英語(yǔ)聽(tīng)力文摘463 比較大的磁體
A: What’s the biggest magnet ever?
B: Well, that's a great question. Well, for starters you’d have to mention whoppers like the hybrid magnet at the National High Magnetic Field Lab in Tallahassee, Florida. This magnet weighs thirty-four tons and stands twenty-two feet tall.
Giant magnets in hospitals, physics labs, and other facilities help in cutting edge research. However, even a magnet the size of a building can’t compete with a magnet the size of a planet.
A: A magnet the size of a planet?
B: The Earth itself is a magnet! Researchers think it’s the effect of convection currents in our planet’s molten interior that causes the entire Earth to behave as one gigantic magnet, with a North and South Pole.
Whenever you look at a compass, what you’re doing is reading the magnetic field of the planet on which you are standing.
A: So that must be the biggest magnet than anywhere.
B: Yet, even a magnet the size of a planet can’t compete with a magnet the size of a star.
A: A star?
B: what about the sun? The sun is a magnet. In this case, the magnetic field is probably generated by swirling plasma. Magnetic storms on the sun are powerful enough to have an effect on satellites and communication systems all the way here on Earth.
A: So is that?
B: Not even close. There are things in space that put all of these magnets to shame.
A: Super magnet in space? What are they?
B: Next time.
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