cosmological constant

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pages: 695 words: 219,110

The Fabric of the Cosmos by Brian Greene


airport security, Albert Einstein, Albert Michelson, Arthur Eddington, Brownian motion, clockwork universe, conceptual framework, cosmic microwave background, cosmological constant, dark matter, dematerialisation, Hans Lippershey, Henri Poincaré, invisible hand, Isaac Newton, Murray Gell-Mann, Richard Feynman, Richard Feynman, Stephen Hawking, urban renewal

Physicists today invoke phrases like “the energy of space itself” or “dark energy” when discussing the meaning of Einstein’s cosmological constant, because if there were a cosmological constant, space would be filled with a transparent, amorphous presence that you wouldn’t be able to see directly; space filled with a cosmological constant would still look dark. (This resembles the old notion of an aether and the newer notion of a Higgs field that has acquired a nonzero value throughout space. The latter similarity is more than mere coincidence since there is an important connection between a cosmological constant and Higgs fields, which we will come to shortly.) But even without specifying the origin or identity of the cosmological constant, Einstein was able to work out its gravitational implications, and the answer he found was remarkable.

In fact, he found that as far as energy and pressure are concerned, a Higgs field that’s caught on a plateau has the same properties as a cosmological constant: it suffuses space with energy and negative pressure, and in exactly the same proportions as a cosmological constant. So Guth discovered that a supercooled Higgs field does have an important effect on the expansion of space: like a cosmological constant, it exerts a repulsive gravitational force that drives space to expand.9 At this point, since you are already familiar with negative pressure and repulsive gravity, you may be thinking, All right, it’s nice that Guth found a specific physical mechanism for realizing Einstein’s idea of a cosmological constant, but so what? What’s the big deal? The concept of a cosmological constant had long been abandoned. Its introduction into physics was nothing but an embarrassment for Einstein.

It’s interesting to note that, years before the supernova results, prescient theoretical works by Jim Peebles at Princeton, and also by Lawrence Krauss of Case Western and Michael Turner of the University of Chicago, and Gary Steigman of Ohio State, had suggested that the universe might have a small nonzero cosmological constant. At the time, most physicists did not take this suggestion too seriously, but now, with the supernova data, the attitude has changed significantly. Also note that earlier in the chapter we saw that the outward push of a cosmological constant can be mimicked by a Higgs field that, like the frog on the plateau, is perched above its minimum energy configuration. So, while a cosmological constant fits the data well, a more precise statement is that the supernova researchers concluded that space must be filled with something like a cosmological constant that generates an outward push. (There are ways in which a Higgs field can be made to generate a long-lasting outward push, as opposed to the brief outward burst in the early moments of inflationary cosmology.

pages: 492 words: 149,259

Big Bang by Simon Singh


Albert Einstein, Albert Michelson, All science is either physics or stamp collecting, Andrew Wiles, anthropic principle, Arthur Eddington, Astronomia nova, Brownian motion, carbon-based life, Cepheid variable, Chance favours the prepared mind, Commentariolus, Copley Medal, cosmic abundance, cosmic microwave background, cosmological constant, cosmological principle, dark matter, Dava Sobel, Defenestration of Prague, discovery of penicillin, Dmitri Mendeleev, Edmond Halley, Edward Charles Pickering, Eratosthenes, Ernest Rutherford, Erwin Freundlich, Fellow of the Royal Society, fudge factor, Hans Lippershey, Harlow Shapley and Heber Curtis, Harvard Computers: women astronomers, Henri Poincaré, horn antenna, if you see hoof prints, think horses—not zebras, Index librorum prohibitorum, invention of the telescope, Isaac Newton, John von Neumann, Karl Jansky, Louis Daguerre, Louis Pasteur, luminiferous ether, Magellanic Cloud, Murray Gell-Mann, music of the spheres, Olbers’ paradox, On the Revolutions of the Heavenly Spheres, Paul Erdős, retrograde motion, Richard Feynman, Richard Feynman, scientific mainstream, Simon Singh, Solar eclipse in 1919, Stephen Hawking, the scientific method, Thomas Kuhn: the structure of scientific revolutions, unbiased observer, V2 rocket, Wilhelm Olbers, William of Occam

Obviously he hoped that his purer approach would lead to an accurate description of the universe, but for Friedmann it was the beauty of the equation and the majesty of the theory that took precedence over reality—or, indeed, over expectation. Friedmann’s research came to a climax in 1922, when he published an article in the journal Zeitschrift für Physik. Whereas Einstein had argued for a finely tuned cosmological constant and a finely balanced universe, Friedmann now described how different models of the universe could be created with various values of the cosmological constant. Most importantly, he outlined a model of the universe in which the cosmological constant was set to zero. Such a model was effectively based on Einstein’s original formula for gravity, without any cosmological constant. With no cosmological constant to counteract gravitational attraction, Friedmann’s model was vulnerable to gravity’s relentless pull. This gave rise to a dynamic and evolving model of the universe. For Einstein and his colleagues, such dynamism was associated with a universe that would be doomed to cataclysmic collapse.

Many cosmologists were happy with Einstein’s cosmological constant, because it seemed to do the trick of making general relativity compatible with a static eternal universe. But no one had much of a clue about what the cosmological constant actually represented. In some ways it was on a par with Ptolemy’s epicycles, inasmuch as it was an ad hoc tweak that allowed Einstein to get the right result. Even Einstein sheepishly admitted that this was the case when he confessed that the cosmological constant was ‘necessary only for the purpose of making a quasi-static distribution of matter’. In other words, it was a fudge that Einstein used to get the result that was expected, namely a stable and eternal universe. Einstein also admitted that he found the cosmological constant ugly. Talking of its role in general relativity, he once said that it was ‘gravely detrimental to the formal beauty of the theory’.

On the single occasion on which he had bowed to peer pressure, he was proved to be wrong. Later he would call the cosmological constant the greatest blunder of his entire life. As he wrote in a letter to Lemaître: ‘Since I have introduced this term I had always a bad conscience…I am unable to believe that such an ugly thing should be realised in nature.’ Although Einstein was keen to abandon his cosmic fudge factor, cosmologists who still believed in an eternal, static universe were convinced that the cosmological constant was an essential and valid part of general relativity. Even some Big Bang cosmologists had become quite fond of it and were reluctant to lose it. By retaining the cosmological constant and varying its value, they could tweak their theoretical models of the Big Bang and modify the universe’s expansion. The cosmological constant represented an anti-gravity effect, so it made the universe expand faster.

pages: 186 words: 64,267

A Brief History of Time by Stephen Hawking


Albert Einstein, Albert Michelson, anthropic principle, Arthur Eddington, bet made by Stephen Hawking and Kip Thorne, Brownian motion, cosmic microwave background, cosmological constant, dark matter, Edmond Halley, Ernest Rutherford, Henri Poincaré, Isaac Newton, Magellanic Cloud, Murray Gell-Mann, Richard Feynman, Richard Feynman, Stephen Hawking

If this happened, the universe would be in an unstable state, with more energy than if the symmetry had been broken. This special extra energy can be shown to have an antigravitational effect: it would have acted just like the cosmological constant that Einstein introduced into general relativity when he was trying to construct a static model of the universe. Since the universe would already be expanding just as in the hot big bang model, the repulsive effect of this cosmological constant would therefore have made the universe expand at an ever-increasing rate. Even in regions where there were more matter particles than average, the gravitational attraction of the matter would have been outweighed by the repulsion of the effective cosmological constant. Thus these regions would also expand in an accelerating inflationary manner. As they expanded and the matter particles got farther apart, one would be left with an expanding universe that contained hardly any particles and was still in the supercooled state.

However, given Einstein’s record of ill-founded opposition to gravitational collapse and the uncertainty principle, maybe this was an encouraging sign. The solution Gödel found doesn’t correspond to the universe we live in because we can show that the universe is not rotating. It also had a non-zero value of the cosmological constant that Einstein introduced when he thought the universe was unchanging. After Hubble discovered the expansion of the universe, there was no need for a cosmological constant and it is now generally believed to be zero. However, other more reasonable space-times that are allowed by general relativity and which permit travel into the past have since been found. One is in the interior of a rotating black hole. Another is a space-time that contains two cosmic strings moving past each other at high speed.

This behavior of the universe could have been predicted from Newton’s theory of gravity at any time in the nineteenth, the eighteenth, or even the late seventeenth century. Yet so strong was the belief in a static universe that it persisted into the early twentieth century. Even Einstein, when he formulated the general theory of relativity in 1915, was so sure that the universe had to be static that he modified his theory to make this possible, introducing a so-called cosmological constant into his equations. Einstein introduced a new “antigravity” force, which, unlike other forces, did not come from any particular source but was built into the very fabric of space-time. He claimed that space-time had an inbuilt tendency to expand, and this could be made to balance exactly the attraction of all the matter in the universe, so that a static universe would result. Only one man, it seems, was willing to take general relativity at face value, and while Einstein and other physicists were looking for ways of avoiding general relativity’s prediction of a nonstatic universe, the Russian physicist and mathematician Alexander Friedmann instead set about explaining it.

pages: 282 words: 89,436

Einstein's Dice and Schrödinger's Cat: How Two Great Minds Battled Quantum Randomness to Create a Unified Theory of Physics by Paul Halpern


Albert Einstein, Albert Michelson, Arthur Eddington, Brownian motion, clockwork universe, cosmological constant, dark matter, double helix, Ernest Rutherford, Fellow of the Royal Society, Isaac Newton, John von Neumann, lone genius, Murray Gell-Mann, New Journalism, Richard Feynman, Richard Feynman, Schrödinger's Cat, Solar eclipse in 1919, The Present Situation in Quantum Mechanics

Similarly, the cosmological constant term, through inelegant, performed the task Einstein set out to accomplish: preserving cosmic stability. In 1917, Einstein published his static universe model, including the cosmological constant as part of his field equations. However, he couldn’t rightfully claim that his solution was unique. Dutch mathematician Willem de Sitter cleverly demonstrated that in the absence of matter, Einstein’s field equations produced solutions that would blow up exponentially, driven ever outward by the cosmological constant. De Sitter’s model showed that as long as the cosmological constant exists, emptiness is unstable. Given that he added the cosmological constant term as a stopgap, rather than based on scientific observation, Einstein did not take de Sitter’s model very seriously. He conceded, however, that progress in understanding the dynamics of the universe would require far more astronomical measurement.

