Daily Archives: 12月 12, 2012

concave & convex

The Adventurers looked down over the rocky decline that separated them from the stronghold of the Cabal. A wisp of pale smoke drifted up from a round ventilation hole, marking the spot.

“I think I see a path,” Francis Hebert said. “See there?”

Max shielded his eyes. “Dammit, I can’t tell whether that’s concave or convex. This place is crazier than chopsticks for a snake.”

Larry Niven And Steve Barnes, The Barsoom Project, 1989.

Concave means ‘having an outline or surface curved like the interior of a circle or sphere’. Convex means ‘having an outline or surface curved like the exterior of a circle or sphere’. [The New Fowler’s Modern English Usage, Revised 3rd ed.]
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anode & cathode

Over the next few years, Faraday merged his knowledge of chemistry with the developing field of electricity. Years before, Davy had figured out how to separate metals by passing an electric current through them. Faraday called this process electrolysis, the chemical decomposition of a compound by sending an electric current through it. In 1833, he established two basic laws of electrolysis. The first law stated that the quantity of metal liberated was proportional to the quantity of electricity used. The second law stated that the electricity required to liberate the unit equivalent mass of any element was precisely the same. To describe his research, he had to make up several new words, including anode, cathode, electrode, electrolyte, anion, and cation. These are now an essential part of scientific vocabulary.

Katherine Cullen, Physics : The People behind the Science, Chelsea House, 2006.

anode【名詞】
【電気】 アノード 《正電荷が流れ出す電極; ⇔ cathode》:
1 （電解槽・電子管の）陽極.
2 （蓄電池などの）陰極.
［ギリシャ語 ‘a way up’ の意］[研究社新英和中辞典]

cathode【名詞】
【電気】 カソード 《正電荷が流れ込むほうの電極; ⇔ anode》:
1 （電解槽・電子管の）陰極.
2 （蓄電池などの）陽極.
［ギリシャ語 ‘a way down’ の意］[研究社新英和中辞典]

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