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Ether, or luminiferous Ether, was the hypothetical substance through which electromagnetic waves travel. It was proposed by the greek philosopher Aristotle 
and used by several optical theories as a way to allow propagation of light, which was believed to be impossible in "empty" space.
It was supposed that the ether filled the whole universe 
and was a stationary frame of reference, which was rigid to electromagnetic waves but completely permeable to matter. Hooke endorsed the idea of the existence of the ether in his work Micrographia (1665), and other several philosophers of the 17th century, including Huygens, did the same. At the time of Maxwell's mathematical studies of electromagnetism, ether was still assumed to be the propagation medium and was imbued with physics properties such as permeability and permittivity.
In 1887, a crucial experiment was performed by Michelson and Edward Morley in an attempt to detect the existence of the ether. The experiment, named the Michelson-Morley experiment in honor of its authors, shocked the scientific community by yielding results which implied the non-existence of ether. This result was later on used by Einstein to refute the existence of the ether and allowed him to develop special relativity without this artificial (and non-existent) constraint.
An instructive case-history is found in the recent history of science. In the 19th century most physicists accepted the old idea that all of space is filled with an elusive substance called the "luminiferous ether". It was well known that light, and all other electromagnetic waves traveled very well through a vacuum. Yet other waves, sound, for example, required a material medium, and a common classroom experiment showed that a ringing bell in a glass vacuum jar could not be heard, yet it could be clearly seen to be vibrating. At this time, analogical thinking was rather prevalent in physics, and by analogy, physicists assumed that light must also have some material medium, a medium that was present even in the best vacuum we could produce in a bell-jar.
All the other "manifestations of the ether", such as comet's tails and the perihelion of Mercury, that had once seemed so persuasive were found to have other explanations.
Did these experiments "disprove the ether"? I wouldn't put it that way. None of these, or any other experiment could disprove the general idea of an all-pervading ether. The point is that there is simply no experimental evidence for the ether, and no need for it in any of our physical laws or theories. You can't disprove something that isn't there, or something that doesn't affect anything material in any way. Yet even today, there are non-scientists who desperatly seek to revive this 19th century ether concept. Why? The idea seems so "right" to them. They cannot imagine light moving through "nothing". They are a classic case of people who have an emotional commitment to an appealing naive concept, and will bend physics and logic to try to justify that idea.
WHO DISLODGED THE ETHER?
(Reprinted from Psi Report no.59, December 1993)
After the last lecture meeting, we brought home a box of books, on the first stage of its journey from the SSPR library (Glasgow branch) to the SSPR library (Edinburgh branch). A book “ETHER AND REALITY” by Sir Oliver Lodge caught my eye, published by Hodder & Stoughton in 1925. As stated in the preface, it is “an attempt to set forth in intelligible fashion something of what is known about The Ether and its Functions” (author’s capital letters). What I found odd was that Sir Oliver Lodge, writing as a scientist, deals with the ether “as a substance with ascertainable physical properties” whereas, as far as I could recall, the famous Michelson-Morley experiment found no evidence for the Earth’s movement through the ether some years earlier, at the end of the 19th century -1887 to be precise.
To quote from a 1975 physics text, the experiment showed “no effect attributable to the ether; therefore no necessity for assuming the existence of an ether.” So what was Sir Oliver writing about nearly 40 years later? He even quoted Einstein in support of the ether hypothesis:
“There is a weighty argument to be adduced in favour of the ether hypothesis. To deny the ether is ultimately to assume that empty space has no physical qualities whatsoever ... According to the general theory of relativity (Einstein 1905), space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time.”
Lodge sums up the properties of ether as follows: “It is a universal connecting medium, filling all Space to the furthest limits, penetrating the interstices of the atoms without break in its continuity. So completely does it fill Space that it is sometimes identified with space … it appears as empty space because we have no sense organ for its appreciation …The first function of the ether is to weld the atoms together by cohesion, and the planets and stars together by gravitation. The second function is to transmit vibrations from one piece of matter to another.”
Watch this space: the physics of an empty box
Adapted from a radio lecture for the general public
Prof Denis Weaire
Trinity College Dublin
The Newtonian ether
In throwing off the fanciful science of the middle ages, and concentrating on what could be observed, Isaac Newton and his contemporaries constructed a new view of the world in which the contact and collision of solid bodies was the dominant theme. But even at the heart of Newton's greatest triumph - accounting for the planetary orbits in terms of a new law of gravitation - there lay an uncomfortable paradox. The law of gravitation is one of action-at-distance, between bodies across empty space. As Newton himself said:
"That one body may act upon another at a distance, through a vacuum, without the mediation of anything else by and through which their action may be conveyed from one to the other, is to me so great an absurdity that I believe no man, who has in philosophical matters a competent faculty of thinking, can ever fall into it".
Gravity and other forces which act at a distance were strongly at odds with the new outlook, so it was necessary to retain the ether in one form or another, as a fluid medium through which such interactions could be passed. The ether could also carry light, which was already recognised as a sort of wave or vibration. It was natural then to think of light waves in ether as the analogue of sound waves in air.
In Dublin, Newton's philosophy was taught by Dr. Richard Helsham, who was a physician as well as a physicist. He attended Dean Swift and enjoyed many a good dinner party with him and other Dublin intellectuals. His lectures on Natural Philosophy (published posthumously in 1739) contain an interesting problem, which was to be properly solved a century later by another Irishman, George Gabriel Stokes: what is the drag force on a sphere which moves through a fluid? Helsham's motivation for including this was the recognition that the Earth should move through the ether and might be subject to a drag force, like a soccer ball moving through the air.
There was no evidence of such a drag, nor indeed of any effects of the ether other than the physical properties which it was invented to rationalise. At that stage, arguments about the ether debate were more ad hoc philosophy than physics.
One hundred years later, mathematicians such as Stokes had made such progress in describing elastic solids and fluids that they felt ready to construct a full theory of the ether. The ensuing debate occupied the whole of the 19th century, and it is intertwined with two of the greatest achievements of that century. They were the theory of heat, and the development of an understanding of light waves.
The many varieties of material ether
Although formidable mathematics was brought to bear on the ether, it remained elusive. Light waves do not quite correspond to the vibrations of any simple solid or liquid that we know. In an effort to fit the facts, several attempts were made to make analogies with unusual materials.
For example, Osborne Reynolds got very excited by the notion that the ether might have the properties of sand. It was to be granular. He recognised that this kind of material had been overlooked by the elasticity specialists and had strange properties. They are indeed very strange - if you put a large stick into a jar of sand you may easily pull it out, but if you simply tap the jar sharply, the sand will instantly settle in such a way that the whole jar can be raised by lifting the stick. If you step on wet sand at the beach, you will see as Reynolds did that sand becomes dry around your foot, when common sense says it should become wetter. Such observations drew great admiration from the likes of Lord Kelvin (who shared with Reynolds his birthplace of Belfast), but only bemusement from Reynolds' colleagues as regards the nature of the ether. His rather undisciplined ideas are well regarded today, for granular materials are a hot topic of research and - to be fair to Reynolds - we don't understand them much better than he did.
Stokes thought the ether was more like a jelly or a wax, or like the cup of thick chocolat au lait that Sir Gabriel enjoyed one day in a Paris café, when he wrote to Lord Kelvin in Glasgow about his idea.
Kelvin himself thrashed around with ether models for fifty years. In one of these he conceived the ether as a special kind of liquid foam, and again this has a resonance in materials research today. The hypothesis he made about the ideal structure of a foam of equal-sized bubbles remained controversial for a hundred years. It was overthrown by my research student, Robert Phelan in 1994, when he was the first to find a structure of lower energy - 0.3% less. A headline at the bottom of the front page of the Irish Times read "Throwing shapes at Trinity". I have regretted ever since that I had not fed the paper a better headline "Ireland beats Scotland by 0.3%" It was the morning of the international rugby match against that country.
The end of the ether
When Kelvin conceived his foam model, lying in bed in his country house, the idea of a material ether was already in decline. Its death warrant had been signed by James Clerk Maxwell when he produced a combined theory of electricity and magnetism, out of which light waves emerged naturally as fluctuations of electric and magnetic fields.
But even Maxwell himself did not at once discard the idea of an ether. Indeed he described it as follows:
"The vast interplanetary and interstellar regions will no longer be regarded as waste places in the Universe. We shall find them to be already full of this wonderful medium; so that no human power can remove it from the smallest portion of space or produce the slightest flaw in its infinite continuity".
