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新的开始加油! This is Scientific Americans' 60-Second Science. I am Steve Mirsky. Got a minute?
Happy New Year! And don’t feel bad about taking today off. After all, you’ve traveled far. And I’m not talking about the trip home from the party last night. According to NASA, just by being on the planet earth in the last year, you’ve 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 earth’s orbit is an ellipse, with the sun at one of the two focal points. He also figured out the planet goes faster when it’s at perihelion, nearer the sun, than when it’s at aphelion, its furthest distance. Which would explain why summer seems to zip by, except the seasons are a function of the tilt of the earth’s axis, 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. I'm Steve Mirsky.
Take today off 休假
Zip n. 拉链;活力,精力;尖啸声,撕裂声;一种程序压缩的档案文件格式
vt. 给...以速度;拉上或拉开拉链
vi. 拉开或拉上;以尖啸声行进
Get back
Orbit 轨道
Ellipse 椭圆形
Focal points 焦点,中心
Perihelion[,per?'hi?l??n]n. [天] 近日点;最高点
Aphelion [æp'hi?l??n] n. 远日点
A function of the tilt of the earth's axis {tilt 倾斜 axis轴}
Rotate 旋转;循环
Sweep n. 打扫,扫除;范围;全胜
vt. 扫除;猛拉;掸去
vi. 扫,打扫;席卷;扫视;袭击
很多术语啥的 很多词都不熟 Having a kid changes everything, from your sleep schedule to the status of that formerly spare room.The stable of bacteria that live in a woman’s gut is also transformed when their host becomes pregnant. So finds research in the journal Cell.
The study looked at women in Finland. The women’s microbial makeup changed dramatically between the first and third trimesters. The array of microbes in the gut went from looking normal in the first three months of a pregnancy to resembling what’s found in patients suffering from metabolic disease in the last three.
But some of the symptoms of that condition—like weight-gain and slower sugar metabolism—can be beneficial to pregnant women, supporting energy storage that helps a fetus develop. Other symptoms, like inflammation, demonstrate that the immune system is functioning properly as a pregnancy comes to term.
Scientists don’t yet fully understand what brings about the changes in gut bacteria—immune function is a suspect, but factors like hormonal signals aren’t ruled out. The research suggests that other changes to the body, like puberty or old age, could also bring about microbial makeovers.
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