托福听力段子7. 理科段子:地理冒险
Good morning, class. Before we begin today, I would like to address an issue that one of you reminded me of after the last lecture. As you may recall, last time I mentioned that Robert E. Peary was the first person to reach the North Pole. What I neglected to mention was the controversy around Peary’s pioneering accomplishment. In 1910, a committee of the national geographical society examined Commodore Peary’s claim to have reached the North Pole on April 6th’ 1909 and found no reason to doubt him. This judgment was actually confirmed by a committee of the US congress in 1911. Nevertheless, Peary’s claim was surrounded by controversy. Tins was largely due to the competing claim of Doctor Frederic Cook who told the world he had reached the Pole a four-year earlier. Over the decades Peary was given the benefit of the doubt, but critics persisted in raising questions about his navigation and the distances he claimed to have covered. So the Navigation Foundation spent an additional 12 months of exhaustive examination of documents relating to Peary’s polar expedition. The documents supposed Peary’s claims about the distances he covered. After also conducting an extensive computer analysis of photos taken by Peary at the pole, they concluded that Pierre and his companions did in fact reach the near vicinity of the North Pole on April 6th. 1909. OK, today we’re going to talk about exploration of the opposite end of the world, I assume you all read chapter 3 in our text and are now familiar with the names: Emerson and Scott.
托福听力段子8.理科段子:天文学
In ancient times, many people believed the earth was a flat disc. Well over 2,000 years ago; the ancient Greek philosophers were able to put forward two good arguments proving that it was not. Direct observations of heavenly bodies were the basis of both these arguments. First, the Greeks knew that during eclipses of the moon the earth was between the sun and the moon, and they saw that during these eclipses, the earth’s shadow on the moon was always round, they realized that this could be true only if the earth was spherical, It the earth was a flat disc, then its shadow during eclipses would not be a prefect circle; it would be stretched out into a long ellipse. The second argument was based on what the Greeks saw during their travels. They noticed that the North Star, or Polaris, appeared lower in the sky when they traveled south, in the more northerly regions, the North Star appeared to them to be much higher in the sky. By the way, it was also from this difference in the apparent position of the North Star that the Greeks first calculated the approximate distance around the circumference of the earth, a figure recorded in ancient documents says 400.000 stadium, that’s the plural of the world stadium. Today, it’s not known exactly what length one stadium represents, but let’s say it was about 200 meters, the length of many athletic stadiums. This would make the Greek’s estimate about twice the figure accepted today, a very good estimate for those writing so long before even the first telescope was invented.