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Post by Data Cable on Feb 3, 2010 14:12:56 GMT -4
Whoever this guy is, he clearly needs serious medical help and about twenty years of remedial education. See my sig for a quote which used to be on his Apollo Data page, demonstrating his grasp on basic orbital mechanics.  |
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Feb 3, 2010 14:56:38 GMT -4
Hi I was waiting to see what explanations you guys came back with, but I am afraid none of them answer my original query. Your query has been answered. What we must now do is work on your understanding of the answers. I will repeat, how can a spacecraft orbiting a celestial body suddenly go into reverse orbit. It can’t and it didn’t. The spacecraft, and consequently the camera, simply made a change in attitude, that is, the spacecraft changed the direction it was pointing while its speed and direction of travel remained unchanged. (The orientation of a spacecraft is entirely independent of the direction it is traveling.) Since the camera was flipped around, we see new terrain entering the field-of-view from the opposite side. It defies all laws of physics, and if you guys are as educated as you claim you are, then please explain, because as it stands the film is clearly fake, and I therefore side with Sam Colby on this issue. Nothing in the video defines physics. The only thing that is flawed it your interpretation of what you are seeing. BOB B You cannot see what is blindingly obvious. If your understanding were obvious, everyone here would agree with you. The fact that no one agrees with you should be an indication that perhaps you are the one that has a problem here. GWIZ The film is not Apollo 9. All of the film was broadcast on the Discovery channel as being Apollo 8. If true, then Discovery channel made a mistake. The view of the CSM in Earth orbit is from the Apollo 9 mission. Are you telling me that Apollo 8 did not orbit the Earth. Apollo 8 did orbit Earth briefly before heading to the Moon; however, there is no film of it in orbit. Apollo 9 is the only Apollo mission in which two manned spacecraft – the CSM and the LM – where in Earth orbit at the same time. The film of the CSM was shot from the LM during this test mission. JAYUTAH It is not a 180 degree yaw, and anybody can see it is a full 360 degree rotation. It is mostly definitely not a full 360-degree rotation. I and everyone else but you seem to agree that it is a 180-degree rotation. If you are correct, then please convince us of such with something more than “anyone can see.” I will repeat again, how can a spacecraft orbiting a celestial body, ie, the Moon, Earth, or any other planet, suddenley go into reverse orbit? I repeat again that it can’t and it didn’t. The referenced film it not evidence of a spacecraft suddenly going into a reverse orbit. It is evidence of a spacecraft making a 180-degree change in attitude. |
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Post by JayUtah on Feb 3, 2010 15:16:34 GMT -4
Hi I was waiting to see what explanations you guys came back with, but I am afraid none of them answer my original query.Yes, they do. JASON Frame rate and angle does not come into it.Yes, they do. The frame rate determines the perception of the rapidity of the movement. Orbital footage was typically shot at 6 frames per second. When played back at a conventional 24 frames per second, motion appears to be sped up. The angle (i.e., line of sight) determines how rotational motion will be interpreted. Consider driving in a convertible. Look straight up, and while looking up turn right. You will see the sky simply rotate. Now look straight ahead and make another right turn. You will see the scenery sweep across your field of view from right to left. The motion of the car is the same in both cases, but your perception of it depends entirely on which direction you look. In this video the camera is not pointing straight down, as you seem to have assumed. If the camera is pointed slightly forward, or left or right, then rotational motion will introduce a "sweep" component to the line of sight during the rotation. That sweep will be negated by forward orbital motion during a certain portion of the turn, producing the illusion that the vehicle has stopped. Further, you seem to be operating under the delusion that a spacecraft must always be pointing in the direction that it's going. In this case the spacecraft's forward motion has not changed, but the orientation of the spacecraft (and the camera attached to it) have changed. I will repeat, how can a spacecraft orbiting a celestial body suddenly go into reverse orbit. It defies all laws of physicsOnly the small subset of the laws of physics that you seem prepared to consider. It has been carefully explained to you what is happening in this video, including an explanation of the laws of physics that you apparently didn't know about before you went off on it being "fake", and a dispelling of the delusions and assumptions that are feeding your conclusion. Now it's simply up to you to either learn it or continue to pound your fist on the table. if you guys are as educated as you claim you are, then please explain...Been there, done that. You simply stubbornly refuse to think about it. You have latched onto one interpretation of the visual, which is based on your wrong assumptions regarding physics and optics, and you refuse to consider that anything else can be true. You presume that you know enough about physics to reason properly here. Clearly photographic interpretation is not something you're good at. JAYUTAH It is not a 180 degree yaw, and anybody can see it is a full 360 degree rotation.Try again. 180 degrees is half a circle. 360 degrees is a full circle. If it had gone 360 degrees, it would have ended up going in the same direction as before. If it "reversed direction" that would be 180 degrees.
