The Luminiferous Ęther

Nineteenth century science experiments in light diffraction and interference determined that light behaved like a transverse wave. However, a wave could not exist without a medium to transmit it. The theorists of the day, Young and Fresnel, proposed that the universe was filled with an invisible substance they called the 'ęther'. This ęther had remarkable qualities that made it both rigid yet intangible, strong yet tenuous. Lord Kelvin, one of the foremost scientists of the Victorian age, described it thus:
     "Now what is the luminiferous ęther? It is matter prodigiously less dense than air - millions and millions and millions of times less dense than air. We can form some sort of idea of its limitations. We believe it is a real thing, with great rigidity in comparison with its density: it may be made to vibrate 400 million million times per second; and yet be of such density as not to produce the slightest resistance to any body going through it."
(From a lecture on the Wave Theory Of Light, delivered at The Academy Of Music, Philadelphia, Under The Auspices Of The Franklin Institute, September 29th, 1884, by Sir WilliamThomson (Lord Kelvin) 1824-1907)
In the universe of Space: 1889, Professor Etienne Moreau hypothesized that the ęther, like the matter and energy of the universe, was not evenly distributed because its interaction with matter caused thin patches, vortices and even compact clumps. He theorized that the interaction of matter, energy and ęther meant the former could be used to manipulate the latter. Thomas Edison turned Moreau's theories into practice by formulating his 'Movement Cycle' and 'Release Cycle', which described the relationships between the three. That, in turn, allowed him to build a working Ęther Propeller and opened the solar system to exploration and exploitation by the human race.

The game resources describe the ęther as analogous to an ocean, complete with currents and edies. Two charts in Conklin's Atlas of the Worlds show huge ęther wakes trailing behind each planet, which are pressed into outward expanding spirals by the Sun's disruption of the ęther. Some have interpreted this to mean that the ęther generates drag on bodies moving through it, and that this would effect ęther flyers (spacecraft) traveling between planets by creating an upper limit on their velocity. And, indeed, the description of Edison's 'Release Cycle' does state that ęther binds, then releases, matter, which suggests that ęther might generate some sort of drag on the matter passing through it. However, this is not supportable in practice. If the ęther were to retard the motion of objects, then the planets, moons, asteroids, comets and all other bodies in orbit around the sun would gradually loose velocity and spiral inward, to eventually crash into the sun. Some have suggested that the outward ęther pressure from the sun would counteract this, and that might work for the planets, but would not explain how the numerous moons and retrograde asteroids maintain their orbits. No, as Lord Kelvin stated in the quote above, the ęther can not 'produce the slightest resistance to any body going through it'.

If there is no drag from the ęther, then does that mean that ęther flyers have no upper limit on their velocity? Not necessarily. Even without ęther drag, there may be practical limits to how fast an ęther flyer can go. An ęther propeller requires power and limited power generation capability will create a practical limit on velocity for a time. Eventually, research and engineering will push this limit higher as new power sources are discovered. A more difficult practical limit to overcome will be that of shielding. Even at the speeds at which ęther flyers already travel (Tempest's maximum velocity is 205,000 feet per second, compared to about 3,000 f/s for a high power rifle bullet) impacts with small meteroites is a serious problem. At higher velocities, the dust that fills interstellar space would be a deadly threat, literally eroding away the spacecraft. Another practical limitation may be the inherent characteristics of the ęther propeller and the way it interacts with the ęther. Gerry Harris has suggested that 'at a certain point the ęther propeller's efficiency drops off considerably (it literally cavitates in the ęther)'. This is a neat idea. I had originally thought it not a perfect analogy since I assumed the ęther was infinitely rigid, as proposed by the theorists of the late 19th century, but I have lately adopted the modern theory that the ęther is a fluid (see below). That makes Gerry's "ęther cavitation" very appealing as a natural limit on flyer speed.

