History of Physics Group meeting “From Newton to the free electron laser”

Lecture 3: Psychical and optical research between Lord Rayleigh’s naturalism and dualism

Gregory Bridgman

Mr Bridgman is a PhD student whose research explores how and why a concept of “colour vision”, and its cognate nexus of scientific practices and theories, managed to negotiate its place within an older family of “colour” related sciences, in 19th century Britain.


My notes from the lecture (if they don’t make sense then it is entirely my fault)

I have to be honest that when I read the title of this lecture I was rather bemused as the only time I had come across the phrase “psychical research” was to do with ghosts and mediums. What on earth has this got to do with science? I hope my notes will answer this but I have to confess I didn’t understand some of the lecture.




Sir Joseph Larmor FRS FRSE DCL LLD (11 July 1857 – 19 May 1942) was an Irish physicist and mathematician who made innovations in the understanding of electricity, dynamics, thermodynamics, and the electron theory of matter. His most influential work was Aether and Matter, a theoretical physics book published in 1900.

He looked for reconciliation between old and new ideas in physics, continuing with a search for interactions between the ether and electrons. He used the rhetoric of destruction, clearly placing the new ideas in the context of a dramatic revolution. The issue at stake was the abandonment of old ideas, of traditional tenets of physics.

He did not want to discard Newton’s laws, strongly believing that the new should be reconciled with the old. Initially he was a supporter of relativity but rejected later on.

Larmor, Joseph (1900): Aether and matter: a development of the dynamical relations of the aether to material systems, on the basis of the atomic constitution of matter: including a discussion of the influence of the Earth’s motion on optical phenomena: being an Adams Prize Essay in the University of Cambridge (Cambridge: Cambridge University Press)

Larmor, Joseph] (1922): ‘A Type of Ideal Electric Atoms’, Nature, 110 (30 December): 873

Larmor, Joseph (1923): ‘On the nature and amount of the gravitational deflexion of light’, Philosophical Magazine (Series 6) 45(265): 243-256


Larmor’s work, though rooted in the classical physics in which he had been trained, eventually led to the breakdown of classical physics and the rise of relativity theory and quantum mechanics.

He was described as ‘one who rekindled the dying embers of the old physics to prepare the advent of the new’.



Larmor’s proposal of an electric theory of matter was overshadowed by Einstein’s papers on relativity and the development of quantum theory. He is remembered as the first person to give the formula for the radiation of energy from an accelerated electron and he was also the first to explain the effect of a magnetic field in splitting the spectrum into multiple lines. As mentioned earlier, he was one of the last physicists to really believe in strict Newtonian mechanics, as physics was being taken over around this time by the theories of relativity and quantum mechanics.




John William Strutt, 3rd Baron Rayleigh, OM, PC, PRS (12 November 1842 – 30 June 1919), was a British scientist who made extensive contributions to both theoretical and experimental physics.

In 1919, Rayleigh served as President of the Society for Psychical Research. As an advocate that simplicity and theory be part of the scientific method, Rayleigh argued for the principle of similitude. He was not convinced of spiritualism but remained open to the possibility of supernatural phenomena.


The Society for Psychical Research (SPR) is a nonprofit organisation in the United Kingdom. Its stated purpose is to understand events and abilities commonly described as psychic or paranormal. It describes itself as the “first society to conduct organised scholarly research into human experiences that challenge contemporary scientific models.”

The Society for Psychical Research (SPR) originated from a discussion between journalist Edmund Rogers and the physicist William F. Barrett in autumn 1881.


Psychical research prompted many nineteenth and twentieth century physicists to reflect critically on practices commonly used in the fields with which they were professionally associated.

Physicists’ tolerance of the practical problems in psychical research owed much to what they perceived to be comparable issues in an established scientific field. Their explicit comparisons of psychical research to experimental physics were not merely rhetorical strategies designed to give scientific credibility to psychical research: they reflected a genuine conviction that these apparently divergent areas of enquiry shared many experimental problems and might share solutions. The focus on British physicists arises principally from the fact that, more than most professional scientists involved in psychical research in the decades around 1900, they volunteered some of the most illuminating insights into the shared problems of experiment in established and psychical sciences. It is not surprising that the same individuals feature in much recent work on the problems of experimental practice in nineteenth century sciences. They were among those who, in their pursuit of accurate measurement and the stabilisation of novel, transient and unruly effects, went to extraordinary lengths to avoid, measure and investigate environmental disturbances, and to master recalcitrant apparatus.

In 1919 the Rayleigh used the cases of meteorites and ball lightning to illustrate scientists’ eventual acceptance of capricious physical phenomena that they once deemed impossible and to warn ‘those scientific men who are so sure that they understand the character of Nature’s operations as to feel justified in rejecting without examination reports of occurrences which seem to conflict with ordinary experience’.

Psychical research and the troubles of experimental physics Richard Noakes https://core.ac.uk/download/pdf/20551489.pdf

Turner, F. M. (1974). Between Science and Religion: The Reaction to Scientific Naturalism in Victorian England. New Haven, CT: Yale University Press.

B. Lightman, Victorian popularizers of science: designing nature for new audiences (University of Chicago Press, 2007)

M. Stanley, ‘Where naturalism and theism met: the uniformity of nature’, in Victorian scientific naturalism: community, identity, continuity (ed. G. Dawson and B. Lightman), (University of Chicago Press, 2014)

Some scientists wondered if the results from some experiments were dependent on the experiments being viewed. Did the mind affect the results?

What is psychical research?

Definition of psychical research: the investigation of phenomena that appear to be contrary to physical laws and that suggest the possibility of mental activity existing apart from body



The National Laboratory of Psychical Research was established in 1926 by Harry Price, at 16 Queensberry Place, London. Its aim was “to investigate in a dispassionate manner and by purely scientific means every phase of psychic or alleged psychic phenomena”

The National Laboratory of Psychical Research was a rival to the Society for Psychical Research.

There were competing views on spiritualism.

Mind, matter and colour


Visible light is a form of electromagnetic radiation. White light or the spectrum of light visible to us is a mixture of many wavelengths. When light hits an object, its electrons absorb energy and jump to a higher energy level.

However, because they need stability, the electrons soon fall down to a lower, more stable energy level, transmitting energy and this energy can be in the form of visible light.

We detect objects because visible light is reflected off them and it is this reflected light that our eyes detect and label as colour if the light contains certain wavelengths. This is how objects effuse light; they absorb some wavelengths and scatter others. A white surface reflects all the light, whereas a dark surface absorbs every bit, reflecting nothing. We perceive an object as red because it absorbs all wavelengths of light except red, which is reflected.


At the back of our eye on the retina is a tremendously thin sheet of cells that are sensitive to light, and are therefore called photoreceptors. The retina contains two types of receptors: rods, which detect the level of brightness or darkness, and cones, which are responsible for generating colour.

The photoreceptors correspond to three primary colours: red, green and blue (Note: physics primary colours are different to art primary colours). Thus, we have 3 cones that activate for each colour. It is necessary to point out that the receptors aren’t intrinsically responsive to the colours red, green and blue, but the wavelengths we see and label are red, green and blue.


The comparative process then combines these colours to form all the colours that we find in our lives. Thus, every hue in the world is some combination of red, green and blue.

We mustn’t forget that the brain also plays a part in the colours we see. Nobody will see a shade of a colour in the same way as you. Also a colour will affect you differently to someone else.


Are objects coloured? And what is the nature of the colour properties?


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