Galileo: Epistemology not Optics

Posted by $ MikeMarotta 5 months, 4 weeks ago to Science
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It is commonly claimed that Galileo did not perceive the rings of Saturn because the telescope he was using was not capable of magnifying the image. That is not true. After Galileo, astronomers needed another 50 years to think about the problem and re-imagine it. They needed to ask the right questions. Christiaan Huygens was the first to perceive the structure as a ring. However, it was another 200 years before the ring was understood as a system of particles, rather than a rigid body. The problem was epistemology, not optics.

In Introduction to Objectivist Epistemology, Ayn Rand asserted that a sensation must be identified to become a percept. A set of percepts, identified and integrated by common attribute becomes a perception. A set of perceptions integrated by their common characteristics are given a name and thereby made into a concept. Concepts are further abstracted by their essential distinguishing characteristics, according to objective context, into wider (and more powerful) ideas. Without identification, a sensation alone is meaningless. Not knowing what to expect, Galileo could not perceive the rings of Saturn correctly.

Just as it took time for the nature of Saturn’s rings to be teased out from the observations, so, too, did someone 400 years after Galileo finally put 2 and 2 together. In 2005, the science of epistemology informed astronomy.

“Saturn was first seen through the telescope by Galileo in the summer of 1610. In the ensuing half century, Saturn's strange appearances became a celebrated puzzle. The problem was often not the poor quality of telescopes: a number of observers drew images that we would interpret as showing a ring around the planet. It was also a problem of concepts because for several decades observers had the wrong model in mind when they observed the planet. Thus we could say that their telescopes could show them the ring, but their preconceptions did not allow them to see it. The manner in which Christiaan Huygens arrived at the solution, in the winter of 1655-56, shows that more than good telescopes were necessary, although for rhetorical reasons Huygens maintained the opposite. And Huygens's ring-theory, [elegant] as it was, had several shortcomings that were slowly fixed--often by others.” -- “Saturn through the Telescope: The First Century” by Albert Van Helden. American Astronomical Society, DPS meeting #37, Bulletin of the American Astronomical Society, Vol. 37, p.620. Pub Date: August 2005.

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  • Posted by $ mshupe 5 months, 4 weeks ago
    A set of percepts must be integrated by common attributes to become a perception? Does this mean a percept is not perceived until it has been repeated and understood as unit? In the case of Saturn's rings, what was the wrong model that prevented an accurate concept from being formed?
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    • Posted by $ 5 months, 4 weeks ago
      A sensation must be identified. Rand had much to say about Helen Keller and Anne Sullivan. Helen Keller's world was undifferentiated chaos until Anne Sullivan taught her by touch to identify sensations. Without identification, a pinprick is only pain.

      It is a common error to understand induction as requiring multiple instances to form a generalization. We all learn it that way, especially in science classes where we repeat experiments. However, as David Harriman demonstratred in The Logical Leap one instance is enough if it is properly integated with previous knowledge. (He holds master's degrees in physics and philosophy. Leonard Peikoff wrote the introduction to the book.) If you can identify the pinprick as different from a feather's tickle, that mental act creates the percept from the sensation.

      (@ewv may have a better explanation of Ayn Rand's theory of epistemology.)

      As for the rings of Saturn, it was not so much that their model was wrong as that there was no model at all. No one had any reason to expect that planets have rings. Observation and reason led to our understanding that the Earth is a sphere. By Aristotle's time c. 350 BCE that was pretty much accepted. As a consequence, it was assumed that the planets, sun, stars, etc., were all spheres. It was common knowledge (among the educated and thoughtful) that the Moon is a sphere, but we just see one side of it. No one who was educated thought of it as a disk facing flat-on to us. But no one had ever seen an orb in space with a ring around it. Even the occasional haloes around the Moon and Sun did not lead to that expectation.

      So, when Galileo viewed Saturn, he integrated the perception into his existing knowledge and suggested that it could be three bodies, two small spheres near a larger one. When the rings disappeared because they were edge-on to us, he was stumped. Their reappearance explained nothing. Astronomers had to think about it for 50 years.
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  • Posted by Lucky 5 months, 4 weeks ago
    sensation must be identified to become a percept
    Percept Is this precept or perceivable?

    Either, true.
    This may be what I describe as- you cannot see anything for which you have no words.
    But your explanation, tho' with more and longer words, covers the ground better.
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