I gave a talk on the ether in Oxford in February and here I’ve attempted to cut it down to a length that a normal person might want to read but obviously I’ve failed miserably. There’s an even longer version here.
In Lord Rayleigh’s 1942 biography of J. J. Thomson (1856 – 1940), he noted that the esteemed physicist had not taken the ‘fashionable view about ether’. Instead, Thomson continued to see this mysterious medium as a fundamental part of the physical world. He believed that everything was connected, that nature was ultimately continuous, while his more fashionable peers promoted discontinuity of matter and energy. Thomson’s view certainly does seem unfashionable now, and, to some, pretty stupid. Wasn’t this several decades after the ether had been definitively disproved by the 1887 Michelson-Morley experiment? (No, not really, this was how it was discussed much later, but at the time it was very much open to interpretation, and even Einstein didn’t reference it in his famous 1905 relativity paper. It was only after a few physicists had decided, for whatever reason, to abandon the ether, that suddenly the experiment became a lot more important.) Of course, there were other issues in the early twentieth century – relativity and quantum theory and increasing evidence suggesting that the world was just a load of particles separated by empty space. But a lot of physicists (and wireless technologists) were reluctant to immediately abandon a theory they really rather liked, and debates about the ether continued throughout the early decades of the twentieth century. Furthermore, these debates were related to other stuff going on at that time, other challenges to long-held beliefs (more on that later), which made a defence of the ether more valuable than it perhaps seems now.
Some guys talking about the ether c.1913
In 1909, Thomson described study of the ether as ‘perhaps the most fascinating and important duty of the physicist’, while Oliver Lodge declared that ‘matter acts on matter only through the ether’. (Lodge later thought he could talk to his dead son through the ether, but it’s a nice idea, don’t knock it.) Their views were entirely at odds with those of Norman Campbell, an experimental physicist at the prestigious Cavendish Laboratory in Cambridge, then under the directorship of Thomson. Campbell didn’t seem too worried about what his boss thought, and made no secret of his desire to ultimately remove all unobservables, particularly the ether, from physics. He relished Niels Bohr’s development of quantum theory in 1913, as both a lovely example of an experimentally verified theory (take that ether) and a big push for discontinuity. (Campbell thought that continuity was a bit last century.) Campbell was joined in his support for discontinuity by another Cambridge physicist, James Jeans, who was generally happy to take on board new ideas so long as they had a firm empirical backing. (Incidentally, Lodge privately described Jeans as ‘a difficult rude man’ and suggested that this was a consequence of him being ‘too well off’.) Jeans led a discussion on radiation at the 1913 meeting of the British Association for the Advancement of Science, and framed the debate in terms of continuity versus discontinuity, placing himself firmly on the side of discontinuity. He proposed not just abandoning the ether, but also relying on a purely descriptive principle (like relativity).
Lodge fought back against this view at that very same meeting. He didn’t say anything during Jeans’ radiation discussion, although he did invite the committee to continue the debate at his house the following Sunday. But he had a much larger platform anyway – the presidential address. For an hour and a half Lodge criticised what he called ‘modern tendencies’ in science, including the current ‘irresistible impulse to atomise everything’, which he saw as not only a problem in physics, with subatomic particles and quantum radiation, but also in biology with the emergence of Mendelian heredity. He also accused modern science of denying the existence of anything which could not be readily sensed or measured (take note, Jeans and Campbell). And he complained that ancient postulates were being pulled up from the roots. To make his point absolutely clear, Lodge titled his talk ‘Continuity’, here referring to continuity of matter and energy, but also continuity of thought, a link between the past and the present, a physics that would hold onto the ether and Newton’s laws.
A commitment to the ether was in some ways a commitment to the past, an aversion to revolution. Look at Frederick Soddy, the chemist who had worked with Rutherford on radioactivity. He reviewed the 1913 edition of Campbell’s book Modern Electrical Theory (which argued against the need for an ether in physical theories) and suggested that it didn’t go far enough and a more drastic reconsideration of physics was needed. Soddy was a chemist, so longheld physical theories were perhaps less important to him than they were to a theoretical physicist. He was also not one to bow down in the face of tradition more generally. In the 1920s and 1930s Soddy campaigned for economic, social and institutional reform. There was perhaps here a connection between his attitude towards rejection of long held theories in physics, and rejection of tradition more generally. For Soddy, where a system was no longer working, be it economical, social or scientific, the answer often lay in dramatic reform.