Only after fifty years of refinement and familiarisation of Maxwell's work did its leading proponents - the Maxwellians - firmly insist that all the properties of light could be found in Maxwell's theory.
It was against that background that Kelvin maintained his personal determination that the ether was a "real thing". Your models, said George Francis Fitzgerald, provide at best an allegory of the ether. "Certainly not an allegory on the banks of the Nile " replied Kelvin in a fitting joke for two Irishmen to share.
And even the Maxwellians kept the word ether to stand, at least poetically, for empty space endowed with Maxwell's properties, and perhaps a little more. Listen, for example, to the triumphant George Francis Fitzgerald of TCD in 1888, the acknowledged leader of the Maxwellians, telling the world the significance of the experiment of Henrich Hertz. (This experiment generated electromagnetic waves, similar to light waves but of long wavelength, by means of an electrical circuit, in accordance with Maxwellian ideas. As well as that fundamental significance it may be regarded as the invention of radio transmission).
Fitzgerald: "It was a great step in human progress when man learnt to make material machines
when he used the elasticity of his bow and the rigidity of his arrow to provide food and defeat his enemies.
It was a great advance when he learnt to use the chemical action of fire, when he learnt to use water to float his boats and air to drive them.
When he used artificial selection to provide himself with food and domestic animals.
For two hundred years he has made heat his slave to drive his machinery.
Fire, water, earth and air have long been his slaves,
But it is only within the last few years that man has won the battle lost by the giants of old.
Has snatched the thunderbolt from Jove himself.
And enslaved the all-pervading ether!"
Around the same time the material ether was dealt another blow by the experiment of Michelson and Morley, which echoes that old problem in Helsham's textbook. This failed to detect any effect of the bodily notion of the ether relative to the earth, upon light waves propagating in that ether. In today's physics textbooks, this is given a decisive role in killing off the ether, but it was in reality only one small chapter in its gradual demise. Incidentally, it was not crucial to the inspiration of Einstein's relativity either - but of such convenient myths is school and undergraduate teaching constructed.
Voices from beyond
There is another side to this story which is both amusing and sad. The mysterious ether was eagerly adopted by the spiritualists who became fashionable in the Victorian period, as a pseudoscientific justification of their claims.
By 1870 spiritualism, transplanted from the United States, had taken firm root in England. Mediums, professional and amateur, proliferated. The upper classes delighted in their performances and the leading exponents were national celebrities.
The movement found an early and influential champion from the first rank of the scientific establishment in the person of Sir William Crookes. He was impelled into that dark circle by the tragic loss of a brother. Gradually he was attracted by another emotion - he spoke of "peculiar temptations". These were embodied in the shapely form of Miss Florence Cook. Her seances featured the materialisation of another young girl, Katie King.
The scene is comic. A trivial piece of trickery, practised in the half-light, deceived an eminent man of science, whose hormones must have ruled his head. No wonder that a Hollywood movie has been considered.
Some scientists remained staunchly resistant to the new fashion and the constant invocation of the ether to support it: Faraday, Tyndall and Kelvin were all outspoken against it. But many others - such as Rayleigh, J.J. Thomson, Ramsay, Crookes and Lodge took what Kipling called "the oldest road, the craziest road of all" leading to nothing but "sorrow in store".
Remember, in order to understand their astonishing credulity, that this was the time when all sorts of new rays emerged in the laboratory. These were both real - in the case of x-rays and various emanations from radioactive substances - and imaginary, the products of self-delusion. The spurious N-rays, discovered in France by Blondlot, were and observed in Dublin by Felix Hackett, who published his findings. It seems that only the UCD students refused to believe him!
From this to the world of occult phenomena was a small step. Of the scientists who took up took it, and became devotees of spiritualism, Oliver Lodge was the most steadfast. He was more of a heavyweight academic physicist than Crookes, and indeed he tempered his advocacy with caution most of the time. In fact he was a Maxwellian, and a great admirer of his colleague across the Irish Sea, George Francis Fitzgerald. One day when walking along the Dublin Quays, I happened to step into Lafayette's old photographic studio, which happily remains there. There, to my amazement, stood on an easel a magnificent photographic portrait of Lodge.
"Do you know who that is?" I said. " Yes", said the Manager confidently, "it is Sir Oliver Lodge " and then he smiled. "But who was Sir Oliver Lodge?" Now he knows. For the studio it was just their prize example of turn-of-the-century work. For me it was like suddenly meeting an old friend.
Despite his fervent support for Maxwell's theory, Lodge still believed that, as an Irish comedian used to say "There's more". The ether was, he said, "the primary instrument of mind, the vehicle of soul, the habitation of spirit".
But like Kelvin, eventually he found himself struggling against a flood tide of scepticism as the new century dawned.
Just when it seemed that it had all been a waste of time, the paroxysm of grief engendered by the Great War created a new clientele of eager believers. In 1915, Lodge's youngest son Raymond was killed in Flanders. In his anguish he turned again to spiritualism and soon made contact with his lost, loved son.
He recounted the whole story in his book "Raymond", with the now customary chapters on life, death and the ether. It was a huge success. As the war drew to a close, the tenth edition was already being printed.
Spiritualism has since declined, but it exerts a powerful hold on a dedicated minority. The Society for Psychical Research, founded in 1882, still exists. It presumably meets regularly to engage in earnest discussions of the ether.
And perhaps this will always be so as long as we yearn for something more than a brief life and bereavement. As Yeats said :
Though grave-diggers' toil is long,
Sharp their spades, their muscles strong,
They but thrust their buried men
Back in the human mind again
HISTORY OF THE WIRE COMMUNICATIONS: BEGINNINGS OF THE TELEGRAPH AND THE TELEPHONE.
Sir Oliver Lodge, then professor of the The University of Liverpool and the professor Augustus Righi, of the University of Bologna, granted considerable attention to the discovery of Hertz and made many investigations on the properties of the vibrations of the ether. In 1889, professor Edouard Eugène Désiré Branly (1844 - 1940), French physicist, professor of The Catholic University of Paris, made the important discovery that a tube containing small metal filings placed in a crystal tube became more compact under the influence of the ether vibrations. With the Branly's coherer it was then possible, by means of the disposition shown in the attached figure, to ring a bell placed remotely of a condenser that produced a spark by discharge as it has been indicated previously. When the terminals of the loaded condenser were close enough so that the spark jumped , the vibrations of the ether caused that the metallic filings that were loose in the coherer tighten and form a mass compact enough to establish the connection between the battery and the bell.
1909. Lodge, a physicist and writer, was involved in the development of the wireless telegraph. He coined the term coherer and gained the syntonic (or tuning) patent from the United States Patent Office. More controversially, he was a longtime researcher into psychic phenomena and a dedicated believer in Spiritualism. After 1900 he became prominent in psychical research, believing strongly in the possibility of communicating with the dead. After he lost his son Raymond during WW1 he was convinced to have established contact with him through a medium. The investigation of the nature and properties of the Ether of Space was the most fascinating branch of Physics for Lodge. He presents his findings in this volume. Contents: The Luminiferous Ether and the Modern Theory of Light. The Interstellar Ether as a Connecting Medium; Influence of Motion on Various Phenomena; Experiments on the Ether; Special Experiment on Ethereal Viscosity; Ethereal Density; Further Explanations Concerning the Density and Energy of the Ether; Ether and Matter; Strength of the Ether; and General Theory of Aberration. See other titles by this author available from Kessinger Publishing.
"THE ETHER OF SPACE."; Sir Oliver Lodge Writes Entertainingly Upon the Intangible and Inaccessible "Something" which Occupies the Vast Interplanetary Spaces of the Universe. A FASCINATING BRANCH OF PHYSICS. Some Highly Interesting Comments Upon a Substance We Cannot See, Hear, Feel, Taste, Smell, Exhaust or Weigh.
June 26, 1909, Saturday
THE NEW YORK TIMES REVIEW OF BOOKS,
SEES GREAT FUTURE IN STUDY OF ETHER; Sir Oliver Lodge Believes Our Present Knowledge May Shrink to a "Pinpoint."
Special Cable to THE NEW YORK TIMES.
