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Posts Tagged ‘CWJ’

Two and a Half Cultures

Recently I was in Washington, D.C., and attended a local “Science Cafe” event featuring visual artists whose art is inspired by science.  (A theme for the evening was Leonardo da Vinci, whose restless mind not only created some of the greatest art ever but also pondered flying machines, tanks, and other investigations into technology and nature. The cafe even specially created a namesake drink, a mixture of beer, vodka, and wine which didn’t taste nearly as vile as it sounded.)  Naturally the question came up of the reverse: how does art informs science?

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Slicing Through the Gordian Knot of Quantum Gravity: Alternatives to String Theory (Part 3 of 3)

Quantum mechanics is the physics of the smallest of things, while general relativity is the physics of the largest. Not surprisingly, many physicists have been obsessessed with finding a Theory of Everything (TOE) that encompasses both limits.

This has not been easy.

In previous posts I’ve written of the difficulties that arise in creating a coherent theory of quantum gravity, and how one popular approach, string theory, attempts to solve the problem. String theory is not a failure, but neither has it been the overwhelming success quantum mechanics and general relativity have been. In particular, string theory has in general failed to make verified predictions in fundamental particle physics. (NB: some of the mathematical techniques of string theory have been applied to other areas of physics, but this is not the same thing.)

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Quantum Gravity, Part 2: A Thread ( or String) Leading Out of the Maze?

A good public relations campaign can do wonders.

Science is empirical. If there is no experiment, no observation, then an idea is truly relegated to “it’s just a theory.” [1]

Yet, consider string theory, a mathematical exercise so intricate Einstein’s general relativity is easy in comparison, and with no experimental evidence backing it whatsoever.

In the popular imagination, however, string theory dominates modern physics. Popularizations of string theory have topped bestseller charts. Friends and neighbors ask me about string theory. Students tell me they want to be string theorists, even though they, along with most of the public, are unsure what string theory even is.

In this essay I’ll attempt to untangle string theory for you, explain what it’s good for, why there are such devoted proponents, and what the skeptics say. Read the rest of this entry »

The Knotty Problem of Quantum Gravity: Part 1

You may have been in this situation:

You have two friends, your two best friends, both witty, fun, and thoughtful. An hour or so spent with either one leaves your brain buzzing with new ideas and insights. “I gotta get these two together,” you think.

You arrange a dinner, but the evening is a disaster. Your friends are incompatible in ways so deep, so fundamental, they can barely stand to be in the same room.

Now imagine your friends are physics theories; and not just any theories, but the two most revolutionary theories of the twentieth century, explaining entire libraries of data, predicting new, mind-blowing phenomena. They are quantum mechanics and general relativity.

And they do not play nice with each other.

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Jabberquarky

Among the stereotyped traits of of scientists are literal-mindedness, pedantry, and most of all, a complete lack of humor. This goes doubly so for physicists and astrophysicists.

And yet… a second thought brings one to all those oddly evocative names:

The Big Bang.

Black holes.

Strange quarks.

Superstrings.

Anyons.

Other fields have their fantabulous names as well: the idea of a Velociraptor chasing you has thrilled dinophillic children for years, and who couldn’t love a gene called SonicHedgehog? But I’m going to focus on the origin of whimsical names in physics and, a bit, in astrophysics.

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The Limits of Knowledge, Part IV: Too Clever for Its Own Good

(Last in a series; see Part I, Part II, and Part III)

“Clever Hans” was a mathematician who lived a century ago. He was also a horse, a genius horse who could add, subtract, multiply, and even calculate dates, giving the answer by tapping his hoof.

But it was discovered in 1907 that Clever Hans was in fact no better at arithmetic than any other horse.  Has was just reading subtle, unconscious cues from his owner,  tapping until he reached the expected answer.

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Is science real? Is it objective knowledge of a world independent of us? Or is it just a cultural invention, an arbitrary game, something we project onto the world, with scientists tapping out results until, like Clever Hans, we get the result we unconsciously want?

