College students have long been the first to jump on hot new technology: They swapped e-mails a decade before the Web went mainstream and toted MP3 players while everyone else plugged into sandwich-size Walkmans. What gives?

A reader inquires: On a flight recently, I left my cellphone on by accident,
and yet the plane did not fall out of the sky. Aren't "personal electronic
devices" supposed to be a danger to cockpit controls?

The National Air and Space Museum in downtown Washington, D.C., is the most visited museum in the U.S., but it long ago ran out of room and was forced to put many of its prized aviation artifacts -- the space shuttle Enterprise, the Enola Gay, the SR-71 Blackbird and scores of other airplanes and space vehicles -- in long-term storage, hidden in darkened hangars. Those historic airplanes are finally seeing the light of day.

Reproductive human cloning aims to make a baby. Therapeutic cloning aims to create embryonic stem cells that could be used to cure diseases or grow replacement organs. Scientists generally make a medical and ethical distinction between the two types of cloning, but John Charles Kunich and the U.S. House of Representatives do not.

Hydrogen is going to be big!

Las Vegas has an earthquake problem. Recent geologic and geophysical studies indicate that no less than eight active fault lines cut through the valley in which it sits; together they create the potential for a magnitude 6.5 or greater temblor. While no one can predict when such a quake might strike, Catherine Snelson, an assistant professor of geophysics at the University of Nevada, Las Vegas, might soon be able to predict which areas will be hardest hit when the big one comes -- a critical step in directing emergency response.

The roadblock appears out of nowhere -- two Caprice Classics aligned nose to nose across three lanes of backcountry asphalt. I have two options: Ram through the cars (and risk wrecking my own in the process) or spin around and speed away. I decide on the latter, just in time to see a third Caprice pull up alongside me. Its driver grins wickedly from behind the barrel of a Glock 9mm. I slap the transmission into reverse, stand on the accelerator pedal, and turn the wheel hard to the right. Rubber burns and tires squeal as my car careens into a 180-degree spin.

My first truly modern car was an '85 Saab 900. I know it was modern because it had a shift-up indicator light, presumably designed to help me save gas -- a yellow gearshift symbol that glowed brightly every time the revs reached about 2,500. Had I obeyed it, I'd have been motoring around like a Freightliner looking for a Hoboken loading dock.

A reader inquires: Why don't we just take all the nuclear waste, throw it into a rocket, then launch the rocket into the Sun? Would this make the Sun explode?

Professional competitive eating, like soccer, is not as popular in the United States as it is in the rest of the world, where expert gorgers compete for tens of thousands of dollars per tournament. But we are arguably a nation of amateur competitive eaters, 30.5 percent of us obese and the rest on the Atkins diet, everyone striving to eat as many strips of bacon as possible in 15 minutes. We also have an annual nationwide de facto competitive-eating event. You may know it as Thanksgiving.