Gravitas

I have not as yet been able to discover the reason for these properties of gravity from phenomena, and I do not frame hypotheses. For whatever is not deduced from the phenomena must be called a hypothesis; and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy. In this philosophy particular propositions are inferred from the phenomena, and afterwards rendered general by induction.

     [Isaac Newton, Mathematical Principles of Natural Philosophy, 1713]

We really know very little about matter, but we’re not quite as continent as Newton was when it comes to framing hypotheses. Descriptions of behavior, however precisely measurable, do not explain what really happens. Two bodies will exert a force on one another based on their masses and distance, but why that force is operating is not thereby explained. Quantum physics offers the notion that the force of gravity is mediated by a mass-less particle called the graviton (a hypothetical particle). In Relativity, Einstein offered as his hypothesis that mass causes time and space, the two combined in a single continuum called spacetime, to bend or to deform in some way thus creating a groove or slope in what (presumably) is an otherwise unchanging “environment.” This deformation is then used to explain gravitational effects. But what exactly are space and time? For Newton they were absolute and entirely unchangeable let’s call them realities; mass could not change either one or the other. For Immanuel Kant they were, at the same time, immaterial and thus insubstantial, in the human mind as a priori organizing principles enabling us to understand sensory experience and therefore ideas. But because they were linked to sensory experience, they were also empirically real. In other words we don’t really have an explanation—hence framing no hypotheses is indicated—at least in “experimental philosophy.”

Space and time are inherently involved in any kind of explanation of gravity, be it by gravitons or spacetime deformations—or invisible, intangible dark matter used by most astronomers to explain gravitational anomalies in star rotations around galaxies far away. That hypothesis, incidentally, has the small problem of increasing the total mass of the universe by huge gob. Visible matter is supposedly 4 and dark matter is 96 percent of the universe. Now supposing we did detect a graviton finally. Where would that leave us? It would leave us wondering what makes gravitons detach from one kind of mass to rush at the speed of light, and presumably no faster, to another essentially same kind of mass. And why then would this exchange become a “force”?

The description of the behavior of bodies must suffice us, I presume, because breakthroughs in the future will not provide any more knowledge than we have at present—only yet other hypotheses. Going down to have lunch now, I wonder if my mass will bend spacetime ever so, ever so faintly. Presumably so, if Einstein is correct.

Has a Crack Appeared?

I came across an interesting and recent development in physics dating to 2009. The Scientific American reported on the matter on November 24, 2009 (link); New Scientist had an article on it dated August 9, 2010; that article is not online, but a summary of it is presented by The Daily Galaxy (March 24, 2011, link).

The discoverer in question is a physicist working at the University of California, Berkeley named Peter Horava or Petr Hoyava or, most likely, Petr Hoava. (That box stands for an r with a caron on top of it; the ASCII code is not recognized by Blogger.) Horava is also, according to Wikipedia, a member of the theory group at Lawrence Berkeley National Laboratory. Horava’s discovery, working with an allotrope (read “form of”) carbon known as graphene, is that the behavior of this carbon at near absolute zero temperatures suggests that Einstein’s spacetime may not be real at all, that gravity acts differently in different temperatures, that the warping of space and time by mass may be illusory. What we see is caused by gravitation which does not act uniformly everywhere. This view appears to confirm  the claims of quantum physics that gravity is due to an exchange of particles, like electromagnetism, in this case the graviton, not due to the deformation of spacetime.

Now this discovery is beginning to make waves for a reason. It promises, finally, a unified theory of gravitation which will make the results observed by general relativity and quantum physics agree with each other—but, to be sure, at some expense to General Relativity’s claim to universal applicability. Well.

And there is more. As might be expected, views of black holes, the big bang, dark matter, dark energy, and the expansion of the universe all appear in very different light. For this reason, rather than summarily dismissed, Horava’s suggestions and modified equations are getting a lot of attention from quantum physicists.

I note this here because spacetime is my favorite bête noire. Yet it is so fundamental to general relativity that any crack that separates those two words means a revolution in physics. Unfortunately I cannot hope personally to check the results however much I’d like to. It would require me to master Maxwell’s equations presented in his On Physical Lines of Force (link), the Lorenz transformations that “correct” or “complete” them, and—for that matter—the evolution of concepts as rendered in the language of mathematics all the way from the days of aether to the present. I haven’t got the right stuff. But I have a very keen intuition!

Near-Forgotten Genius

I came across the quote that follows in an effort to understand better certain aspects of theoretical dimensions beyond the familiar three. My search was prompted by reading Michio Kaku’s Hyperspace. That book basically concerns string theory. The quote:

Time is a man-made reference used for convenience and as such the idea of a “curved space-time” is delusional, hence there is no basis for the Relativistic “space-time” binomium concept. I hold that space cannot be curved, for the simple reason that it can have no properties. It might as well be said that God has properties. He has not, but only attributes and these are of our own making. Of properties we can only speak when dealing with matter filling the space. To say that in the presence of large bodies space becomes curved is equivalent to stating that something can act upon nothing. I, for one, refuse to subscribe to such a view. [Nikola Tesla quoted in New York Herald Tribune, September 11, 1932]

The world is vast, my education spotty, hence I recognized the name but could not do much more than that. The thought expressed, however, is most congenial. I’ve always had major problems both with spacetime and with time dilation—thus the concept that time slows down with speed of travel, and the astronaut wandering out there at near-light speed would return from his years-long trip to find that he was much younger than his twin brother. At one time I spent real concentrated time studying Einstein’s theories—in the original, at that—and came to the conclusion that while clocks certainly did slow down with speed, it was the clocks that misbehaved, not time. Therefore I’m not persuaded that time dilation has been proved. I have similar problems with thinking of time as a dimension (except as a math token) and with dimensions beyond the conventional three.

Today I checked into the Serbian, Nikola Tesla (1856-1943). He was an inventor of genius. We owe him the discovery of alternating current, modern electric power plants, the AC motor, and wireless power transmission. He also built the first hydroelectric power plant, with a fellow called Westinghouse, at Niagara Falls—a place I used to haunt once when I worked for Carborundum. Tesla also clashed with other greats of his time whose names are household words while he has been as good as forgotten. A nice summary of this very strange man’s very strange and adventurous life is provided in a YouTube film (link). A listing of some thirty-six devices and principles developed by Tesla is available on Wikipedia’s article on this man (link).