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Post by chew on Feb 3, 2010 16:15:28 GMT -4
Whoever this guy is, he clearly needs serious medical help and about twenty years of remedial education. See my sig for a quote which used to be on his Apollo Data page, demonstrating his grasp on basic orbital mechanics. That's the guy??? I remember reading that a few years ago. The other day, a co-worker was reading some HB website and couldn't believe how ignorant the author was. "That's nothing", I said, and told him about the math in your sig. |
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Post by chew on Feb 3, 2010 16:25:04 GMT -4
This is a protractor. It is used to measure angles. This one is graduated in degrees. Note half a circle is 180 o.  |
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Post by drewid on Feb 3, 2010 16:49:04 GMT -4
The angle is easy enough to check...
Hang on..
I'll be back in half an hour or so.
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Post by drewid on Feb 3, 2010 17:54:12 GMT -4
I took a series of frames from the video. As you can see there are a number of surface features that make it easy to track. Then I overlaid them on top of each other, rotating them so that the surface features lined up. There's a little lens distortion at the edges, I'm guessing its a reasonably wide angle. Centre of frame has a light patch which shows up more in later frames, probably due to the camera angle changing with respect to the sun. So the rotation is a shade over 180 degrees, with a slight change in direction of perhaps <3 degrees. (difficult to tell from this short clip.)  Definitely not 360 degrees, and definitely no "reverse" of orbit. There's a larger version of the overlay here, be warned it's big.  |
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Post by BertL on Feb 3, 2010 17:57:25 GMT -4
If the orbit would suddenly reverse, wouldn't you be seeing the same terrain you saw before? If I walk down the street past a barber shop and decided to turn around and walk back, I'd pass the same barber shop again.
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Post by drewid on Feb 4, 2010 4:38:53 GMT -4
That went quiet.
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Post by gwiz on Feb 4, 2010 6:41:37 GMT -4
GWIZ The film is not Apollo 9. All of the film was broadcast on the Discovery channel as being Apollo 8. Are you telling me that Apollo 8 did not orbit the Earth. It is hardly my problem if the Discovery Channel also mix up their films. That clip is definitely Apollo 9. On the Spacecraftfilms Apollo 9 DVD, it's disc 2, chapter 6. |
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Post by echnaton on Feb 4, 2010 11:27:11 GMT -4
Nice work, drewid.
Could this maneuver included a change of orbital plane as well?
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Feb 4, 2010 12:17:06 GMT -4
I concur. Could this maneuver included a change of orbital plane as well? No, this appears to be a simply change in attitude. A plane change generally requires the spacecraft to thrust at or near a right angle to the direction of travel. The spacecraft was rotating throughout the maneuver with no evidence of thrusting. Off the top of my head, I have no immediate explanation for the apparent 3-degree change in direction. |
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Post by echnaton on Feb 4, 2010 12:26:47 GMT -4
Thanks for the explanation. I thought the right angle thrust might have taken place, but with further thought it seems it would have shown up in a stopping in the rotation of the photos surrounding the time the engine was active.
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Post by drewid on Feb 4, 2010 14:47:55 GMT -4
Actually looking at it again it's probably a lot less than that. I'll check later. It could well be BEBKAC.
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Feb 4, 2010 14:56:42 GMT -4
Thanks for the explanation. I thought the right angle thrust might have taken place, but with further thought it seems it would have shown up in a stopping in the rotation of the photos surrounding the time the engine was active. That's my reasoning as well -- it looks like the spacecraft never stopped rotating. A 3-degree plane change would have required an SPS burn of about 6 seconds, which isn't very long, but I see no evidence that the vehicle stopped at all during the yaw maneuver. Furthermore, there is no record of a orbit plane change for Apollo 8 -- the only lunar orbit SPS burns where LOI, orbit circularization, and TEI. |
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