Saturday, February 26, 2011

We May Be Martians

It's possible that all lifeforms on Earth are descended from very distant ancestors that lived on Mars. If Mars was once a warm and wet place, then it could have provided the conditions for life to arise just as well as Earth did. There could have been an independent origin of life on Mars, several billions of years ago, that led to simple, unicellular organisms inhabiting niches across the Martian surface. These organisms, of course, would need to be transported to Earth intact for this theory to hold.

This is where meteorite impacts come into play. It turns out that numerous meteorites have been found in Antarctica that were originally from Mars. An interplanetary rock swap like this can happen when a huge object—like an asteroid or comet—impacts a planet and blasts pieces of its surface into space. Our own moon was formed this way, according to the prevailing hypothesis. Alas, these surface fragments are sent on all sorts of trajectories around the Sun, some of which may eventually cross paths with Earth. If any Mars rocks are large enough to survive entry into Earth's atmosphere, they hit the surface and are thus known as meteorites.

We can be confident these meteorites are from Mars because scientists have analyzed the composition of air bubbles inside them, bubbles that were formed during the catastrophic impact event on Mars. These bubbles are made of the same gases, in the same proportions, as the Martian atmosphere.

The rest of the story explains itself. It's reasonable to question whether lifeforms could survive a catastrophic blast into space, an interplanetary transit of perhaps millions of years, the descent through Earth's atmosphere, and the impact with Earth's surface. What we do know is that many lifeforms on Earth, known as extremophiles, can evolve and thrive in incredibly hostile environments. So there's a chance, albeit a remote one, that we are all Martians. 

Tuesday, February 22, 2011

The Impressionist Effect

Impressionism seeks to accomplish something photography can't. It offers an impression of a scene—the feeling of a mere glance. When you glance at a scene in the real world, your mind does not have time to register the details. What is memorable is the general color scheme and the feelings that are associated with it. In an Impressionist painting, the details of a scene are conveyed in a way not unlike the mind's recording of a momentary glance. A painting is static; it allows the viewer time to seek out the details. But unlike a photograph, Impressionism doesn't convey details. It forces the viewer to experience the feeling of a mere impression—no matter how long he stares at it—and this is why it can do something photography can't.

Brush strokes of the Impressionist artist Berthe Morisot
The brushwork of the
 Impressionist Berthe Morisot
The invention of the camera had a dramatic effect on art because it suddenly could record the world better than even the greatest artists. It led to something of a new purpose in art, but the art establishment would resist this at first. In 1872 the French painter Claude Monet titled a work Impression, Sunrise. Critics mocked the painting as an unfinished sketch, labeling Monet and similar artists derisively as impressionists. But Monet had no reason to "finish" his paintings; he knew what he was doing and what effect he was trying to create.

Artists create the Impressionist effect by using solid, visible brush strokes of alternating color. You know you are looking at pure Impressionism when these brush strokes dominate the entire composition. There is no attempt to hide the strokes because the details of the subject are not important. The mind is what mixes colors together and forms patterns. The emotional response to viewing an Impressionist painting will depend on the viewer's past experiences—it will more strongly evoke the feelings of actually being there than a photograph will. The subconscious seems to quickly uncover a photograph's true nature, but all too often it is fooled by a good Impressionist painting.

Saturday, February 19, 2011

Review: The Handmaid's Tale

Margaret Atwood's The Handmaid's Tale is perhaps strongest in its aesthetic descriptions of life in the Republic of Gilead, a dystopian society set in New England. Gilead is a nation of biblical austerity, which fosters a sort of quasi-romance among the characters between episodes of brutality and oppression. The story warns of the dangers of extremism—of all types—because Gilead is exactly that: a backwards theocracy with a taste for the Old Testament.

The Handmaid's Tale by Margaret Atwood bookRead more reviews on AmazonThe writing style of The Handmaid's Tale is informal; relaxed sentence structures and quirky punctuation may distract some readers at first, but probably won't further into the novel. Atwood's use of the stream of consciousness mode seems to work well as a means of exposing the story's background.

The author's explanation of how this republic came about—through a military coup led by Christian extremists—is not particularly convincing; it may have been a stronger novel without the attempt to connect all the dots between 1980s America and Gilead. Some "historical notes" on Gilead serve as an epilogue to the story, but they are laced with dated political commentary. The strongest of which is probably the environmental cautions on nuclear and other toxic waste, which cause widespread infertility for the women in the novel.