This very brief characterisation of Soddy is hopefully not too tenuous a link to my next point, which is . . .
It’s not just physics that was apparently having a revolution.
This period saw revolutions in Mexico and China, the Agadir crisis of 1911, and the (less extreme but closer to home) 1911 Parliament Act. At the same time, there was a more vague move towards the modern, with technology causing people’s lives to change at unprecedented speed. It seemed like the present was becoming disconnected from the past. And this was reflected in art and literature of the period, in the writers who abandoned linear narrative, and the painters who abandoned our basic idea of, for example, what a face looks like. Everywhere, it seemed like longheld ideas were being discarded and authority was under threat.
And the connection between physics and everything else was made explicit by one of Oliver Lodge’s colleagues at Birmingham University, the mathematics lecturer Samuel Bruce McLaren. In 1913, McLaren had written an article in the Philosophical Magazine, a well-respected (although this is debatable at this point) physics journal edited by Lodge. In it, he accused ‘Einstein’s idea of the Quantum’ of being ‘destructive of the continuous medium and all that was built upon it in the nineteenth century’. McLaren’s desire to retain the continuous medium of the ether was more than simply a commitment to a physical principle. He began his article by declaring that ‘the unrest of our time has invaded even the world of Physics, where scarcely one of the principles long accepted as fundamental passes unchallenged by all’. The problem was not simply the discontinuity of energy, but rather the discontinuity of progress, of physics proceeding not by gradually building upon the work of those who had gone before, but by tossing old theories aside and replacing them with wildly different ones. And this predicament was not exclusive to physics. Indeed, quite the opposite: McLaren believed that a more general ‘unrest of our time’ had infected physics, and he referred to a ‘spirit of revolution’. He was relating the developments in physics to a broader cultural and social shift, tying together ‘modern’ physics with modernity in general.
So that was the state of affairs around 1913. The ether’s future was uncertain and for a select few physicists this was a big deal. But there wasn’t a great deal of wider awareness at this point. This was to change, and the change happened quite soon after everybody’s fears about revolution had been realised, with the First World War. And for physicists, Einstein’s General Theory of Relativity was published in 1916, extending his earlier theory to encompass gravitation. It now posed more of a threat to the ether, and there was also the possibility of providing experimental verification of the theory. This was achieved in 1919, with the expeditions to look at an eclipse, which resulted in The Times declaring a ‘Revolution in Science’, and a speedy attempt at damage control by those physicists who didn’t want to be associated with revolution. (I’ve already written about this once so that’ll do – but if you plan on reading the rest of this post, you might need to look at that other one for some details)
The astronomer and eclipse expeditioner, A. C. D. Crommelin, quickly leapt to the ether’s defence, assuring people that of course they could keep it, they just had to accept that it didn’t have any effect on the motion of bodies, or anything really. Arthur Stanley Eddington, mastermind of the expedition, supported a similarly diplomatic ether, one that could quietly slot into modern physics without causing a fuss. Unsurprisingly, Campbell saw this as a bit of a cop out, accusing Eddington’s ether of being so different from the old one as to be unrecognisable. Lodge, meanwhile, stubbornly clung not just to an ether, but to the ether of the nineteenth century. He even went so far as to suggest that this ether contained enormous amounts of energy locked up inside of it, and that while ‘extraordinary and expensive means’ would be needed to detect the movement of the ether at all, he saw no reason why such an experiment shouldn’t be undertaken and publicly funded.
