听写必备上半年SSS文本全集听写必备.docx

1、听写必备上半年SSS文本全集听写必备SSS 2009-01-01This is Scientific Americans60-Second Science. Im Steve Mirsky. Got a minute?Happy New Year! And dont feel bad about taking today off. After all, youve traveled far. And Im not talking about the trip home from the party last night. According to NASA, just by being on

2、the planet Earth in the last year, youve zipped about 584 million miles around the sun to get back where you were. At an average speed of about 67,000 miles per hour. Again, not talking about the drive home last night.Of course, the trip was not a perfect circle. As Kepler showed, the Earths orbit i

3、s an ellipse, with the sun at one of the two focal points. He also figured out the planet goes faster when its at perihelion, nearer the sun, than when its at aphelion, its farthest distancewhich would explain why summer seems to zip by, except the seasons are a function of the tilt of the Earths ax

4、is, not its different distances from the sun. And the Earth rotated 365 and a quarter times during its sweep around the sun. The trip took 8,766 hours. Or 31,557,600 seconds. Or 525,960 minutes just like this one.Thanks for the minute for Scientific Americans 60-Second Science. Im Steve MirskySSS 20

5、09-01-02This is Scientific Americans60-Second Science. Im Cynthia Graber. This will just take a minute.Mosquitoes carry nasty diseasesdengue fever, west nile, malaria. But the microbes that cause those diseases dont attach themselves to the mosquitoes and then immediately latch onto their next victi

6、m. They need time to grow and replicate in the mosquito before migrating to the bugs salivary glands. For example, the dengue fever virus takes about two weeks to incubate. So researchers from the University of Queensland in Australia and Central China Normal University are looking at a way to short

7、en the lives of mosquitoesand thus curtail their disease-transmitting ability. Researchers worked with a bacterial parasite called Wolbachia that infects numerous insect species. They spent three years adapting it to infect the Aedes aegyptimosquito, which carries dengue fever. It cut the lives of t

8、he mosquitoes by more than half. Those results were reported in the January 2nd issue of the journal Science. The scientists say that because Wolbachia shortens a mosquitos life, the insects are that much less likely to pass on the diseases they carry. So a relatively inexpensive and effective human

9、 disease prevention program could be to mass-infect mosquitoes with Wolbachia. Which should make the medical community buzz.Thanks for the minute for Scientific Americans 60-Second Science. Im Cynthia Graber.SSS 2009-01-05This is Scientific Americans60-Second Science. Im Steve Mirsky. Got a minute?W

10、e residents of the Milky Way should have a little extra skip in our step today. Turns out our home galaxy is much bigger and moving a lot faster than we previously thought. Thats what researchers from the HarvardSmithsonian Center for Astrophysics reported January 5th at the meeting of the American

11、Astronomical Society. Older studies of our galaxys structure and motion used indirect measurements. But we can now use radio telescopes to directly observe certain features of the galaxy when were in very different places in our orbit around the sun. And using traditional surveying methods, such as

12、triangulation, researchers came up with the new figures.First, were moving about 600,000 miles per hour in our galactic orbit, a lot zippier than the old estimate of 500,000. And the Milky Ways total mass is about half again as much as we used to think. Which means were about as massive as the nearb

13、y Andromeda Galaxy. The Milky Ways bigger mass does mean a greater chance of a gravity-driven collision with Andromeda. But if that clash occurs, at least now were in the same weight-class.Thanks for the minute for Scientific Americans 60-Second Science. Im Steve Mirsky.SSS 2009-01-06 Tune in every

14、weekday for quick reports and commentaries on the world of science- itll just take a minute. A study presented at the meeting of the American Astronomical Society finds that the debris surrounding white dwarf stars is similar to the content of rocky planets-which means that rocky planets could be co

15、mmon to stars like our sun. Cynthia Graber reports.SSS 2009-01-06This is Scientific Americans60-Second Science. Im Cynthia Graber. This will just take a minute.If we want to learn more about our planet and other planets in the universe, we can get some help from stars that are long dead and gone. Th

16、ats what U.C.L.A.s Michael Jura said at the American Astronomical Society meeting January 5th. His team used observations from NASAs Spitzer Space Telescope to investigate dead white dwarf stars. Dust and debris swirl around young stars. The pieces clump together to form asteroids and bigger planets. When a star like our sun finally dies, it blows itself up, bright red. Then it shrinks down into a s