"The first man I saw was of a meagre aspect, with sooty hands and face, his hair and beard long, ragged and singed in several places. His clothes, shirt, and skin were all of the same colour. He had been eight years upon a project for extracting sunbeams out of cucumbers, which were to be put into vials hermetically sealed, and let out to warm the air in raw inclement summers."
– Jonathan Swift, Gulliver’s Travels (1726)
The image of the mad scientist has a long pedigree in western culture. It’s there in Swift’s satire of the experiments conducted by members of London’s Royal Society in the early 1700s. There it is again, a century later, in the figure of Victor Frankenstein and then another century later with Rotwang, the crazed genius of Fritz Lang’s Metropolis. More recently, Christopher Lloyd offered a benign version as Doc Emmett Brown in the Back to the Future franchise.
I’m not sure that last week’s vote to strip Pluto of its planetary status necessarily helped matters.
More than 2400 members of the International Astronomers’ Union (IAU) had gathered in Prague for their triennial general assembly. After much discussion and debate at the final session last Thursday they passed a resolution designed to clarify the scientific definition of a planet. "A planet is a celestial body," the resolution declared, "that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit."
This was bad news for Pluto, which fulfilled the first two criteria (it goes round the Sun and it’s ball-shaped) but not the third (it shares its orbit with a lot of other space stuff). As a result, even if this had not been the IAU’s intent, Pluto is no longer our Solar System’s ninth planet; instead, it is now a "dwarf planet" (surely an oxymoron), a status it shares with possibly hundreds of other orbiting spheres.
Pluto may count itself as unlucky. Only a week before the crucial vote, some members of the IAU had proposed a looser definition that did not include the "clear the neighbourhood around its orbit" provision. Had this resolution passed, not only would Pluto have been saved but three more bodies — Pluto’s companion Charon, Ceres and 2003 UB313 (aka Xena) — would have been declared bona fide planets.
Alternatively, Pluto might consider itself fortunate that it has been called a planet for as long as it has. Discovered only in 1930, Pluto’s precise nature has always been difficult to pin down. Originally, scientists believed the new discovery to be roughly the size of Earth, and christened it a planet as (a) this seemed only fair and (b) there was no other suitable word. Since then, however, Pluto’s size has been dramatically reassessed. Its diameter (2,300 km) is less than one-fifth that of Earth’s (12,750 km), while its mass is just one-fifth of the Moon’s.
There are other, more technical, reasons for doubting Pluto’s claim to true planethood. For one thing, while the other eight planets orbit on more or less the same plane (level with the Sun’s equator), Pluto’s orbit is tilted by 17 degrees. And then there’s the question of composition. Pluto consists mainly of rock and ice, which sets it apart from the four "terrestrial" planets (Mercury, Venus, Earth, Mars) and the four "gaseous" giants (Jupiter, Saturn, Uranus, Neptune). In short, it just doesn’t seem to fit in.
It’s no surprise, then, that many astronomers came to believe that it had been a mistake to designate Pluto as a planet in the first place. In 1999, the IAU toyed with the idea of recasting Pluto as a "minor planet" but backed down in the face of opposition. Doubts remained, however, and fully resurfaced at last week’s gathering. This time, by redefining the nature of a planet, the IAU was able to downgrade Pluto without specifically targeting it. Nicely done.
So what? "The public is not going to get excited by the fact that Pluto has been kicked out," said CalTech’s Mike Brown shortly before last week’s vote. "For astronomers, this doesn’t matter one bit. We’ll go out and do exactly what we did." Others agree, feeling that the change in classification is mostly irrelevant. "Pluto — and all Solar System objects — are mysterious and exciting new worlds that need to be explored and better understood," echoed Louis Freidman of the Planetary Society in California.
Well, maybe… but maybe not. Is there really a "need" to explore Pluto, especially now that it is no longer planet number nine but only a small lump of rock? After all, not only is Pluto tiny, but it’s also very remote. At almost 6 billion kilometres from the Sun, Pluto is 1.5 billion km beyond its nearest planetary neighbour Neptune. Such vast distances make exploration difficult. Previous planned missions to Pluto have been scrapped on three occasions, while the most recent — the New Horizons probe launched in January this year — will not approach the planet (sorry, dwarf planet) until 2015.
And what will it find? Pluto’s atmosphere consists mainly of nitrogen, methane and carbon monoxide — think of a big, poisonous fart — while its surface temperature is approximately -2300C (a big, cold poisonous fart). "Mysterious and exciting"? Not so sure about that.
But then last week’s IAU vote was not really about Pluto, but about how science reaches new consensus. And it’s that aspect of the Prague gathering that raises the spectre of the mad scientist.
By the time the vote was taken on Thursday, only 424 of the original 2400 or so delegates remained to participate. And rather than conduct a secret ballot, the assembled scientists instead sat in an open auditorium and voted by raising a yellow card. No official count was recorded, such was the strength of support for the resolution. But wait. Those who did vote represented only a handful of the world’s 10,000 or so professional astronomers. "I’m embarrassed for astronomy," said Alan Stern, leader of the New Horizons project, in response to the decision. "Less than five percent of the world’s astronomers voted."
Even had more shown up, it still seems doubtful that such matters can or should be determined by a simple show of hands. Maybe the small things in life — what’s for dinner, who’s the next Canadian Idol, who should run the country — can be decided in this fashion, but should major shifts in scientific knowledge? Photos of the Prague vote — showing grim-faced elderly men and women, raising their cards like so many old-time trade unionists — sit ill with the basic principles of the scientific method (Observe-Hypothesize-Test-Conclude-Repeat).
And what of those who voted against the resolution, who defended Pluto’s claim to be a planet? Are they simply wrong? Is their science inferior? Will they now accept the newly imposed order of the universe? Probably not, for already there is talk of a petition and a counter-campaign to reinstate Pluto.
Ah, those crazy scientists…. |
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