哪位能翻译一下，earth穿过meteor stream是一天还是一年？

toseetoo · 发表于 2010-4-21 16:10:51

Whenever the Earth passes through a meteor stream, a meteor shower occurs. Moving at a little over 1,500,000 miles per day around its orbit, the Earth would take, on average, just over a day to cross the hollow, computer-model Geminid stream if the stream were 5,000 years old. Two brief periods of peak meteor activity during the shower would be observed, one as the Earth entered the thick-walled “pipe” and one as it exited. There is no reason why the Earth should always pass through the stream’s exact center,so the time interval between the two bursts of activity would vary from one year to the next.
想不明白，前面说1天就过了，后面说时间跨度要一年或者两年。如果是因为不能一定穿过中心点，那interval range 也应该是1天到1年怎么会是one year to the next。影响做题。谢谢。

toseetoo · 发表于 2010-4-21 20:57:32

可能没有上下文不好读，贴上。

A meteor stream (meteor stream: 流星群) is composed of dust particles that have been ejected from a parent comet at a variety of velocities. These particles follow the same orbit as the parent comet, but due to their differing velocities they slowly gain on (gain on: v.逼近, 超过, 侵蚀) or fall behind the disintegrating comet until a shroud of dust surrounds the entire cometary orbit. Astronomers have hypothesized that a meteor stream should broaden with time as the dust particles’ individual orbits are perturbed by planetary gravitational fields. A recent computer-modeling experiment tested this hypothesis by tracking the influence of planetary gravitation over a projected 5,000-year period on the positions of a group of hypothetical dust particles. In the model, the particles were randomly distributed throughout a computer simulation (computer simulation: 计算机模拟) of the orbit of an actual meteor stream, the Geminid. The researcher found, as expected, that the computer-model stream broadened with time. Conventional theories, however, predicted that the distribution of particles would be increasingly dense toward the center of a meteor stream. Surprisingly, the computer-model meteor stream gradually came to resemble a thick-walled, hollow pipe.
Whenever the Earth passes through a meteor stream, a meteor shower (meteor shower: n.[天]流星雨) occurs. Moving at a little over 1,500,000 miles per day around its orbit, the Earth would take, on average, just over a day to cross the hollow, computer-model Geminid stream if the stream were 5,000 years old. Two brief periods of peak meteor activity during the shower would be observed, one as the Earth entered the thick-walled “pipe” and one as it exited. There is no reason why the Earth should always pass through the stream’s exact center, so the time interval between the two bursts of activity would vary from one year to the next.
Has the predicted twin-peaked activity been observed for the actual yearly Geminid meteor shower? The Geminid data between 1970 and 1979 show just such a bifurcation, a secondary burst of meteor activity being clearly visible at an average of 19 hours (1,200,000 miles) after the first burst. The time intervals between the bursts suggest the actual Geminid stream is about 3,000 years old.
请各位牛牛指点.

handmade · 发表于 2010-4-26 13:53:19

额。正好我做过这个。我觉得是这样，你把流星群想成一个铁管的横截面，因为文中说到hollow，中空。
然后地球从一侧穿到另一侧要穿过“铁管”的两层壁，所以导致会遇到两次shower的高峰，还有一个interval。
（之前写的太误导了，我不得不改了。。）

toseetoo · 发表于 2010-4-27 00:29:32

但是最后一段又说The Geminid data between 1970 and 1979 show just such a bifurcation, a secondary burst of meteor activity being clearly visible at an average of 19 hours (1,200,000 miles) after the first burst. The time intervals between the bursts suggest the actual Geminid stream is about 3,000 years old. 是指two bursts之间19hours，也就是穿过这个hollow stream要19hours.
谢谢！

handmade · 发表于 2010-4-28 02:24:07

我真的错了，当时刚刚看过这文章，回答的时候不仔细。
我来纠正自己的错误，给出原文中红色部分的第一句说明了，如果这个stream是5000年形成的，那么地球穿过hollow需要花一天时间。
而下文1970 and 1979 show just such a bifurcation, a secondary burst of meteor activity being clearly visible at an average of 19 hours (1,200,000 miles) after the first burst. The time intervals between the bursts suggest the actual Geminid stream is about 3,000 years old。说到这里花了19小时，略小于一天，而预估的形成时间是3000年，也略小于5000。正是由上面的理论推出来的结果。
请忘记我说的关于穿过“壁”的东西吧。。。。

toseetoo · 发表于 2010-4-28 17:40:29

no worry, tks buddy.
不过 There is no reason why the Earth should always pass through the stream’s exact center, so the time interval between the two bursts of activity would vary from one year to the next. 这里所说from one year to the next到底是什么东西的时间跨度呢。百思不得其解。

哪位能翻译一下，earth穿过meteor stream是一天还是一年？

我错了

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