Some grew tired of the constant arguments about this mysterious substance and its role in modern physics. At the 1920 meeting of the British Association (the first since the eclipse results), Eddington chose to talk not about relativity, but the internal constitution of stars – a far more innocuous subject. The astronomical journal the Observatory noted an absence of relativity at the meeting, suggesting this was ‘because those chiefly concerned had become a little jaded with the strenuous conflict’. Lodge, however, was clearly still enjoying the conflict, and contributed a ‘controversial note on relativity’, in which he suggested that relativists should perhaps ‘be regarded as Bolsheviks and pulled up’. Oh thanks Lodge, thought Eddington (presumably) as he desperately tried to downplay connections between relativity and revolution.
Sneaky sneaky Oliver Lodge
Lodge was also confusing non-physicists, implying consensus where there really wasn’t any. Using his considerable public presence, he spent much of the 1920s writing about modern physics and the ether as if it was only a handful of extreme revolutionaries who disagreed with him. His 1924 book Atoms and Rays described the ether as the fundamental ‘cementing substance’ that held everything together and was responsible for the transmission of. His 1927 book Modern Scientific Ideas (which first appeared as a radio broadcast) insisted that continuity remained ‘the fundamental idea to which scientific philosophy will in the last resort return’. Here his discussion of quantum energy was centred on an exploration of how this new phenomena could explain interactions between matter and the ether.
Lodge wasn’t just an old hack writing books that nobody read. People did read them and his physicist peers reviewed them favourably. And in 1924, he was invited to write the introductory article for a book accompanying the ‘Pure Science’ exhibit of the British Empire Exhibition (a massive state-funded celebration of the craftsmanship, agriculture and trading and transport organisations of all of the territories of the British Empire). Lodge was actually appointed Vice-Chair of the Pure Science organising committee (which was otherwise filled with Cambridge types), despite making it very clear that he really didn’t have time to attend any meetings at all. But that didn’t matter, as he was only there to write his book contribution, on ‘Radiation’.
Here, Lodge noted that it was generally accepted that the material universe is composed of atoms, before asking:
‘But is there anything else?’
Lodge wondered if there was a third thing, beyond the two electrical units, and concluded that yes, ‘There certainly is a third thing; and, without the slightest controversy, that third thing is radiation – radiation and all that it implies. The most usual view of radiation is that it consists of waves in a connecting medium, commonly called “the ether,” and that this same unique and only ether is responsible for gravitative attraction, for electric and magnetic attractions, and for cohesion: that is, for all the forces which tend to bring bodies together, while motion tends to keep them apart. This, however, is a fact which may be expressed by different people in different ways: there are some who do not care to use the term “ether,” and are not sure of the nature of the waves, but no one can doubt the fact of radiation.’
That pesky Lodge was sort of saying that of course there was an ether, and most people agreed on this, and those who didn’t agree may have just been calling the ether by another name. (Not true Lodge, you troublemaker.) In Lodge’s defense, he did concede an apparent move away from continuity, saying that ‘radiation is showing signs of becoming atomic or discontinuous. The corpuscular theory of radiation is by no means so dead as we thought it was. And: ‘A definite experiment has proved that the smooth motion of matter as a whole has no grip on the ether.’
At the same time, he continued to push his ether research project (which had somehow not received the massive amounts of funding Lodge was convinced it deserved):
‘Whatever be the truth in this matter, a discussion on radiation will continue for a long time, and the outcome cannot fail to yield a much closer insight into the connexion between ether and matter – a problem of the highest physical and philosophical interest, which may have consequences of the utmost importance to humanity.’
The fashionable view
So Lodge was doing a pretty good job of spreading the unfashionable view far and wide, and Eddington was trying to keep everybody happy. Who was spreading the fashionable view? This job fell mostly (in my opinion) to non-physicists.
Peter Chalmers Mitchell was a highly regarded biologist, but also science writer for The Times. He was the man responsible for The Times’ 1919 ‘Revolution in Science’ article, although presumably not the headline, which doesn’t really match up with a fairly balanced account of the meeting. However, that same paper also featured an editorial by Mitchell, where he revealed his views far more freely, declaring that, based on the eclipse results, ‘the scientific conception of the fabric of the universe must be changed’.While a third prediction of Einstein’s remained in doubt, Mitchell suggested that ‘it is confidently believed by the greatest experts that enough has been done to overthrow the certainty of ages and to require a new philosophy of the universe, a philosophy that will sweep away nearly all that has hitherto been accepted as the axiomatic basis of physical thought’.
