Question: Our little 3-pound brains take millions of "snapshots," recording sounds, smells, tastes, time sequences, a continuous running commentary — all day, every day. You'd think overload would set in.

Answer: Maybe, except the brain has a secret: It cheats, says Harvard's Daniel Gilbert in "Stumbling on Happiness." Faithful representation like a DVD isn't the way. Ask eyewitnesses "How fast were the two cars were going when they collided?" and you'll get a different answer than if you ask, "How fast were the cars going when they smashed into each other?" In other words, the question itself helps shape our answer.

Dozens of experiments show that our brains more "reweave" experiences than "retrieve" them. Information acquired after an event can alter memory of the event. There's an economy to this as we recall the gist, then fill in the details later, possibly changing them with each retelling. For instance, we'll store in memory: "Went to dinner last week; it was disappointing," along with a few standout features: tough steak, corked wine, snotty waiter. Then when recalling the experience, we'll quickly reweave the "story" by fabricating much of it. "This happens so quickly and effortlessly, we have the illusion that the entire thing was in our heads the entire time."

Question: In the spirit of the John Lennon song, "Imagine" the Olympic Games taken to their most idealistic.

Answer: They would stress cross-cultural understanding, de-emphasizing nationalism and commercialism, says Robert B. Woods in "Social Issues in Sports" (drawing on Bruce Kidd). Athletes would compete as "global citizens," with national uniforms, flags and anthems eliminated. Sponsorship money and TV airtime would be used to promote world harmony via healthy bodies and minds.

Another idea/ideal: "Floating Olympic stadiums," already technically feasible, to be built inexpensively on "floating modules" and shipped to locations other than just the wealthiest nations (proposed by architect Michael Burt of the Israel Institute of Technology). This would help prevent the "Sydney Olympic blues," with costly villages and facilities later standing as ghost towns. Instead of being economics-driven, the Olympics would serve as a communal engine for the betterment of humankind. Make that a gold medal for us all!

Question: How might skiers caught in a down-rushing avalanche save themselves by being like a Brazil nut shaken in a container full of peanuts? What must they carry along in order to do this?

Answer: With an emergency avalanche balloon in a backpack, a skier caught in flowing snow pulls the triggering rip-cord to inflate the balloon with nitrogen gas from a cylinder, says Jearl Walker in "The Flying Circus of Physics." This draws in outside air and provides an upward buoyancy force due to the gas being less dense than the snow. Thus rising near the top of the flow like the Brazil nut in the container, skiers stand a much better chance of survival.

