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Old October 11th 18, 10:18 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Neil DeGrasse Tyson headed down same loony road as Carl Sagan?

The centrepiece of astrophysics is certainly the so-called 'inverse square law' which appeared to give legs to the idea that experimental sciences scale up to planetary dynamics. The fact that it wasn't a law in Kepler's proposal doesn't seem to deter the empiricists from making it that way but then again, this is the way academics have operated for centuries.

The statement from Kepler first appears daunting and is probably unhelpful as it distracts from the nuts and bolts of observations tied to variable orbital speeds where he was most effective -

"The proportion existing between the periodic times of any two planets
is exactly the sesquiplicate proportion of the mean distances of the
orbits, or as generally given,the squares of the periodic times are
proportional to the cubes of the mean distances." Kepler

In a gentler light and a more expansive explanation, it is easy to see he is equalising observations in speeds and distance from the Sun rather than explaining orbital motions -

"But it is absolutely certain and exact that the ratio which exists
between the periodic times of any two planets is precisely the ratio
of the 3/2th power of the mean distances, i.e., of the spheres
themselves; provided, however, that the arithmetic mean between both
diameters of the elliptic orbit be slightly less than the longer
diameter. And so if any one take the period, say, of the Earth, which
is one year, and the period of Saturn, which is thirty years, and
extract the cube roots of this ratio and then square the ensuing ratio
by squaring the cube roots, he will have as his numerical products the
most just ratio of the distances of the Earth and Saturn from the sun.
1 For the cube root of 1 is 1, and the square of it is 1; and the cube
root of 30 is greater than 3, and therefore the square of it is
greater than 9. And Saturn, at its mean distance from the sun, is
slightly higher than nine times the mean distance of the Earth from
the sun." Kepler

Sir Isaac tried to turn this trivial correlation on its head by trying to mesh it with the behavior of experimental sciences and objects at a human level. The followers of Newton haven't a clue nor want to know how he tried to reduce astronomy to the level of experimental sciences but it involves wrecking astronomical insights and methods including how the motions of the planets are resolved by a moving Earth.

The under developed adults here don't have the confidence nor the competence to stack up Newton's notions with the approach of the first Sun centered astronomers so they lean on the old familiar 'take-my-word-for-it' convictions they picked up at school from previous generations of followers.

People should enjoy what Kepler tried to do before moving on to more meaningful material rather than disappearing down the rabbit hole of theorists.