Finally, dating back to his earliest papers on general relativity, published in 1917, Schrödinger maintained an active interest in the cosmological constant term, which Einstein had discarded. 206 The Last Waltz: Einstein’s and Schrödinger’s Final Years Einstein had set aside the cosmological term in light of Hubble’s discovery of cosmological expansion. Schrödinger, on the other hand, thought the term was essential, albeit small. He made a case for the cosmological constant in his 1950 book Space-Time Structure, a comprehensive survey of general relativity and related theories. He argued that one advantage of his affine theory was that it explained the source of the cosmological constant in a natural way and mandated that it have a value that was small but not zero.11 Schrödinger’s advocacy of a small but nonzero cosmological constant was certainly prescient. It matches well today’s picture of an accelerating universe, propelled by unknown dark energy.

To remedy the situation, he took the rather drastic step of adding an extra term to the geometric side of his equations to produce what he saw as credible solutions. Known as the “cosmological constant” and symbolized by the Greek letter lambda (Λ), the term acts as a hedge against gravitational instability by stretching the geometry of space in the opposite direction. He didn’t assign the cosmological constant any physical meaning, but at the time he saw it as essential to the integrity of his theory. In our desert canopy analogy, imagine that the entire structure we had constructed was slowly sinking into the sand. Rather than rebuild the structure from scratch, we might elect to build mechanical devices around the periphery that grab the canvas and stretch it outward. We wouldn’t win any architecture awards for our design, but it would do the job. Similarly, the cosmological constant term, through inelegant, performed the task Einstein set out to accomplish: preserving cosmic stability.

pages: 634 words: 185,116

From eternity to here: the quest for the ultimate theory of time by Sean M. Carroll


Albert Einstein, Albert Michelson, anthropic principle, Arthur Eddington, Brownian motion, cellular automata, Claude Shannon: information theory, Columbine, cosmic microwave background, cosmological constant, cosmological principle, dark matter, dematerialisation, double helix,, gravity well, Harlow Shapley and Heber Curtis, Henri Poincaré, Isaac Newton, John von Neumann, Lao Tzu, lone genius, New Journalism, Norbert Wiener,, Pierre-Simon Laplace, Richard Feynman, Richard Feynman, Richard Stallman, Schrödinger's Cat, Slavoj Žižek, Stephen Hawking, stochastic process, the scientific method, wikimedia commons

When Einstein first proposed the cosmological constant in 1917, his motivation was to explain a static universe, one that wasn’t expanding or contracting. This wasn’t a misguided philosophical stance—it was the best understanding according to the astronomy of the day; Hubble wouldn’t discover the expansion of the universe until 1929. So Einstein imagined a universe in delicate balance between the pull of gravity among galaxies and the push of the cosmological constant. Once he learned of Hubble’s discovery, he regretted ever introducing the cosmological constant—had he resisted the temptation, he might have predicted the expansion of the universe before it was discovered. THE MYSTERY OF VACUUM ENERGY In theoretical physics, it’s not easy to un-invent a concept. The cosmological constant is the same as the idea of vacuum energy, the energy of empty space itself.

We don’t know much about dark energy, but we do know two very crucial things: It’s nearly constant throughout space (the same amount of energy from place to place), and also nearly constant in density through time (the same amount of energy per cubic centimeter at different times). So the simplest possible model for dark energy would be one featuring an absolutely constant density of energy through all space and time. And in fact, that’s an old idea, dating back to Einstein: He called it “the cosmological constant,” and these days we often call it “vacuum energy.” (Some people may try to convince you that there is some difference between vacuum energy and the cosmological constant—don’t fall for it. The only difference is which side of the equation you put it on, and that’s no difference at all.) What we’re suggesting is that every cubic centimeter of space—out in the desolate cold between the galaxies, or at the center of the Sun, or right in front of your face—there is a certain amount of energy, over and above whatever comes from the particles and photons and other things that are actually located in that little cube.

So if we were to look closely enough at empty space, we would see particles flashing into and out of existence, representing quantum fluctuations of the vacuum itself. These virtual particles are not especially mysterious or hypothetical—they are definitely there, and they have measurable effects in particle physics that have been observed many times over. Virtual particles carry energy, and that energy contributes to the cosmological constant. We can add up the effects of all such particles to obtain an estimate for how large the cosmological constant should be. But it wouldn’t be right to include the effects of particles with arbitrarily high energies. We don’t believe that our conventional understanding of particle physics is adequate for very high-energy events—at some point, we have to take account of the effects of quantum gravity, the marriage of general relativity with quantum mechanics, which remains an incomplete theory at the moment.

pages: 81 words: 28,120

Illustrated Theory of Everything: The Origin and Fate of the Universe by Stephen Hawking


anthropic principle, Arthur Eddington, cosmological constant, dark matter

If this happened, the universe would bein an unstable state, with more energy than if the symmetry had been broken.This special extra energy can be shown to have an antigravitational effect. Itwould act just like a cosmological constant. Einstein introduced the cosmological constant into general relativity when hewas trying to construct a static model of the universe. However,in this case,the universe would already be expanding. The repulsive effect of this cosmo-logical constant would therefore have made the universe expand at an ever-increasing rate. Even in regions where there were more matter particles thanaverage, the gravitational attraction of the matter would have been out-weighed by the repulsion of the effective cosmological constant. Thus, theseregions would also expand in an accelerating inflationary manner. As the universe expanded, the matter particles got farther apart.

Yet so strong was the belief in a static universe that it per-sisted into the early twentieth century. Even when Einstein formulated thegeneral theory of relativity in 1915, he was sure that the universe had to bestatic. He therefore modified his theory to make this possible, introducing a so-called cosmological constant into his equations. This was a new “antigravity”force, which, unlike other forces, did not come from any particular source, butwas built into the very fabric of space-time. His cosmological constant gavespace-time an inbuilt tendency to expand, and this could be made to exactlybalance the attraction of all the matter in the universe so that a static universewould result. Only one man, it seems, was willing to take general relativity at face value.While Einstein and other physicists were looking for ways of avoiding generalrelativity’s prediction of a nonstatic universe, the Russian physicist AlexanderFriedmann instead set about explaining it.

Renormalization, however, has a serious drawbackfrom the point of view of trying to find a complete theory. When you subtractinfinity from infinity, the answer can be anything you want. This means thatthe actual values of the masses and the strengths of the forces cannot bepredicted from the theory. Instead, they have to be chosen to fit the observa-tions. In the case of general relativity, there are only two quantities that can beadjusted: the strength of gravity and the value of the cosmological constant. Butadjusting these is not sufficient to remove all the infinities. One therefore hasa theory that seems to predict that certain quantities, such as the curvature ofspace-time, are really infinite, yet these quantities can be observed andmeasured to be perfectly finite. In an attempt to overcome this problem, a the-ory called “supergravity” was suggested in 1976. This theory was really just gen-eral relativity with some additional particles.

pages: 279 words: 75,527

Collider by Paul Halpern


Albert Einstein, Albert Michelson, anthropic principle, cosmic microwave background, cosmological constant, dark matter, Ernest Rutherford, Gary Taubes, gravity well, horn antenna, index card, Isaac Newton, Magellanic Cloud, pattern recognition, Richard Feynman, Richard Feynman, Ronald Reagan, Solar eclipse in 1919, statistical model, Stephen Hawking

To stabilize his theory he added an extra term, called the cosmological constant, whose purpose was essentially to serve as a kind of “antigravity”—preventing things on the largest scale from clumping together too much. Then in 1929, American astronomer Edwin Hubble made an astonishing discovery. Data taken at the Mount Wilson Observatory in Southern California demonstrated that all of the other galaxies in the universe, except for the relatively close ones, are moving away from our own Milky Way galaxy. This showed that space is expanding. Extrapolating backward in time led many researchers to conclude that the universe was once far, far smaller than it is today—a proposal later dubbed the Big Bang theory. Once he realized the implications of Hubble’s findings, Einstein discarded the cosmological constant term, calling it his “greatest blunder.”

Indeed, too much dark energy in the cosmos would be no fun at all—the universe would eventually tear itself apart in a catastrophic scenario called the Big Rip. Some physicists have represented dark energy by restoring Einstein’s once-discarded cosmological constant term to general relativity. Although adding such a constant antigravity term would be a simple move, it could use some physical motivation. Physicists would be loath to add anything to a well-established theory without understanding the need for the new term on a fundamental level. That would mean interpreting the field theory behind it. Current field theories, however, support a much larger value of the vacuum energy that would need to be almost, but not exactly, canceled out to yield a reasonable cosmological constant. Thus, matching experimental bounds for cosmic acceleration has proven a daunting task. Moreover, if dark energy were a constant throughout space and time, it would never lose its effect.