February 1, 1914, Sunday
LONDON, Jan. 31. -- Sir Oliver Lodge this week inaugurated the new lecture theatre of the Bedford College for Women with an address on that "Ether of Space," which has been a puzzle for all philosophers since Newton and which promises to play a leading part in scientific discoveries of the future.
Throughout his career Lodge was a prolific author and published many works. One of the most influential was the book Modem Views of Electricity, written in 1889. In it he compared the ether, of which he was one of the most persuasive believers, to an elastic jelly filling all space; he compared magnetism to whirlpools in that jelly, or to interlocking wheels. Although his theories were later proven incorrect, at the time Lodge's work included one of the most advanced theories of physics and electricity. It stimulated research that would later prove his theories wrong.
Lodge was also a President of the Society for Psychical Research. He expressed a belief in telepathy and the opinion that the easiest way to communicate with the planet Mars would be by means of gigantic geometrical figures drawn on the Sahara Desert. For many years, Lodge had been investigating psychic phenomena with his friend Sir Arthur Conan Doyle. This won him a different kind of following and inevitably some criticism from academic quarters. But Lodge, a practising Christian, never wavered from what he believed to be the truth. He wrote at the time: "I am as convinced of continued existence on the other side of death as I am of existence here." Seven years before his death, Oliver Lodge summed up his feelings on the after-life in his last book, My Philosophy: "The universe seems to me to be a great reservoir of life and mind. The unseen universe is a great reality. This is the region to which we really belong and to which we shall one day return." Before his own death in 1940, aged 89, Lodge deposited a sealed message with the Society for Psychical Research, hoping to send the message from ‘‘the other side'' through a medium. But independent observers were not convinced by attempts to contact his spirit.
Sir Oliver Lodge was a world-renowned physicist and a fearless champion of survival. One could not really call him a proponent of the Spiritualist Movement, but he was, surely, an avid believer in Spiritualist concepts.
Sir Oliver sought to bring together the transcendental world with the physical universe. He affirmed, with great conviction, that life is the supreme, enduring essence in the universe; that it fills the vast interstellar spaces; and the matter of which the physical world is composed is a particular condensation of ether for the purpose of manifesting life into a conscious, individual form.
Sir Oliver's first experiences in psychical research dates back to 1883 and 1884, when he was invited by Mr. Malcolm Guthrie to join his investigations in thought transference in Liverpool, England.
His most notable observations in physical mediumship were made with the famous Italian medium, Eusapia Paladino. He attended four sittings with Eusapia and reported his findings in the Journal of the Society for Psychical Research, November, 1884. He accepted the reality of the phenomena observed through the medium, and he wrote the following concerning his observations:
"However the facts are to be explained, there is no further room in my mind for doubt. Any person without invincible prejudice who had had the same experience would come to the same broad conclusion, viz., that things hitherto held impossible do actually occur.
"If one such fact is clearly established, the conceivability of others may be more readily granted, and I concentrated my attention mainly on what seemed to me the most simple and definite thing, viz., the movement of an untouched object in sufficient light for no doubt of its motion to exist.
"This I have now witnessed several times; the fact of movement being vouched for by both sight and hearing, sometimes also by touch, and the objectivity of the movement being demonstrated by the sounds heard by an outside observer, and by permanent alteration in the position of the objects.
"The result of my experience is to convince me that certain phenomena usually considered abnormal do belong to the order of nature, and as a corollary from this, that these phenomena ought to be investigated and recorded by persons and societies interested in natural knowledge."
Few books can have been received with such a storm of protest, amazement and incredulity as that which greeted the publication of Raymond by Sir Oliver Lodge in November 1916.
Colleagues of the distinguished physicist were appalled by its contents; friends who did not share his beliefs worried about his mental health; and the general public began to regard him as a gullible crank.
The reason? The secondary title of his famous work was 'Evidence for Survival of Memory and Affection after Death', and it consisted mainly of conversations he claimed to have had with his much-loved youngest son, Second Lieutenant Raymond Lodge, who was killed by a shell in Flanders on September 14, 1915.
Chapter 14: She Convinced Sir Oliver Lodge of Survival
Story of Mrs. Eleonore E. Piper
Beyond Human Personality, Being a detailed description of the Future life
The following essays were written automatically by Miss Geraldine Cummins in precisely the same manner as those contained in the book entitled The Road to Immortality. They purport to be communicated by the late F. W. H. Myers, one of the founders of the Society for Psychical Research and explain his conception of life after death in greater detail than was possible in the earlier volume.
In the above mentioned book is also presented a series of evidential cases which would seem to answer Professor MacBride's question (p. 10) and to offer cogent proof of the survival of human personality. It has not, therefore, seemed necessary to include in the present volume these and other evidential cases received through the mediumship of Miss Cummins. For such evidence readers are referred to the previous volume and also to various articles which have appeared in Light, the Journal of the Society for Psychical Research and other psychic papers during the last few years.
In his Foreword to The Road to Immortality, Sir Oliver Lodge describes Miss Cummins as "an amateur trance-writer... an amanuensis of reasonable education, characterised by a ready willingness for devoted service and of transparent honesty."
The present volume was sent to him and in a letter to me he says that he has "no reason to doubt the likeness to Myers' utterances except perhaps what is said about solar beings and about conditions of life
Mountain Paths
by
MAURICE MAETERLINCK
Translated by
ALEXANDER TEIXEIRA DE MATTOS
NEW YORK
DODD, MEAD AND COMPANY
1919
MESSAGES FROM BEYOND THE GRAVE
1
SIR OLIVER LODGE is one of the most distinguished men of learning in our day. He is also one of the oldest, most active and most prominent members of that well-known Society for Psychical Research which, founded in 1882, has ever since striven to study with irreproachable scientific precision all the wonderful, inexplicable, occult and supernatural phenomena which have always baffled and still elude the comprehension of mankind. In addition to his purely scientific works, of which, not being qualified to judge, I do not speak, he is the author of some extremely remarkable books, such as Man and the Universe, The Ether of Space and The Survival of Man, in which the loftiest and most daring metaphysical speculations are constantly controlled by the most prudent, wise and steadfast common sense. Sir Oliver Lodge, therefore, is at the same time a philosopher and a practical, working scientist, accustomed to scientific methods which do not readily allow him to go astray; he has, in a word, one of the best-balanced brains that we could hope to meet; and he is convinced that the dead do not die and that they are able to communicate with us. He has tried to make us share his conviction in The Survival of Man. I am not sure that he has quite succeeded. True, he gives us a certain number of extraordinary facts, but they are facts which, in the last resort, can be explained by the unconscious intervention of intelligences other than those of the dead. He does not bring us the irrefutable proof, such as we should consider, for instance, the revelation of an incident, a detail, a piece of information so absolutely unknown to any living creature that it could come only from a spirit no longer of this world. We must admit, however, that such a proof is, as he says, as difficult to conceive as to provide.
I will not enter into the details of the numerous sittings which preceded or followed this one; nor will I even undertake to summarize them. To share the emotion aroused, we must read the reports which faithfully reproduce these strange dialogues between the living and the dead. We receive the impression that the departed son comes daily closer and closer to life and converses more and more easily, more and more familiarly with all those who loved him before he was overtaken by the shadows of the grave. He recalls to each of them a thousand little forgotten incidents. He remains among his own kindred as though he had never left them. He is always present and prepared to answer. He mingles so completely in their whole life that no one any longer thinks of mourning his loss. They question him about his present state, ask him where he is, what he is, what he is doing. He needs no pressing; he at once declares himself astonished at the incredible reality of that new world. He is very happy there, reforming himself, condensing himself, so to speak, and gradually finding himself again.
