Did Ben Franklin really discover electricity with a kite?
Everybody has heard the famous story of how pioneering experimenter–and part-time founding father–Ben Franklin tied a key to a kite string and flew the kite in a thunderstorm. The kite was hit by lightning, and zap! Franklin had discovered electricity.
Fried Franklin
Well, it makes a better story than it does an experiment. The danger is that lightning is not something you want to play with, and you certainly don’t want to attract it to yourself! Were this story to be true, I’m afraid, the result would have been fried Franklin.
What Ben actually did in his famous 1752 experiment was to cause some excess electrical charge near a storm cloud to ground out through his kite string–still an impressive demonstration, but a much less powerful prospect than an actual lightning strike.
Myths
Nor is it true that Franklin discovered electricity, as people tend to say. What he was trying to do was to demonstrate that lightning itself is simply a powerful electric discharge between the clouds and the earth. In this he was entirely correct.
Now, did you know that two of the basic terms we use even today to describe electric charge were coined by Franklin? Next time.
本.富蘭克林沒有被雷擊
本.富蘭克林真的靠一只風(fēng)箏發(fā)現(xiàn)了電嗎?
大家都聽過這個有名的故事:本.富蘭克林這位開創(chuàng)性的實(shí)驗(yàn)者兼開國之父如將一把鑰匙系到風(fēng)箏線上,并在電閃雷鳴的惡劣天氣下放風(fēng)箏。風(fēng)箏被閃電擊中燒毀了,于是富蘭克林發(fā)現(xiàn)了電。
燒焦的富蘭克林
我們最好把它當(dāng)成一個故事而非實(shí)驗(yàn)。這個實(shí)驗(yàn)的危險之處在于:閃電不是你能玩耍的東西,當(dāng)然你也不想引“電”上身。如果這個故事是真的,恐怕富蘭克林早已被燒焦了。
在1752年這次著名的實(shí)驗(yàn)中,本所做的就是將暴風(fēng)云附近的過量電荷通過風(fēng)箏線引到地面上來,雖然相比實(shí)際雷擊威力要小很多,但它仍是一個令人印象深刻的證明。
神話
事實(shí)上,富蘭克林也沒有像人們所說的那樣發(fā)現(xiàn)了電。他所努力做的一切就是要證明:閃電本身只是云和地球之間的一種威力巨大的放電現(xiàn)象,在這一點(diǎn)上,他是完全正確的。
時至今日我們?nèi)杂靡悦枋鲭姾傻膬蓚€基本術(shù)語是富蘭克林創(chuàng)造的,你知道嗎?這個問題我們下次詳述。