As Russian theorist Alexander Friedman had demonstrated in previous work, depending on the density of the universe compared to a critical value, this growth would either continue forever or reverse course someday. Recent astronomical results have indicated, however, that not only is the universe’s expansion continuing, it is actually speeding up. Consequently, some theorists have suggested a revival of the cosmological constant as a possible explanation of universal acceleration. Today, thanks to detailed measurement of the background radiation left over from the Big Bang, the scientific community understands many aspects of how the early universe developed and acquired structure. This radiation was released when atoms first formed and subsequently cooled as space expanded. Hence, it offers a snapshot of the infant universe, showing which regions were denser and which were sparser.

pages: 233 words: 62,563

Zero: The Biography of a Dangerous Idea by Charles Seife


Albert Einstein, Albert Michelson, Arthur Eddington, Cepheid variable, cosmological constant, dark matter, Edmond Halley, Georg Cantor, Isaac Newton, John Conway, Pierre-Simon Laplace, place-making, probability theory / Blaise Pascal / Pierre de Fermat, retrograde motion, Richard Feynman, Richard Feynman, Solar eclipse in 1919, Stephen Hawking

The cold, dead matter of the stars would decay away, leaving nothing but a smear of radiation that spreads equally throughout the universe. The cosmos would be a cold soup of dimming light. It would be death by ice. To Einstein, these ideas were abhorrent. Like Aristotle, he implicitly assumed that the universe was static, constant, and eternal. The only way out was to “correct” his equations of general relativity to stave off the impending destruction. He did this by adding a cosmological constant, an as yet undetected force that counteracts the force of gravity. The cosmological constant’s push would balance out gravity’s pull; instead of collapsing, the universe could stay in a steady balance, neither collapsing nor expanding. Postulating the existence of such a mysterious force was a desperate act. “I have…again perpetrated something about gravitation theory which somewhat exposes me to the danger of being confined in a madhouse,” wrote Einstein, but he was so worried about the impending destruction of the universe that he was forced to take such a dramatic step.

By comparing how fast galaxies were receding at different eras in the past, the astronomers were able to track how fast space-time was expanding. The answer they got was an odd one. The expansion of the universe isn’t slowing down. It might even be speeding up. The supernova data imply that the universe is getting bigger and bigger, faster and faster. If this is the case, there is little chance of a big crunch, because something is opposing the force of gravity. Once again physicists are talking about the cosmological constant—the mysterious term that Einstein added to his equations to balance the push of gravity. Einstein’s biggest blunder might not have been a blunder after all. The mysterious force, once again, might be the force of the vacuum. The tiny particles that seethe through space-time exert a gentle outward push, stretching the fabric of space-time imperceptibly. Over billions of years, that stretch adds up, and the universe inflates faster and faster.

The End of Time. Hanover, N.H.: University Press of New England, 1996. Thorne, Kip. Black Holes and Time Warps. New York: W. W. Norton, 1994. Thorpe, J. A. Elementary Topics in Differential Geometry. New York: Springer-Verlag, 1979. Thucydides. History of the Peloponnesian War. Trans. Rex Warner. London: Penguin Books, 1954. Turok, Neil, and S. W. Hawking. “Open Inflation, the Four Form and the Cosmological Constant.” Los Alamos National Labs Archive: hep-th/9803156 v4. The Upanishads. Trans. Juan Mascaro. London: Penguin Books, 1965. Urmson, J. O., and Jonathan Ree, eds. The Concise Encyclopedia of Western Philosophy and Philosophers. London: Routledge, 1996. Valenkin, Naum Yakovlevich. In Search of Infinity. Trans. Abe Shenitzer. Boston: Birkhauser, 1995. Vilenkin, Alexander. “The Quantum Cosmology Debate.”

pages: 335 words: 95,280

The Greatest Story Ever Told—So Far by Lawrence M. Krauss

Albert Einstein, complexity theory, cosmic microwave background, cosmological constant, dark matter, Ernest Rutherford, Isaac Newton, Magellanic Cloud, Murray Gell-Mann, RAND corporation, Richard Feynman, Richard Feynman, Richard Feynman: Challenger O-ring, the scientific method

While the inferred energy density of empty space is today greater than the energy density of everything else we see in the universe, in absolute terms, on the scale of the energies associated with the masses of all elementary particles we know of, it is minuscule in the extreme. No one has any sensible first-principles explanation using known particle physics mechanisms for how the ground-state energy of the universe could be nonzero—resulting in Einstein’s cosmological constant—and yet so small as to allow the kind of gentle acceleration we are now experiencing. (One plausible explanation does exist—first due to Steve Weinberg—though it is speculative and relies on speculative ideas about possible physics well beyond the realm of anything we currently understand. If there are many universes, and the energy density in empty space, assuming it is a cosmological constant, is not fixed by fundamental physics constraints, but instead randomly varies from universe to universe, then only in those universes in which the energy in empty space is not much bigger than the value we measure would galaxies be able to form, and then would stars be able to form, and only then planets, and only then astronomers . . .)

Naturally the questions arise, What could be causing this current accelerated expansion, and What is the source of this new kind of energy? Two possibilities present themselves. First, it could be a fundamental property of empty space, a possibility actually presaged by Albert Einstein shortly after he developed the General Theory of Relativity, which he realized could accommodate something he called a “cosmological constant,” but which we now realize could simply represent a nonzero ground-state energy of the universe that will exist indefinitely into the future. Or second, it could be energy stored in yet another invisible background scalar field in the universe. If this is the case, then the next obvious question is, will this energy be released in yet another, future inflationary-like phase transition as the universe continues to cool down?

Nevertheless, the universe is the way it is, and the fact that current fundamental theory does not make a first-principles prediction that explains something as fundamental as the energy of empty space implies nothing mystical. As I have said, lack of understanding is not evidence for God. It is merely evidence of a lack of understanding. Given that we do not know the source of the inferred energy in empty space, we are free to hope for the best, and in this case perhaps that means hoping that the cosmological constant explanation is correct rather than its being due to some as yet undiscovered scalar field that may one day relax into a new state, releasing the energy currently stored in space. Recall that because of the coupling of the Higgs field to the rest of the matter in the universe, when the field condensed into its electroweak symmetry-breaking state, the properties of matter and the forces that govern the interactions of matter changed dramatically.

pages: 692 words: 127,032

Fool Me Twice: Fighting the Assault on Science in America by Shawn Lawrence Otto


affirmative action, Albert Einstein, anthropic principle, Berlin Wall, Brownian motion, carbon footprint, Cepheid variable, clean water, Climategate, Climatic Research Unit, cognitive dissonance, Columbine, commoditize, cosmological constant, crowdsourcing, cuban missile crisis, Dean Kamen, desegregation, double helix, energy security, Exxon Valdez, fudge factor, ghettoisation, Harlow Shapley and Heber Curtis, Harvard Computers: women astronomers, informal economy, Intergovernmental Panel on Climate Change (IPCC), invisible hand, Isaac Newton, Louis Pasteur, mutually assured destruction, Richard Feynman, Richard Feynman, Ronald Reagan, Saturday Night Live, shareholder value, sharing economy, smart grid, Solar eclipse in 1919, stem cell, the scientific method, The Wealth of Nations by Adam Smith, Thomas Kuhn: the structure of scientific revolutions, transaction costs, University of East Anglia, War on Poverty, white flight, Winter of Discontent, working poor, yellow journalism, zero-sum game

Lemaître had noticed that Einstein’s general theory of relativity would have implied that the universe was expanding but for a troublesome little mathematical term called the cosmological constant that Einstein had inserted into his equations. Lemaitre saw no convincing reason why the cosmological constant should be there. In fact, Einstein himself had originally calculated that the universe was expanding, but he was a theoretician, not an astronomer. When he turned to astronomers for verification of his theory, he found that almost all of them held the notion that the universe existed in a steady state and there was no motion on a grand scale. So in deference to their observational experience, Einstein adjusted his general theory calculations with a mathematical “fudge factor”—the cosmological constant—that made the universe seem to be steady. Lemaître had independently been working off the same mathematical principles that Einstein had originally laid out, and in 1927 he wrote a dissenting paper in which he argued that the universe must be expanding, and that if it was, the redshifted light from stars was the result of this expansion.

This meant to him that the universe is not infinitely old; it has a certain age, and that the moment of creation—which British astronomer Fred Hoyle later mockingly called the “big bang”—was analogous to God’s first command at the beginning of the good abbé’s most cherished book, the Bible: Let there be light. Hubble’s meticulously reported logic and observations convinced Einstein that he had been wrong about the cosmological constant. He made a pilgrimage from Germany to Mount Wilson Observatory outside of Pasadena, where he joined Hubble, Humason, Lemaître, and others to make a stunning public announcement. Unlike Shapley, Einstein changed his position and removed the cosmological constant from his general theory of relativity, later calling it “the biggest blunder of my life.” The universe was indeed expanding. SCIENCE ROCK STAR This dramatic mea culpa by Einstein drew even more attention to Hubble and the striking depictions of the immense universe coming from the swashbuckling astronomers atop the 5,715-foot Mount Wilson.

