Gravity Simulator http://www.orbitsimulator.com/cgi-bin/yabb/YaBB.pl General >> Discussion >> Lunisolar precession test-verification http://www.orbitsimulator.com/cgi-bin/yabb/YaBB.pl?num=1307543076 Message started by wil on 06/08/11 at 07:24:36

 Title: Lunisolar precession test-verification Post by wil on 06/08/11 at 07:24:36 http://en.wikipedia.org/wiki/Transit_of_Venusand:http://eclipse.gsfc.nasa.gov/transit/catalog/VenusCatalog.htmlVery nice numerology...  ;)=======Venus transits cycle: 243 and +8 years (second transit).What this means?I think, pentagon must turn around 72 degrees among: 243 - 251 years!Venus synodic period: 583.92 days.Sidereal year: 365.256363 days:243 * 365.256363 / 583.92 = 152.00249;it's too far - cycle can't finish before first transit!Tropical year: 365.24219 d:243 * 365.24219 / 583.92 = 151.996596;Good! Cycle will close in next 8 years.----------- What is orbital period of earth - from simulations?Average - 100 or 250 years should suffice.

 Title: Re: Lunisolar precession test-verification Post by Tony on 06/08/11 at 13:38:08 I'm not quite sure I follow what you're getting at, or what this has to do with testing and verifying Lunisolar precession, but it's easy to play around with transits of Venus in Gravity Simulator.  Make Earth the focus object, and you can watch Venus trace out its pentagram.  The pentagram turns much slower than 72 degrees in a couple hundred years.  Venus traces one of the 5 points of the pentegram at each inferior conjunction, which occur 1 synodic year apart.  The points of the pentegram are roughly 72 degrees from each other.  Venus doesn't trace them out in order.  It does it in a star pattern, similar to the order you're supposed to tighten the lug nuts of your car's wheel (assuming 5 lug nuts).  It takes Venus 5 synodic periods to trace out the entire pentegram.  5 synodic periods takes 8 years.  That's why transit pairs are 8 years apart.  Here is a gsim file so you can try this yourself.  Make sure you're using the beta version to take advantage of all the features.http://orbitsimulator.com/gravity/simulations/VenusTransit.gsimYou'll see that Venus traces out the following:http://orbitsimulator.com/gravity/images/venustransit1.gifThe Earth and Moon are the dot in the middle.  The Sun is yellow.  Venus is red and white.  Red means it's below the ecliptic, and white means above.  So where red and white meet is where Venus crosses the ecliptic.  A transit can only happen when the ecliptic crossing occurs at inferior conjunction. So the bottom point of the pentegram is where a transit will happen.  This represents 2012.  As you run the simulation, you'll see that the each successive pentagram almost overlaps the previous one.  This image shows two overlapping pentagrams.  If you run the simulation long enough, you'll see that it takes over 100 years for the tip of a pentegram to line up with the ecliptic crossing again, producing another transit.

 Title: Re: Lunisolar precession test-verification Post by wil on 06/10/11 at 19:30:36 Thank You very much!And Yes! There is no lunisolar precession!  ;DYou can check it very easy in this simple simulation.Look at this data:event          : correct date time ----  time from GSim -> error differenceLunar ecipse : 2004-04-04 20:30 ---- 22:27 -> +117 minutesVenus transit: 2004-06-08  8:20 ---- 08:34 -> + 14Solar eclipse  : 2004-10-14  3:00 ---- 04:40 -> +100Lunar ecipse : 2004-10-28  3:04 ---- 04:53 -> +109Solar eclipse  : 2005-04-08 20:37 ---- 22:12 -> + 95Lunar eclipse : 2008-02-21  3:26 ----  4:22 -> + 56Solar eclipse  : 2008-08-01 10:22 ---- 11:02 -> + 40Solar eclipse  : 2010-07-11 19:35 ---- 19:50 -> + 15Solar eclipse  : 2011-07-01  8:39 ----  8:45 -> +  6Solar eclipse  : 2012-05-20 23:54 ---- 23:35 -> - 19 Venus transit: 2012-06-06  1:29 ----  1:08 -> - 21You see how moon drifts about 20 minutes per year, because sidereal year is incorect - too long?With lunisolar precession theory (rather ancient hypothesis) venus transits are only poorly approximated (standard gravitational parameter is only lowered, and planets circle slower, but not moons!).============Pentagon rotates 72 degris in 250 years - correct years!1250y per full cycle, and it is perfect.5 synodics periods:5 * 583.92 / 365.24219 = 7.99368 years and pentagon rotates:  8 - 7.9936 = -0.0064 = -0.0008 [360°/y].250y * -0.0008 * 360°/y = -72°; After 243 years we see transit, because we are now looking from next vertex - advanced 72 degrees (we don't see central transits, but two almost symmetric and sepparated ~8y).Calculations are simple - we have synodic period, venus node can even dance...Gravity Simulator shows Venus node moves: ~10'' / y;It's orbit's precession in ecliptic plane, but ecliptic plane precesses in invariant plane of Solar System - nearly Jupiter orbit. Then we may extract ecliptic precession from parameters of Jupiter orbit.