Some postmodernists think the latter is true, and point to experiments swayed by unexamined assumptions, including the “Clever Hans” effect in animal intelligence experiments.   They then conclude that all science is equally rigged.

The critiques have some validity, but the examples are heavily weighted towards the sociological and anthropological sciences; that is, we easily fool ourselves concerning issues that touch upon us as humans.

But on the other end of the spectrum the story is different.  Out among the cold reaches of the galaxies and nestled in the hearts of atoms, we have found disturbing truths so contrary to human experience that they can’t be the result of some Very Clever Hans, trying to please our subconscious prejudices. Read the rest of this entry »

The Limits of Knowledge, Part III: Big Surprises in Little Packages

(Part of a continuing series: part I and part II)

I love tales of serendipitous scientific discovery. A spot of mold in a Petri dish leads to penicillin, a spill on the stovetop becomes vulcanized rubber. The true hero is penetrating curiosity: instead of dumping a ruined experiment in the trash, the keen-eyed scientist frowns and wonders: what does this mean?

Most stories of serendipity occur among test tubes and Bunsen burners, but today computers allow numerical experiments and computational “accidents.” And one of the most paradigm-shattering accidents of the twentieth century involved neither dawdling clocks moving at the speed of light, nor slippery electrons dancing around an atom, but humble calculations of the weather.

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The Limits of Knowledge, Part II: Precise Uncertainty

(Second in a series on the limits of knowledge; see the first post here.)

Of all branches of modern science, quantum mechanics is most seen as magic–either a nihilistic, quasi-Voldemortesque dark magic that needs to be overthrown, or else a wonderful wand that can be waved to justify anything, and I mean anything.

To be sure, Einstein’s relativity disquiets many people.  Without trustworthy, absolute clocks, who can boast about trains running on time?

But quantum mechanics is an order of magnitude stranger. The quantum world is fundamentally uncertain and fuzzy, with slippery wavefunctions leaping from one state to another. Even Einstein himself, who helped to father the field, hated it.

As I’ve written in an earlier post, many SF authors choose either to rebel and literally write quantum mechanics out of the equation, or to use quantum mechanics as a convenient justification for neato pseudo-scientific wish-fulfillment.

All of this is because of fundamental misunderstandings about quantum mechanics. Read the rest of this entry »

The Limits of Knowledge, Part I: Point of View

Science will not do your homework for you.

Some questions can be answered by science:  “What happens when I add an acid to a base?” and “What happens if I stick this fork into a wall socket.” Others, such as “Does God exist, and if so, why is He not running the Universe to my liking?” and “What is good? What is evil? Does this make me look fat?” can not.

In the ancient world, a business card reading “philosopher” gave one license to inquire into everything, and I mean everything. Aristotle (the Philosopher) wrote on topics ranging from ethics to politics to zoology to cosmology. For any question he had an answer.

But job descriptions change. Part of the evolution of natural philosophy, under nascent scientists such as Francis Bacon and Galileo, was to drop some questions, for example teleology (“for what purpose”), and  focus solely on reproducible, material observations.

Science is about limitations, but limitation is the source of the power of science. Indeed, the history of the physical and mathematical sciences in the twentieth century includes not only discovering the vastness of the cosmos and the infinitesimal secrets of the atom, but also making shocking discoveries what we cannot know.

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Thinking Outside Very Small Boxes

Every few years there comes from the distant Mountains of Science a new technological magic, a Panacea that will cure all ills, a Genie that will grant all wishes, a Silver Bullet that will slay all evils. In the 1950s it was nuclear power; later it was computers; later still the bounty of the Space Age; later still genetics. People still believe the Internet will make everyone fabulously wealthy for free (and yes this is a retread of computers, much as nuclear power was a retread of the idea very early in the twentieth century that Radioactivity is Good For You). And one technomagical fad still going strong in SF is nanotechnology: Teensy-Robots Who Will Turn Us All Into Gods, or Else Kill Us All.

Well, maybe.
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