| I've never been a baseball fan. I spent 4 years of my life in Boston, where the Red Sox are life for most people, and I regret to say I never went to a single game. Well, I didn't know what I was missing out on, because watching baseball on tv was supremely boring, especially if you don't really understand the rules.
I saw my first major league baseball game in person at Camden Yards in Baltimore today. Orioles vs Tampa Rays: Rays win 11-6 after a very slow start, in which they were down 0-5 after 3 innings. I was lucky enough to have friends who were into baseball there with me, and they were able to explain to me the intricacies of the game. It requires much more strategy than I'd thought, and it is really fun to try to keep an eye on the entire field (which is huge), the scoreboard, the pitcher, and batter, and the ball which is traveling ridiculously fast. If I could throw and catch, I might even enjoy playing it one day. Running and strategically hitting balls is very appealing. Learning to throw balls in interesting ways would be awesome, particularly because all the physics involved would amuse me.
I heard a very bad explanation for why curve balls curve today-- someone said that the spinning of the ball caused one side to be lighter than the other. That is not true. The masses of the sides of the ball do not change due to spinning, and even if they do slightly, it will be an even distribution of the inner mass of the ball to the outside of the ball (the way a centrifuge works). What actually happens is called the Magnus effect by physicists. http://en.wikipedia.org/wiki/Magnus_effect Essentially what happens is that the airflow going over one side of the spinning ball is faster than the airflow going over the other side. Faster airflow means less pressure on one side than the other, causing the ball to also experience a force in a direction perpendicular to the direction the ball was thrown. One way to understand this is to think about the curious fan displays you often see in superstores like WalMart. They take a powerful fan, point it up towards the ceiling and turn it on, and then stick an inflated beachball above it. The beachball will bounce up and down in what seems to be an invisible column of air, but it is forever suspended and never flies off or falls down. Why doesn't the beachball just fly off due to the air from the fan pushing it away? It's because of the difference in air pressures caused by the fan. The faster moving air blowing from the fan, creating a column upwards, has lower air pressure than the stationary air outside the range of the fan. When the ball moves towards the edges of the column of faster moving air, it encounters higher pressures that force it back towards the middle (where the pressure is lower). Same thing happens with the ball. If you think about it carefully, though, if this perpendicular force is constant, then the ball does not curve. It just happens to move in a slightly different, but still straight, line. What causes the ball to curve (as far I understand it) is the additional resistance caused by the air, which slows the ball and its spin. This makes the perpendicular force nonconstant, so the ball curves. Similar things happen with spinning golf and tennis balls, and perhaps even soccer balls, though I'm not sure.
Isn't physics fun? :) |
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| I can't seem to get up the motivation to do anything these days. And there's so much freaking work to do before school ends, and so many things to get set for after I'm done with school. I just can't do it.
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