But I must set a limit to speculation and, lest I exceed the limits of this essay, I must pass by two or three revelations less striking than that of the photograph, but pretty strange notwithstanding. Obviously, it is not the first time that such manifestations have occurred; but these are really of a higher quality than those which crowd several volumes of the Proceedings. Do they furnish the proof for which we ask? I do not think so; but will any one ever be able to supply us with that compelling proof? What can the discarnate spirit do when trying to establish that it continues to exist? If it speak to us of the most secret, the most private incidents of a common past, we reply that it is we who are reviving those memories within ourselves. If it aim at convincing us by its description of the world beyond the grave, not all the most glorious and unexpected pictures of that world which it might trace are worth anything as evidence, for they cannot be controlled. If we seek a proof by asking it to foretell the future, it confesses that it does not know the future much better than we do, which is likely enough, seeing that any knowledge of this kind implies a sort of omniscience and consequently omnipotence which can hardly be acquired in a moment. All that remains to it, therefore, is such little snatches of evidence and uncertain attempts at proof as we find here. It is not enough, I admit; for psychometry, that is to say, a similar manifestation of clairvoyance between one living subconsciousness and another, gives almost equally astonishing results. But here as there these results show at least that we have around us wandering intelligences, already enfranchised from the narrow and burdensome laws of space and matter, that sometimes know things which we do not know or no longer know. Do they emanate from ourselves, are they only manifestations of faculties as yet unknown, or are they external, objective and independent of ourselves? Are they merely alive in the sense in which we speak of our bodies, or do they belong to bodies which have ceased to exist? That is what we cannot yet decide; but it must be acknowledged that, once we admit their existence, which at this date is hardly contestable, it becomes much less difficult to agree that they belong to the dead.
Past and Future
By Sir Oliver Lodge
It is possible that the ether can automatically retain a record of the past capable of being deciphered and interpreted by intelligence. By suitable devices records may indeed he incorporated in matter, as in photographic plates and gramophone disks, but, like all material aggregates, such records fade or wear out, whereas the clarity of an etheric record continues undiminished for ever. When we look through a telescope at a nebula or star cluster we are gazing on the distant past - thousands or even millions of years ago - and extracting information from it. Thus is the past brought to our present apprehension. Not by such aid can we directly apprehend the future. Yet we can anticipate, plan, and to some extent predict: and what we can thus do consciously we may be able perhaps to do more mystically by intuition or inspiration. It becomes a question well worthy of attention, how far the future is accessible, whether it is decipherable to beings of any kind, whether it in any sense already exists, and what power our faculties have of catching glimpses of the future as well as of the past. Unfortunately this enquiry is at present hampered by obsolete legislation; the common sense of mankind has decided that the future is hopelessly inaccessible. But the common sense of mankind has before now decided many other things which have turned out wrong. A spherical and revolving earth, flying annually round the sun was repugnant to common sense at one time. The intuitions of genius may be a guide worth following up and submitting to verification: the presumptions of uninstructed ignorance are apt to lead us astray into positions whence extrication is troublesome. Security in a false position devoid of any real foundation can only be sustained or bolstered up by the abominable resources of persecution: a brutal buttress of blundering bigotry which Ecclesiastics and Legislators have not scrupled to employ in the past.
Linking survival after death with sub atomic physics is censored in Great Britain.
Introduction by Michael Roll.
This article by Sir Oliver Lodge was published in The Queen's Hospital Annual in 1933 (Birmingham). It is because this great scientist wrote articles and published books along these lines that he has been vilified by obscurants who have taken control of scientific teaching throughout the world.
Sir Oliver Lodge was the first person to send a radio message, one year before Marconi! His great contribution to science has been deliberately played down solely because the powerful materialists are terrified that millions may find out he was correct in saying that we all survive death.
The same treatment has been meted out to Sir William Crookes who actually proved by repeatable experiments under laboratory conditions that the subject of survival after death is a branch of physics - natural philosophy. Crookes was a President of the Royal Society, inventor of the Cathode-ray tube. Look up x-rays in the encyclopaedia, Crookes was the pioneer of subatomic physics - proving that reality exists beyond our five physical senses.
Censorship and character assassination are the only weapons that those with a great deal to lose from the truth have in their armoury. The attack on Sir William Crookes has been so vicious that he now carries the emotive labels of liar, cheat, crank, fraud, gullible idiot, Spiritualist, and they have also tagged on that he was a heterosexual sex maniac, just in case the other labels are not enough.
This Sir Oliver Lodge article will be censored by every large circulation paper and magazine in the world. People will only begin to find out just how badly they are being deceived by their leaders and teachers if this pamphlet is passed from hand to hand.
The December, 1932 ish of Modern Mechanix immortalized this wondrous and loony German machine that measured the drift of the ether, "that impalpable substance which, according to one school of thought, fills the space in which the universe swims." 
It is an apparatus to measure the drift of the ether, that impalpable substance which, according to one school of thought, fills the space in which the universe swims. Theoretically the motion of the earth, passing through this ether, should set up a drift comparable to the breeze generated by the motion of an automobile through the air. To determine if such a drift actually does exist, the elaborate optical apparatus shown on this page was built by German scientists It consists of four arms on a perpendicular axis, containing a series of mirrors, lenses, and reflecting plates. A ray of light enters at the top of the device and is bounced back and forth thousands of times, finally emerging at the bottom, where its passing leaves a record on a photographic plate.
This article follows the development of physicist Oliver Lodge's religio-scientific worldview, beginning with his reticent attraction to metaphysics in the early 1880s to the full formulation of his 
ether theology
in the late 1890s. Lodge undertook the study of psychical phenomena such as telepathy, telekinesis, and ectoplasm to further his scientific investigations of the ether, speculating that electrical and psychical manifestations were linked phenomena that described the deeper underlying structures of the universe, beneath and beyond matter. For Lodge, to fully understand the ether was to force from the universe an ultimate Revelation, and psychical research - as the most modern and probatory science - was poised to replace religion as the means of that disclosure. © 2007 Wiley Periodicals, Inc.
Psychotronics began to become an organized discipline in the West when the Society for Psychical Research was established in London in 1882 (Jane Oppenheim, 1986). Many of the 19th Century's most famous scientists joined this Society. Among them were such noted scientific giants as Lord Rayleigh, J. J. Thomson, William Crookes, and Sir Oliver Lodge. In 1922, Sir Oliver Lodge wrote an article presenting his views on psychic science (J. Arthur Thomson, 1922), which were strongly influenced by his belief in the ether. The concept of an ether is experiencing a great revival at the present time, so it is of interest to consider the following quote from this 1922 article:
United States Psychotronics Association
"Some of us are beginning to suspect that these psychical entities are able to utilize the properties of the ether, too—that intangible and elusive medium which fills all space—and if that turn out to be so, we know that this vehicle or medium is much more perfect, less obstructive, and more likely to be permanent, than any form of ordinary matter can be. For in such a medium as ether, there is no wearing out, no decay, no waste or dissipation of energy such as is inevitable when work is done by ponderable and molecularly constituted matter-that matter about which chemists and natural philosophers have ascertained so many and such fascinating qualities. Physicists, chemists, and biologists have arrived at a point in the analysis of matter which opens up a vista of apparently illimitable scope. Our existing scientific knowledge places no ban on supernormal phenomena; rather, it suggests the probability of discoveries in quite novel directions."
It appears that to Sir Oliver Lodge, psychotronics was merely an extension of physical science.
Even though the term psychotronics has been constantly used in this article, it was not coined until the 19th Century _ when it appears to have originated with the Soviets, who began very active research in the late 1950's in an area they referred to as psychoenergetics (Krippner, Rubin, 1974). To the Soviets, however, psychotronics was merely a subset of psychoenergetics. In America today, the I term psychotronics is being used to include all phenomena I which the Soviets referred to as "psychoenergetics."
One might define the area of psychotronics as that domain of human inquiry which includes the study of all phenomena that are created by the direct interaction of the living force, vril, with the ether medium. Here, the term vril is far more inclusive than the term "bioplasma" which is only a certain expression of the vril. To the psychotronic investigator, thoughts are things, and they lie at the foundation of all phenomena, physical and non-physical.
The development of psychotronics in the United States is of recent origin. In December, 1969, the American Association for the Advancement of Science formally admitted the Parapsychological Association into its ranks. Thus the of study of paranormal phenomena can henceforth be I pursued with some official sanction, a blessing which has been hard to win.
Prior to 1972, if one was asked about the state of psychic research in the United States, about all that would s come to mind would be the work of Dr. J. B. Rhine at Duke University which began in the 1935 time frame. Indeed, until the early 1970's, work in psychotronics was kept alive in the United States only by a very few devoted scientists and laymen receiving little or no support, official or otherwise. Even today, support for such work is difficult to obtain. However, there is now a much larger number of dedicated researchers painfully advancing the state of the art.
