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Terrorism

Conventional wisdom: A nuclear attack is the biggest terrorist threat we face.

The hard science: Making a nuclear bomb is excruciatingly difficult. North Korean leader Kim Jong Il spent billions making one—starving his people in the process—and even his bomb fizzled. When it was tested in 2006, it released the energy equivalent of about half the jet fuel of each of the planes that crashed into the World Trade Center towers.

But even if a nuclear bomb fizzles, can’t it spread deadly radioactivity? And what about a “dirty bomb,” a smaller weapon specifically designed to do just that? This threat is also mostly exaggerated. In reality, a dirty bomb would leave very few immediate casualties. That’s because radioactivity, once spread after an explosion, drops below the threshold for radiation illness. A dirty bomb might not even cause an observable increase in cancer rates. Perhaps that’s why al Qaeda instructed Chicago gang member José Padilla to abandon his goal of making a dirty bomb and told him instead to blow up apartment buildings using natural gas—which would have a greater chance of killing a large number of people. What is most scary is that al Qaeda seems to understand this fact better than many politicians.

Message for Obama: Many people may worry most about the drama of nuclear terrorism, but as 9/11 showed, it’s far easier for terrorists to inflict massive damage with commercially available explosives such as jet fuel or gasoline.

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Energy

Conventional wisdom: Big oil companies are behind our addiction to fossil fuels. If we could break their grip, we would have energy from other sources, such as hydrogen and high-tech batteries.

The hard science: Our gasoline addiction is based in large part on physics and chemistry: Gasoline contains, pound for pound, 15 times more energy than TNT.

But doesn’t hydrogen have even more energy? Yes, per pound, but not per gallon. That’s because a pound of hydrogen takes up a lot more space than gasoline. Even as a liquid—its densest form—it has only one fourth as much energy per gallon as gasoline. And that liquid has to be kept at a very inconvenient -253 degrees Celsius (-423 degrees Fahrenheit). Moreover, hydrogen is not a source of energy, because we can’t mine it; we have to manufacture it either by electrolysis (running an electric current through water to get the H2 from H2O) or from natural gas. Hydrogen is only a means of transporting energy, not an energy source in its own right.

What about high-quality batteries—the kind used in cellphones and laptops? These batteries contain only 1 percent of the energy of their equal weight in gasoline. You can recharge them cheaply, but current batteries typically die after 1,000 charges. If you include the cost of replacement, then they are far more expensive to use than gasoline, though a bit less harmful to our atmosphere.

Message for Obama: The biggest source of clean, cheap energy is energy not used. And conservation doesn’t have to be uncomfortable. Tell people they can turn up their thermostats to any temperature they like, but encourage them to make sure there is some good (and it can be cheap) insulation in the walls of their homes.

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Nuclear Energy

Conventional wisdom: Nuclear power would be great if only we could figure out how to get rid of the horrific waste. Plutonium lasts 24,000 years. There is absolutely no way we can keep that waste safe for such a ridiculously long time.

The hard science: Yes, plutonium has a half-life of 24,000 years, but it is so insoluble in groundwater that most experts agree it is easy to store safely. Additionally, plutonium can be reprocessed for use as fuel in reactors—that’s what France does. The real worry about nuclear waste is the other radioactive elements involved in the process.

How bad is this other waste? The U.S. government has put fantastic restrictions on allowed levels of nuclear leakage. Nevada’s Yucca Mountain nuclear waste storage facility, for example, is required to demonstrate that people living downstream, and drinking all their water from underground wells, will not get more than 15 millirems of radiation exposure each year from leakage. To put that number in perspective, those same people will get an average of 350 millirems per year from nature and typical medical procedures.

It’s true that after 300 years, nuclear waste is still about 100 times more radioactive than the original uranium that was removed from the earth. But even this isn’t as scary as it sounds. If the waste is stored underground in such a way that there’s only a 10 percent chance that 10 percent of it will leak—which should be more than doable—the risk will be no worse than if we had never mined the uranium in the first place.