I study a theory called N=4 super Yang-Mills.
When I say this to someone, I have a pretty good idea of how the conversation will go. First, the person will spend a few moments trying to pronounce the theory’s name. Giving up, they'll then try to bring things back to something they’ve heard of.
“N=4 super… umm… so, is that something they’re testing at the Large Hadron Collider?”
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On the evening of Wednesday, March 23, 1983, Ronald Reagan delivered a televised address about defense and national security. “Let me share with you a vision of the future,” the president began in what was a last-minute addition to the half-hour speech. In Reagan’s vision, we would “embark on a program to counter the awesome Soviet missile threat with measures that are defensive.” It was the first mention of Reagan’s Strategic Defense Initiative (SDI), the plan to change America’s nuclear posture from offensive to defensive. His goal was to render the Soviet nuclear weapons “impotent and obsolete.”
Reagan’s admirers praised SDI while his critics scoffed, calling it a fantasy and assigning it the enduring nickname “Star Wars.” The Soviet Union found itself in the rare position of joining Reagan’s admirers—they had to take SDI more seriously. Soviet leaders feared it was an American plot to disarm their nation or surreptitiously put a battle station in orbit. Reagan's plan naturally compelled them to act.
The Soviet response was a hushed effort that came with the potential to roar. Leadership fast-tracked a space weapons system they hoped would disable US anti-missile satellites. The gist of this plan? The Soviets would use their own space program to launch weapons into orbit: nuclear missiles and lasers.
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There has never been anything like the Saturn V, the launch vehicle that powered the United States past the Soviet Union to a series of manned lunar landings in the late 1960s and early 1970s. The rocket redefined "massive," standing 363 feet (110 meters) in height and producing a ludicrous 7.68 million pounds (34 meganewtons) of thrust from the five monstrous, kerosene-gulping Rocketdyne F-1 rocket engines that made up its first stage.
At the time, the F-1 was the largest and most powerful liquid-fueled engine ever constructed; even today, its design remains unmatched (though see the sidebar, "The Soviets," for more information on engines that have rivaled the F-1). The power generated by five of these engines was best conceptualized by author David Woods in his book How Apollo Flew to the Moon—"[T]he power output of the Saturn first stage was 60 gigawatts. This happens to be very similar to the peak electricity demand of the United Kingdom."
Despite the stunning success of the Saturn V, NASA's direction shifted after Project Apollo's conclusion; the Space Transport System—the Space Shuttle and its associated hardware—was instead designed with wildly different engines. For thirty years, NASA's astronaut corps rode into orbit aboard Space Shuttles powered by RS-25 liquid hydrogen-powered engines and solid-propellant boosters. With the Shuttle's discontinuation, NASA is currently hitching space rides with the Russians.
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Over the past couple of weeks, Ars has started receiving e-mails about a topic that doesn't really fit into our normal areas of coverage: homeopathy. The belief that the administration of nothing more than water can have a medicinal affect certainly isn't technology, and it only peripherally touches upon science, in the sense that any health benefits it provides seem to involve the placebo affect. Nevertheless, many of the practitioners of homeopathy have tried to claim the mantle of science, creating scientific-sounding explanations for "water memory"—the idea that a substance can actually gain potency as it is diluted out of existence. These practitioners even formed a peer-reviewed journal to discuss their findings. Six years ago, the journal Homeopathy ran a special issue on these explanations, and the Ars writers teamed up to tackle the bizarre distortions of science that it contained. So in honor of World Homeopathy Week (which we just received a press release for), we're going to run an updated version of that story. Not because we think there's a value in talking about homeopathy. Rather, by scientifically evaluating homeopathy's attempts to sound scientific and revealing it to be nothing more than "pseudoscience," we think it's possible to learn something about the scientific process and the reasoning that drives it. In turn, we can possibly learn to recognize other areas where scientific reasoning has ended up on the rocks. This feature was originally published on September 11, 2007.
Science can be a tricky thing to define, and it's sometimes easier to contrast it with some of the arguments that pose as science. Unfortunately, most of those issues are entangled with implications that keep the basic question—is this science?—obscured by emotional responses. Thus, the science of climatology has become entwined with political, economic, and policy issues. The science of evolution conflicts with the political and religious goals of some individuals. Even basic scientific questions about the nervous system get embroiled in family and personal health issues when topics like autism and radio frequency radiation are broached.
That's why a special edition of the journal Homeopathy appears to be a gift, allowing us to look at science and pseudoscience without getting entangled with politics and religion. Homeopathy claims to be a form of medical practice that's based on the principle that "like cures like." Given a set of symptoms, a homeopath will identify an herb or chemical that causes similar symptoms. Following a predefined ritual, the homeopath performs a series of dilutions of that chemical that continue well beyond the point where there should be no molecules of it left—the final solution is essentially well-shaken water.