I believe that the initial impulse which started serious development of psychotronics in the United States was the publication of the book Psychic Discoveries Behind the Iron Curtain (Ostrander & Schroeder, 1970). This book stimulated private researchers in the United States to organize and attempt to reproduce Soviet work in psychotronics. Ken Johnson, Howard Burgess, and I nearly simultaneously reproduced the Kirlian camera in early 1971. Controversy still surrounds this device which is reported to be able to detect the living "bioplasma field" around the human body by causing a high voltage electrical corona to interact with it, an effect which reminds one of the interaction of iron filings with a magnetic fiel
Electric Theory of Matter by Sir Oliver Lodge 1904
Matter then appears to be composed of positive and negative electricity and nothing else. All its newly discovered, as well as all its long-known, properties can thus be explained:--- even the long-standing puzzle of "cohesion" shows signs of giving way. The only outstanding still intractable physical property is "gravitation," and no satisfactory theory of the nature of gravitation has been so far forthcoming. I doubt however if it is far away. It would seem to be a slight but quite uniform secondary or residual effect due to the immersion of a negative electron in a positive atmosphere. It is a mutual force between one atomic systemand another, which is proportional to the number of electrons in each. It is quite doubtful whether it is displayed to be an isolated or disembodied electron, but the act of immersing an electron in its attracting atmosphere may develop it. We know too little about electricity, especially about positive electricity, to be able to justify or expand such a guess; but, as a guess and no more, I venture to throw it out: believing it to be a static residual strain effect not due even to corpuscular motion, or to any other modifiable circumstance, but inherent in the constitution of each atom, whether it be an entire complex or be, broken up into simpler substances.
If it be true that every atom occupies the same volume of space, then gravitation might seem to be an effect depending on the crowdedness of electrons; but when an atom, breaks up into unequal parts, the smaller portion must in that case undergo considerable expansion, and that would be inconsistent with the constancy of gravitation, if it depended on crowdedness: hence I think it more probable that it depends on some interaction between positive and negative electricity, and that it is generated when these two come together, that is whenever an atom of matter is formed.
The formation of an atom of matter out of electricity is a new idea, and has as yet no experimental justification. The breaking up of complex atoms into simpler forms, and the partial resolution of an atom into dust or constituent electrons, is all that is as yet experimentally justifiable and all therefore that ought to be mentioned; but the inverse process seems to me naturally to follow, and I look to the time when some, laboratory workers will exhibit matter newly formed from stuff which is not matter, instead of as now only recognizing the transmutation of some pre-existing complex atoms into simpler atoms. The evolution of matter was glimpsed as a brilliant dream by Sir W. Crookes, when he presided over the Chemical Section of the British Association in Birmingham in 1886: he may Yet live to see his dream come true.
The family relationship between the atomic weights of the elements, described by Mendelejeff and others, paved the way for and suggested the vision: scientific. progress ever Since has brought it nearly to realization; and the splendid mathematical theories of J. J. Thomson and Larmor, concerning the properties and powers of electric charges, have now rendered possible a far greater precision of imagination than was then possible, and have engendered the conception of an atom of matter composed wholly of electricity:---which thus steps on to the stage as the fundamental and really atomic substance.
The Physical basis of life still eludes us; and until we are willing to look outside our material environment into another order of things, the full truth concerning life and mind will I believe continue to be unrecognizable. But let us always remember that both life and mind have a physical basis, a complete material aspect: it may be possible for the mechanism of this aspect to be dragged to the light of day and displayed, perhaps as clearly and definitely as we hope before long to be able to display the constitution of matter itself. Let not the reader of this article assume that it represents more than the gropings of a searcher after knowledge, illuminated by the light of his brethren, trained quickly to seize and understand, and trying to act as an instructed guide or interpreter amid the haze; though he recognizes, and would have others recognize, that the haze has not yet lifted, and that accordingly his statements must be understood as nothing more than an approximation to the truth.
Sir Oliver Lodge on Radium
On Tuesday January 5, 1904, Sir Oliver Lodge, the British scientist and Fellow of the Royal Society was in Birmingham where he delivered two lectures on radium.
What follows, for your amusement and edification, is an extract from the January 8, 1904 issue of 'The Engineer' newspaper which covered the event commenting quite liberally upon the worth of Sir Oliver's statements.
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On Tuesday, Sir Oliver Lodge delivered in Birmingham two lectures on radium - the second to working men. The Town Hall was filled, and not nearly enough room was available for all those who desired to attend. Dr. Lodge had, however, very little to tell his audience that was new. There were, however, certain statements made by Sir Oliver Lodge which demand careful consideration.
It is useless to lecture in a language that cannot be understood by anyone save the lecturer and perhaps a select few. The time has come, we think, for stating very plainly that unless the physicist can hit upon language that will convey definite ideas it is well that he should not theorise about facts.
Dr. Lodge told his hearers that electricity exists in small particles; that atoms consist of positive and negative electricity; and nothing else.
Here at one fell swoop we have all existing concepts of ultimate matter cleared away, and in return we get electricity.
No one knows what electricity is, but not very long since it was taught by the physicist that it was an ether vibration akin in its nature to light. It is a suggestive fact that Sir Oliver Lodge did not once mention the ether, and, so far as can be seen, science seems to have dispensed with its services in the future.
If matter is also cleared out, it becomes essential that some definition of electricity should be aimed at. We are told that radium emits particles, and that these particles must be electricity, and as there is nothing but electricity left, it appears that radium is itself electricity.
It will not do to say that electricity consists of particles, and that particles consist of electricity. It will not be easy to persuade a sailor that an armour plate is nothing but electricity, or an engineer that coal, water, steam, and cast iron are the same.
The impression left on the mind by talk like this is that Sir Oliver Lodge has no very definite ideas himself about the constitution of the universe.
At all events, ordinary brains cannot follow him into transcendental regions which are indistinguishable from metaphysics.
Spiritualism and Electromagnetism
In an article on “Ether” for the Encyclopedia Britannica Maxwell wrote
Ether or Aether (aiqhr probably from aiqw I burn) a material substance of a more subtle kind than visible bodies, supposed to exist in those parts of space which are apparently empty… Whatever difficulties we may have in forming a consistent idea of the constitution of the aether, there can be no doubt that the interplanetary and interstellar spaces are not empty, but are occupied by a material substance or body, which is certainly the largest, and probably the most uniform body of which we have any knowledge. Whether this vast homogeneous expanse of isotropic matter is fitted not only to be a medium of physical interaction between distant bodies, and to fulfill other physical functions of which, perhaps, we have as yet no conception, but also ... to constitute the material organism of beings exercising functions of life and mind as high or higher than ours are at present - is a question far transcending the limits of physical speculation.
Some of Maxwell’s close friends and followers were less cautious in their ethereal speculations. For example, in 1873 Peter Guthrie Tait, along with Balfour Stewart, wrote a book entitled “The Unseen Universe”, expounding on the probable spiritual functions of the luminiferous ether.
We attempt to show that we are absolutely driven by scientific principles to acknowledge the existence of an Unseen Universe, and by scientific analogy to conclude that it is full of life and intelligence - that it is in fact a spiritual universe and not a dead one.
Tait was enamored of William Thomson’s idea that matter consists of Helmholtzian vortices in a perfect fluid ether. The book (which enjoyed huge popularity in its time) argued that the forms of matter and mind survive eternally as configurations of spirit in the ether.
Lord Rayleigh, who was Maxwell’s successor as head of the Cavendish Laboratories at Cambridge from 1879 to 1884, and President of the Royal Society from 1905 to 1908, also served as President of the Society for Psychical Research. He is well known for his experiment of 1902 which was designed to detect evidence of the luminiferous ether, and for the discovery of the element argon (for which he was awarded the Nobel prize for physics in 1904). His interest in psychical phenomena is less well known, but his obituary in 1919 reported on an address he had given to the Society for Psychical Research, in which
... he recalled some experiments in hypotonic suggestion in which he took part at Cambridge in the sixties of last century, and which convinced him of the possibility of influencing unwilling minds by suggestion. Later he became interested in the doings of [Daniel Dunglas] Home and other so-called mediums, and though he pronounced the results on the whole to be disappointing, he found some of the incidents difficult to explain.
Among those “difficult to explain” incidents were levitations performed by Home. A contemporary of Rayleigh’s, Sir William Crookes, discoverer of the element thallium, and researcher in the field of radioactivity, reported that
On three separate occasions I have seen him raised completely from the floor of the room… On each occasion I had full opportunity of watching the occurrence as it was taking place…
The number of well-attested incidents of levitation led some people to speculate that some kind of mass hypnosis was involved. Hypnotism itself had only recently been recognized as a genuine phenomenon, the word having been coined by the Scottish surgeon James Braid in the 1840s. As an aside, about a century later, another Nobel prize winner, Richard Feynman, one of the founders of modern quantum electrodynamics, was also interested in hypnotism. He wrote about volunteering to be a subject for a demonstration of hypnosis while he was a student at Princeton.
