Davy Jones, quien fuera líder de la banda estadounidense The Monkees, murió a los 66 años en su casa de Florida, a causa de un ataque al corazón.
Why Things Are Going Downhill, Very Fast
The Washington Post March 17, 1995 | Joel Achenbach Why are some bobsled teams faster than others, even though they’re all basically just canned meat sliding down a chute?
Admit it, you fantasize about winning a gold medal at the Olympics, even though you are technically an old fat person with no talent. The odd thing about these fantasies is that they have to have some very slight degree of plausibility. You probably don’t think about winning the gold medal in weightlifting, or winning anything in a swimming pool. But you figure the 90-meter ski jump doesn’t look so hard.
And what about bobsledding? Couldn’t you be, like, one of the middle guys in the four-man bobsled? Aren’t we all fairly talented at sitting?
Unfortunately it’s more complicated than that. The difference between a gold medal and no medal at all is usually less than one second. That makes it all the more important that the teams find ways to go ever so marginally faster. The best bobsled teams know how to shave small fractions of time off their run. There are three ways to do it: site how to shave
1. The push. This is the part where physical strength, speed and agility come into play. Everyone pushes. It’s why you probably couldn’t be one of the middle people — you aren’t sufficiently fast, strong and lithe. The U.S. team tried using Herschel Walker, the football player, but the tactic bombed. Walker could push, but he wasn’t so great at jumping into the sled. Don’t expect to see any more part-time bobsledders on the U.S. team.
2. The design of the sled. Bobsledding is like the soap box derby, you get to make your own vehicle.
3. Steering. Yes, a bobsled has to be steered. Only one person is the driver. After the push, the other people in the sled are just cargo. The driver has to figure out precisely how to take the curves.
The secret is: Not too high on the curve. Not too low. Not too much steering, not too little.
In fact it’s like a complicated mathematics equation. We spoke to Mont Hubbard, a mechanical engineer at the University of California at Davis who has designed a bobsled simulator that allows bobsledders to figure out the fastest way to steer down the run. He explains that steering involves friction. The runners under the sled bite into the ice. So you don’t want to steer too much, because you’ll slow down the sled.
But if you don’t steer at all, and just go with the flow so to speak, the sled will ride up high on the curve. That will make the distance the sled has to travel ever so slightly longer. A foot here, a foot there makes a huge difference.
“A terrible driver can kill the best push,” he says.
Complicating matters is that each curve has to be treated differently. For example, you don’t want to go through the first curve as quickly as possible. This seems paradoxical at first. Why wouldn’t you want to have the best time out of the first curve? Because you might lose velocity. The quickest way through the curve is to steer low and take the shortest route. But the steering involves friction and you lose velocity. So you take a longer route, time-wise and distance-wise, but retain more velocity.
By the time you reach the last curve, your tactics should have changed. By then you can steer a lot, taking the short cut, losing velocity, because the run is almost over and the cost of losing some steam is more than made up for by the shorter distance you travel.
The bottom line is: You have as much chance of winning the gold in the bobsled as you do in synchronized swimming.
The Mailbag:
Paul Clarke of Washington asks:
“If the Earth moves from west to east, why does the wind tend to go in the same direction? I would think it (air) would be left behind and appear to come from the east.” Dear Paul: Shockingly, the rules that apply to the United States do not apply to the entire planet. We have westerlies. Some places have easterlies. It depends on latitude. Just think about what happens with hurricanes. In the tropics they move to the west, from off the coast of Africa toward the United States. If they drift too far north they can get blown back east. website how to shave
Columbus sailed on easterly winds. That’s why he landed in the Caribbean, because the winds at that latitude are easterlies. To return to the Old World he sailed north and caught westerly winds. If you keep going north, toward the Arctic, you run into easterlies again.
Your question assumes that the atmosphere isn’t attached very firmly to the Earth, that it’s a loose covering that can easily slip, like a toupee. That’s not quite right. It generally moves with the Earth. If you want to know what causes wind, we advise you to remember the phrase “convection cells.” These are big wads of air that get heated up by the sun and have an itch to go somewhere.
We are tempted to discuss the Coriolis effect, but it is one of those temptations that should always be resisted.
Linda Ahlgren of Utica, Mich., writes:
“Please tell me why we have to put up with the interminable credits scrolling by at the end of a movie. Why would the producers think anyone would care about all that?” Dear Linda: You mean you’re not curious to see who the Key Grip was?
A source in The Industry tells us that the end credits are stipulated in the union contract. The movie business uses mostly unionized labor. The credits aren’t there for you; they’re there for the workers, it’s proof of what they put on their resumes. Besides which, if you’ve ever seen a movie made, it’s tedious, difficult, unglamorous work. Don’t begrudge those people their two seconds of fame.
Joel Achenbach
