Oliver in Quantum-Gravity-land

By Alessio Rocci

[Note: highlighted words link to the Glossary at the end of the post.]

Historically, the term Quantum Gravity (QG) has had many meanings. Today it is often associated with the idea that the gravitational field must be quantized, but we do not know how to construct this theory in a consistent way. From the birth of General Relativity (GR) in 1915 until today, many approaches have tried to face, in a broad sense, the problem of harmonizing the quantum principles that govern the microscopic world. GR is actually our best theory describing the gravitational field.

In 1916, Albert Einstein was the first to argue that quantum effects must modify his general theory.1 In fact, he had in mind Bohr’s principle of stationary orbits, which had already modified the classical idea of the atomic collapse in the case of the energy loss due to electromagnetic wave emission, and that seemed to suggest that a similar solution was needed to avoid the energy loss caused by gravitational wave emission. Presumably he did not know, at that time, that this kind of atomic collapse is characterized by a time of the order of 1037s, that is an enormous lack of time compared with the life of our Universe: recent results give approximately (4,354±0,012)x1017s.2 The first attempt to quantize the gravitational field appeared in 1930, in two papers published by Léon Rosenfeld. For this reason, the years running from 1916 to 1930 are often referred to as the prehistory era of QG, a period that collects all attempts to harmonize the microscopic world with GR, or with others theories of gravity.

The prehistory era is divided in two half-periods by a wall: the birth of Quantum Mechanics (QM) in 1925-1926. We are interested in the ambien first half-period, when one of the big problems was the origin of Bohr’s stationary orbits and when the application of GR to the microscopic world was not broadly accepted. In fact, in the first four years after the birth of GR, the only experimental test of Einstein’s theory was the amazing calculation of Mercury’s perihelion time-precession. Things started to change in UK after Sir Frank Watson Dyson announced, in 1919, Sir Arthur Eddington’s results of the eclipse expedition: starlight was deflected in the sun’s gravitational field by the exact amount predicted by Einstein.3 At this point Sir Oliver Lodge enters our story. In fact, he was very active in the field of Relativity during those years.4 As the general interest of the scholars for GR suddenly rose exponentially, Lodge also started to consider the new theory of gravitation and its connection with the microscopic world. In fact, even if Lodge is famous for his hard defense of the aether concept, he always looked at the scientific world with a very open mind and tried to face all of the popular problems of his time. He started to consider various problems connected with GR. Here we arrive at the year 1921, a very special year for Lodge production. Maintaining his old-fashioned vocabulary, Lodge writes a Letter to Nature, strongly impressed by a George B. Jeffery’s paper, where GR is applied to the microscopic world, as all pioneers of QG tried to do.5 Referring to the electrical theory of matter and GR, Lodge uses Jeffery’s results in order to infer something new about the origin of the gravitational field of an electron and he speculates about its interior. For this reason, we included Sir Oliver Lodge in the prehistory of QG.

Peter Rowlands writes that ‘Lodge’s analyses of contemporary work were frequently accompanied by brilliant speculations’.6 Indeed, many brilliant speculations are raised in the letter to Nature and would become prevalent in the whole production of the year. In the brief communication, Lodge notes some inconsistencies connected with the electrical theory of matter, which in fact contradict Einstein’s equivalence principle, as it would be pointed out e. g. by Enrico Fermi two years later.7 In the letter, Lodge also discusses how GR tells us that the origin of the electron mass should not have an electromagnetic origin. Last, but not least, he rightly points out that the new Jeffery’s result ‘does not apply in the interior of an electron, if an electron has any interior’, putting the old idea of composite electron and the modern concept of elementary particle on equal footing. With these comments, Lodge ends his incursion into the history of QG, but we can continue to track the other ideas that he developed in this period. Lodge himself attracts attention in his papers, published in the Philosophical Magazine.8 In ‘On the supposed weight and ultimate fate of radiation’, Lodge introduces the idea of refractive index of light in a gravitational field that he uses to correctly describe what happens to the light-cone, approaching the Schwarzschild radius.9 He poses the following questions: ‘What happens to light when, in free modified ether, it is stopped relatively to a gravitational mass? Does it retain its energy…tie itself into electrons and add to the mass of the body?’10 Lodge’s idea is amazing: doesn’t it resemble the modern concept of Black Hole accretion? In ‘Ether, Light and Matter’, Lodge associates the idea of the quantum with closed curves of magnetic lines, and has in mind the electromagnetic nature of the mass as he writes: ‘I ventured on a speculation that matter is a sink as well as a source of radiation… Annulling of the electric component in a ether wave… may also liberate the magnetic component…’.11 Lodge’s imagination goes further: ‘the problem is whether part of the magnetic circulation, left stranded, could not cease to be oscillatory and become continuous and permanent; and whether the synchronous electric pulses of myriads successive waves could not accumulate as a separated pair of opposite electric charges’.12 Doesn’t it resemble the modern idea of pair creation? In his successive paper, Lodge tries to go deeper and deeper with this idea: ‘Referring to previous papers… if it is ever possible to separate … a positive and a negative electron bringing them into practical existence from absolute neutrality … the uniting force must … follow the law: [here Lodge inserts a mathematical formula for the force, that mixes the gravitational force with an elastic force] The opposite charges may be thought of as initially united by an elastic thread of zero length… till it snaps.’13 The idea, exposed by Lodge, resembles the quark anti-quark string model of the seventies!

