Quotes of the Day

The busy mind of Newt Gingrich has been much in the news lately. He's the man of grand ideas — a thinker, a theorist, the big brain in a GOP field of bureaucrats and simpletons. Don't believe it? Don't worry; Gingrich himself will tell you.

Gingrich's mind indeed does churn. The problem is, he approaches ideas the way a gluttonous gourmand approaches food — with a rich, complex and subtle appetite but also a hopeless weakness for corn dogs and Twinkies. If it's edible — or, in his case, imaginable — he's interested. This can be awkward, particularly when he steps outside his comfort zone of history and public policy and starts to muck around with science.

Much has been made of some of Gingrich's wackier ideas in the past few weeks, beginning with his oft repeated worry that a rogue state with a nuclear weapon could shut down the U.S. power grid. To give Gingrich his due, there's a grain of truth in his fears. Scientists agree — theoretically, at least — that a missile detonated at the right altitude could trigger what's known as an electromagnetic pulse (EMP) that could fry the circuits of whatever country lay below. The one experiential data point that supports this idea occurred in 1962, when an atmospheric test of an American atomic weapon caused street lights in Hawaii to go temporarily dark.

Of course, it's a big step from that to shutting down an entire country, especially when the bad actors Gingrich imagines blacking out America are the Iranians and North Koreans, who have nowhere near the missile technology or targeting know-how to pull off such a stunt — at least without being detected — and in the case of the Iranians, don't even have a bomb yet. What's more, if either country did want to launch a strike, it would be a whole lot easier to go the point-and-shoot route: pick a city and try to take it out directly. Yet Gingrich has continued to sound the EMP alarm, arguing that preparing for such an attack should be an important part of the country's defense posture.

"In theory, a relatively small device detonated over Omaha would knock out about half the electricity generated in the United States," he warned in Iowa last week, according to the New York Times.

Gingrich's advocacy of space mirrors — albeit years ago, in a 1984 book — has provoked an eye roller too. The thinking is that scientists could position giant mirrors in space that would point toward Earth, reflecting sunlight downward and creating as much illumination as several full moons. This would eliminate the need for nighttime lighting on highways and serve as a deterrent to crime by brightening shadowy neighborhoods.

Put aside what this would do to the day-night cycle under which all life on Earth is accustomed to operating; put aside what it would do to the simple business of looking up and trying to see a star. The technical obstacles are dizzying. The U.S. has already orbited one whopping-big mirror — a slab of polished glass inside the Hubble Space Telescope that measures close to 8 ft. (2.4 m) in diameter. But reflective space mirrors would have to be far bigger, perhaps the size of a football field. Even the massive International Space Station, which measures 357 ft. (109 m) across, appears to be little more than a moving star at the lowest point of its orbit, 234 miles (376 km) above ground. To provide permanent illumination to a target area, you'd have to position your mirrors a whole lot farther away — in geosynchronous orbit, 22,236 miles (37,786 km) above sea level, so that their rate of revolution would match the rotation of the globe.

The weight problem alone makes this impossible — at least if you are trying to fly a giant mirror made of glass, like the Hubble's. While University of Arizona engineers have developed mirror material only 0.04 in. (1 mm) thick, this doesn't address other problems, like the cost of launching and maintaining the mirrors, not to mention keeping so big a target safe from meteors and other space debris. All of this seems to be an awful lot of trouble to go to for an illumination problem that highway lights and porch lamps already solve rather neatly.

It's Gingrich's advocacy of moon mining, however, that is getting the most attention — and drawing the most derision — partly because it's a drum he doesn't seem willing to quit banging. For the most part, the moon is a pretty prosaic mix of very familiar materials, including silicon, iron, calcium, aluminum, potassium and phosphorus. There is, however, also helium-3. A light isotope of common helium, helium-3 streams toward Earth all the time as part of the storm of charged particles coming from the sun, but our planet's magnetic field deflects most of it. This is not so on the moon, which has a magnetic field far weaker than Earth's. What makes this important is that helium-3 also turns out to be a crackerjack fuel for fusion reactors — far more efficient than the deuterium currently used. But it's not just a matter of going to the moon, scooping up what you need and powering the world on it.

First of all, a practical fusion reactor has not yet been invented, and there's no realistic projection for when one might be, though scientists have been trying for decades. What's more, the moon's helium-3 is not just there for the taking. Apollo samples revealed that the isotope is present in lunar soil in concentrations no greater than 30 parts per billion. Harrison Schmitt, the lunar-module pilot on Apollo 17 and the only geologist to walk on the moon, estimates that it would take 220 lb. (100 kg) of helium-3 to power a city the size of Dallas for one year and that to collect that much, you'd have to dig a trench 0.75 miles square by 9 ft. deep (1.9 sq km by 2.7 m).

That's a lot of digging, and it doesn't even touch the cost of getting the stuff home. Even aboard cheap rockets like the Russian Proton, it costs $2,200 to launch a pound of payload to low-Earth orbit. The shuttle, nobody's idea of a bargain ship, cost $8,100 per lb. Things are a lot cheaper on the moon, where lower gravity means everything weighs less, but that doesn't mean every ounce doesn't cost a lot. There's a reason the skin of the Apollo lunar module was no thicker than three sheets of aluminum foil and that its windows were triangular — a shape that shaved a few ounces off the framing and sealant that would have been needed for round windows of approximately the same size.

In the latest presidential debate, Gingrich responded to Mitt Romney's criticism of the moon-mining concept by not responding. "I'm happy to defend the idea that America should be in space and should be there in an aggressive, entrepreneurial way," he said — which most people agree with and which is not what Romney was questioning at all.

Answering evasively, of course, is what politicians do, as is dreaming big dreams of New Frontiers and Great Societies and shining cities on hills. But dreams aren't science — and politicians, for the most part, aren't scientists. Newt Gingrich may play one on TV, but that doesn't mean anyone is required to listen.

• Jeffrey Kluger