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Occasionally, we here at Ars like to nerd out about things that aren't smartphones, processors, or dark matter. For a few of us on staff, one of those nerdy pastimes involves the plant biology that is literally right in our backyards. People pick up gardening for numerous reasons, but one reason I got into it was because of the science. There's so much to learn about plant biology when you go hands-on, even at a small scale. I grow a lot of stuff in my Chicago garden, and while not everything is a success, it provides great opportunities to learn and iterate.
But not a lot of people are into gardening, relatively speaking. Or so I thought—when I semi-jokingly tweeted that I would begin making garden posts here on Ars, the response was overwhelmingly positive. So we thought we would experiment with a weekend feature on cloning plants to get things started.
Tomatoes are some of the most popular fruits to grow at home, and they're my personal favorite as well. Depending on where you live, you might have a long enough growing season to get back-to-back plantings going, and it's not always fun to start from seed. Or you might want to give away some plants to friends and neighbors. You might even have a friend who grows amazing tomatoes and you want one of those for yourself.
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You've seen the video, right? An image of what looks like an azure-colored metal floor plate appears, backed by some "Streets Have No Name" guitar knock-off. A mysterious hand is getting ready to soak this thing with a squeeze bottle full of water, but the first squirt yields puzzling results. Water beads up and shoots off the surface, leaving the plate bone-dry. Then the title: "What is Ultra-Ever Dry?"
That sequence has played out nearly two million times through YouTube (it's literally more popular than some official Justin Bieber offerings). The video is an endless cycle of items shrugging off water, mud, oil, dirt, paint, and other stickiness with eye-popping ease. Ultra-Ever Dry claims to be a "revolutionary super hydrophobic coating that repels water and refined oils using nanotechnology." Clearly, either the company has made a pact with the devil and gained supernatural powers, or it's got some awesomely talented materials people.
We were just as amazed as most of you were, and we knew we had to try this stuff out. Two hundred dollars and one expense report later, I had a box full of Ultra-Ever Dry cans sitting on the floor of my office, ready to be applied to things various and sundry.
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Though the day dawns cool, the deck of NASA's Neutral Buoyancy Laboratory (NBL) remains warm—a side effect of keeping 6.2 million gallons of water at a constant 86°F. I stare down into the largest indoor body of water in the world and feel a surge of vertigo. Here, astronauts practice for spacewalk missions at the International Space Station (ISS), and today I'll watch them do it.
The pool measures 202 feet long, 101 feet wide, and 40 feet deep, extending 20 feet down from the elevated deck and then an additional 20 feet below the floor level. Its wall and floor are white, though they're smudged and darkened from years of repositioning model test stands. Spread throughout the water are life-sized component mock-ups of the ISS, looking exactly like some giant child's Tinker Toy set. Refraction causes the perspective to bend sharply away until it's obscured by the reflection of the ceilings and walls.
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Are we alone in the Universe? For years, people have been making predictions, many using the Drake equation. That involves the use of various educated guesses about the frequency of planets, how many are habitable, and so on. Until about a decade ago, most of the values in the equation remained just that, however: guesses.
In the last dozen years, we've witnessed an amazing transformation in science and appear to be on the verge of several more. The existence of planets orbiting other stars—exoplanets—has gone from a hypothetical to a reality. We've now got a catalog of thousands of potential planets. In many cases, we even have an idea about their size, composition, and temperature. Some of them orbit stars that are, in galactic terms, right next door.
The result has been an incredible buzz of information—over the course of this winter, there were a series of updated estimates on the number of planets in the galaxy (answer: lots) along with various ways of slicing and dicing the numbers. How many Earth-like planets? How many orbiting stars like our Sun? In every case, the numbers were staggeringly large, with the possibility Earth could be one of millions, if not billions, of similar planets in our galaxy alone.
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This week, Japanese researchers announced that they have at last secured video footage of a giant squid in its natural habitat more than 2,000 feet below the surface of the Pacific Ocean.
News accounts naturally went for the "kraken" headlines. "The Kraken wakes: first images of giant squid filmed in deep ocean," wrote Reuters, while the New York Post adopted the variation "The kraken lives! Giant squid captured on film for first time."
Well—this "kraken" may have been captured on film for the first time, but writers have been writing about it since writers could write, and they have had plenty to say. Some of it has even been accurate.
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In our first installment, we wrote several programs that really did nothing more than illustrate a concept. Let's turn the complexity up a notch and compose a program that actually solves a problem. The problem we are tasked with: given the high temperature of the past three days, compute the average and standard deviation.
To do this, we are going to need to implement an algorithm, the programming equivalent to a set of directions. It gives the major steps that one must take in order to solve a problem, but the details of how are left up to the programmer who implements the algorithm. For our problem at hand, we could write out our algorithm as follows:
So, let us set out to implement our remedial algorithm in MHF:
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