#41
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Polar astronomy
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#42
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Polar astronomy
On Thursday, March 8, 2018 at 11:26:42 AM UTC-7, Bill wrote:
I can't think of any professional level endeavor where that his sort of lackadaisical, sloppy, piecemeal approach would provoke anything but scorn from any audience. I am not defending him from the charge of being a crackpot, because that he obviously is, but simply noting that when he occasionally, if only by accident, gets something right it should be acknowledged. His view that astronomy should be a quasi-mystical activity is obviously to be dismissed. His idea that we are anti-Copernican if we relate the Earth's rotation directly to the inertial frame of the fixed stars is wrong and silly. But, in connection with his mistaken framework, when he points out that there is a distinction between the way retrograde motion is manifest in the inferior planets and the superior planets - well, he is pointing out something real. In the case of the inferior planets, we are indeed looking at those planets' real orbits around the Sun - although it would be more apparent from, say, the Moon, without an atmosphere, than on Earth, where it was once thought that Venus was two distinct bodies, the evening star and the morning star. With Mars or Jupiter, their real orbits around the Sun have retrograde motion added to them; with Venus and Mercury, the retrograde motion is caused by their real orbital motion on the opposite side of the Sun. He may impute a different significance to this fact than we would, but the fact is real none the less. So even if he is getting parts of the story wrong, since he is here mentioning something quite real, to say he is ludicrously wrong, 100% wrong, or saying the exact opposite of the truth just isn't accurate. John Savard |
#43
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Polar astronomy
http://www.popastro.com/images/plane...ary%202012.jpg
20th /July/2010 to 20th/January/2012 found in the jpg image address. It is not enough to pronounce that the illusory loop of Mars or indeed any of the slower moving planets with larger orbital circumferences than the Earth are resolved though an overtaking perspective while leaving the direct/retrogrades of the faster moving planets unattended. All the whining directed at me doesn't alter the fact that direct/retrogrades of the slower moving planets is accepted separately to the perspectives of Venus and Mercury. If somebody can insert an illusory loop into the actual loop of Venus in the 18 month sequence of images above then good for them, everyone else can stay with an animated graphic long enough to watch Venus and Mercury move in one direction against the stars until they reach their widest point before turning back in front of the Sun where they move in the opposite direction - https://www.youtube.com/watch?v=MdFrE7hWj0A http://www.theplanetstoday.com/ As Venus and Mercury are currently are an evening appearance they are to the left of the Sun and will eventually overtake us before becoming a morning appearance to right of the Sun due to our slower motion. So we do see Venus and Mercury both as actual loops and in direct/retrograde. |
#44
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Polar astronomy
With Mars or Jupiter, their real orbits around the Sun have retrograde
motion added to them; with Venus and Mercury, the retrograde motion is caused by their real orbital motion on the opposite side of the Sun. That remark about how you know better? I apologize and withdraw it. |
#45
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Polar astronomy
On Thursday, March 8, 2018 at 6:26:42 PM UTC, Bill wrote:
I can't think of any professional level endeavor where that his sort of lackadaisical, sloppy, piecemeal approach would provoke anything but scorn from any audience. "This apparent erratic movement is called "retrograde motion." The illusion also happens with Jupiter and the other planets that orbit farther from the sun." https://mars.nasa.gov/allaboutmars/nightsky/retrograde/ So much for scorn when they already make the distinction without promoting how direct/retrogrades of the faster planets play out against the slower moving Earth. That distinction first happened in this newsgroup so I shrug and enjoy the fact that they at least strive to make the distinction without filling in the details for Venus and Mercury which requires an entirely different approach. I guarantee that any teacher who teaches their students the principles which distinguishes the illusory loop of Mars from the actual loop of Venus by analogy or by use of imaging will get a satisfaction rarely experienced. It is because the direct/retrograde modification is new that it gives the talented plenty of leeway to express the principles as they see fit. |
#46
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Polar astronomy
On Thu, 8 Mar 2018 10:44:16 -0800 (PST), Quadibloc wrote:
On Thursday, March 8, 2018 at 11:26:42 AM UTC-7, Bill wrote: I can't think of any professional level endeavor where that his sort of lackadaisical, sloppy, piecemeal approach would provoke anything but scorn from any audience. I am not defending him from the charge of being a crackpot, because that he obviously is, but simply noting that when he occasionally, if only by accident, gets something right it should be acknowledged. His view that astronomy should be a quasi-mystical activity is obviously to be dismissed. His idea that we are anti-Copernican if we relate the Earth's rotation directly to the inertial frame of the fixed stars is wrong and silly. But, in connection with his mistaken framework, when he points out that there is a distinction between the way retrograde motion is manifest in the inferior planets and the superior planets - well, he is pointing out something real. In the case of the inferior planets, we are indeed looking at those planets' real orbits around the Sun - although it would be more apparent from, say, the Moon, without an atmosphere, than on Earth, where it was