That is why it has power: It enables us to affect the physical world in ways we couldn’t before. The observations and knowledge extend incrementally, by the contributions, risks, and suffering of many. They do not extend in sudden and dramatic paradigm shifts, and they didn’t in Einstein’s day, either. In fact, many of the ideas Einstein developed were done collaboratively, with considerable debate, a prime example being the cosmological constant. His early papers were extensions of the work of Max Planck, the Austrian physicist Ludwig Boltzmann, and others, and his revolutionary findings on Brownian motion were independently discovered by Polish physicist Marian von Smoluchowski, who was also building on Boltzmann’s work. Hubble’s revolutionary discovery of the expansion of the universe also extended from ideas that were talked about for years.

pages: 397 words: 109,631

Mindware: Tools for Smart Thinking by Richard E. Nisbett


affirmative action, Albert Einstein, availability heuristic, big-box store, Cass Sunstein, choice architecture, cognitive dissonance, correlation coefficient, correlation does not imply causation, cosmological constant, Daniel Kahneman / Amos Tversky, dark matter, endowment effect, experimental subject, feminist movement, fixed income, fundamental attribution error, glass ceiling, Henri Poincaré, Intergovernmental Panel on Climate Change (IPCC), Isaac Newton, job satisfaction, lake wobegon effect, libertarian paternalism, loss aversion, low skilled workers, Menlo Park, meta analysis, meta-analysis, quantitative easing, Richard Thaler, Ronald Reagan, selection bias, Socratic dialogue, Steve Jobs, Steven Levy, the scientific method, The Wealth of Nations by Adam Smith, Thomas Kuhn: the structure of scientific revolutions, William of Occam, Zipcar

But of course there is no such property as levity, and gravity is a relation between objects rather than a property of a single object. Einstein had to add a cheater factor to his theories about the nature of the universe, namely, the cosmological constant, in order to account for what he was confident was the steady state of the universe. But of course the universe isn’t in a steady state as had been assumed since the time of Aristotle. As a Westerner thoroughly imbued with Greek assumptions about stasis, Einstein had a gut instinct that the universe should be constant, so he resorted to the cosmological constant to preserve the assumption. Chinese dialectical reasoning had an impact on the physicist Niels Bohr, who was highly knowledgeable about Eastern thought. He attributed his development of quantum theory in part to the metaphysics of the East.

Nothing has actually been explained. The French playwright Molière derides such explanations when he has a character attribute a sleeping potion’s effect to its “dormative virtues.” Ptolemy’s epicycles were an ad hoc solution to the problem that heavenly bodies did not orbit the earth in the perfect circles that were presumed by his contemporaries to be the necessary pattern of motion. Einstein’s postulation of the cosmological constant, noted in Chapter 14, was a special-purpose fix to the theory of general relativity. It was postulated just to account for the “fact” that the universe was in a steady state. Oops. It isn’t in a steady state. An astronomer has come up with an ad hoc theory to account for the failure of Mercury to orbit the sun in the way demanded by Newton’s theory. The astronomer simply posited that the sun’s center of gravity shifts from its center to the surface—when and only when the planet in question is Mercury.

California California, University of, Berkeley Canadian TV (CTV) News categorization causality; assessment of; correlation versus; cultural differences in notions of; epiphenomena lacking significant; hypotheses generated by; judgments about; of relationships between variables cellular biology change; principle of; stability and; of status quo Chast, Roz Chetty, Raj Chevrolet Chicago; University of, Wisdom Network China; ancient; values and beliefs in Chinese language chi square Choi, Incheol choice; architecture of; institutional; outcomes of; sunk cost principle in; theories of; unconscious processes in; and value of human life Christianity; evangelical Churchill, Winston circular reasoning climate change clinical psychology Clinton, Bill CNN TV News Coca-Cola company coding cognitive dissonance cognitive processes; invalid approaches to improve cognitive psychology Collins, Francis conclusions; in dialectical reasoning; multiple regression analysis based; valid versus invalid conditional logic confabulation confirmation bias Confucianism Confucius Congress, U.S. conjecture consciousness; unconscious versus consensus, expert construals; see also inference; interpretation Consumer Reports context; choice influenced by; cultural differences and; dispositional factors versus contractual schemas contradiction(s) correlation; causation versus; coding and; experimental evidence versus; illusory; of influences on mood cosmological constant; multiple regression analysis of; of test scores and IQ cost-benefit analysis; in institutional choice and public policy; in political campaigns; pragmatic reasoning schemas and; strengths and weaknesses of; tragedy of the commons and; in valuation of human life covariation creationism critical incident stress debriefing (CISD) cultural differences; in beliefs; context and; in reasoning curves Dallas Chamber of Commerce Darley, John Darwin, Charles decision theory deconstructionists deductive reasoning defeasible reasoning Democratic Party Dennett, Daniel deontic schemas dependent variables; see also outcome variables Derrida, Jacques descriptive microeconomics designs, within versus between developmental psychology dialectical reasoning; context, causality, and contradiction in; culture and aging and; stability and change in; wisdom and Dickens, William dispersion dispositions, personal Dobzhansky, Theodosius double-blind randomized studies Drowned and the Saved, The (Levi) Drug Abuse Resistance Education (D.A.R.E.) program Drunk Tank Pink (Alter) Dubner, Stephen Durant, Will Early Childhood Longitudinal Study (ECLS) Eastern culture, differences between Western culture and, see cultural differences East Germany ecology economics; academic careers in; behavioral; classical; of cultural differences in social orientation; of decision theory; logic taught in courses on; macro- and micro-; Nobel Prize in; opportunity costs in; sunk costs in; see also cost-benefit analysis Eddington, Arthur S.

pages: 291 words: 81,703

Average Is Over: Powering America Beyond the Age of the Great Stagnation by Tyler Cowen


Amazon Mechanical Turk, Black Swan, brain emulation, Brownian motion, Cass Sunstein, choice architecture, complexity theory, computer age, computer vision, computerized trading, cosmological constant, crowdsourcing, dark matter, David Brooks, David Ricardo: comparative advantage, deliberate practice, Drosophila,, endowment effect, epigenetics, Erik Brynjolfsson, eurozone crisis, experimental economics, Flynn Effect, Freestyle chess, full employment, future of work, game design, income inequality, industrial robot, informal economy, Isaac Newton, John Markoff, Khan Academy, labor-force participation, Loebner Prize, low skilled workers, manufacturing employment, Mark Zuckerberg, meta analysis, meta-analysis, microcredit, Myron Scholes, Narrative Science, Netflix Prize, Nicholas Carr, pattern recognition, Peter Thiel, randomized controlled trial, Ray Kurzweil, reshoring, Richard Florida, Richard Thaler, Ronald Reagan, Silicon Valley, Skype, statistical model, stem cell, Steve Jobs, Turing test, Tyler Cowen: Great Stagnation, upwardly mobile, Yogi Berra

Since string theory is widely believed to be mathematically consistent, many hope that it fully describes our universe, making it a theory of everything. String theory is known to contain configurations that describe all the observed fundamental forces and matter but with a zero cosmological constant and some new fields. Other configurations have different values of the cosmological constant, and are metastable but long-lived. This leads many to believe that there is at least one metastable solution that is quantitatively identical with the standard model, with a small cosmological constant, containing dark matter and a plausible mechanism for cosmic inflation. It is not yet known whether string theory has such a solution, nor how much freedom the theory allows to choose the details. That was the easy part. Now: String theories also include objects other than strings, called branes.

pages: 281 words: 78,317

But What if We're Wrong? Thinking About the Present as if It Were the Past by Chuck Klosterman


a long time ago in a galaxy far, far away, Affordable Care Act / Obamacare, British Empire, citizen journalism, cosmological constant, dark matter, Edward Snowden, Elon Musk, Francis Fukuyama: the end of history, Frank Gehry, George Santayana, Gerolamo Cardano, ghettoisation, Howard Zinn, Isaac Newton, non-fiction novel, obamacare, pre–internet, Ralph Nader, Ray Kurzweil, Ronald Reagan, Silicon Valley, Stephen Hawking, the medium is the message, the scientific method, Thomas Kuhn: the structure of scientific revolutions, too big to fail, Y2K

The film is elucidated through the words of many perceptibly brilliant people, a few of whom spend much of the movie expressing dark apprehension over what will happen if the massive $9 billion LHC does not locate the Higgs particle. The person most openly nervous is the theorist identified as the academic star of his generation: Nima Arkani-Hamed. Born to a pair of Iranian doctors in 1972 and raised in Canada, the long-haired Arkani-Hamed directly states that if the Higgs particle can’t be found, he will have wasted at least fifteen years of his life. Later, when discussing the bizarre numeric perfection of the “cosmological constant,”42 he says something that guys in his position don’t usually say. “This is the sort of thing that really keeps you up at night,” Arkani-Hamed says. “It really makes you wonder if we’ve got something about the whole picture—the big picture—totally, totally, totally wrong.” Or maybe not. Spoiler alert: They find the particle. The experiment works. The previous fifteen years of Arkani-Hamed’s life were not in vain.