To summarize, I would like to express my opinion on ativan Lodge’s idea about the distinction between pure and applied science, emerging from the papers that we discussed briefly. Lodge’s speculations are very abstract models and could be thought as an incursion into pure science. But every speculation he did was always followed by a precise calculation, as if to try to connect it with reality, as requested by applied science. As an example, I mention that Lodge calculated the temperature at which the pair creation should take place. Finding too big a number, he comments: ‘I confess I had hoped that this ebullition temperature would not have been so high, so that there might have a chance of reaching it, at least locally, in the sun or some of the stars’.15 It is my opinion that Lodge never tried to distinguish between pure and applied science and I think that Lodge’s philosophy is well described by the following sentence:

For undoubtedly general relativity, not as a philosophic theory but as a powerful and comprehensive method, is a remarkable achievement […] but, notwithstanding any temptation to idolatry, a physicist […] must remember that his real aim and object is absolute truth […] that his function is to discover rather than to create […[ and that beneath and above and around all appearances there exists a universe of full-bodied, concrete, absolute, Reality.16

On 31 of October 1921, Lodge was in Liverpool, lecturing on ‘Relativity’ to the Literary and Philosophical Society and, on the same day in 2014, we were in Liverpool to give honor to this great scholar, at the third workshop of ‘Making Waves’.


quantized: the terms quantum, quantization, quantized always refer to the fact that atomic world follows new laws, discovered from the beginning of last 20th century, often referred as quantum laws, that are deeply different from the laws of the macroscopic world, usually referred as classic laws. Gravity governs the microscopic and the macroscopic world. This fact implies that, at least for this reason, we need some synthesis between gravity and quantum laws. [back]

Bohr’s principle of stationary orbits: Bohr’s model of atom is the most popular image of quantum world (see the logo of the sitcom The Big Bang Theory). In this model electrons move around a nucleus made of protons and neutrons, like Earth and other planets do around the sun. But due to classic laws, an electron should emit electromagnetic waves, like a mobile do while ringing, loose its energy and fall towards the nucleus. Bohr postulated the existence of stationary orbits, where the electron does not irradiate, in order to let the atom live!. [back]

gravitational wave: Einstein discovered that his famous equations, describing the dynamic of a gravitational field produced by a body, also describe the process of emission of waves, called gravitational waves. Phentermine weight loss by gravitational wave emission by the Pulsars has become another important test for GR. [back]

Mercury’s perihelion time-precession: lets something have a fixed direction into the sky, like polar star for the sailors. The perihelion of a planet is the point occupied by the planet when it is closest to the Sun. The position of a perihelion is not fixed with respect to direction you choose: it rotates with a time that, in the case of Mercury, is about 43 seconds of arc per century. The Mercury’s time-precession puzzled the physicists from the birth of Newton’s theory of gravity and was correctly explained for the first time by GR. [back]

Electrical theory of matter: due to this theory the origin of mass should emerge from Maxwell’s electromagnetic theory applied to a rigid sphere electron model. The idea started with a Thomson’s formula, that express electron mass using the electric charge, the sphere radius and some fundamental constants of Maxwell’s theory. [back]

Einstein’s equivalence principle: Einstein defined it as like the most beautiful idea he ever had. Let suppose you are falling freely with a heavy ball in your hands. If you open your arms, the ball will fall with you. Now let’s imagine that you and your heavy ball shut in an elevator. If you don’t know that you’re falling, what you see is the absence of gravity, exactly like astronauts of the International Space Station do. If you reverse this idea you get the equivalence principle: gravity is due to an acceleration field that in GR is created by a curved geometry, exactly like roller coaster’s rails, generated by a mass. [back]

refractive index of light: like every mass does, light follows the curved geometry created by a big mass (see the Einstein’s equivalence principle in this dictionary). This phenomenon is called light bending and it could be described throughout the analogy with the phenomenon of refraction, where the bending of light is due to the change of the medium’s density that the light is traveling through. [back]