Another limit to ęther flyer velocity may be the speed of light. I have read opinions that because Space: 1889 assumes the ęther is real, that it is a non-Einsteinian universe and that special and general relativity do not apply. I don't see why this must be true. Einstein stated quite clearly that he never said that special relativity did away with the ęther, only that it made it unnecessary. He also allowed (in an address delivered on May 5th, 1920, in the University of Leyden) that 'we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ęther', though he went on to say that it was unlike the classical theory of ęther in that 'the idea of motion may not be applied to it'. But, even leaving that admittedly limiting view out of the discussion, it is interesting that modern physics is coming around to a view of the universe that includes some elements of the ęther. When the Michaelson-Morley experiment showed that the ęther could not exist, as it was then understood, science swung to the opposite extreme and decided that space was completely empty and that the vacuum of space was absolute. But the advent of quantum mechanics has modified that view. Now space is full of 'virtual particles' and 'zero point energy' and it seems that the 'void' of space is really not empty at all. Unfortunately, the word 'ęther' has become associated with crackpot theories of metaphysics and carries the same kind of connotations in the world of physics as does 'cold fusion', so modern ęther theories are likely to use other terminology, like 'zero point field', 'Newtonian framework', or 'physical vacuum state', instead. See 'Theories of the Aether' for a comprehensive list of sites that discuss current ęther theory, ranging from the loopy to the quite serious.

In his article, "Aether One or the Other" (Analog, March 2000), Jeffery Kooistra discussed some aspects of modern ęther theory. One point he makes is that the Michaelson-Morley experiment only invalided the rigid, mechanical ęther that was hypothesized in the 19th century (and, apparently, there is even doubt that it really did that), but modern theory of the ęther is that it is a dynamic fluid. It explains the Michaelson-Morley experiment result by having the ęther near the surface of the Earth move along with it. Thus, locally, there was no difference in the speed of light along the different paths of the interferometer because the ęther was stationary relative to the experiment. Kooistra also suggests that it may be time to bring back a 19th century theory that matter is not in the ęther but of the ęther. There were attempts in the 1800's to model atoms as vortices in the ęther, but the theorists could not get the mathematics to work out. They were close, according to Kooistra. He points out that the formulas of electrodynamics (formulated by Maxwell in the era of ęther theories) and the formulas of perfect fluid hydrodamics are identical. He quotes Sir Horace Lamb's book, Hydrodynamics: "There is an exact correspondence between the analytical relations above developed and certain formulae in Electro-magentism . . . . Hence, the vortex-filaments correspond to electric circuits, the strengths of the vortices to the strengths of the currents in these circuits, sources and sinks to positive and negative poles, and, finally, fluid velocity to magnetic force." (Hydrodynamics, Sir Horace Lamb, page 210, First published in 1879). The problem with the math was that the convective dirivatives are nonlinear and solving the equations requires far more computing power than was available in the 1800's, so the hydrodynamics equations we use are linearized, simplified forms that make the the math not just easier, but doable. That's why the ęther theorists of the 19th century had such a hard time, they didn't have the computers to solve the equations. If they had, we might have ended with a unified ęther/electrodynamic theory with subatomic particles being a sort of "structured ęther" instead of bits of matter floating in space. I don't want to rewrite the whole article here (Kooistra looks at several other problems and quotes noted scientists like Einstein, Feynman and Pauli about statements each made that supported a fluid ęther solution to those problems), but the gist was that perhaps the answers to some of the unsolved questions in modern physics might be found by looking at a perfect fluid ęther model.

So, what is my interpretation of the ęther? In other words, how does it work in my stories? Newtonian physics are not in any way invalidated and certainly apply to ęther flyers as they would to a spacecraft using a conventional rocket engine. I think that the physics of the Space: 1889 universe are actually the same as ours and that the Ęther Propeller is using some aspect of quantum mechanics, zero point energy fields, or a yet undiscovered twist in the ever unfolding fabric that is modern physics. But the scientists of that universe did not have our history of research to draw upon, so they could only interpret their observations in terms of the theory they did have, the ęther theory. And, perhaps, if they had been equipped with the right resources (like enough computing capability) they would have gotten that theory to work and taken a short cut to a point we may be approaching right now. Maybe an ęther propeller is in our future!

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Space:1889 is Frank Chadwick's registered trademark for his game of Victorian Era space-faring. He has granted permission for the use of the background of Space:1889 for the stories presented here. All text, illustrations, photographs and design are © 2000-2002 Dan Thompson, except where otherwise noted.