., 197–98 Byrne, David, 68–70 Campbell, Joseph, 74 “Canon Fodder” (GQ column), 242–45 Carey, John, 70 Carlin, Dan, 201–5, 215 Carlin, Lynn, 201 Caro, Robert, 51 Carter, Amy, 79 Catastrophe (TV show), 167 Catholic Church, 117–18, 134 ceilings in movies, visibility of, 244 certainty, 6–7, 10 changes in the world, dealing with, 248 Chicago Daily Tribune, 232n children’s involvement in sports, 190–91 Chronicles (Dylan), 230 Citizen Kane (film), 90, 244 Citizenfour (film), 236 Civil War, US causes, 233–34 literature, 22, 155 Civil War, The (film), 155 classical music, 72, 73 climate change disagreement about, 239–41 future consequences of, 240 no middle-of-the-road position on, 240–41 “clutch” scenarios in sports, 250n Coates, Ta-Nehisi, 52 Cobain, Kurt, 92n collective conscious, 2 Colophon, The, 92–93 color The Dress (viral phenomenon), 146–47 Homer’s description of Aegean Sea, 147–48 light, influence of, 149 shiny/matte distinction, 148 subjective nature of, 147–50 commercial success, 27–30, 56, 77 communication methods, 15–16 consensus, scientific, 112–13 conspiracy theories, 133–34, 145 Constitution, US, 207–12, 220–21 consumer reviews, 7–8 Contemporary Kafka, 35–39, 41–43 content, too much, 10, 33 Cooper, Alice, 144 Cooper, Dennis, 54n Copernicus, Nicolaus, 99, 116, 117 Corrections, The (Franzen), 57 Cosby Show, The (TV show), 174 cosmic rays, 125n cosmological constant, 130 criticism, 7–8, 10, 78 Crosby, Bing, 77 Dark Net, The (Bartlett), 37 Davydov, Denis, 156 Declaration of Independence, 212–13 Deep Web, 37–39 “Deflategate” scandal, 41 democracy, 215–16, 219 Descartes, René, 137, 149–50 “Dewey Defeats Truman” headline, 232n Díaz, Junot, 25–27, 39 Dick, Philip K., 31 dictatorships, 215 dimethyltryptamine (DMT), 141–42 dinosaurs, 97–98 disco music, 79–80 disrespect for past classic works, 243–45 Do Not Sell at Any Price (Petrusich), 81 Domino, Fats, 79 “Don’t Stop Believin’” (song), 71 Dr.

It was suggested that if we were a simulation, you’d have to put in a limit to something that goes on within it. And this cutoff could be the program’s pre-calculated limit for the energy level of these cosmic rays. We could be up against that boundary. It’s an intriguing thought that we’re all just one big simulation. That being said . . . it would be hard to swallow.” 42 The cosmological constant is the value of the energy density of the vacuum of space. Now, I don’t understand what that means. But it’s one of those “twenty numbers” Brian Greene mentioned a few pages back—a number that has a value so specific and so inimitable that the universe as we know it could not exist if it were even .0001 percent different. 43 This is a super-fun book, but I don’t understand how the publisher was supposed to market it: It rejects every possible conspiracy theory, yet would only be of interest to people who are actively obsessed with conspiracy theories (and who would read this book with the sole purpose of examining the details of theories the author is illustrating to be false).

pages: 661 words: 169,298

Coming of Age in the Milky Way by Timothy Ferris


Albert Einstein, Albert Michelson, Alfred Russel Wallace, anthropic principle, Arthur Eddington, Atahualpa, Cepheid variable, Chance favours the prepared mind, Commentariolus, cosmic abundance, cosmic microwave background, cosmological constant, cosmological principle, dark matter, delayed gratification, Edmond Halley, Eratosthenes, Ernest Rutherford, Gary Taubes, Harlow Shapley and Heber Curtis, Harvard Computers: women astronomers, Henri Poincaré, invention of writing, Isaac Newton, John Harrison: Longitude, Karl Jansky, Lao Tzu, Louis Pasteur, Magellanic Cloud, mandelbrot fractal, Menlo Park, Murray Gell-Mann, music of the spheres, planetary scale, retrograde motion, Richard Feynman, Richard Feynman, Search for Extraterrestrial Intelligence, Searching for Interstellar Communications, Solar eclipse in 1919, source of truth, Stephen Hawking, Thomas Kuhn: the structure of scientific revolutions, Thomas Malthus, Wilhelm Olbers

This was a completely novel idea, and one for which there was, at the time, no observational evidence whatever: The astronomers he consulted informed Einstein that stars wander more or less randomly through space, but display no concerted motion of the sort that would suggest cosmic expansion or contraction. Faced with this disjunction between his theory and the empirical data, Einstein reluctantly concluded that there must be something wrong with the theory, and he modified its equations by adding a term that he called the cosmological constant. Symbolized by the Greek letter lambda, the new term was intended to make the radius of the universe hold steady with the passing of time. Einstein never liked the cosmological constant. He called it “gravely detrimental to the formal beauty of the theory,” pointing out that it was nothing more than a mathematical fiction, without any real physical basis, one that had been introduced solely to being the theory into accord with the observational facts. As he wrote in 1917: [W]e admittedly had to introduce an extension of the field equations of gravitation which is not justified by our actual knowledge of gravitation….

Looking out to San Francisco, eighteen hundred miles away, the Chicagoans would find that its velocity of recession was fully eighteen hundred miles per hour. And that, a velocity-distance relation, is what Hubble found for the galaxies. It was also, of course, just what the general theory of relativity had predicted, at least before being fettered by the lambda term. (Fumed Einstein, “If Hubble’s expansion had been discovered at the time of the creation of the general theory of relativity, the [cosmological constant] would never have been introduced.”)2 Yet Hubble, like Slipher, was isolated by the gulf that still separated the world of the American observational astronomers from that of Einstein and the other leading theoretical physicists in Europe. Hubble knew next to nothing of general relativity; neither did his boss, George Ellery Hale, who confessed that “the complications of the theory of relativity are altogether too much for my comprehension,” adding, “I fear it will always remain beyond my grasp.”3 Nor had either man heard of relativity’s prediction that the universe might be expanding.

The fact that they are massive, combined with their high velocities, means that they pack considerable energy—from 108 to more than 1022electron volts. Cosmogony. The study of the origin of the universe. Cosmology. (1) The science concerned with discerning the structure and composition of the universe as a whole. Combines astronomy, astrophysics, particle physics, and a variety of mathematical approaches including geometry and topology. (2) A particular cosmological theory. Cosmological constant. A term sometimes employed in cosmology to express a force of “cosmic repulsion,” such as the energy released by the false vacuum thought to power exponential expansion of the universe in the inflationary universe models. Whether any such thing as cosmic repulsion exists or ever played a role in cosmic history remains an open question. Coulomb barrier. Electromagnetic zone of resistance surrounding protons (or other electrically charged particles) that tends to repel other protons (or other particles of like charge).

pages: 696 words: 143,736

The Age of Spiritual Machines: When Computers Exceed Human Intelligence by Ray Kurzweil


Ada Lovelace, Alan Turing: On Computable Numbers, with an Application to the Entscheidungsproblem, Albert Einstein, Any sufficiently advanced technology is indistinguishable from magic, Buckminster Fuller, call centre, cellular automata, combinatorial explosion, complexity theory, computer age, computer vision, cosmological constant, cosmological principle, Danny Hillis, double helix, Douglas Hofstadter, Everything should be made as simple as possible, first square of the chessboard / second half of the chessboard, fudge factor, George Gilder, Gödel, Escher, Bach, I think there is a world market for maybe five computers, information retrieval, invention of movable type, Isaac Newton, iterative process, Jacquard loom, Jacquard loom, John Markoff, John von Neumann, Lao Tzu, Law of Accelerating Returns, mandelbrot fractal, Marshall McLuhan, Menlo Park, natural language processing, Norbert Wiener, optical character recognition, ought to be enough for anybody, pattern recognition, phenotype, Ralph Waldo Emerson, Ray Kurzweil, Richard Feynman, Richard Feynman, Robert Metcalfe, Schrödinger's Cat, Search for Extraterrestrial Intelligence, self-driving car, Silicon Valley, speech recognition, Steven Pinker, Stewart Brand, stochastic process, technological singularity, Ted Kaczynski, telepresence, the medium is the message, There's no reason for any individual to have a computer in his home - Ken Olsen, traveling salesman, Turing machine, Turing test, Whole Earth Review, Y2K

In contrast, humans are a lot smarter than just a quantum greater than total stupidity (of course, your view may vary depending on the latest news reports). THE END OF THE UNIVERSE What does the Law of Time and Chaos say about the end of the Universe? One theory is that the Universe will continue its expansion forever. Alternatively, if there’s enough stuff, then the force of the Universe’s own gravity will stop the expansion, resulting in a final “big crunch.” Unless, of course, there’s an antigravity force. Or if the “cosmological constant,” Einstein’s “fudge factor,” is big enough. I’ve had to rewrite this paragraph three times over the past several months because the physicists can’t make up their minds. The latest speculation apparently favors indefinite expansion. Personally, I prefer the idea of the Universe closing in again on itself as more aesthetically pleasing. That would mean that the Universe would reverse its expansion and reach a singularity again.

Ultimately, intelligence will be a force to reckon with, even for these big celestial forces (so watch out!). The laws of physics are not repealed by intelligence, but they effectively evaporate in its presence. So will the Universe end in a big crunch, or in an infinite expansion of dead stars, or in some other manner? In my view, the primary issue is not the mass of the Universe, or the possible existence of antigravity, or of Einstein’s so-called cosmological constant. Rather, the fate of the Universe is a decision yet to be made, one which we will intelligently consider when the time is right. TIME LINE 12 HOW TO BUILD AN INTELLIGENT MACHINE IN THREE EASY PARADIGMS As Deep Blue goes deeper and deeper, it displays elements of strategic understanding. Somewhere out there, mere tactics are translating into strategy. This is the closest thing I’ve seen to computer intelligence.