He started to work on me, and soon I got into a position where he said “You can’t open your eyes”. I said to myself “I bet I could open my eyes, but I don’t want to disturb the situation: Let’s see how much further it goes”. It was an interesting situation. You’re only slightly fogged out, and although you’ve lost a little bit, you’re pretty sure you could open your eyes. But of course you’re not opening your eyes, so in a sense you can’t do it… I found hypnosis to be a very interesting experience. All the time you’re saying to yourself , “I could do that, but I won’t” – which is just another way of saying that you can’t.
Feynman also wrote about a psychiatric exam he was given to see if he was fit to be drafted, and during one of the interviews he admitted that he sometimes talked with his deceased first wife. This admission led to a series of questions about whether he believed in the “supernormal”. Feynman answered “I don’t know what the supernormal is”, and the questioner said “It’s what Sir Oliver Lodge and his school believe in”. Lodge had been a prominent physicist in the late 19th and early 20th centuries. He invented the coherer in 1887, making possible the first practical wireless communications. He also devoted much effort to a study of the luminiferous ether. He wrote in his book “The Ether of Space”
The universe we are living in is an extraordinary one; and our investigation of it has only just begun. We know that matter has a psychical significance, since it can constitute brain, which links together the physical and the psychical worlds. If any one thinks that the ether, with all its massiveness and energy, has probably no psychical significance, I find myself unable to agree with him.
Like his friend Arthur Conan Doyle, Lodge was a strong supporter of the spiritualist movement (and remained so, even after many of the original founders of the movement had confessed to being frauds), and he ardently believed in the possibility of communicating with the dead. In 1919 he wrote a book called “Raymond” about his attempts to communicate with his son, who had been killed in 1915 during the first world war. It’s interesting that the early development of wireless communication (not to mention modern field theories) seems to have been motivated, at least in part, by efforts to identify a mechanism for immortality and to communicate with departed spirits. In a sense, these efforts succeeded, because they led to the realization that the electromagnetic images of everyone who has ever lived have propagated out into space, and could (in principle) still be seen by sufficiently distant observers (or even by ourselves, taking reflections into account) with sufficiently sensitive detectors. We also have the photographic techniques, developed during the 19th century, recording electromagnetic patterns in a more permanent medium. This technology led to its own set of investigations into supernormal images of spirits and fairies discerned on photographic plates.
It’s also interesting to note that both spiritualism and Maxwell’s concept of electro-magnetism involve a “medium”. Some have said that the ether was the creation of British physicists, since they were the most devoted to the concept of a medium as the mechanism for all physical effects. They seemed enthralled by Maxwell’s words at the conclusion of his 1873 work on electricity and magnetism:
All these theories lead to the conception of a medium…, and if we admit this medium as an hypothesis, I think it ought to occupy a prominent place in our investigations, and that we ought to endeavor to construct a mental representation of all the details of its actions, and this has been my constant aim in this treatise.
In other words, as he might almost have said, “the medium is the message”. Ironically, Maxwell himself later gave up his focus on “the details of its action”, and began to adopt a more abstract Lagrangian approach, admitting that although literal mechanical representations may have some heuristic value, they could not claim any ontological status. Most of the subsequent Maxwellians continued this trend toward abstraction, although some (such as Lodge and Thomson) continued to romance the ether.
The parallel progress of spiritualism and the luminiferous ether continued to the close of the 19th century, as both of them lost popularity. The interferometer experiment of Michelson and Morley in 1887 cast doubt on the viability of the mechanistic ether models, and Margaret Fox’s public admission of fraud in 1888 greatly discredited the spiritualist movement. (Her confession is fascinating, explaining how she and her little sister Kate began by making strange noises at bedtime to frighten their mother.) By 1905 the spiritualism craze was definitely waning, and Einstein wrote his famous paper on the electrodynamics of moving bodies, arguing that even the highly abstract ether of Lorentz was superfluous for the description of phenomena.
Subsequently, in the aftermath of the first world war, there was a re-emergence of spiritualism, sometimes attributed to the grief over loved ones lost in the war, and the yearning to communicate with them. As mentioned above, Sir Oliver Lodge lost his son Raymond in the war, and devoted much time and effort afterwards to trying to communicate with him. (When Lodge himself died in 1940 he left behind a sealed message, and instructions for researchers to try to get his spirit to reveal the message; the experiment was not successful.) Oddly enough, the ether of scientific field theories also re-emerged during the first world war. Einstein later acknowledged to Lorentz that the general theory of relativity (completed in 1915, the same year Raymond Lodge was killed) is actually more congenial to an ether interpretation than is the special theory of 1905. This is because spacetime in the general theory is endowed with properties (e.g., curvature) that vary from place to place. Of course, as Einstein explained in his Leyden lecture in 1920, the “ether” of general relativity is profoundly different from the old luminiferous aether of the classical theory of electromagnetism, because the latter was conceived to exist within space and time, whereas the former actually is space and time.
TOWARD A NEW ELECTROMAGNETICS
PART III: CLARIFYING THE VECTOR CONCEPT
After the profound work of Maxwell, the idea of FIELDS OF FORCE became more prominent, until the field concept ruled the day5. The electricians continued, pushing the idea of fields into space and vacuum itself, along the way inventing the idea of "charge effects" existing even in the massless vacuum, with concomitant fields. Meanwhile, they had thoroughly confused chargeless point-smeared, chargeless mass-smeared, length-smeared and time-smeared vectors.
After a set of fundamental experiments designed to detect motion of the material ether yielded essentially null results6, Michelson and Morley were regarded as having completely disposed of the ether -- even though the experiments only disposed of material ethers, and not Lorentz-invariant non-material ethers7. Maxwell's equations and the field concept were elevated to profound importance.8 Then, after Einstein's fundamental relativity work shortly after the turn of the century, the ether concept faded away and the field concept reigned supreme. Indeed, in their enthusiasm the interpreters of relativity went so far as to affirm that one can have a wave without any medium; that is. that something can be moving (waving) without anything there to move!9 And with great glee they pronounced the final end to the idea of "ether" as a medium, even though Einstein himself never did any such thing.10 With the advent of Einstein's General Theory of Relativity, even matter came to be regarded as just a special "kink" or curvature in spacetime or "vacuum nothing."
Quantum mechanics arose and even certainty and determination fell. Chaos, probability, and randomness now assumed the ruling position. Probability waves (and probability fields) arose,11 as did quantum fields of various kinds. The intermingling of these concepts with the concepts of electrodynamics pushed the idea of the field even farther into esoteric realms.
The point is, each of these developing disciplines incorporated and built on the foregoing disciplines. From the beginning of geometry, there was no rigorous definition of a vector, and there is none today.12 From the beginning of mechanics, in their foundations the theorists made grave logical errors by incorporating the geometer's vector; errors so great that today mechanics and electromagnetics are severely flawed, as is everything that came after them and built upon their illogical foundations. Sir Oliver Lodge and Relativity
Lodge's ether was always a more subtle concept than many people have realized: 'Objections to the ether are really objections to the nineteenth century conception based in terms of mechanical models. No such ether exists ... .' 14 'I have abandoned the old material ether of Lord Kelvin and the nineteenth century in favour of some hydrodynamic or other perfect mechanism at present unknown.' 15 The fact that mass is purely electromagnetic in origin, he said, must mean that all energy, including mc2, is due to space. Lodge believed that Einstein, in his later work, fundamentally agreed with him. The two men met in Oxford in June 1933. According to Lodge's notes of their conversation, Einstein said that he had gone through three stages with respect to the ether: first, a belief in the old dynamical theory; second, total disbelief; and finally, a belief that the ether is responsible for everything, though a disbelief that it has motion. 16
Scientific concepts seldom emerge in the clear-cut way that we like to present them, and, though the concept of 'relativity' is predominantly associated with Einstein, many other physicists played a part in shaping the theory. Lodge's contributions, though little understood today, were among the most significant - from early theoretical ideas, like worldlines and the Sagnac effect, through the experimental disproof of ether drag, to the brilliant conjectures concerning gravitational lenses, black holes and neutron stars of his later years. Not least among his contributions is the critical attitude he brought to the foundations of both STR and GTR, and his partial realization, along with Larmor, that the resolution of these difficulties required a deeper understanding in areas that we would now describe as quantum mechanics and particle physics. Some of these difficulties still remain to be resolved today.