Mitchell had already made his views evident in a 1915 book called Evolution and the War. Writing about the separation between mind and reality, he declared that scientific ‘laws’ were of the human mind ‘rather than of the extended world’. This approach has a lot in common with the thoughts of another science writer, J. W. N. Sullivan. Unlike Mitchell, Sullivan wasn’t a practicing scientist, but he had sufficient scientific knowledge to apparently both understand and write about relativity theory – a rare talent. Sullivan viewed science as the result of general beliefs current in any particular age. He was an enthusiastic supporter of the new physics, and wrote endless articles about relativity for publications like the Times Literary Supplement and the literary magazine the Athenaeum. For both Sullivan and Mitchell, revolution was to be expected. And as writers, and not physicists, it was also more exciting than it was threatening.
Sullivan’s views on the ether were made clear in ‘Imagination in Art and Science’, published in the Adelphi magazine in 1924:
‘We are so far from knowing what imaginary entities are admissible that even the most successful acts of the scientific imagination are seen to have been mere approximations to the nature of the reality with which science concerns itself, and approximations precisely because the entities imagined were mythical . . . With the abolition of forces, aethers and the like, and with the advent of the altogether more emancipated kind of imagination that is Einstein’s, science has entered on a new era’.
Furthermore, Sullivan had a lot of influence with fashionable people i.e. not scientists. While Lodge’s work was mostly read by people with at least a moderate pre-existing interest in the subject, Sullivan wrote predominantly in literary magazines, and actively converted the anti-scientific. Sullivan corresponded with modernist writers like Ezra Pound and T. S. Eliot, but his most evident success was Aldous Huxley.
The two men worked together on the Athenaeum after the First World War and became friends. While Huxley originally had little sympathy for the scientific mind, Sullivan was so taken with the changes in physics that he wrote an article on ‘Science and Literature’ in which he considered ‘the serious possibility that literature has lived its day’. And in a letter to John Middleton Murry, editor of the Athenaeum, Sullivan dismissed Murry’s generous review of Ulysses, declaring:
‘The chief reason why present literature is so little important is precisely because the most important thoughts, carrying the most tremendous implications, are not represented in the literature’.
Sullivan’s views certainly had an effect on Huxley, whose 1925 satire Those Barren Leaves, depicted a character, based on Sullivan, celebrating a new ‘exciting age’ where ‘everything’s perfectly provisional and temporary – everything, from social institutions to what we’ve hitherto regarded as the most sacred scientific truths’. Oh thanks Sullivan, thought Eddington (presumably).
The end of the ether
The ether eventually disappeared from physics. It was never really disproved, it just wasn’t needed any more. Modern theoretical physics described what was going on around us using maths, and the maths worked fine without an ether. But in the 1920s, the ether still had a (small) role to play, and there were four main approaches:
1) Lodge’s ether, real and detectable and of not just theoretical, but potentially practical value.
2) Eddington’s ether, so mysterious that it might as well not be there at all. This ether was more of a rhetorical device than anything else, a tool to downplay the destructive effects of intellectual revolution, and to stop Oliver Lodge from calling you a Bolshevik.
3) No ether, a position taken by Campbell and Jeans and Sullivan and Mitchell, by people who either embraced revolution or were at least willing to put up with it.
4) And, finally, there were lots of people who didn’t care one way or another, but I haven’t talked about them, because I’m not sure it’s relevant here, and it takes a lot more research to find out what people didn’t say than what they did.
For those people who did have a mild interest in the ether, many of them would probably get their information from Oliver Lodge. He was famous and prolific, and a trusted scientist. But he wasn’t fashionable. He was an old man with a beard. The fashionable view came from people like Sullivan and his motley crew of writers. It was a view tied in with other forms of modernism, with an excitement about rapid change, about a break with the past. And it’s a view that may have obscured our understanding of the early 20th century, and caused us to forget that the ether didn’t end with the 19th century.