Champernowne, David Chang, Young chaos evolution and evolutionary algorithms and Law of Increasing Chaos Law of Time and Chaos Chelyabinsk ,Chernobyl chess Deep Blue’s playing of legend of inventor of Pick Best Move program for quantum computing and China legend of emperor of chips, computer Moore’s Law and, see Moore’s Law three-dimensional Chuang, Isaac Chuang-tzu Church, Alonzo Church, Ken Churchill, Winston Church-Turing thesis Clarke, Arthur C cochlear implants Cohen, Harold color perception Colossus common sense communication in animals in arts future technologies for compact disc (CD) compact disc read-only memory (CD-ROM) complexity computation achieving human-level capabilities in crystalline density of destruction of information in digital DNA exponential growth of inevitability of on Internet, proposal for irreversibility of Law of Accelerating Returns applied to nanotubes and optical order and quantum, see quantum computing Turing Machine model of see also artificial intelligence; intelligence computers art and, see arts Babbage’s Analytical Engine chips in, see chips, computer consciousness in dependence on first American programmable intelligence of, see artificial intelligence knowledge gathering and sharing by Moore’s Law and, see Moore’s Law neural, see neural nets number of past predictions made about programming of, compared with evolution in schools speed and power of supercomputers in 2009 in 2019 in 2029 world’s first operational Y2K and Computing Machinery and Intelligence (Turing) consciousness brain and in computers/AI Descartes’s dictum and as “different kind of stuff” in evolution as function of pattern, vs. particles human inability to understand logical positivist view of as machine reflecting on itself multiple Plato’s views on quantum mechanics and schools of thought on testability of Turing Test and, see Turing Test Universe and see also identity context continuous speech recognition (CSR) Voice Xpress Plus Cope, David cosmological constant Crick, Francis H. C. cryonics crystalline computing Cser, Jim Curl, Robert deaf persons cochlear implants for death, see mortality Debussy, Claude Deep Blue (chess-playing computer) De Garis, Hugo DENDRAL Dennett, Daniel Descartes, René digital digital computing digital video disc (DVD) dinosaurs disabilities blindness, see blind persons deafness, see deaf persons neural implants and, see neural implants prosthetic devices and in 2009 in 2019 in 2029 disease cancer cryonics and pathogens in, see pathogens see also medicine DNA computing with error correction in in evolution of Homo sapiens vs. primates protein synthesis and see also genes, genetic code Dogbert Donovan Drexler, Eric Dreyfus, Hubert driving drugs Dyson, Esther Earth formation of eating economy, see business, economics, and finance Edison, Thomas Alva education computers in schools teachers and teaching in in 2009 in 2019 in 2029 see also learning Einstein, Albert cosmological constant of on simplification theory of relativity of Eisenhower, Dwight electrocardiogram (EKG) electromagnetic force electrons tunneling of electroweak force Emerson, Ralph Waldo EMI (Experiments in Musical Intelligence) emotions in animals produced by brain stimulation Emperors New Mind, The (Penrose) employment encryption Pretty Good Privacy quantum engines, jet Engines of Creation (Drexler) Enigma code entropy Increasing, Law of, see second law of thermodynamics Evans, Thomas G.

pages: 412 words: 122,952

Day We Found the Universe by Marcia Bartusiak


Albert Einstein, Albert Michelson, Arthur Eddington, California gold rush, Cepheid variable, Copley Medal, cosmic microwave background, cosmological constant, Edmond Halley, Edward Charles Pickering, Fellow of the Royal Society, fudge factor, Harlow Shapley and Heber Curtis, Harvard Computers: women astronomers, horn antenna, invention of the telescope, Isaac Newton, Louis Pasteur, Magellanic Cloud, Occam's razor, Pluto: dwarf planet, Solar eclipse in 1919, William of Occam

Stellar objects would be gravitationally drawn to one another, closer and closer over time. Ultimately, the universe would collapse under the inescapable pull of gravity. So, to avoid this cosmic calamity and match his theory with then-accepted astronomical observations, Einstein altered his famous equation, adding the term λ (the Greek letter lambda), a fudge factor that came to be called the “cosmological constant.” This new ingredient was an added energy that permeated empty space and exerted an outward “pressure” on it. This repulsive field—a kind of antigravity, actually—exactly balanced the inward gravitational attraction of all the matter in his closed universe, keeping it from moving. As a result, the universe remained immobile, “as required by the fact of the small velocities of the stars,” wrote Einstein in his classic 1917 paper.

“A gasp of astonishment swept through the library,” according to an Associated Press reporter in attendance. At a follow-up session a week later, Einstein went further and announced that “the red shift of distant nebulae has smashed my old construction like a hammer blow,” swiftly swinging down his hand to illustrate the point to his audience. Einstein at this stage recognized that he no longer needed his cosmological constant to describe this dynamic universe. His original equations could handle the cosmic expansion just fine, which pleased him immensely. From the start, he had had qualms about the ad hoc addition, believing the constant tarnished the formal beauty of his theory. Tacking on the extra term, he reportedly said, was the “biggest blunder” he ever made in his life. The cocky kid was getting older.

Just weeks before his death he finished the measurement of his five hundredth parallax field at the observatory's Pasadena headquarters. Though he was wrong on spiral rotations, van Maanen remained a world-class surveyor of stellar parallaxes. Georges Lemaître made few notable contributions to cosmology after 1934 but continued to publish reviews and discussions. Although Einstein abandoned the cosmological constant λ in 1931, Lemaître continued to champion it. They had friendly arguments about this issue whenever they met, which led to the joke that “everywhere the two men went, the lambda was sure to go.” Lemaître went on to do important work in celestial mechanics and pioneered the use of electronic computers for numerical calculations. He always hoped the explosive origin of the universe would be validated by astronomical observations and at last received news of the discovery of the cosmic microwave background, the remnant echo of the Big Bang, shortly before he died in 1966.

pages: 654 words: 204,260

A Short History of Nearly Everything by Bill Bryson


Albert Einstein, Albert Michelson, Alfred Russel Wallace, All science is either physics or stamp collecting, Arthur Eddington, Barry Marshall: ulcers, Brownian motion, California gold rush, Cepheid variable, clean water, Copley Medal, cosmological constant, dark matter, Dava Sobel, David Attenborough, double helix, Drosophila, Edmond Halley, Ernest Rutherford, Fellow of the Royal Society, Harvard Computers: women astronomers, Isaac Newton, James Watt: steam engine, John Harrison: Longitude, Kevin Kelly, Kuiper Belt, Louis Pasteur, luminiferous ether, Magellanic Cloud, Menlo Park, Murray Gell-Mann, out of africa, Richard Feynman, Richard Feynman, Stephen Hawking, supervolcano, Thomas Malthus, Wilhelm Olbers

Among much else, Einstein's general theory of relativity suggested that the universe must be either expanding or contracting. But Einstein was not a cosmologist, and he accepted the prevailing wisdom that the universe was fixed and eternal. More or less reflexively, he dropped into his equations something called the cosmological constant, which arbitrarily counterbalanced the effects of gravity, serving as a kind of mathematical pause button. Books on the history of science always forgive Einstein this lapse, but it was actually a fairly appalling piece of science and he knew it. He called it “the biggest blunder of my life.” Coincidentally, at about the time that Einstein was affixing a cosmological constant to his theory, at the Lowell Observatory in Arizona, an astronomer with the cheerily intergalactic name of Vesto Slipher (who was in fact from Indiana) was taking spectrographic readings of distant stars and discovering that they appeared to be moving away from us.

Scientists sometimes also call it vacuum energy or, more exotically, quintessence. Whatever it is, it seems to be driving an expansion that no one can altogether account for. The theory is that empty space isn't so empty at all—that there are particles of matter and antimatter popping into existence and popping out again—and that these are pushing the universe outward at an accelerating rate. Improbably enough, the one thing that resolves all this is Einstein's cosmological constant—the little piece of math he dropped into the general theory of relativity to stop the universe's presumed expansion, and called “the biggest blunder of my life.” It now appears that he may have gotten things right after all. The upshot of all this is that we live in a universe whose age we can't quite compute, surrounded by stars whose distances we don't altogether know, filled with matter we can't identify, operating in conformance with physical laws whose properties we don't truly understand.

Goldsmith, The Astronomers, p. 82. 37 “the best bets these days for the age of the universe . . .” U.S. News and World Report, “How Old Is the Universe?” August 25, 1997, p. 34. 38 “two-thirds of the universe is still missing . . .” Economist, “Dark for Dark Business,” January 5, 2002, p. 51. 39 “The theory is that empty space isn't so empty at all . . .” PBS Nova, “Runaway Universe,” Transcript from program first broadcast November 21, 2000. 40 “Einstein's cosmological constant . . .” Economist, “Dark for Dark Business,” January 5, 2002, p. 51. CHAPTER 12 THE EARTH MOVES 1 “invited the reader to join him in a tolerant chuckle . . .” Hapgood, Earth's Shifting Crust, p. 29. 2 “they posited ancient ‘land bridges' . . .” Simpson, p. 98. 3 “Even land bridges couldn't explain some things.” Gould, Ever Since Darwin, p. 163. 4 “numerous grave theoretical difficulties.”

pages: 574 words: 164,509

Superintelligence: Paths, Dangers, Strategies by Nick Bostrom


agricultural Revolution, AI winter, Albert Einstein, algorithmic trading, anthropic principle, anti-communist, artificial general intelligence, autonomous vehicles, barriers to entry, Bayesian statistics, bioinformatics, brain emulation, cloud computing, combinatorial explosion, computer vision, cosmological constant, dark matter, DARPA: Urban Challenge, data acquisition, delayed gratification, demographic transition, Donald Knuth, Douglas Hofstadter, Drosophila, Elon Musk,, endogenous growth, epigenetics, fear of failure, Flash crash, Flynn Effect, friendly AI, Gödel, Escher, Bach, income inequality, industrial robot, informal economy, information retrieval, interchangeable parts, iterative process, job automation, John Markoff, John von Neumann, knowledge worker, Menlo Park, meta analysis, meta-analysis, mutually assured destruction, Nash equilibrium, Netflix Prize, new economy, Norbert Wiener, NP-complete, nuclear winter, optical character recognition, pattern recognition, performance metric, phenotype, prediction markets, price stability, principal–agent problem, race to the bottom, random walk, Ray Kurzweil, recommendation engine, reversible computing, social graph, speech recognition, Stanislav Petrov, statistical model, stem cell, Stephen Hawking, strong AI, superintelligent machines, supervolcano, technological singularity, technoutopianism, The Coming Technological Singularity, The Nature of the Firm, Thomas Kuhn: the structure of scientific revolutions, transaction costs, Turing machine, Vernor Vinge, Watson beat the top human players on Jeopardy!, World Values Survey, zero-sum game