Light-cone: In Relativity this is an imaginary doubled-cone, whose edges are made of light rays, where we live, and that separates, in a certain sense, the past-cone from the future-cone. [back]

Schwarzschild radius: when the nuclear reactions inside a star end, gravity wins among all exploding forces and the star begins to implode. In some cases the radius of the star can approach the Schwarzschild radius. In this case we could say that a Black Hole has been born, because at the Schwarzschild radius the gravitational force is so strong that even the light cannot escape any more. [back]


1 Albert Einstein,‘Naerungsweise Integration der Feldgleichungen der Gravitation’, Preussische Akademien der Wissenschaften. Sitzungsberichte (1916), 688-696. [back]

2 Planck Collaboration (Ade P. A. R. et al.),‘2013 Planck 2013 results. I. Overview of products and scientific results’, Preprint: astro-ph.CO/1303.5062. [back]

3 Peter Rowlands, Oliver Lodge and the Liverpool Physical Society (Liverpool: Liverpool University Press, 1990). [back]

4 Oliver Lodge, ‘The Gravitational field of an Electron’, Nature, 107 (1921), 392-392. [back]

5 Ibid. [back]

6 Rowlands, p.259. [back]

7 Enrico Fermi, ‘Correzione di una contraddizione tra la teoria elettrodinamica e quella relativistica delle masse elettromagnetiche’, Nuovo Cimento, 25 (1923), 159. [back]

8 Oliver Lodge, ‘On the supposed weight and ultimate fate of radiation’, Philosophical Magazine, 6.41 (1921), 549; Oliver Lodge, ‘Ether, Light and Matter’, Philosophical Magazine, 6.41 (1921), 940; Oliver Lodge, ‘Light and Electron’, Philosophical Magazine, 6.42 (1921), 177. [back]

9 Lodge, ‘On the supposed weight and ultimate fate of radiation’. [back]

10 Ibid., 555. [back]

11 Lodge, ‘Ether, Light and Matter’, 942. [back]

12 Ibid., 943. [back]

13 Lodge, ‘Light and Electron’, 177. [back]

14 Ibid., 183. [back]

15 Oliver Lodge, ‘The Geometrisation of Physics, and Its Supposed Basis on the Michelson-Morley Experiment’, Nature, 106.2677 (1921). [back]

The Alternative Path: Lodge, Lightning, and Electromagnetic Waves

By Bruce J. Hunt

Early 1888, Oliver Lodge performed a series of experiments on electrical oscillations along wires that led him very close to Heinrich Hertz’s discovery, announced that same year, of electromagnetic waves in free space. Within a few years, Lodge and others began to use such waves for wireless telegraphy, laying the foundations for technologies that are now ubiquitous. On the surface this looks like a classic case of ‘applied science’, in which a laboratory discovery was turned to practical use, and in some ways it was. But on digging more deeply, we find that Lodge’s work was itself rooted in an intensely practical concern: the protection of buildings from lightning. The path from lightning protection to the discovery of electromagnetic waves, and then on to their use in telecommunications, was winding and indirect. Following this path will shed light on some important ways in which technology and science can interact.

Lodge’s work on lightning grew out of an invitation from the Society of Arts in London that he deliver two lectures on the subject as a memorial to Dr. Robert Mann, a former president of the Meteorological Society. Lodge read up on the subject, particularly the authoritative 1882 Report of the Lightning Rod Conference, and also performed experiments of his own tramadol, using tea trays to stand in for storm clouds and discharges from large Leyden jars to mimic bolts of lightning.1 This choice of model was the key to almost all that followed, and it turned out to have some flaws—clouds, it seems, are not really much like tea trays. Simply as studies of Leyden jar discharges, however, Lodge’s experiments were valid and valuable; they shed light on several phenomena related to lightning protection, and more importantly, they led him to new discoveries about rapidly oscillating electric currents.