once thought that Venus was two distinct bodies, the evening star and the morning star. With Mars or Jupiter, their real orbits around the Sun have retrograde motion added to them; with Venus and Mercury, the retrograde motion is caused by their real orbital motion on the opposite side of the Sun. He may impute a different significance to this fact than we would, but the fact is real none the less. So even if he is getting parts of the story wrong, since he is here mentioning something quite real, to say he is ludicrously wrong, 100% wrong, or saying the exact opposite of the truth just isn't accurate. John Savard Of course he's not 100% wrong. He's 110% wrong. Behavior-wise. Seriously, when someone states the impossible - then they're telling us that their assertion isn't to be taken as statment of fact. IMO, Niall's remark was a bit of hyperbole/sarcasm - aka: frustration from dealing with our resident Troll/crackpot. As I see it, the way Gerald has repeatedly misportrayed people here for years, and all this trolling of his... I'm afraid I have run out of empathy for him. |
#47
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Polar astronomy
On Thursday, March 8, 2018 at 6:45:27 PM UTC, Gerald Kelleher wrote:
20th /July/2010 to 20th/January/2012 found in the jpg image address. If somebody can insert an illusory loop into the actual loop of Venus in the 18 month sequence of images above then good for them Here you a http://www.davidcolarusso.com/astro/ Set the date to July 2010 and advance one frame at a time. You are welcome. |
#48
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Polar astronomy
Back in 2005 when I proposed that the 26 mile spherical deviation of the planet is linked to plate tectonics via differential rotation of the fluid interior (across latitudes) ,the response of the community was to throw the kitchen sink at rotation without actually mentioning zonal flow across latitudes. I see the same here with direct/retrogrades and the necessary distinction between the faster and slower moving planets so what looks like an improvement becomes a mess in the hands of those who are just chancing their arm.
While the geological proposal remains speculative although supported by visible clues on the surface crust or by using planetary comparisons between the Earth and Venus both dynamically and geologically, the direct/retrograde topic in front of observers is 100% verifiable. I suppose I should kick up a fuss but with the wider community reluctantly pursuing the correct path but the fuller picture will eventually make it out. So, the only means to stop the Sun moving through the constellations so our parent star acts as a central reference for the motions of Venus and Mercury is to adopt the oldest astronomical framework where the stars 'come in season' or in dynamical terms - they are far enough to one side of the Sun to emerge as a dawn appearance. Of course it introduces a slightly more complicated narrative than just comparing the illusory loop of Mars with the actual loop of Venus but observers shouldn't be overly concerned with the complication. The fact is proof of the Earth's orbital motion is the transition of the stars from left to right of the Sun and to ignore that is pretty small. |
#49
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Polar astronomy
On Thursday, March 8, 2018 at 10:01:02 AM UTC-7, wrote:
By contrast, Venus orbits the Sun in 224 days, but does not return to its greatest Eastern elongation for 584 days because of the Earth's orbital motion. That's certainly a good point. The contrast isn't so striking in the case of Mercury, of course. If you look at a diagram of the apparent motion of Mars or Jupiter, you see a circular trail of loops. The circle part - if plotted against the starry background - has the same period as the actual orbits of those planets. A diagram of the apparent motion of Venus or Mercury is also a circular trail of loops. But now the general circle moves through the zodiac... once a year, along with the Sun. So the *loops*, which lead to retrogrades, are due to Venus and Mercury orbiting the Sun, and the overall motion is due to the Earth's motion changing our viewpoint. (How could it be otherwise? Venus and Mercury are always on the same side of the Earth as the Sun, so their orbital motion *can't* take them through a full circle of the Zodiac from our point of view by itself.) That is a fact. I'm not saying that you have to accept that Oriel is right that this is an important fundamental distinction between retrogrades of inferior and superior planets. But there is the old saying that one must give even the Devil his due; and that he has managed to get one thing right, for a change, should be cause for celebration. John Savard |
#50
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Polar astronomy
On Monday, March 5, 2018 at 1:19:07 PM UTC-7, Gerald Kelleher wrote:
If you can distinguish between the open-ended illusory loop of Mars from the closed actual loop of Venus you have already come to understand what Galileo and the original Sun centered astronomers did not and that does nothing to diminish those astronomers. I do not even ask observers to know why their perspectives were incomplete but it does help to know why Venus ad Mercury do not trace out open-ended loops as previous views held - You are expressing a genuine astronomical fact here, but you have also made an error. With the superior planets like Mars and Jupiter, the general apparent motion is due to their actual orbits, while the loops, that give rise to retrograde motion, are due to the Earth's motion. With the inferior planets like Mercury and Venus, the general apparent motion is due to the Earth's motion around the Sun, while loops, that give rise to retrograde motion, are due to their own actual orbits. That is true. And their orbits around the Sun are closed ellipses (neglecting details like perturbation). But the loops due to those closed orbits in their *apparent* paths, which also include the results of the Earth's orbit, are still open-ended - not closed. John Savard |
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