If these can travel at 50% of the speed of light, they can reach some 6×1018 stars before the cosmic expansion puts further acquisitions forever out of reach. At 99% of c, they could reach some 2×1020 stars.16 These travel speeds are energetically attainable using a small fraction of the resources available in the solar system.17 The impossibility of faster-than-light travel, combined with the positive cosmological constant (which causes the rate of cosmic expansion to accelerate), implies that these are close to upper bounds on how much stuff our descendants acquire.18 If we assume that 10% of stars have a planet that is—or could by means of terraforming be rendered—suitable for habitation by human-like creatures, and that it could then be home to a population of a billion individuals for a billion years (with a human life lasting a century), this suggests that around 1035 human lives could be created in the future by an Earth-originating intelligent civilization.19 There are, however, reasons to think this greatly underestimates the true number.

The likely manifestation of this would be the superintelligence’s initiation of a colonization process that would expand in all directions using von Neumann probes. This would result in an approximate sphere of expanding infrastructure centered on the originating planet and growing in radius at some fraction of the speed of light; and the colonization of the universe would continue in this manner until the accelerating speed of cosmic expansion (a consequence of the positive cosmological constant) makes further procurements impossible as remoter regions drift permanently out of reach (this happens on a timescale of billions of years).20 By contrast, agents lacking the technology required for inexpensive resource acquisition, or for the conversion of generic physical resources into useful infrastructure, may often find it not cost-effective to invest any present resources in increasing their material endowments.

pages: 532 words: 133,143

To Explain the World: The Discovery of Modern Science by Steven Weinberg


Albert Einstein, Alfred Russel Wallace, Astronomia nova, Brownian motion, Commentariolus, cosmological constant, dark matter, Dava Sobel, double helix, Edmond Halley, Eratosthenes, Ernest Rutherford, fudge factor, invention of movable type, Isaac Newton, James Watt: steam engine, music of the spheres, On the Revolutions of the Heavenly Spheres, Pierre-Simon Laplace, probability theory / Blaise Pascal / Pierre de Fermat, retrograde motion, Thomas Kuhn: the structure of scientific revolutions

Schofield, “The Tychonic and Semi-Tychonic World Systems,” in Planetary Astronomy from the Renaissance to the Rise of Astrophysics—Part A: Tycho Brahe to Newton, ed. R. Taton and C. Wilson (Cambridge University Press, Cambridge, 1989). 13. For a photograph of this statue, taken by Owen Gingerich, see the frontispiece of my essay collection Facing Up—Science and Its Cultural Adversaries (Harvard University Press, Cambridge, Mass., 2001). 14. S. Weinberg, “Anthropic Bound on the Cosmological Constant,” Physical Review Letters 59, 2607 (1987); H. Martel, P. Shapiro, and S. Weinberg, “Likely Values of the Cosmological Constant,” Astrophysical Journal 492, 29 (1998). 15. J. R. Voelkel and O. Gingerich, “Giovanni Antonio Magini’s ‘Keplerian’ Tables of 1614 and Their Implications for the Reception of Keplerian Astronomy in the Seventeenth Century,” Journal for the History of Astronomy 32, 237 (2001). 16. Quoted in Robert S. Westfall, The Construction of Modern Science—Mechanism and Mechanics (Cambridge University Press, Cambridge, 1977), p. 10. 17.

The Singularity Is Near: When Humans Transcend Biology by Ray Kurzweil


additive manufacturing, AI winter, Alan Turing: On Computable Numbers, with an Application to the Entscheidungsproblem, Albert Einstein, anthropic principle, Any sufficiently advanced technology is indistinguishable from magic, artificial general intelligence, Asilomar, augmented reality, autonomous vehicles, Benoit Mandelbrot, Bill Joy: nanobots, bioinformatics, brain emulation, Brewster Kahle, Brownian motion, business intelligence,, call centre, carbon-based life, cellular automata, Claude Shannon: information theory, complexity theory, conceptual framework, Conway's Game of Life, cosmological constant, cosmological principle, cuban missile crisis, data acquisition, Dava Sobel, David Brooks, Dean Kamen, disintermediation, double helix, Douglas Hofstadter,, epigenetics, factory automation, friendly AI, George Gilder, Gödel, Escher, Bach, informal economy, information retrieval, invention of the telephone, invention of the telescope, invention of writing, Isaac Newton, iterative process, Jaron Lanier, Jeff Bezos, job automation, job satisfaction, John von Neumann, Kevin Kelly, Law of Accelerating Returns, life extension, lifelogging, linked data, Loebner Prize, Louis Pasteur, mandelbrot fractal, Mikhail Gorbachev, mouse model, Murray Gell-Mann, mutually assured destruction, natural language processing, Network effects, new economy, Norbert Wiener, oil shale / tar sands, optical character recognition, pattern recognition, phenotype, premature optimization, randomized controlled trial, Ray Kurzweil, remote working, reversible computing, Richard Feynman, Richard Feynman, Robert Metcalfe, Rodney Brooks, Search for Extraterrestrial Intelligence, selection bias, semantic web, Silicon Valley, Singularitarianism, speech recognition, statistical model, stem cell, Stephen Hawking, Stewart Brand, strong AI, superintelligent machines, technological singularity, Ted Kaczynski, telepresence, The Coming Technological Singularity, Thomas Bayes, transaction costs, Turing machine, Turing test, Vernor Vinge, Y2K, Yogi Berra

We are struck with two possible applications of an anthropic principle, one for the remarkable biofriendly laws of our universe, and one for the actual biology of our planet. Let's first consider the anthropic principle as applied to the universe in more detail. The question concerning the universe arises because we notice that the constants in nature are precisely what are required for the universe to have grown in complexity. If the cosmological constant, the Planck constant, and the many other constants of physics were set to just slightly different values, atoms, molecules, stars, planets, organisms, and humans would have been impossible. The universe appears to have exactly the right rules and constants. (The situation is reminiscent of Steven Wolfram's observation that certain cellular-automata rules [see the sidebar on p. 85] allow for the creation of remarkably complex and unpredictable patterns, whereas other rules lead to very uninteresting patterns, such as alternating lines or simple triangles in a repeating or random configuration.)

That's the common wisdom. But I don't agree with it. My conjecture is that intelligence will ultimately prove more powerful than these big impersonal forces.... So will the universe end in a big crunch, or in an infinite expansion of dead stars, or in some other manner? In my view, the primary issue is not the mass of the universe, or the possible existence of antigravity, or of Einstein's so-called cosmological constant. Rather, the fate of the universe is a decision yet to be made, one which we will intelligently consider when the time is right.94 Complexity theorist James Gardner combined my suggestion on the evolution of intelligence throughout the universe with Smolin's and Susskind's concepts of evolving universes. Gardner conjectures that it is specifically the evolution of intelligent life that enables offspring universes.95 Gardner builds on British astronomer Martin Rees's observation that "what we call the fundamental constants—the numbers that matter to physicists—may be secondary consequences of the final theory, rather than direct manifestations of its deepest and most fundamental level."

pages: 315 words: 93,628

Is God a Mathematician? by Mario Livio


Albert Einstein, Antoine Gombaud: Chevalier de Méré, Brownian motion, cellular automata, correlation coefficient, correlation does not imply causation, cosmological constant, Dava Sobel, double helix, Edmond Halley, Eratosthenes, Georg Cantor, Gerolamo Cardano, Gödel, Escher, Bach, Henri Poincaré, Isaac Newton, John von Neumann, music of the spheres, Myron Scholes, probability theory / Blaise Pascal / Pierre de Fermat, Russell's paradox, The Design of Experiments, the scientific method, traveling salesman

ALSO BY MARIO LIVIO The Equation That Couldn’t Be Solved: How Mathematical Genius Discovered the Language of Symmetry The Golden Ratio: The Story of Phi, the World’s Most Astonishing Number The Accelerating Universe: Infinite Expansion, the Cosmological Constant, and the Beauty of the Cosmos Simon & Schuster 1230 Avenue of the Americas New York, NY 10020 Copyright © 2009 by Mario Livio All rights reserved, including the right to reproduce this book or portions thereof in any form whatsoever. For information address Simon & Schuster Subsidiary Rights Department, 1230 Avenue of the Americas, New York, NY 10020. SIMON & SCHUSTER and colophon are registered trademarks of Simon & Schuster, Inc. Permissions and acknowledgments for reprinted material are listed on pages 307 and 308.

pages: 448 words: 116,962

Singularity Sky by Stross, Charles


anthropic principle, cellular automata, Conway's Game of Life, cosmological constant, Doomsday Clock, Extropian, gravity well, Kuiper Belt, life extension, means of production, new economy, phenotype, prisoner's dilemma, skinny streets, technological singularity, uranium enrichment