The Theory of the Relativity of Motion
By Richard Chace
This classic early introduction to Einstein's theory, written by a prominent physicist, provides an excellent introduction for the uninitiated and the necessary methods for those pursuing the theory's more complicated applications. It considers the two main postulates upon which the theory rests and their experimental evidence, followed by an elementary deduction of the postulates' consequences, a variety of kinematic applications, and the development and application of a particle dynamics theory. The relation between relativity theory and the principle of least action receives a full treatment, and the text concludes with an exposition of a four-dimensional method of expressing and treating the results of relativity theory. 1917 ed.
Ether and the Theory of Relativity
Albert Einstein, an address delivered on May 5th, 1920, in the University of Leyden.
The original version is available in the Collected Papers of Albert Einstein.
See also the Einstein Archives Online.
HOW does it come about that alongside of the idea of ponderable matter, which is derived by abstraction from everyday life, the physicists set the idea of the existence of another kind of matter, the ether? The explanation is probably to be sought in those phenomena which have given rise to the theory of action at a distance, and in the properties of light which have led to the undulatory theory. Let us devote a little while to the consideration of these two subjects.
Outside of physics we know nothing of action at a distance. When we try to connect cause and effect in the experiences which natural objects afford us, it seems at first as if there were no other mutual actions than those of immediate contact, e.g. the communication of motion by impact, push and pull, heating or inducing combustion by means of a flame, etc. It is true that even in everyday experience weight, which is in a sense action at a distance, plays a very important part. But since in daily experience the weight of bodies meets us as something constant, something not linked to any cause which is variable in time or place, we do not in everyday life speculate as to the cause of gravity, and therefore do not become conscious of its character as action at a distance. It was Newton's theory of gravitation that first assigned a cause for gravity by interpreting it as action at a distance, proceeding from masses. Newton's theory is probably the greatest stride ever made in the effort towards the causal nexus of natural phenomena. And yet this theory evoked a lively sense of discomfort among Newton's contemporaries, because it seemed to be in conflict with the principle springing from the rest of experience, that there can be reciprocal action only through contact, and not through immediate action at a distance.
It is only with reluctance that man's desire for knowledge endures a dualism of thls kind. How was unity to be preserved in his comprehension of the forces of nature? Either by trying to look upon contact forces as being themselves distant forces which admittedly are observable only at a very small distance and this was the road which Newton's followers, who were entirely under the spell of his doctrine, mostly preferred to take; or by assuming that the Newtonian action at a distance is only apparently immediate action at a distance, but in truth is conveyed by a medium permeating space, whether by movements or by elastic deformation of this medium. Thus the endeavour toward a unified view of the nature of forces leads to the hypothesis of an ether. This hypothesis, to be sure, did not at first bring with it any advance in the theory of gravitation or in physics generally, so that it became customary to treat Newton's law of force as an axiom not further reducible. But the ether hypothesis was bound always to play some part in physical science, even if at first only a latent part.
When in the first half of the nineteenth century the far-reaching similarity was revealed which subsists between the properties of light and those of elastic waves in ponderable bodies, the ether hypothesis found fresh support. 1t appeared beyond question that light must be interpreted as a vibratory process in an elastic, inert medium filling up universal space. It also seemed to be a necessary consequence of the fact that light is capable of polarisation that this medium, the ether, must be of the nature of a solid body, because transverse waves are not possible in a fluid, but only in a solid. Thus the physicists were bound to arrive at the theory of the ``quas-irigid'' luminiferous ether, the parts of which can carry out no movements relatively to one another except the small movements of deformation which correspond to light-waves.
This theory also called the theory of the stationary luminiferous ether moreover found a strong support in an experiment which is also of fundamental importance in the special theory of relativity, the experiment of Fizeau, from which one was obliged to infer that the luminiferous ether does not take part in the movements of bodies. The phenomenon of aberration also favoured the theory of the quasi-rigid ether.
The development of the theory of electricity along the path opened up by Maxwell and Lorentz gave the development of our ideas concerning the ether quite a peculiar and unexpected turn. For Maxwell himself the ether indeed still had properties which were purely mechanical, although of a much more complicated kind than the mechanical properties of tangible solid bodies. But neither Maxwell nor his followers succeeded in elaborating a mechanical model for the ether which might furnish a satisfactory mechanical interpretation of Maxwell's laws of the electro-magnetic field. The laws were clear and simple, the mechanical interpretations clumsy and contradictory. Almost imperceptibly the theoretical physicists adapted themselves to a situation which, from the standpoint of their mechanical programme, was very depressing. They were particularly influenced by the electro-dynamical investigations of Heinrich Hertz. For whereas they previously had required of a conclusive theory that it should content itself with the fundamental concepts which belong exclusively to mechanics (e.g. densities, velocities, deformations, stresses) they gradually accustomed themselves to admitting electric and magnetic force as fundamental concepts side by side with those of mechanics, without requiring a mechanical interpretation for them. Thus the purely mechanical view of nature was gradually abandoned. But this change led to a fundamental dualism which in the long-run was insupportable. A way of escape was now sought in the reverse direction, by reducing the principles of mechanics to those of electricity, and this especially as confidence in the strict validity of the equations of Newton's mechanics was shaken by the experiments with b-rays and rapid kathode rays.
This dualism still confronts us in unextenuated form in the theory of Hertz, where matter appears not only as the bearer of velocities, kinetic energy, and mechanical pressures, but also as the bearer of electromagnetic fields. Since such fields also occur in vacuo i.e. in free ether the ether also appears as bearer of electromagnetic fields. The ether appears indistinguishable in its functions from ordinary matter. Within matter it takes part in the motion of matter and in empty space it has everywhere a velocity; so that the ether has a definitely assigned velocity throughout the whole of space. There is no fundamental difference between Hertz's ether and ponderable matter (which in part subsists in the ether).
The Hertz theory suffered not only from the defect of ascribing to matter and ether, on the one hand mechanical states, and on the other hand electrical states, which do not stand in any conceivable relation to each other; it was also at variance with the result of Fizeau's important experiment on the velocity of the propagation of light in moving fluids, and with other established experimental results.
Such was the state of things when H. A. Lorentz entered upon the scene. He brought theory into harmony with experience by means of a wonderful simplification of theoretical principles. He achieved this, the most important advance in the theory of electricity since Maxwell, by taking from ether its mechanical, and from matter its electromagnetic qualities. As in empty space, so too in the interior of material bodies, the ether, and not matter viewed atomistically, was exclusively the seat of electromagnetic fields. According to Lorentz the elementary particles of matter alone are capable of carrying out movements; their electromagnetic activity is entirely confined to the carrying of electric charges. Thus Lorentz succeeded in reducing all electromagnetic happenings to Maxwell's equations for free space.
As to the mechanical nature of the Lorentzian ether, it may be said of it, in a somewhat playful spirit, that immobility is the only mechanical property of which it has not been deprived by H. A. Lorentz. 1t may be added that the whole change in the conception of the ether which the special theory of relativity brought about, consisted in taking away from the ether its last mechanical quality, namely, its immobility. How this is to be understood will forthwith be expounded.
The space-time theory and the kinematics of the special theory of relativity were modelled on the Maxwell-Lorentz theory of the electromagnetic field. This theory therefore satisfies the conditions of the special theory of relativity, but when viewed from the latter it acquires a novel aspect. For if K be a system of co-ordinates relatively to which the Lorentzian ether is at rest, the Maxwell-Lorentz equations are valid primarily with reference to K. But by the special theory of relativity the same equations without any change of meaning also hold in relation to any new system of co-ordinates K' which is moving in uniform translation relatively to K. Now comes the anxious question: Why must I in the theory distinguish the K system above all K' systems, which are physically equivalent to it in all respects, by assuming that the ether is at rest relatively to the K system? For the theoretician such an asymmetry in the theoretical structure, with no corresponding asymmetry in the system of experience, is intolerable. If we assume the ether to be at rest relatively to K, but in motion relatively to K', the physical equivalence of K and K' seems to me from the logical standpoint, not indeed downright incorrect, but nevertheless inacceptable.
