Brain Pickings

Posts Tagged ‘science’

07 MARCH, 2012

From Francis Bacon to Hobbes to Turing: George Dyson on the History of Bits

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What Sir Francis Bacon has to do with the dawn of the Internet and the inner workings of your iPhone.

“It is possible to invent a single machine which can be used to compute any computable sequence,” proclaimed twenty-four-year-old Alan Turing in 1936.

The digital text you are reading on your screen, which I wrote on my keyboard, flows through the underbelly of the Internet to transmit a set of ideas from my mind to yours. It all happens so fluidly, so familiarly, that we take it for granted. But it is the product of remarkable feats of technology, ignited by the work of a small group of men and women, spearheaded by John von Neumann at the Institute for Advanced Study in Princeton, New Jersey. Legendary science historian George Dyson traces the history and legacy of this pioneering work in his highly anticipated new book, Turing’s Cathedral: The Origins of the Digital Universe, based on his 2005 essay of the same name — the most comprehensive and ambitious account of that defining era yet, reconstructing the events and characters that coalesced into the dawn of computing and peering into the future to examine where the still-unfolding digital universe may be headed.

It begins with a captivating promise:

There are two kinds of creation myths: those where life arises out of the mud, and those where life falls from the sky. In this creation myth, computers arose from the mud, and code fell from the sky.”

The book is absolutely absorbing in its entirety, but this particular abstract on the history of bits illustrates beautifully Dyson’s gift for contextualizing the familiar with the infinitely fascinating:

A digital universe — whether 5 kilobytes or the entire Internet — consists of two species of bits: differences in space, and differences in time. Digital computers translate between these two forms of information — structure and sequence — according to definite rules. Bits that are embodied as structure (varying in space, invariant across time) we perceive as memory; and bits that are embodied as sequence (varying in time, invariant across space) we perceive as code. Gates are the intersections where bits span both worlds at the moments of transition from one instant to the next.

The term bit (the contraction, by 40 bits, of “binary digit”) was coined by statistician John W. Tukey shortly after he joined von Neumann’s project in November of 1945. The existence of a fundamental unit of communicable information, representing a single distinction between two alternatives, was defined rigorously by information theorist Claude Shannon in his then-secret Mathematical Theory of Cryptography of 1945, expanded into his Mathematical Theory of Communication of 1948. “Any difference that makes a difference” is how cybernetician Gregory Bateson translated Shannon’s definition into informal terms. To a digital computer, the only difference that makes a difference is the difference between a zero and a one.

That two symbols were sufficient for encoding all communication had been established by Francis Bacon in 1623. ‘The transposition of two Letters by five placeings will be sufficient for 32 Differences [and] by this Art a way is opened, whereby a man may expresse and signifie the intentions of his minde, at any distance of place, by objects… capable of a twofold difference onely,’ he wrote, before giving examples of how such binary coding could be conveyed at the speed of paper, the speed of sound, or the speed of light.

That zero and one were sufficient for logic as well as arithmetic was established by Gottfried Wilhelm Leibniz in 1679, following the lead given by Thomas Hobbes in his Computation, or Logique of 1656. ‘By Ratiocination, I mean computation,’ Hobbes had announced. ‘Now to compute, is either to collect the sum of many things that are added together, or to know what remains when one thing is taken out of another. Ratiocination, therefore is the same with Addition or Substraction; and if any man adde Multiplication and Division, I will not be against it, seeing… that all Ratiocination is comprehended in these two operations of the minde.’ The new computer, for all its powers, was nothing more than a very fast adding machine, with a memory of 40,960 bits.”

Turing’s Cathedral, though dense at times, is fascinating in its entirety.

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06 MARCH, 2012

Neil deGrasse Tyson on Space, Politics, and the Most Important Thing to Know About the Universe

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What our sense connectedness has to do with NASA’s budget and the osmosis of rationality and intuition.

Neil deGrasse Tyson might be one of today’s most prominent astrophysicists, but he’s also a kind of existential philosopher, bringing his insights from science into the broader realm of the human condition — a kind of modern-day Carl Sagan with a rare gift for blending science and storytelling to both rub neurons with his fellow scientists and engage a popular-interest audience.

Nowhere does this gift shine more brilliantly than this chill-giving mashup by Max Schlickenmeyer, remixing images of nature at its most inspiring with the narration of Tyson’s answer to a TIME magazine reader, who asked, “What is the most astounding fact you can share with us about the Universe?”

When I look up at the night sky and I know that, yes, we are part of this Universe, we are in this Universe, but perhaps more important than most of those facts is that the Universe is in us. When I reflect on that fact, I look up — many people feel small, because they’re small, the Universe is big — but I feel big, because my atoms came from those stars. There’s a level of connectivity — that’s really what you want in life. You want to feel connected, you want to feel relevant. You want to feel like you’re a participant in the goings on and activities and events around you. That’s precisely what we are, just by being alive.”

Tyson’s new book, Space Chronicles: Facing the Ultimate Frontier, explores the future of space travel in the wake of NASA’s decision to put human space flight essentially on hold, using his signature wit and scientific prowess to lay out an urgent manifesto for the economic, social, moral, and cultural importance of space exploration. This excerpt from the introduction captures Tyson’s underlying ethos and echoes other great thinkers’ ideas about intuition and rationality, blending the psychosocial with the political:

Some of the most creative leaps ever taken by the human mind are decidedly irrational, even primal. Emotive forces are what drive the greatest artistic and inventive expressions of our species. How else could the sentence ‘He’s either a madman or a genius’ be understood?

It’s okay to be entirely rational, provided everybody else is too. But apparently this state of existence has been achieved only in fiction [where] societal decisions get made with efficiency and dispatch, devoid of pomp, passion, and pretense.

To govern a society shared by people of emotion, people of reason, and everybody in between — as well as people who think their actions are shaped by logic but in fact are shaped by feelings and nonempirical philosophies — you need politics. At its best, politics navigates all the minds-states for the sake of the greater good, alert to the rocky shoals of community, identity, and the economy. At its worst, politics thrives on the incomplete disclosure or misrepresentation of data required by an electorate to make informed decisions, whether arrived at logically or emotionally.”

Video via It’s Okay to be Smart

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05 MARCH, 2012

At the End of the Rainbow: Vintage Film about Ultraviolet Light, 1946

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In the beginning, there was ultraviolet light.

In 1946, the Sun-Kraft Corporation commissioned the Handy (Jam) Organization — whom we’ve previously enjoyed in an homage to makers and hands-on creativity, an animated explanation of how radio broadcasting works, a visual tour of mid-century design, and the original Rudolph the Red-Nosed Reindeer animation — to produce a film promoting the history, physics, and health-giving properties of ultraviolet radiation. The result was At the End of the Rainbow — an odd blend of science education and corporate agenda that, nonetheless, far exceeds today’s questionable corporate tie-ins in both public service value and cultural merit.

Part Two explores how an American inventor set out to create an ultraviolet ray generator that would make the sun’s health-giving qualities available at low cost, and what happened next:

For more on the fascinating science of light, see Catching the Light: The Entwined History of Light and Mind.

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