The rest of the letter was filled with idle chatter about fictional friends, reminiscences about trivial and entirely nonexistent shared memories and major (presumably well-documented) ones, and—as far as Martin could see—a content-free blind. He turned to the "dissertation." It was quite long, and he pondered Herman's wisdom in sending it. Did New Republican schoolchildren write eight-page essays about God? And about God's motives, as far as they could be deduced from the value of the cosmological constant? It was written in a precious, somewhat dull style that set his teeth on edge, like an earnest student essay hunting for marks of approval rather than a straight discursive monograph asserting a viewpoint. Then his eyes caught the footnotes: 1. Consider the hypothetical case of a power that intends to create a localized causality violation that does not produce a light cone encompassing its origin point.

pages: 486 words: 148,485

Being Wrong: Adventures in the Margin of Error by Kathryn Schulz


affirmative action, anti-communist, banking crisis, Bernie Madoff, car-free, Cass Sunstein, cognitive dissonance, colonial rule, conceptual framework, cosmological constant, cuban missile crisis, Daniel Kahneman / Amos Tversky, dark matter, desegregation, Johann Wolfgang von Goethe, lake wobegon effect, mandatory minimum, Pierre-Simon Laplace, Ronald Reagan, six sigma, stem cell, Steven Pinker, Tenerife airport disaster, the scientific method, The Wisdom of Crowds, theory of mind, Thomas Kuhn: the structure of scientific revolutions, trade route

I’ve already suggested that error isn’t rare, yet it often seems remarkably scarce in our own lives—enough so that we should take a moment to establish exactly how un-rare it really is. By way of example, consider the domain of science. The history of that field is littered with discarded theories, some of which are among humanity’s most dramatic mistakes: the flat earth, the geocentric universe, the existence of ether, the cosmological constant, cold fusion. Science proceeds by perceiving and correcting these errors, but over time, the corrections themselves often prove wrong as well. As a consequence, some philosophers of science have reached a conclusion that is known, in clumsy but funny fashion, as the Pessimistic Meta-Induction from the History of Science. The gist is this: because even the most seemingly bulletproof scientific theories of times past eventually proved wrong, we must assume that today’s theories will someday prove wrong as well.

pages: 395 words: 116,675

The Evolution of Everything: How New Ideas Emerge by Matt Ridley


affirmative action, Affordable Care Act / Obamacare, Albert Einstein, Alfred Russel Wallace, altcoin, anthropic principle, anti-communist, bank run, banking crisis, barriers to entry, bitcoin, blockchain, British Empire, Broken windows theory, Columbian Exchange, computer age, Corn Laws, cosmological constant, creative destruction, Credit Default Swap, crony capitalism, crowdsourcing, cryptocurrency, David Ricardo: comparative advantage, demographic transition, Deng Xiaoping, discovery of DNA, Donald Davies, double helix, Downton Abbey, Edward Glaeser, Edward Lorenz: Chaos theory, Edward Snowden, endogenous growth, epigenetics, ethereum blockchain, facts on the ground, falling living standards, Ferguson, Missouri, financial deregulation, financial innovation, Frederick Winslow Taylor, Geoffrey West, Santa Fe Institute, George Gilder, George Santayana, Gunnar Myrdal, Henri Poincaré, hydraulic fracturing, imperial preference, income per capita, indoor plumbing, interchangeable parts, Intergovernmental Panel on Climate Change (IPCC), invisible hand, Isaac Newton, Jane Jacobs, Jeff Bezos, joint-stock company, Joseph Schumpeter, Kenneth Arrow, Kevin Kelly, Khan Academy, knowledge economy, land reform, Lao Tzu, long peace, Lyft, M-Pesa, Mahatma Gandhi, Mark Zuckerberg, means of production, meta analysis, meta-analysis, mobile money, money: store of value / unit of account / medium of exchange, Mont Pelerin Society, moral hazard, Necker cube, obamacare, out of africa, packet switching, peer-to-peer, phenotype, Pierre-Simon Laplace, price mechanism, profit motive, RAND corporation, random walk, Ray Kurzweil, rent-seeking, reserve currency, Richard Feynman, Richard Feynman, rising living standards, road to serfdom, Ronald Coase, Ronald Reagan, Satoshi Nakamoto, Second Machine Age, sharing economy, smart contracts, South Sea Bubble, Steve Jobs, Steven Pinker, The Wealth of Nations by Adam Smith, Thorstein Veblen, transaction costs, women in the workforce

In other words, if things had been just a little bit different, then stable suns, watery worlds and polymerised carbon would not be possible, so life could never get started. This stroke of cosmic luck implied that we lived in some kind of privileged universe uncannily suitable for us, and this was somehow spooky and cool. Certainly, there do seem to be some remarkably fortuitous features of our own universe without which life would be impossible. If the cosmological constant were any larger, the pressure of antigravity would be greater and the universe would have blown itself to smithereens long before galaxies, stars and planets could have evolved. Electrical and nuclear forces are just the right strength for carbon to be one of the most common elements, and carbon is vital to life because of its capacity to form multiple bonds. Molecular bonds are just the right strength to be stable but breakable at the sort of temperatures found at the typical distance of a planet from a star: any weaker and the universe would be too hot for chemistry, any stronger and it would be too cold.

pages: 1,737 words: 491,616

Rationality: From AI to Zombies by Eliezer Yudkowsky

Albert Einstein, Alfred Russel Wallace, anthropic principle, anti-pattern, anti-work, Arthur Eddington, artificial general intelligence, availability heuristic, Bayesian statistics, Berlin Wall, Build a better mousetrap, Cass Sunstein, cellular automata, cognitive bias, cognitive dissonance, correlation does not imply causation, cosmological constant, creative destruction, Daniel Kahneman / Amos Tversky, dematerialisation, discovery of DNA, Douglas Hofstadter, Drosophila, effective altruism, experimental subject, Extropian, friendly AI, fundamental attribution error, Gödel, Escher, Bach, hindsight bias, index card, index fund, Isaac Newton, John Conway, John von Neumann, Long Term Capital Management, Louis Pasteur, mental accounting, meta analysis, meta-analysis, money market fund, Nash equilibrium, Necker cube, NP-complete, P = NP, pattern recognition, Paul Graham, Peter Thiel, Pierre-Simon Laplace, placebo effect, planetary scale, prediction markets, random walk, Ray Kurzweil, reversible computing, Richard Feynman, Richard Feynman, risk tolerance, Rubik’s Cube, Saturday Night Live, Schrödinger's Cat, scientific mainstream, sensible shoes, Silicon Valley, Silicon Valley startup, Singularitarianism, Solar eclipse in 1919, speech recognition, statistical model, Steven Pinker, strong AI, technological singularity, The Bell Curve by Richard Herrnstein and Charles Murray, the map is not the territory, the scientific method, Turing complete, Turing machine, ultimatum game, X Prize, Y Combinator, zero-sum game

Einstein sat down in his armchair, and thought about how he would have designed the universe, to look the way he thought a universe should look—for example, that you shouldn’t ought to be able to distinguish yourself accelerating in one direction, from the rest of the universe accelerating in the other direction. And Einstein executed the whole long (multi-year!) chain of armchair reasoning, without making any mistakes that would have required further experimental evidence to pull him back on track. Even Jeffreyssai would be grudgingly impressed. Though he would still ding Einstein a point or two for the cosmological constant. (I don’t ding Einstein for the cosmological constant because it later turned out to be real. I try to avoid criticizing people on occasions where they are right.) What would be the probability-theoretic perspective on Einstein’s feat? Rather than observe the planets, and infer what laws might cover their gravitation, Einstein was observing the other laws of physics, and inferring what new law might follow the same pattern.

Albert Einstein was a great scientist of his era, but that was his era, not this one! Einstein did not comprehend the Bayesian methods; he lived before the cognitive biases were discovered; he had no scientific grasp of his own thought processes. He was too caught up in the drama of rejecting his era’s quantum mechanics to actually fix it. And while I grant that Einstein reasoned cleanly in the matter of General Relativity—barring that matter of the cosmological constant—he took ten years to do it. Too slow!” “Too slow?” repeated Taji incredulously. “Too slow! If Einstein were in this classroom now, rather than Earth of the negative first century, I would rap his knuckles! You will not try to do as well as Einstein! You will aspire to do BETTER than Einstein or you may as well not bother!” Jeffreyssai shook his head. “Well, I’ve given you enough hints.

pages: 1,263 words: 371,402

The Year's Best Science Fiction: Twenty-Sixth Annual Collection by Gardner Dozois


augmented reality, clean water, computer age, cosmological constant, David Attenborough, Deng Xiaoping, double helix, financial independence, game design, gravity well, jitney, John Harrison: Longitude, Kuiper Belt, Mahatma Gandhi, mass immigration, Paul Graham, Richard Feynman, Richard Feynman, Richard Feynman: Challenger O-ring, Search for Extraterrestrial Intelligence, Skype, stem cell, theory of mind, Turing machine, Turing test, urban renewal, Wall-E

These things never really last.’ ‘You’re right.’ She slumped back into her seat. ‘This fucking world . . . Oh, why did I come here?’ Seriantep glanced up at the inconstant lumetubes, beyond to the distant diadem of her people’s colonies, gravid on decades of water. It was a question, Fejannen knew, that Serejen had asked himself many times. A postgraduate scholar researching space-time topologies and the cosmological constant. A thousand-year-old post-human innocently wearing the body of a twenty-year-old woman, playing the student. She could learn nothing from him. All the knowledge the Anpreen wanderers had gained in their ten thousands year migration was incarnate in her motes. She embodied all truth and she lied with every cell of her body. Anpreen secrets. No basis for a relationship, yet Serejen loved her, as Serejen could love.