Who you gonna call? Michael Faraday!


Michael Faraday (1791-1867) is one the greatest scientists of all time and his contributions to physics and chemistry are immense and his name can be found associated with all manner of phenomena. The unit of capacitance known as the ‘Farad’ is named after him. Amongst all his contributions to science, perhaps the one that had the most impact on the public was his discovery of the law of electromagnetic induction, that if a wire and a magnet are in motion relative to each other, a current will flow in the wire. This forms the basis of our public electricity systems and the working of electric motors.

Less well known is that he was instrumental in debunking the idea of ‘table tipping’ that was in vogue in the mid-19th century as part of a general rise in so-called spiritual phenomena. This involved people sitting around a table with their fingers pressing vertically down on it, and the table would start to move sideways and tilt and even rise off the ground. This was claimed to be due to spirits acting. These phenomena were investigated and many deliberate frauds and hoaxes were uncovered but there still remained some residual phenomena in which the table moved sideways in a seemingly deliberate fashion.

Faraday was intrigued and, given his major role in discovering the forces of nature, it seems like he was being pressed to explain what was going on. He must have felt that a new mysterious force was worthy of investigation and, being the great scientist that he was, decided to do some experiments. The results of his investigations were published in a letter to the Times on June 30, 1853 and in an article to the Athenaeum on July 2, 1853, both of which can be seen in a collection of his papers Experimental Researches in Chemistry and Physics (p. 382-391).

He concluded that many of the people taking part in the séances were honorable people and not trying to deceive and that they genuinely believed that spirit forces were at work and acting through them and were curious about the nature of the forces involved. During these séances, the people thought they were pushing directly down on the table and not sideways so that any sideways motion was not due to them.

So his first test was to see if they were unconsciously influencing the motion of the table and, if so, whether that knowledge alone would cause the phenomenon to stop. In his Athenaeum article, what he did was to have an upper large piece of cardboard resting on a smaller piece of cardboard, and both placed on top of the table. The two pieces were held together by soft cement that would yield slightly. If the table was moving by itself, then the bottom piece would move more than the top. If the participants were moving the table, then the top piece would move more than the bottom. The results were clear. The people were moving the table and not vice versa.

He also set up an index that would show the participants if they were the ones driving the sideways motion and if that knowledge stopped the motion.

It was soon seen, with the party that could will the motion in either direction (from whom the index was purposely hidden), that the hands were gradually creeping up in the direction before agreed upon, though the party certainly thought they were pressing downwards only. When shown that it was so, they were truly surprised; but when they lifted up their hands and immediately saw the index return to its normal position, they were convinced. When they looked at the index and could see for themselves whether they were pressing truly downwards, or obliquely so as to produce a resultant in the right- or left-handed direction, then such an effect never took place. Several tried, for a long while together, and with the best will in the world; but no motion, right or left, of the table, or hand, or anything else occurred.

He ends his article by saying that he is a little ashamed for having had to do these experiments at all because in this day and age and in this part of the world, they should not have been required. In his letter to the Times where he summarizes his conclusions, he makes a lament about the state of the public mind that would take such things seriously and the willingness of people to jump to conclusions and ascribe phenomena to forces about which they know nothing.

Permit me to say, before concluding, that I have been greatly startled by the revelation which this purely physical subject has made of the condition of the public mind. No doubt there are many persons who have formed a right judgment or used a cautious reserve, for I know several such, and public communications have shown it to be so; but their number is almost as nothing to the great body who have believed and borne testimony, as I think, in the cause of error. I do not here refer to the distinction of those who agree with me and those who differ. By the great body, I mean such as reject all consideration of the equality of cause and effect, who refer the results to electricity and magnetism, yet know nothing of the laws of these forces, -or to attraction, yet show no phenomena of pure attractive power,- or to the rotation of the earth, as if the earth revolved around the leg of a table, – or to some unrecognized physical force, without inquiring whether the known forces are not sufficient, – or who even refer them to diabolical or supernatural agency, rather than suspend their judgment, or acknowledge to themselves that they are not learned enough in these matters to decide on the nature of the action. I think the system of education that could leave the mental condition of the public body in the state in which this subject has found it, must have been greatly deficient in some very important principle.

Given that Faraday came from a very poor family, had little formal education, and was largely self-taught, this was a stinging indictment of the elite education system that many of the readers of the Times would have had. It is also interesting that Faraday was religious, belonging to an offshoot of the Church of Scotland and active in church affairs, but he was not willing to go along with any old supernatural idea that came along. He practiced what we now refer to as methodological naturalism, which involves avoiding the facile invoking of supernatural forces in scientific investigations, like what intelligent design advocates do.

Comments

  1. Mano Singham says

    No, that Faraday is the unit given to the amount of charge in a mole of electrons and is used in electrolysis. The Farad is the unit of capacitance.

  2. Johnny Vector says

    Faraday in chemistry is the charge of Avogadro number of electrons. Is it the same as Farad?

    No. They don’t even have the same units. A Faraday is a unit of charge. A Farad is a measure of capacitance, which has units of length (in sensible systems like cgs), or if you prefer, charge over potential.

    Also, that’s a very clever experiment! I’ll have to remember that approach next time I need to make a cheap shear meter.

  3. invivoMark says

    I’m not sure how his stage presence was, but it sounds like Faraday would have made an excellent magician. He could have had a gig like Penn & Teller, if he wanted to try and change public perceptions about the supernatural.

  4. Mano Singham says

    Thanks for pointing out all the typos which I have now corrected.

    This is the third time I think that I have written pubic when I meant to write public. There may be some Freudian implications here …

  5. Rob Grigjanis says

    It is also interesting that Faraday was religious

    As was Maxwell, and more recently, Abdus Salam. They all seemed to see themselves as discovering the wonders of creation, without being constrained by scriptural “interpretations”.

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