Many of Lodge’s experiments involved what he called ‘the alternative path’: he would arrange various conductors and insulators, connect them to his Leyden jars, charge them with an electrostatic generator, and see which path the resulting discharge followed. In the course of these experiments, he found many cases, particularly of what he called ‘impulsive rush’, that did not behave the way orthodox theories of lightning protection would have predicted. This led Lodge to criticize some of the conclusions of the Lightning Rod Conference and landed him in heated controversies with some of its defenders. Lodge also noticed some new and unexpected phenomena, particularly when he discharged the Leyden jars into pairs of long parallel wires. Not only did sparks sometimes jump between the wires, but the sparks were longest at their ends, as if the current was surging along the wires and producing a ‘recoil kick’ as it reflected off their ends. Lodge knew that Leyden jars discharges could produce oscillating currents and, partly prompted by his junior colleague A. P. Chattock, he now concluded that these were forming actual electromagnetic waves that were moving at the speed of light through the space surrounding the wires. Here, Lodge thought, was the long-sought confirmation of Maxwell’s theory of the electromagnetic field. He appended a section on these waves along wires to a paper on ‘Lightning Conductors’ that he sent off to the Philosophical Magazine in June 1888, and he set off on a hiking holiday in the Tyrolean Alps with fond hopes that his discovery would be the hit of the upcoming meeting of the British Association, set for September in Bath.2 He soon found, however, that Hertz had performed even more striking experiments on electromagnetic waves in Germany, and Lodge presented his own work simply as a confirmation of Hertz’s.

Lodge continued to work on lightning protection, working with Alexander Muirhead to patent and market an arrester for use on telegraph and power lines, and in 1892 publishing a book on Lightning Conductors and Lightning Guards that brought together his previous writings on the subject.3 Eventually he and others recognized the deficiencies in his experimental model of lightning, in particular the fact that storm clouds (unlike tea trays) do not act as connected conductors, and their discharges, though very sudden, are not generally oscillatory. But while Lodge’s work on electrical discharges was rooted in the practical problem of lightning protection, its real value lay elsewhere, in the scientific evidence it provided for the existence of electromagnetic waves, and in the eventual use of those waves for wireless telegraphy. Lodge’s work on wireless telegraphy did not grow out of pure undirected scientific research, nor did it grow out of a deliberate effort to produce a wireless communications system. Instead its development followed an ‘alternative path’, starting in one technological context and ending in a quite different one, passing along the way through realms of scientific experiment and theory.

Bruce J. Hunt

1Symons, George James, ed., Lightning Rod Conference (London: E. & FN Spon, 1882). [back]
2Oliver Lodge, ‘On the Theory of Lightning Conductors’, Philosophical Magazine, 26 (1888): 217-230. [back]
3Oliver Lodge, Lightning Conductors and Lightning Guards (London: Whittaker and Co, 1892). [back]

Pure and Applied Science at the University of Birmingham, 1890-1919

By Di Drummond

My paper at the third workshop explored the role that Oliver Lodge had in forming a balance between pure and applied science subjects, and between the Sciences and the Arts and Humanities, and, as a result, in laying the foundations of the University of Birmingham. Birmingham was a new form of higher education, the first civic university in England. This was characterised by the Applied Sciences, but there was a concern on the part of Birmingham’s founders for the pure sciences and, in time, the Arts and Humanities, to be included in the portfolio of subjects.

Birmingham is often seen as a product of the political networks and liberal ethos of the University’s founder, the politician and statesman Joseph Chamberlain. Certainly, his campaign was key in raising the finances the University required from amongst the local industrial and commercial elite. Chamberlain was also instrumental in developing the governing structure of the new institution. In contrast, Lodge’s role as the first Principal of the University from 1900, until his retirement in 1919, has been neglected. This paper attempts to restore Lodge’s importance. As a pure scientist who developed practical outcomes from his research while he was Professor of Physics at Liverpool, Lodge argued for the reliance of applied on pure science from the 1880s. This was key to the nature of the new university. So too was Lodge’s belief in a ‘liberal’/’liberal arts’ university education, this being seen as important in preventing scientists and those in the applied sciences from becoming too narrow and utilitarian in their attitudes. Lodge’s wider political values also proved important in the shaping of the new university. While the history of Chamberlainite municipal liberalism in the city of Birmingham was key in forming the relationship between the University and the Midland region, Lodge’s Fabianism, with its ‘municipal socialism’, had some influence in ensuring that local political and professional interests were represented in the governing system of the University of Birmingham.

Di Drummond

Lodge and Mathematics: Counting beans, interpreting symbols, and Einstein’s blindfold

By Matthew Stanley

Oliver Lodge was deeply in awe of the achievements of James Clerk Maxwell. He saw all his work as expanding the Maxwellian worldview, but he struggled with one of its most distinctive features: the mathematization of nature. Lodge acknowledged that the sophisticated mathematics involved were beyond his abilities, and developed his own nuanced understanding of the role and significance of mathematics in physics.

Lodge’s early obstacle to following Maxwell’s mathematical example was his exclusion from the Cambridge pedagogical tradition. Maxwell’s Treatise was an exceptionally difficult text, and Cambridge figures such as W.D. Niven had to work extremely hard to make sense of it and pass that that knowledge on to their students. Lodge, however, did not have access to this system and wrote that he ‘always regretted that I didn’t go through the Cambridge grind; for I am somewhat isolated from all those who did’.1 Instead, he learned mathematics from O.M.F.E Henrici at University College London, who taught German-style projective geometry and graphical methods instead of Cambridge analysis. This visual, practical style can be easily seen in Lodge’s famous mechanical models.

