Q. What's the current thinking on the old question, Are two snowflakes ever exactly alike?
A. All ice crystals are basically hexagonal, whether shaped as simple plates, bullets, needles, solid or hollow columns, dendrites, sheaths, says Askthe-weatherman.Com. Falling, they're a work-in-progress, riding air currents up and down, maybe for an hour or more, through regions of differing temperatures and humidities that leave their marks of growth and shape.
"Indeed it is extremely unlikely that two COMPLEX snow crystals will look exactly alike," says California Institute of Technology physicist Kenneth G. Libbrecht. But how about two small crystals? Consider that not all water molecules are alike, with about 1/1000 being atypical. Since even a small snow crystal has about a thousand million billion (18 zeros) water molecules, about a million billion (15 zeros) will be these "rogues," scattered throughout in unique ways. So given a trillion trillion (24 zeros) crystals/year falling on Earth, the chance of two ever having the same water molecule layout is essentially zero!
The only exception would be tiny crystals with only maybe 10 molecules, all of which just MIGHT fit identically to some other crystal. "But they'd have to be assembled in a lab to be seen, and would be invisible to the naked eye."
Q. Two New Year's Eve champagne puzzlers: Why do the bubbles in the drink rise so much faster than beer bubbles, and exactly how fast does the cork fly, for those carelessly popping it in a nearby celebrant's direction?
A. Beer is loaded with proteins that stick to the uprising bubbles, creating drag that slows their ascent, says Jearl Walker. As for champagne pressure, it's about six times normal atmospheric pressure (15 x 6 = 90 psi), which can send the cork shooting out at about 50 km/hr (30 mph), more than enough to badly injure an eye.
Q. When it is noon in New York City, Winnipeg, Amsterdam or Greenwich, what time is it at the North Pole?
A. It can be any time you want! The concept of time zones, which are based on longitude, falls apart at the poles, where all longitudinal lines intersect, says New Mexico Institute of Mining and Technology geophysicist Rick Aster. Here the sun simply spirals around the sky, moving from 23.5 degrees below the horizon at the winter solstice to 23.5 degrees above in mid-summer.
Local noon for anywhere is defined as when the sun is at its maximum elevation, adds University of Alaska-Fairbanks geophysicist Paul Layer. At the poles, the sun does not rise in the morning and set in the evening but is at approximately a constant elevation for all of a 24-hour day. "Exactly at the North Pole, sunrise is on the Spring equinox and sunset on the Fall equinox: So a year and a 'day' are the same thing!"
For scientists doing work at the South Pole (little happens at the North Pole), say Aster and Layer, they need to synchronize their clocks to an agreed-upon time zone, possibly based on clocks of the nation of origin or maybe Coordinated Universal Time (UTC), which is the standard time at the prime (Greenwich) meridian at 0 degrees longitude.
Q. A great party trick: Print CARBON in red, DIOXIDE in blue, then have guests peer at the words through the long stem of a wine glass held over the paper. Notice that CARBON appears inverted but not DIOXIDE. How can this be?
A. Remind your audience that a prism breaks down sunlight into a rainbow of colors. So maybe the lens-like stem acts differently on the red and blue wavelengths? But that seems incredible.
De-mystification occurs when you view CARBON DIOXIDE through the back of the paper turned upside down. Do you get it now? It has nothing to do with the two colors. Both words were inverted but this is masked because DIOXIDE is symmetrical about a horizonal mid-line.
Expect a few groans from anybody who fell for this.
Q. Legend has it the King of Persia asked the inventor of the game of chess what he wanted as a reward. "A grain of wheat on the 1st board square, 2 grains on the 2nd square, 4 grains on the 3rd, 8 on the 4th, etc." was his answer. Did the king comply?
A. Sounds reasonable. But if you run 2 to the 63rd power through a calculator, you'll see the 64th square alone would have needed 9,223,372,036,854,775,808 grains -- more than the world's annual wheat production, says Richard Phillips in "Numbers: Facts, Figures & Fictions."
This is like trying to fold a sheet of paper in half 63 times, thus doubling the thickness with each fold. The betting is you won't make it to 10.
Q. Science teacher asked the class how a barometer could be used to determine the height of a tall building. They came up with plenty of creative ways, but not the "right" way. Can you guess what the students suggested?
A. Wacky way #1: Drop the barometer off the roof and time its fall to the street. Distance down = 16 feet x the number of seconds squared. Ex: 5-second drop = 400 feet.
#2: Lower the barometer on a long rope, then measure the rope.
#3: On a sunny day, compare shadow proportions. Ex: If the barometer's shadow is 5 times the barometer's length, then the building is 5 times as tall as its shadow is long.
#4: Count off barometer lengths to the roof as you climb the stairs, then multiply by the barometer's length.
#5: Knock on the building superintendent's door and say, "Hey, Mr. Super, I've got this cool barometer I'll give you if you tell me the height of this building..."
NONE OF THE ABOVE gets close to the textbook way of measuring building height, using the drop in barometric pressure from the street to the roof, and converting: Ex: A 2%-pressure-drop indicates a 540-foot skyscraper.
Comments on this page are closed.