|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
The so-called inverse square law
Despite comments on the demise of sci.astro.amateur, the people involved in magnification and identification have moved to moderated forums so don't have to deal with anything outside their celestial sphere hobby. It is true that the childish noiseboxes have flourished in the absence of magnification hobbyists but who reads that stuff anyway.
The statement known as 'Phenomenon IV' is quite a mouthful - "That the fixed stars being at rest, the periodic times of the five primary planets, and (whether of the sun about the earth, or) of the earth about the sun, are in the sesquiplicate proportion of their mean distances from the sun...This proportion, first observed by Kepler, is now received by all astronomers; for the periodic times are the same, and the dimensions of the orbits are the same, whether the sun revolves about the earth, or the earth about the sun." Newton The Sun moving around the Earth is a daily rotation observation while the Earth running a circuit around the Sun is an orbital motion so there is no equivalency as a matter of common sense. It is a badge of intelligence to realize where he was getting the equivalency but unfortunately nobody else can work through the details where Huygen's creates an equivalency , not based on the Sun around the Earth and visa versa, but rather the motion of the Earth and the apparent motion of the Sun through the constellations - "Here take notice, that the Sun or the Earth passeth the 12. Signes, or makes an entire revolution in the Ecliptick in 365 days, 5 hours 49 min. or there about, and that those days, reckon'd from noon to noon, are of different lenghts; as is known to all that are vers'd in Astronomy. Now between the longest and the shortest of those days, a day may be taken of such a length, as 365 such days, 5. hours &c. (the same numbers as before) make up, or are equall to that revolution: And this is call'd the Equal or Mean day, according to which the Watches are to be set; and therefore the Hour or Minute shew'd by the Watches, though they be perfectly Iust and equal, must needs differ almost continually from those that are shew'd by the Sun, or are reckon'd according to its Motion. But this Difference is regular, and is otherwise call'd the Aequation.." Huygens It is not possible to fit the Equation of Time(keeping) into the orbital period of the Earth as that facility relies on the noon observation hence it is an outrigger of the calendar 365/366 day format. A lot to do and nobody around to do it. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Inverse square law | G=EMC^2TreBert | Misc | 17 | November 8th 14 01:35 AM |
Inverse Square Law ????? | herbert glazier | Misc | 3 | April 12th 11 01:52 PM |
Life and the Inverse square! C and C please | Jonathan | Policy | 15 | January 25th 10 01:48 PM |
inverse-square law through geometry | Brian Tung | Amateur Astronomy | 13 | November 10th 04 04:21 PM |
Inverse Square Law | G=EMC^2 Glazier | Misc | 4 | January 4th 04 01:03 PM |