rapidity inconceivable to others. This remembered life must also have a last moment, and this last moment its own last moment, and so on, and hence, dying is itself eternity, and hence, in accordance with the theory of limits, one may approach death but can never reach it.

— Arthur Schnitzler, Flight Into Darkness, 1931

| Death · Science & Math

Con Proofing

John von Neumann suggested a way to flip a suspect coin and produce fair results: Flip it twice.

Tails-heads decides in favor of one party, heads-tails the other. The two results are equally likely, even with a biased coin. (If it comes up heads-heads or tails-tails, flip it twice again.)

| Science & Math