We’ve all grown up knowing that the speed of light is everywhere constant at 300 million meters/second (in a vacuum). On a quasar that is receding from the earth at a speed of, say, 240 million m/s, the speed of light is measured to be 300 million m/s. On some distant earth that is approaching our earth at a speed of, say, 180 million m/s, light transmitted in a vacuum has a speed of 300 million m/s, and so forth. This is in accordance with Einstein’s special relativity.
Furthermore, we grew up believing that the speed has always been constant throughout the 15-billion-year life of the universe. The purpose of this essay is to point out that some of these tenets may be inaccurate.
In order to do so, the essay includes several nutty statements [numbered (1) to (4)]. Please, therefore, maintain strict confidentiality with regard to these revelations. Above all, don’t admit to the “big shots” of cosmology that you have read any of this stuff.
(1) It is absurd to believe that light can propagate through a vacuum. Here we should turn to the propagation of sound through air, say, for guidance. Air consists of molecules in rapid, elastic motion as they bump into each other. A loudspeaker cone vibrates, of course, to produce sound: On its outward swing it compresses adjacent molecules; like stacked dominoes, each molecule pushes the next, and the wave of compression thus sails across the room. When the cone completes its cycle via its inward swing, it creates a partial vacuum in adjacent molecules of air; this wave of expansion reaches your ears right behind the wave of compression. What you hear, of course, is repetitive cycles of compression and expansion.
In propagating the sound, the molecules display elasticity (they bounce back), but the rate at which they bounce back is limited by their inertia (density). The elasticity and density depend on pressure and temperature. Let’s only consider pressure: the speed of sound is proportional to the square root of pressure (approximately). At sea level at 20 degrees C, the speed is around 344 m/s; use a pump to increase the pressure by a factor of four, and the speed of sound doubles.
Now look at the propagation of light. It consists of an electric field (such as the shock you can get from a “live” wire) whose field lines are at right angles to those of a magnetic field (such as the gadget used to hold promissory notes to the side of your refrigerator). In a beam of light that is moving to the right, the electric field can be vertically oriented, say, while the magnetic field is horizontal. These fields are vibrating very rapidly (now that the politicians have introduced, and desensitized, us to “trillions,” I can reveal that the fields of visible light vibrate at around 500 trillion times a second).
So what is an electric field? Nobody knows. It is some kind of stress—so many volts per meter. But if a vacuum is nothing, how can there be a stress in nothing? Similarly, nobody knows what is a magnetic field—so many “lines of force” per square meter. How can there be lines of force in nothing at all, in a vacuum? As a beam of light moves to the right in a “vacuum,” its electric field has to transfer stress to the right; i.e., it has to push and pull on its neighbor to the right. Similarly, the magnetic field (at right angles) has to push and pull on its neighbor to the right, analogous to the way in which a sound wave travels.
(2) James Clerk Maxwell (1831-1879) and his contemporaries “invented” the ether as the medium whose “molecules” are pushed and pulled by a propagating electromagnetic field (EMF). Although the ether, like air, is “invisible,” it has very real characteristics that are routinely measured for a vacuum or any other “material.” The same equation for the speed of sound is analogously valid for the speed of light. Corresponding to density and elasticity for sound we have, for the ether, permeability and the reciprocal of permittivity. But we can only define the ether by what we measure—so many henries/meter and farads/meter. Beyond this, like for an electric or magnetic field, one must confess to a very un-blissful ignorance. In fact, it is embarrassing, in a way, to harness the EMF for the benefit of mankind without knowing what it is or how it propagates!
Alas, some 80 years ago, the leading physicists, armed with the rules of quantum mechanics (QM), abandoned the ether. According to QM, an electromagnetic wave can somehow travel through a vacuum. In a sound wave, the original energy is handed over, from molecule to molecule, like a bucket brigade passing water from one person to the next. But what is the travelogue of an EMF photon (the smallest bit of energy) that left a quasar 10 billion years ago? How did it get here? The QM view is that the original energy, in the form of a tiny wave packet, actually traveled to our shores (where it was usually converted into some other form of energy). The ether viewpoint is that the original energy was passed on from one “molecule” of ether to the next via the aforementioned “pushes and pulls.”
An important argument against the existence of an ether surfaced in 1887. A.A. Michelson (1852-1931) and E.W. Morely (1838-1923) assumed that the earth is moving relative to the ether, like a boat in a stream. They measured the velocity of light downstream, across stream, and upstream. Their apparatus was sensitive enough to respond to the difference between the speed of the earth as it circles the sun (30,000 m/s) and the speed of light (10,000 times as fast). Their result was always the same—no evidence of an ether effect!
There are two explanations: As the QM people subsequently assumed, the ether does not exist. The other possibility is that:
(3) The ether moves with the earth because every large object (sun, earth, moon, etc.) carries its own ether as it hurtles through space. This in turn implies that the ether is capable of contraction and expansion. Visualize the earth, like a comet, swinging around the sun as a blob of ether: On the downstream side, where the earth’s ether is moving 0.01% faster than that of the sun, it gets compressed; at the upstream side, where it is moving 0.01% slower, it slightly expands.
(4) The velocity of light changes in accordance with the ether compression or expansion. This comes from analogy with the velocity of sound, which (as mentioned above) is proportional to the square root of pressure.
If the speed of light is not a constant after all, then a big “can of worms” has been opened. Over the 15-billion-year life of the universe, as it expanded, the ether “pressure” decreased and the velocity of light decreased. According to this, the velocity could have been much higher than 300 million m/s in the period following the Big Bang.
If the speed of light changes, this could be accompanied by a general change in the speed of physical-chemical processes. Spectral colors could be different. The Red Shift (due to reduced frequency received if an object is receding from earth), Blue Shift (increased frequency for an approaching object), and even the Big Bang itself come under fire.
A caveat: It is dangerous to go beyond “guidance” from a sound wave. Sound is an easily visualized vibration of tiny springs in the same direction as the propagation. With an EMF, in contrast, propagation is at right angles to both the electric and magnetic fields. The ether is like no day-to-day object with which we are familiar; exposure of its inner workings probably requires magnification going beyond that of an “elementary” particle such as an electron. Will we ever be able to say that we have finally isolated THE elementary particles? And find out why an electron weighs 1840 times less than a neutron or proton? And, of course, why the speed of light (nowadays) is 300 million m/s?
Yes, the “big shots” were correct—let’s not rock the boat. Getting rid of the ether certainly simplified matters (and energies), and made the weird aspects of quantum mechanics more palatable. In our search for the truth, however, it is premature to permanently write off the ether.