[Physics] Physics Digest, Vol 8, Issue 4

[cj at mb-soft.com]

Since some of you have become interested in Io, Europa and their friends, you KNOW that we have an obvious resolution to the "dispute" you describe.  Just get someone (or soome computer) to do the math I did 25 years ago, but now instead of calculating for 1996 events as I had done, do it for the coming 2021 events.  And then we can all WATCH with out wristwatches ready.  Again, I personallly do not see the events that involve Ganymede and Calllisto as being as important, as the move slower in larger orbits and they are physically larger.  So my fascination remains with Io and Europa, which "whiz" past each other, every few hours.  In most orbits, the shadow of one passes above or below the other and no excitement.  When the various Nodes are just right, a mutual total or annular eclipse can occur.  In my calculations, that seemed to only happen about three times in the 1996 cycle,  The information you have found seem to suggest that only a handful of mutual Io/Europa total eclipses occurred in 2009 and in 2015.  But if somebody does accurate enough math for 2021, we can all be looking through our telescopes or binoculars at the right time.  THEN, if we SEE a 900 second event, sobeit.  Or however long it would be seen to last, fine, but history has shown that VERY few astronomers have ever seen these events, so someone need to do the (nasty) math to make sure that WE can be added to that short list.  I would LOVE to witness it, but I am really too old now to abuse my brain as I did 25 years ago.  Maybe I can get Jan Meeus to do the math for 2021,  but he is pretty old now too.

Bonus:  IF the prediction math is good enough, say to the nearest thousandth of a second, and we each have equally accurate wristwatches, we may also get a "one-way speed of light" as well.

Carl Johnson 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.tuks.nl/pipermail/physics/attachments/20170806/80367c77/attachment.html>