A Little-Known 18th Century English Polymath — Professor Alan Zinober — 15th June 2020

A poly­math is ‘a person of great and varied learn­ing’ and this cer­tainly described the Reverend John Michell ( 25 Dec 1742 — 12 April 1793).

Michell was a nat­ural philo­sopher and a cler­gy­man and seems to be almost unknown although he was:

  • The first person to sug­gest that earth­quakes are caused by move­ment of rocks beneath the Earth’s sur­face.
  • Someone who pro­duced cheap per­man­ent mag­nets.
  • The one who sug­ges­ted that the force between two mag­nets fol­lowed the inverse square law.
  • The first person to sug­gest that ‘Dark Stars’ (now called ‘Black Holes’) exist.

John Michell was edu­cated at Queens College.

He later became a Professor who taught Arithmetic, Theology, Geometry, Greek, Hebrew and Philosophy.

He had to relin­quish his lec­tur­ing post when he mar­ried because only single men were allowed to lec­ture at the col­lege.

He became Rector at a church near Leeds, but con­tin­ued his interest in Philosophy and Astronomy.

Michell the­or­ised that a very massive sun would have such a huge grav­it­a­tional field that its escape velo­city would be so large that light would not be able to escape from it.

Because of this it would not be vis­ible but it would affect the motion of a binary star nearby.

He called this type of body ‘a Dark Star’.

He knew Cavendish, Benjamin Franklin and Priestley, and he wrote to Cavendish about his ideas about the effect of grav­ity on light.

Michell was not a par­tic­u­larly out­go­ing person so he did not pub­lish his many ideas widely.

This is pos­sibly why he is not well known but is con­sidered by many to be the greatest unsung sci­ent­ist of all time.

Alan Zinober’s Zoom meet­ing con­tained much more inter­est­ing inform­a­tion and was some­thing com­pletely new to Stumperlowe Probus.  It was a wel­come treat for the many mem­bers that ‘atten­ded’.