Gutenberg and Spectacles

Arendt in The Human Condition, Chapter VI, singles out the Reformation, global navigation and the combination of the telescope as technical instrument and astrophysics as "universal" science.

Any reader might ask why not spectacles and the printing press?  When the early phenomenologists adopted the slogan "To the things themselves!", no one was expected to be excluded by having to rely on spectacles: phenomenology was not exclusively or primarily focused on perception and appearances.

In one early text, "Phenomena" are roughly what we would call the constellations visible in the Mediterranean sky - a sky somewhat different from ours as the northern celestial pole was not Polaris as it is today, some two millenia later.

A more important phenomenon is the "moon illusion" as it is not dependent on either telescope or spectacles. This illusion need not be subsumed under issues of apparent numerical measure.  It is quite possible that Arendt was not aware of the illusion and how it was resolved - the nature of this appearance, if you will - by science and critical dialogue.

In the arc of the sky, the full moon, high in a winter sky, subtends less than a single degree of arc - about the width of your little pinkie extended above you at arms length.  Call this by some neologism such as "lunar-spatial-form-in-high-sky-hand" for some non-numerical astronomy.  The rising full moon at the horizon appears to be - is said to be - much larger. If the high moon is a "dime-size" then the rising moon is a "nickel-size" - or sleeve-button-sized versus front-button-sized, to address Heidegger's numeric phobia.  Pupil-of-lion versus iris-of-lion.  What you will.

The telescope is another matter: the "sickle" Venus is larger in the field of a given telescope than the "full" Venus.

At the time Arendt was writing - during the 1950's - there was no star that appeared larger when in focus at high-magnification within a given star-pattern or asterism than when at low magnification in that same field.  This is not so for a planet, a cluster or a nebula.  With allowance for the distinct differences between the resolved image at optical limit in a refractor and in a reflector telescope, stars remain "points" of light.  Only recently has the "surface of a star" been explored - other than the sun.

What was critical was the discovery that so many stars are in fact double stars and some even triple.  To Herschel we owe the confirmation that true binary stars - not virtual or "optical" apparent doubles (one star appearing near another (only due to our relative alignment of star-A and star-B from earth at some point in her orbit) - obeyed Newtonian mechanics (to a good approximation given his instruments.)

Our understanding of our solar system is that it might more readily have been a binary arrangement of a yellow star with a smaller star - perhaps a brown dwarf comprised of what today are our four gas-giant planets.  Our sun likely began in a cluster of stars: the fate of the solar dust ring was to be a mix of rocky planets, asteroids, gas planets, icy debris and residual dust.

It is not an illusion that Venus appears larger in one phase than in another.  Nor does it require Arendt's "Archimedean" standpoint to think about this. Insight alone will not resolve this - did not resolve this.

The moon illusion is a critical absence in Chapter VI of Arendt's book - as much are the concepts of acceleration, limit, group and symmetry - not to mention the orbit of Mercury.

If only Arendt had written a book on Emmy Noether, Edith Stein and the destiny of the thinking woman at Goettingen!

see: Dorian Cairns recall of Husserl on near, far and astronomy.
also see: Sonja Kovalevsly (Sofia Kovalevskaya); Sophie Germain
more recently: Maria Skłodowska, Julia Robinson, Louise Volders
among philosophers: Susanne Langer, Susan Stebbing, E. Anscombe, Philippa Foot, Iris Murdoch