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Post by JayUtah on Aug 15, 2009 18:34:48 GMT -4
Because the minor zoom in (not zoom out) was made exactly on time to provide a better view of the free fall.
How is this not purely an assumption of motive?
If someone would think that this is just a coincidence, the odds of doing the said zoom during the free fall instead are much bigger.
Why?
Also, all previous zooms are in perfect coordination with the free fall demonstration.
Isn't "coordination" a subjective determination?
You are just chock full of assumptions in this thread. That's why we can't take you seriously as an analyst.
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Post by JayUtah on Aug 15, 2009 18:17:18 GMT -4
Why do you assume that timing was intentional?
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Post by JayUtah on Aug 15, 2009 18:12:04 GMT -4
Why do you presume that the zoom occurred immediately in response to anything seen on the screen?
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Post by JayUtah on Aug 15, 2009 17:25:09 GMT -4
They would behave very differently in the presence of atmosphere. In vacuum, the uncertainty would be greatly reduced.
That's not what I meant. Confining your answer to only those trials that occur in an atmosphere, why do different feathers fall differently in air?
No, that is why we have to rely on what we can interpret from this unique video.
But the video is only one trial. If the same feather would be expected to behave differently when dropped under the same general conditions, how would one go about determining whether this video represented some baseline condition or whether it is one of any number of expected variations?
No, that is why I have some questions and remain undecided.
That's not what I mean. In any video of any event, do you purport that you (or any other photographic analyst) would be able to explain every observation in the video?
So far I estimate almost zero initial linear velocity and the presence of initial non-zero angular velocity.
Estimate or assume? What is the basis for your assignment of values to those properties?
I do not really expect that a repelling electrostatic effect should be observed.
Why? What is your basis for selectively considering electrostatic effects?
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Post by JayUtah on Aug 15, 2009 17:21:32 GMT -4
If during its eventual rotation around its shaft axis the vane is most of the time parallel to the line of sight, its RBG pattern would be difficult to detect with approximately 200 horizontal lines per frame. Still not an answer. You have named some putatively aerodynamic effects and you have predicted that those effects will result in a certain aerodynamic behavior in the feather. What did you do to confirm that your predictions based on first-order aerodynamics are accurate in terms of how a falcon feather really falls in air?
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Post by JayUtah on Aug 15, 2009 17:09:47 GMT -4
The two barbs of the vane are asymmetric with respect to the rachis. There is no afterfeather as well.
Not an answer. What did you do to confirm that the feather would reliably behave as you predict it would?
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Post by JayUtah on Aug 15, 2009 16:56:08 GMT -4
...its own the tendency most of the time would be to propagate through the air with its vane surface parallel to the vertical direction thus reducing the drag to a minimum.What did you do to confirm this hypothesis? What first- and second-order effects did you consider?
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Post by JayUtah on Aug 15, 2009 16:54:54 GMT -4
Every individual feather would behave very differently indeed.Why is every feather expected to behave differently? Is one individual feather expected to perform exactly the same on every drop trial? That is why one should interpret only the available information from the video.Do you presume that you can explain everything you see in the video? ...one should assume that only the gravity and the initial linear and angular velocities should be taken into account for the estimation of the free fall.And do you presume that you can properly discern from the video what the values of all those properties are? However, the static electricity could also slow down the feather for a few frames, something for which there is no visual tendency in the video.Must it?
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Post by JayUtah on Aug 15, 2009 0:48:16 GMT -4
What a great essay! It should be noted that some of the J-missions ran into problems because their radiators had view factors to the lunar mountains surrounding the landing sites.