The next position which it was possible to take up in face of this state of things appeared to be the following. The ether does not exist at all. The electromagnetic fields are not states of a medium, and are not bound down to any bearer, but they are independent realities which are not reducible to anything else, exactly like the atoms of ponderable matter. This conception suggests itself the more readily as, according to Lorentz's theory, electromagnetic radiation, like ponderable matter, brings impulse and energy with it, and as, according to the special theory of relativity, both matter and radiation are but special forms of distributed energy, ponderable mass losing its isolation and appearing as a special form of energy.
More careful reflection teaches us, however, that the special theory of relativity does not compel us to deny ether. We may assume the existence of an ether,; only we must give up ascribing a definite state of motion to it, i.e. we must by abstraction take from it the last mechanical characteristic which Lorentz had still left it. We shall see later that this point of view, the conceivability of which shall at once endeavour to make more intelligible by a somewhat halting comparison, is justified by the results of the general theory of relativity.
Think of waves on the surface of water. Here we can describe two entirely different things. Either we may observe how the undulatory surface forming the boundary between water and air alters in the course of time; or else with the help of small floats, for instance we can observe how the position of the separate particles of water alters in the course of time. If the existence of such floats for tracking the motion of the particles of a fluid were a fundamental impossibility in physics if, in fact, nothing else whatever were observable than the shape of the space occupied by the water as it varies in time, we should have no ground for the assumption that water consists of inovable particles. But all the same we could characterise it as a medium.
We have something like this in the electromagnetic field. For we may picture the field to ourselves as consisting of lines of force. If we wish to interpret these lines of force to ourselves as something inaterial in the ordinary sense, we are tempted to interpret the dynamic processes as motions of these lines of force, such that each separate line of force is tracked through the course of time. It is well known, however, that this way of regarding the electromagnetic field leads to contradictions.
Generalising we must say this: There inay be supposed to be extended physical objects to which the idea of motion cannot be applied. They may not be thought of as consisting of particles which allow themselves to be separately tracked through time. In Minkowski's idiom this is expressed as follows: Not every extended conformation in the four-dimensional world can be regarded as composed of worldthreads. The special theory of relativity forbids us to assume the ether to consist of particles observable through time, but the hypothesis of ether in itself is not in conflict with the special theory of relativity. Only we must be on our guard against ascribing a state of motion to the ether.
Certainly, from the standpoint of the special theory of relativity, the ether hypothesis appears at first to be an empty hypothesis. 1n the equations of the electromagnetic field there occur, in addition to the densities of the electric charge, only the intensities of the field. The career of electromagnetic processes in vacuo appears to be completely determined by tliese equations, uninfluenced by other physical quantities. The electromagnetic fields appear as ultimate, irreducible realities, and at first it seems superfluous to postulate a homogeneous, isotropic ether-medium, and to envisage electromagnetic fields as states of this medium.
But on the other hand there is a weighty argument to be adduced in favour of the ether hypothesis. To deny the ether is ultimately to assume that empty space has no physical qualities whatever. The fundamental facts of mechanics do not harmonize with this view. For the mechanical behaviour of a corporeal system hovering freely in empty space depends not only on relative positions (distances) and relative velocities, but also on its state of rotation, which physically may be taken as a characteristic not appertaining to the system in itself. In order to be able to look upon the rotation of the system, at least formally, as something real, Newton objectivises space. Since he classes his absolute space together with real things, for him rotation relative to an absolute space is also something real. Newton might no less well have called his absolute space ``Ether''; what is essential is merely that besides observable objects, another thing, which is not perceptible, inust be looked upon as real, to enable acceleration or rotation to be looked upon as something real.
It is true that Mach tried to avoid having to accept as real something which is not observable by endeavouring to substitute in inechanics a mean acceleration with reference to the totality of the masses in the universe in place of an acceleration with reference to absolute space. But inertial resistance opposed to relative acceleration of distant masses presupposes action at a distance; and as the modern physicist does not believe that he may accept this action at a distance, he comes back once inore, if he follows Mach, to the ether, which has to serve as medium for the effects of inertia. But this conception of the ether to which we are led by Mach's way of thinking differs essentially from the ether as conceived by Newton, by Fresnel, and by Lorentz. Mach's ether not only conditions the behaviour of inert masses, but is also conditioned in its state by them.
Mach's idea finds its full development in the ether of the general theory of relativity. According to this theory the metrical qualities of the continuum of space-time differ in the environment of different points of space-time, and are partly conditioned by the matter existing outside of the territory under consideration. This space-time variability of the reciprocal relations of the standards of space and time, or, perhaps, the recognition of the fact that ``empty space'' in its physical relation is neither homogeneous nor isotropic, compelling us to describe its state by ten functions (the gravitation potentials g), has, I think, finally disposed of the view that space is physically empty. But therewith the conception of the ether has again acquired an intelligible content, although this content differs widely from that of the ether of the mechanical undulatory theory of light. The ether of the general theory of relativity is a medium which is itself devoid of all mechanical and kinematical qualities, but helps to determine mechanical (and electromagnetic) events.
What is fundamentally new in the ether of the general theory of relativity as opposed to the ether of Lorentz consists in this, that the state of the former is at every place determined by connections with the matter and the state of the ether in neighbouring places, which are amenable to law in the form of differential equations,; whereas the state of the Lorentzian ether in the absence of electromagnetic fields is conditioned by nothing outside itself, and is everywhere the same. The ether of the general theory of relativity is transmuted conceptually into the ether of Lorentz if we substitute constants for the functions of space which describe the former, disregarding the causes which condition its state. Thus we may also say, I think, that the ether of the general theory of relativity is the outcome of the Lorentzian ether, through relativation.
As to the part which the new ether is to play in the physics of the future we are not yet clear. We know that it determines the metrical relations in the space-time continuum, e.g. the configurative possibilities of solid bodies as well as the gravitational fields; but we do not know whether it has an essential share in the structure of the electrical elementary particles constituting matter. Nor do we know whether it is only in the proximity of ponderable masses that its structure differs essentially from that of the Lorentzian ether; whether the geometry of spaces of cosmic extent is approximately Euclidean. But we can assert by reason of the relativistic equations of gravitation that there must be a departure from Euclidean relations, with spaces of cosmic order of magnitude, if there exists a positive mean density, no matter how small, of the matter in the universe. In this case the universe must of necessity be spatially unbounded and of finite magnitude, its inagnitude being determined by the value of that inean density.
If we consider the gravitational field and the electromagnetic field from the standpoint of the ether hypothesis, we find a remarkable difference between the two. There can be no space nor any part of space without gravitational potentials; for these confer upon space its metrical qualities, without which it cannot be imagined at all. The existence of the gravitational field is inseparably bound up with the existence of space. On the other hand a part of space may very well be imagined without an electromagnetic field; thus in contrast with the gravitational field, the electromagnetic field seems to be only secondarily linked to the ether, the formal nature of the electromagnetic field being as yet in no way determined by that of gravitational ether. From the present state of theory it looks as if the electromagnetic field, as opposed to the gravitational field, rests upon an entirely new formal motif, as though nature might just as well have endowed the gravitational ether with fields of quite another type, for example, with fields of a scalar potential, instead of fields of the electromagnetic type.
Since according to our present conceptions the elementary particles of matter are also, in their essence, nothing else than condensations of the electromagnctic field, our present view of the universe presents two realities which are completely separated from each other conceptually, although connected causally, namely, gravitational ether and electromagnetic field, or as they might also be called space and matter.
Of course it would be a great advance if we could succeed in comprehending the gravitational field and the electromagnetic field together as one unified conformation. Then for the first time the epoch of theoretical physics founded by Faraday and Maxwell would reach a satisfactory conclusion. The contrast between ether and matter would fade away, and, through the general theory of relativity, the whole of physics would become a complete system of thought, like geometry, kinematics, and the theory of gravitation. An exceedingly ingenious attempt in this direction has been made by the mathematician H. Weyl,; but I do not believe that his theory will hold its ground in relation to reality. Further, in contemplating the immediate future of theoretical physics we ought not unconditionally to reject the possibility that the facts comprised in the quantum theory may set bounds to the field theory beyond which it cannot pass.
Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with the quality characteristic of ponderable inedia, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it.