Lodge greatly enjoyed mathematics and admired those who truly mastered it (including his brother Alfred, a professor of mathematics). However, he never felt that he was among that special class of people who could reason properly using only equations as a guide. This did not dampen his enthusiasm for mathematics. He was impressed with how an equation could bring together and unify scattered facts and observations, and felt that familiarity with mathematics was essential for appreciating science in an aesthetic sense. He believed that the lack of that familiarity was responsible for the dismissal of science by ordinary people. He complained about how the ‘mathematical ignorance of the average educated person has always been complete and shameless’.2

The restoril core problem, however, was less the people than it was the teachers. Lodge objected to the basic Victorian assumptions of how mathematics should be taught. For example, geometry tended to be taught through the process of memorizing Euclid and expecting a student to synthesize all the abstract propositions as one complete system. Rather that this systematic approach, Lodge said, students should be encouraged to experiment with ‘handled things’ like counters or beans and thus discover mathematical laws for themselves. This way, students would be excited by their subjective discoveries and develop an interest in the subject. Their inevitable mistakes in this process would only deepen their appreciation for the correct mathematical laws that they learned later on.

Students would come away from this teaching method with an incomplete knowledge of mathematics. Lodge was confident that this was acceptable, because the student would have developed a sense of the concrete meaning of mathematical symbols and laws (as opposed to solely considering them as abstract entities). He was deeply concerned that scientists have a correct grasp of this issue.

On one hand, a scientist might be too obsessed with the numbers associated with an equation. Lodge mocked the military engineer Sir A.G. Greenhill for demanding that formulae have every number and conversion factor explicitly written out. These sort of ‘practical men’ erred by thinking that ‘symbols express numbers, not things’. Whereas physicists like Lodge knew that ‘symbols may express things and not numbers’.3

On the other hand, someone might be dazzled by the aesthetic beauty of an equation and forget that under the abstraction was a physical concept. Careless mathematicians might hide – intentionally or not – their ignorance under an otherwise beautiful equation. This, Lodge wrote, is where Einstein went wrong. He objected that relativity reduced all the basic categories of physics to pure mathematics, and in doing so ‘leaves us in the dark as to mechanism’.4 That is, it gave us equations but did not explain anything. The equations were so abstract that they gave us no actual information about the world. Physics was supposed to be about modeling the world in the manner of Maxwell and Kelvin. Equations were nice to have, but they could not substitute for concrete physical meaning.

Lodge wanted a ‘full blooded’ universe.5 By this he meant a universe of physical sensations and conceptions based on ordinary experience, rather than solely on ‘complex mathematical machinery’.6 This was where he thought modern physics had failed, and Victorian physics had triumphed. Einstein had blindfolded himself with beautiful mathematics and did not realize that he had gone astray.

Lodge spent his career arguing that physics needed to have the right balance of pure xanax and concrete mathematics. No one should be surprised that Lodge held up Maxwell as the exemplar of the correct mix of physical understanding and symbolic power. Faraday did not have enough pure maths; Einstein had too much. Einstein had been entranced by aesthetic beauty as a mathematical method, rather than as something that was found at the end of a well-established theory. Models were the touchstone that allowed physicists to set up reliable equations while also preventing unchecked mathematical adventuring. Some beings of extraordinary ability could move beyond their models – as when Maxwell developed his more abstract electromagnetic system. But according to Lodge, such people were few and far between – and included neither Einstein nor himself.

Matthew Stanley

1Oliver Lodge, Past Years (New York: Scribner’s Sons, 1932), p.88. [back]
2Oliver Lodge, Easy Mathematics, Chiefly Arithmetic; Being a Collection of Hints to Teachers, Parents, Self-Taught Students and Adults, and Containing Most Things in Elementary Mathematics Useful to be Known (London: Macmillan and Co., 1906), p.viii. [back]
3Oliver Lodge, ‘The meaning of symbols in applied algebra’, Nature, 55 (1897), 246-7 (p.247). [back]
4Oliver Lodge, ‘The new theory of gravity’, Nineteenth Century, 86 (1919), 1189-1201 (pp.1200-1). [back]
5Oliver Lodge, ‘Einstein’s real achievement’, Fortnightly Review, 110 (1921), 353-372 (p.372). [back]
6Lodge, ‘Einstein’s real achievement’, p.370. [back]