The protagonist's abandonment of all resistance toward the end of the story cannot be admired, but it's worth noting that literature need not be inspirational or didactic—the characters in The Handmaid's Tale are not ideal but they are believable.

Wednesday, February 16, 2011

The Space Shuttle Is Not Economical

The American physicist Gerard K. O'Neill wrote a book in the late '70s about how we could construct enormous rotating space colonies and launch a huge fleet of solar power satellites. He was imagining that the Space Shuttle would launch from 60 to 120 times a year, with a cost as low as $10 million per flight. As it turned out, we never launched more than 9 shuttles in one year and it ended up costing more like $500 million per launch. This cost is well over a billion dollars each flight if one considers program costs like the design, construction, and upgrading of the shuttles. How did we go from O'Neill's lofty vision to the current state where we're lucky to get four launches in a year?

Space Shuttle orbiter landing on runway
The stylish but expensive orbiter
Part of the problem is that NASA has tried to push the reliability of the shuttle to an extreme. To return to Earth successfully, the shuttle must get through the launch phase in pristine condition. Yet it is not placed at the safest spot of the bundle of rockets that carry it into space: the top. Instead it's attached to the side, in the path of debris falling off the external tank—the large red fuel tank in the center of the bundle. The shuttle's design is unnecessarily complicated and risky, and it's impractical to make this shuttle safer than a simpler capsule. NASA tries to, though, by spending a fortune tightening every bolt.

The shuttle is also notorious for launch delays. There are simply too many valves, sensors, and seals that can fail, and NASA won't launch if any of them do. This is to say nothing, of course, of the years the shuttles were completely grounded. They didn't fly for 975 days after the loss of Challenger, and 907 days after Columbia. We should consider the Space Shuttle's cost and schedule performance before committing to any similar launch scheme.

Saturday, February 12, 2011

No Such Thing as Supernatural Phenomena

The world of ideas is cluttered with nonsensical references to supernatural and paranormal events. While some of these hypothetical events cannot be disproved, it makes no sense to refer to them as supernatural. If they are more than just imaginary, then they are detectable through measurement. If they are impossible to measure, then they are not events or phenomena and are merely imaginary.

For example, an alien spacecraft either crashed near Roswell, New Mexico in 1947 or did not. If one did, it would have been possible to observe the spacecraft physically—by viewing light reflected off of it, or perhaps by analyzing its wreckage and impact crater on the ground. Evidence of a particular phenomenon may be difficult to detect and interpret, but it nonetheless must exist. If we detect no evidence of a spacecraft near Roswell, it would mean one of two possibilities—that no spacecraft landed in 1947, or that one did land but the evidence is too subtle for us to understand. What makes no sense is to say that a spacecraft did crash, but that no evidence exists in the physical universe.

When a scientific theory fails to explain strange phenomena, then it is not a good theory. But the natural world is far weirder than anything ever imagined by theologians, psychics, witch doctors, or UFO hoaxers. Physicists have observed phenomena on the quantum scale that eludes all human intuition, and the same is true about very large scales. Just because something is weird does not mean it is supernatural.

Wednesday, February 9, 2011

Review: Resurrection

Piero della Francesca's Resurrection shows that the Renaissance was in full swing by 1460. In this work the viewer has no trouble perceiving depth, due in part to Piero's mastery of perspective. Piero is known today as an Italian painter, but his interests in his own time extended to mathematics—especially geometry. His concern with geometry can be seen in the triangular arrangement of the sleeping soldiers and Christ, and also in a book Piero wrote around 1480 on how to achieve perspective using line and color.

Resurrection by Piero della Francesca art
We can further note the influence of Renaissance culture in the subjects of the painting. You would be hard-pressed to find a medieval painting that depicted people resting so naturalistically, especially alongside the figure of Christ. Resurrection shows the dual concerns of the earthly and the "divine" that characterized the Renaissance. Artists tormented themselves trying to reconcile human life with the promises of Christianity, and Piero's work demonstrates this very struggle. It is commonly said that the sleeping figure whose head intersects Christ's flag pole is a depiction of Piero himself. If so, this contact could represent Piero's desire to connect with the divine and personally experience the rebirth of Christ's resurrection—a rebirth shown in the trees and foliage of the painting as one looks from left to right.

