C: How do they know the load limit on bridges, Dad?
D: They drive bigger and bigger trucks over the bridge until it breaks. Then
they weigh the last truck and rebuild the bridge.
C: Why does the sun set?
D: It's because hot air rises. The sun's hot in the middle of the day, so it
rises high in the sky. In the evening then, it cools down and sets.
C: Why does it go from east to west?
D: Solar wind.
C: Why does the sky turn red as the sun sets?
D: That's all the oxygen in the atmosphere catching fire.
C: Where does the sun go when it sets?
D: The sun sets in the west. In Arizona actually, near Flagstaff.
C: Oh.
D: That's why the rocks there are so red.
C: Don't the people get burned up?
D: No, the sun goes out as it sets. That's why it is dark at night.
C: Doesn't the sun crush the whole state when it lands?
D: Ha ha, of course not. Hold a quarter up. See, the sun's just about the
same size.
C: I thought I read that the sun was really big.
D: You can't believe everything you read, I'm afraid.
C: So how does the sun rise in the east if it lands in Arizona each night?
D: Well, time for bed.
C: Dad, how come old photographs are always black and white? Didn't they
have color film back then?
D: Sure they did. In fact, those old photographs ARE in color. It's just the
WORLD was black and white then.
C: Really?
D: Yep. The world didn't turn color until sometime in the 1930s, and it was
pretty grainy color for a while, too.
C: That's really weird.
D: Well, truth is stranger than fiction.
C: But then why are old PAINTINGS in color?! If the world was black and
white, wouldn't artists have painted it that way?
D: Not necessarily. A lot of great artists were insane.
C: But... but how could they have painted in color anyway? Wouldn't their
paints have been shades of gray back then?
D: Of course, but they turned colors like everything else in the '30s.
C: So why didn't old black and white photos turn color too?
D: Because they were color pictures of black and white, remember?
C: Dad, will you explain the theory of relativity to me? I don't understand
why time goes slower at greater speed.
D: It's because you keep changing time zones. See, if you fly to California,
you gain three hours on a five-hour flight, right?
So if you go at the speed of light, you gain MORE time, because it doesn't
take as long to get there. Of course, the theory of relativity only works if
you're going west.