A Word In Edgewise: Different Ways of Looking at Things

By E.B. Boatner March 3, 2016

Categories: Causes, Education, Our Affairs



It took a hundred years to prove, but Albert Einstein was right. Gravity does make waves, and the fabric of space-time does alter.

Einstein calculated, as part of his General Theory of Relativity, that gravitational waves had to exist, although no one had ever found one, or had yet invented a way to measure them.

They existed at the juncture of a genius mind and a pencil and paper, but Einstein himself thought they might never be detected, going back and forth about their reality. He died in in 1955, never having seen proof of the waves or of the black holes necessary to create disturbances of the magnitude needed to be audible in backwater Terra.

You can read the full story in the mainstream media; the dogged work of thousands of scientists over decades to build LIGO (Laser Interferometer Gravitational-Wave Observatory), culminating on September 12, 2014, with a “chirp.” Like running your fingernails over a piano from lowest A to middle C, one scientist noted. Small (roughly 5mm over a one-sextillion-meter distance), but audible.

Two black holes of 29 and 36 solar masses circled one another until they collided, some 1.3 billion years ago, bending space-time, and sending out gravitational waves through the universe — to LIGO who, by a fluke, was on at the time, and caught the waves two years ahead of the ETA.

Since Einstein worked out the necessary existence of the players, scientists have worked and built and scrapped and reworked and rebuilt to create LIGO, with its 2.5-mile-long arms, polished mirrors, contained vacuum, and state of being soundproofed to all but that “chirp,” on the premise that if a gravitational wave alters space-time, then a beam of light, moving at a constant speed in total vacuum, will take less time to travel the contracted distance than the non-contracted distance.

And so it was.

A sound after centuries of visual (and later, electromagnetic) exploration of the universe, a voice, calling in the key of C. What other senses will the unknown share with humankind? It will depend on how we humans use the gift of our minds and view our role in the cosmos.

There was another point of view in this same week’s news; a sign outside an unnamed church proclaiming: “The more ‘Educated’ we become the farther we move away from God.”

One Response to A Word In Edgewise: Different Ways of Looking at Things

    By Rodney A. Brooks
    author of “Fields of Color: The Theory That Escaped Einstein”.

    The current discovery of gravitational waves at LIGO (Laser Interferometer Gravitational-Wave Observatory) has captured the imagination of the public. It will stand as one of the great feats of experimental physics, in addition to the famous Michelson-Morley experiment of 1887 which it resembles. In fact by comparing these two experiments, you will discover that understanding gravitational waves is not as challenging as you assume.

    Contraction. Michaelson and Morley measured the speed of light at varying times as the earth moved around its orbit. To their – and everyone’s – surprise, the speed turned out to be constant, independent of the earth’s motion. This finding caused great consternation until George FitzGerald and Hendrick Lorentz came up with the sole possible explanation: objects in motion contract. Einstein then showed that this contraction is a repercussion of his Principles of Relativity, but without saying why they contract (other than a need to conform to his Principles). In fact Lorentz had previously given a partial explanation by showing that motion affects the way the electromagnetic field interacts with charges, causing objects to contract. However it wasn’t until Quantum Field Theory came along that a full explanation was found. In QFT, at least in Julian Schwinger’s version, everything is made of fields, even space itself, and motion affects the manner all fields interact.

    Waves. Electromagnetic waves, e.g., radio waves, have long been understood and accepted as a natural phenomenon of fields. Now in QFT gravity is a field and, just as an oscillating electron in an antenna sends out radio waves, so a large mass moving back and forth will send out gravitational waves. But it didn’t take QFT to show this. Einstein also believed that gravity is a field that obeys his equations, just as the EM field obeys the equations of James Maxwell. In fact gravitational waves have been accepted by many physicists, from Einstein on down, who regard gravity as a field.

    Curvature. But what about “curvature of space-time”, which many people nowadays say is what causes gravity? You may be surprised to learn that’s not how Einstein saw it. He thought that the gravitational field causes things, even space itself, to contract, similar to the way motion causes contraction. In fact Einstein used this analogy to show the similarity between motion-induced and gravity-induced contraction: they both affect the way fields interact. It is this gravity-induced contraction that is sometimes knowned as “curvature”.

    Evidence. The first uncovering of gravitational waves was done at LIGO, using a device similar to Michelson’s and Morley’s. In both experiments the time for light to travel along two perpendicular paths was compared, but because the gravitational field is much weaker than the EM field, the distances in the LIGO apparatus are much more substantial (miles instead of inches). Another difference is that while Michelson, not knowing about motion-induced contraction, expected to see a change (and found none), the LIGO staff used the known gravity-induced contraction to see an alteration when a gravitational wave passed through.

    Fields of Color: The theory that escaped Einstein explains Quantum Field Theory to a lay audience, without any math. If you want to learn more about gravitational waves or about how QFT resolves the paradoxes of Relativity and Quantum Mechanics, read Chapters 1 and 2, which can be seen free at quantum-field-theory.net.

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