从另一个角度看问题
写洪堡的间隙,翻了两本书。一本书中提到科学史上电的往事,也是
为洪堡解剖“电鳗”作序,里面提到电与青蛙的一桩公案,尤其省发
人,我这里叙述一下。
1750年,本杰明*富兰克林把风筝放入雨云中,测中打雷是一种放电
。18世纪末,两位意大利人对电着迷,Luigi Galvani & Alessandro
Volta。伏打很有名,Galvani也很渊源。我说源渊,是科学名词上的
字根(电解?)。Galvani是一位医生,他发现,如果把青蛙连在两种
不同金属的线路中,比如铜和铁,或者铜与锌,青蛙的肌肉会收缩。
1791年他发表了自己的研究成果,以为“动物电”产生于神经,经过
金属传入肌肉。
伏打,是一位物理学家,他从另一个角度看这个问题。神经并未发电
,他以为,这是两种金属间产生电流的作用,动物组织这里不过是传
导。为证明他的观点,伏打用化学电解液取代青蛙,产生出了电力。
这个不需要任何动物作中介。
一个是Physicist,一个Physician。Galvani并不认输,除去金属,
他重做这个试验,用控制青蛙的神经直接导致青蛙肌肉的抽动。这是
科学史上的一桩很好的公案,各自在各自的科学领域内对同一现象进
行研究。各自发现自己独特的科学领域,伏打电池,生物电。
洪堡解剖“电鳗”就是属于后者。自然,前者也有续曲。比如奥斯特
发现磁针在电导线周围会偏向,电动磁。而法拉弟,从另一个角度看
问题,在磁场中强迫金属导线的运动(切割磁力线),也能生电。这电
动机就发明出来了。当然法拉弟的本份工作是电解,跟戴维跟过很长
一段时间(化学),电镀,Galvanize,用的就是Galvani的名。
再换大一点角度。马赫说物理学的牛顿表述并不唯一,这个在德国科
学时代很惊醒。我想说一说光学的牛顿表述--粒子说。当时歌德就
提出人主体对光色的感受,基于他对矿物和艺术、心理的体悟,写出
了《颜色学》。粒子说在纯物理领域内也经历了波动说(杨),波粒
二象性(爱因斯坦),现在的光是纯物理的了,纯客体,没有人!好
在我前不久去大都会博物馆,买到了一本歌德的《颜色学》,非常朴
实的科学探索,综合全面,至少对艺术家绝对珍贵。我就记得叔本华
一直称道歌德的科学研究,并且在他的《四重根》里对视觉的奇特性
进行过探索。
现在人把颜色纯客体化了,除了数学就是物理,全然忘了人本身的视
觉。这个很悲观,我对视觉也没有多少研究,只觉得人的视觉可以不
一样,对各波段的感觉可以不一样,对色彩可以很敏感,或者很迟顿
或者纯粹色盲。现在人很分离,大艺术家对色彩敏感的吓人,而一般
人,对色彩学门都未入,比如对比色,一窃不通。
故而欣赏色彩艺术--美术,尤其是现代艺术很难入,多是不知所云
。更可怕的是,许多商业艺术家的创作也根本是不知所云。
另一个角度???乘着走题走得还不是太远,赶紧刹住。
- Re: 从另一个角度看问题posted on 08/02/2009
我今天多喝了点,眼花,从电读到视觉,晕了。
不打住,就该讲到脚气了。xw 喝多了? - posted on 08/07/2009
今天读书,又读到脑电,心电,并且有脑电图,心电图。看来中国自
古言“心”,四种“心”并不是没有根基。当然脑子是思维的,那心
电是干什么的呢?想心思的?
http://www.mayacafe.com/forum/topic1sp.php3?tkey=1229456255
这里是维基bioelectricity,比中文的严格些:
Bioelectromagnetism (sometimes equated with bioelectricity) refers to the electrical, magnetic or electromagnetic fields produced by living cells, tissues or organisms. Examples include the cell membrane potential and the electric currents that flow in nerves and muscles, as a result of action potentials. It is not to be confused with bioelectromagnetics, which deals with the effect on life from external electromagnetism.
Description
Biological cells use bioelectricity to store metabolic energy, to do work or trigger internal changes, and to signal one another. Bioelectromagnetism is the electric current produced by action potentials along with the magnetic fields they generate through the phenomenon of electromagnetism.
Bioelectromagnetism is studied primarily through the techniques of electrophysiology. In the late eighteenth century, the Italian physician and physicist Luigi Galvani first recorded the phenomenon while dissecting a frog at a table where he had been conducting experiments with static electricity. Galvani coined the term animal electricity to describe the phenomenon, while contemporaries labeled it galvanism. Galvani and contemporaries regarded muscle activation as resulting from an electrical fluid or substance in the nerves.
Bioelectromagnetism is an aspect of all living things, including all plants and animals. Some animals have acute bioelectric sensors, and others, such as migratory birds, are believed to navigate in part by orienting with respect to the Earth's magnetic field. Also, sharks are more sensitive to local interaction in electromagnetic fields than most humans. Other animals, such as the electric eel, are able to generate large electric fields outside their bodies.
In the life sciences, biomedical engineering uses concepts of circuit theory, molecular biology, pharmacology, and bioelectricity. Bioelectromagnetism is associated with biorhythms and chronobiology. Biofeedback is used in physiology and psychology to monitor rhythmic cycles of physical, mental, and emotional characteristics and as a technique for teaching the control of bioelectric functions.
Bioelectromagnetism involves the interaction of ions. There are multiple categories of Bioelectromagnetism such as brainwaves, myoelectricity (e.g., heart-muscle phenomena), and other related subdivisions of the same general bioelectromagnetic phenomena. One such phenomenon is a brainwave, which neurophysiology studies, where bioelectromagnetic fluctuations of voltage between parts of the cerebral cortex are detectable with an electroencephalograph. This is primarily studied in the brain by way of electroencephalograms.
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