The Existentialist Cowboy: 2011-05-29

Saturday, June 04, 2011

The Man Who Changed the Universe

by Len Hart, The Existentialist Cowboy

The year 1564 is noteworthy for several reasons. John Calvin and Michelangelo died. Shakespeare and Galileo Galilei were born.

It was Galileo, upon the shoulders of great Renaissance artists and Neo-Platonists who preceded him, who may have ignited the beginnings of the Scientific Revolution early in the 17th century. He did so by demonstrating the extraordinary effectiveness of the experimental observation of nature and coupling that observation with the analytical power of mathematics.

The revolution is still underway, still challenging entrenched orthodoxies, fallacies, and medieval mindsets.

Galileo believed that nature was inherently mathematical, that mathematics was the language of nature, and that mathematics was the key to understanding the reality behind the appearance of natural phenomena--for example, accelerated and parabolic motions.
--Prof. Joseph W. Dauben, The Art of Renaissance Science: Galileo and Perspective

A Revolution in Thought

Galileo revolutionized physics before Newton. He showed how observation and careful measurement may lead to "hidden causes". For Galileo, those "hidden causes" represented the pervasive mathematical unity underlying nature and, indeed, the Universe itself.

It is Einstein who is most often associated with the concept of the curvature of space-time. But, in fact, Einstein might not have thought about it so clearly had not Galileo laid down a framework, a 'scientific method', within which both Newton and Einstein would later flourish.

Consider, for example, Galileo's contribution to our understanding of the curvature of space-time. To do so, we must understand the "parabola:"

Parabola, plane curve consisting of all points equidistant from a given fixed point (focus) and a given fixed line (directrix). It is the conic section cut by a plane parallel to one of the elements of the cone. The axis of a parabola is the line through the focus perpendicular to the directrix. The vertex is the point at which the axis intersects the curve. The latus rectum is the chord through the focus perpendicular to the axis. Examples of this curve are the path of a projectile and the shape of the cross section of a parallel beam reflector.

Before Galileo, a cannon ball was thought to either fall abruptly upon "losing its impetus" or that it described "some sort" of curve but no one knew what kind of curve or even if it was a curve. It was Galileo who understood that a projectile fired from a cannon is a falling body. Significantly, all falling bodies --even those apparently falling straight down from a fixed point --describe a 'curve'. That is so because the 'fixed point' is merely theoretical. The entire universe and everything in it is in motion.

A Glimpse of Space-Time

Galileo's work --his measurements of the rate of acceleration of all falling bodies --that made it possible to imagine orbiting bodies literally "falling" about a larger one in predictable orbits --the moon around the earth, the earth around the sun, the sun about the center of our galaxy, the Milky Way. All orbits can be described and the results are consistent with Galileo's findings.

Fast forward to the 20th Century. Einstein equates gravity with the curvature of space-time, an insight that reprised in another context, another paradigm, Galileo's discovery that the paths of missiles and projectiles are parabolas.

Einstein went cosmological, envisioning a falling elevator with a hole in the side admitting a beam of light. The graphed path of the traversing light beam --over the time it takes to traverse the falling elevator --is Galileo's parabola. Thus —in two monumentally important paradigm shifts —Galileo and Einstein —-we glimpse the very curvature of space-time itself.

Newton may have posited a "force" to explain "falling" but the equation describing the rate of falling bodies —a curve if graphed horizontally over time —is Galileo's. It was Einstein who understood that the same curvature may describe space-time and render moot Newton's "force", a force that literally reached out into space and acted upon another body instantaneously. For Einstein, gravity was not a force that 'reached out an grabbed ya'; it was, rather, the very shape of space-time. In a sense, Einstein, like Galileo before him, had 'changed' the universe.

Of Space, Time & Einstein

With this insight, the Universe is changed —seen in a completely different way. This is important in at least two ways:

it changes our understanding of the Universe hitherto thought of as a clockwork in absolute space;
it illustrates the very nature of creativity.

Both Galileo and Einstein were able to perceive previously unknown relationships in seemingly unrelated phenomena.

The Big TOE of Science

The current search for TOE (Theory of Everything) is a culmination of this turn of thought. And the verdict is still out on whether the Universe is "closed" and will ultimately implode, or whether it will simply go on expanding forever, perhaps swallowed up by infinite and empty space. But these areas of inquiry would have been forever closed had not Galileo and others opened the door.

Renaissance artists, Leonardo da Vinci in Italy and Albrecht Durer in the North, had evinced an interest in the realistic depiction of nature from the early 15th century on. Leonardo's notebooks, for example, are a revelatory fusion of intuitive and cognitive thinking. Da Vinci was especially skilled at analytical and verbal descriptions of natural events while depicting them "artistically" in detailed sketches, paintings, and analytical diagrams.

It is the path from Leonardo to Galileo that unites the burgeoning interests in science and art under an umbrella of shared values: humanism. It is here that free thought flourished in the very shadow of ignorance, superstition, and the Inquisition. Were it not for that, even now, we could not walk in the sunshine.

The Nature of Time