The figure of Jesus in Resurrection appears unduly muscular and flashy. He pauses to stare straight ahead, his leg propped, almost arrogantly, on his defeated sarcophagus, his arm holding in triumph the banner of the Pope. This contrasts with my impression of a more humble Jesus, one without concern for ostentatious displays. Aldous Huxley, writer of Brave New World, compared Christ's figure in Resurrection to that of a Greek athlete and noted his "physical and intellectual power." I'm not sure why Piero depicted Christ as such, as Jesus's power seemed to be neither physical nor intellectual.

Sunday, February 6, 2011

Earth-like Exoplanets Are Hard to Detect

Recent discoveries of exoplanets, or extrasolar planets, suggest that they are common in the universe. For these planets to have life—at least life as we know it—they need to be quite similar to Earth. Planets larger than Earth often have enough gravity to retain thick and crushing atmospheres, while planets much smaller than Earth would let atmospheres escape into space. Assuming a planet had the proper size, it could probably only harbor life if it was in its star's habitable zone—the band of space around a star where temperatures would be suitable for liquid water.

Artist conception of exoplanet Kepler-10b
Artist's rendering of the exoplanet
Kepler-10b 
Thus the search for exoplanets is focused on Earth-like planets within their star's habitable zone. The methods of detecting exoplanets, however, are biased in favor of large planets that orbit close to their star; these kinds of planets are often called "hot Jupiters" because of their size and scorching proximity to their suns.

Hot Jupiters, which are not likely to have life, are commonly discovered because it is much easier to detect an exoplanet indirectly—by its effect on its star—than through a direct observation. In one method, astronomers look for a wiggle in a star's location that could only be caused by the gravitational influence of planets. Contrary to common vernacular, planets don't orbit stars. Instead, both planet and star orbit their collective center of mass. Since stars are very massive, they move only slightly compared to their planets. Astronomers can pick up on this movement and infer the presence of planets—but only if the planets are large and close enough to significantly influence their star. Smaller and more distant planets are less likely to be detected.

Another indirect method of detection is called the transit method. It watches for planets that transit, or pass in front of, their parent stars. Astronomers can't see the planets in detail, but they measure the reduction in brightness of the star being transited. Larger reductions mean larger planets. The transit method is quite capable of finding Earth-sized planets, but it still is better at finding those that orbit close to their suns. The problem is that it requires a solar system's orbital plane—the plane in which planets orbit—to be near perfectly aligned with Earth's line of sight. Only in this condition would a planet transit its star from our point of view. The further out a planet orbits, the more perfect this alignment must be. Since all these detection methods favor finding hot Jupiters, Earth-like exoplanets in the habitable zone should be even more common than our discoveries suggest.

Wednesday, February 2, 2011

Economic Intervention

There seem to be two justifications given for a government to intervene in a market economy. It's worthwhile to distinguish between them. Before you can consider whether the government should intervene, you need to know the goal of the intervention. The enforcement of contracts and the resolution of fraud don't count as interventions because they are the basis of a market economy.

The first justification is a matter of national survival and well-being. During the Second World War, the U.S. government offered contracts to Detroit-based automakers to produce tanks, airplanes, and armaments. Everyone understood that the reason was national survival. The same could perhaps be said about the Apollo Program, so far as it helped America compete in the Cold War. The same, in fact, is behind monetary policy—which is concerned with stabilizing the money supply—and stimulus packages, which are aimed at accelerating an economic recovery. And the same is the goal of some policies on environmental protection. These efforts are designed to preserve the nation and promote its well-being, so there should be little surprise that mainstream political parties can find common ground on such issues.

Politicians follow party lines much more consistently when the other justification is offered—the justification of fairness. The debate on economic fairness is based much less on practicality and survival, and much more on one's moral sentiments. People can reason with each other as to what economic arrangement will best ensure national prosperity, but there is simply no way to use logic to reconcile different opinions on economic fairness. These moral sentiments stem from our biology, and they manifest themselves differently in different people. For this reason people have debated economic fairness—without success—since time immemorial. It would help elucidate our political discussions if people identified the goal of potential economic intervention.