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Post by JayUtah on Aug 14, 2009 9:29:53 GMT -4
I did not jump into conclusions of any kind.Not buying the backpedaling this time. This is the good point of being neutral and having no prejudice but keeping open mind and retaining curiosity.Hogwash. Anyone who knows anything about photogrammetry expects the angles you identified to be different, and knows why. Your statement is meaningless either as a joke or as an initiation of a meaningful discussion. Further, as I noted, you suddenly changed your major premise. Open-mindedness does not mean entertaining ignorant propositions. its vane seems to be heavier than its shaft because the shaft is in the air.You have offered the hypothesis that the disposition of the feather on the ground is due to a disposition of mass that is improper for a feather. Please explain and defend.
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Post by JayUtah on Aug 14, 2009 6:43:35 GMT -4
The angles seem different, aren't they? Wow: you really have no clue what you're doing, do you? The pictures are taken from two different positions along completely different lines of sight. Why do you believe it's valid to compare directly the two angles you identify, as you've done? And this is yet another line of reasoning aimed at the same conclusion, and one that completely invalidates the premise of your previous line of reasoning. Your previous attempt required that the still photo be of the actual feather as it fell, so that you could reason from the plume-high disposition and correlate it to the drop. Now you're trying to argue that the still photo and the video footage are of different trials because the feather allegedly is lit differently in each. You are fumbling around trying to backfill any line of reasoning toward your desired conclusion.
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Post by JayUtah on Aug 13, 2009 20:50:57 GMT -4
Here is the thread, everyone could share his/her knowledge voluntarily without insinuating that others know less.But if the problem with your argument is that it is argued from naive and uninformed premises, then where do we stand? You propose that "common sense" is a valid basis for knowledge when it suits you, but you ignore professional training and experience when it disagrees with you. What does that say? Once again, I do not know the answers.Can you please, after repeated requests, state your question?
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Post by JayUtah on Aug 13, 2009 20:48:08 GMT -4
You just repeat yourself to infinity and never provided any useful information.You are the proponent. You have the burden of proof. I help you to identify that burden, which you utterly refuse to bear. I find I have to repeat myself because you sidestep the important questions. They don't go away just because you prefer to focus where you think you can make headway. Prove yourself, tell me more about your practical feather experience. ;DAs I said, I have 25 years' experience in fluid dynamics. From that basis I dispute your claim. I do not have to provide a counter-claim in order to take issue with yours, which is patently unsupported. However, it does mean I am not prepared to accept your naive assertions to the tune of feathers always behaving the same. If you cannot substantiate that feathers governed principally by aerodynamics always land plume downward, then bollocks to that as a premise that you can determine whether a feather has fallen through air based on how it appears to have landed. Now kindly stop trying to shift the burden of proof and provide, at long last, some substance.
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Post by JayUtah on Aug 13, 2009 18:50:08 GMT -4
The reseau plate and the lens are in completely different parts of the camera. The reseau plate is a standard Hasselblad feature of the data-acquisition variant of their medium-format cameras. It was available before Apollo and is still available. The Zeiss Biogon has undergone a number of design revisions, but is still fundamentally the same optical design.
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Post by JayUtah on Aug 13, 2009 18:45:56 GMT -4
I simply demonstrated what the case would be if one blindly trusts the raw information being posted online by the NASA curator.In other words you got caught basing an argument on information of unknown or dubious quality, and really have not let up in that approach for nearly 30 pages. You tried to tell us we had to accept a certain drop height because some anonymous NASA employee wrote so on a web page. When the rest of us immediately took a more practical and defensible approach, you did not embrace it; you insisted on the "published" figure. We need no lesson in the dangers of blind trust, but apparently you do. And yes, I consider questions which are contradicting the status quo in order to put them to an exhaustive test.The methodology by which you propose to test them is seriously flawed, and you consider a discussion of those flaws to be out of bounds. I never stated anything that could be considered as a final answer to the discussed hammer-feather drop.It remains constantly unclear what, if anything, you are actually stating, whether you characterize it as a question, a hypothesis, or a conclusion. You say you are "undecided," but you won't even explain what it is you're undecided about. I mentioned about hoax alternatives which fit within the same level of uncertainty which is used to back the status quo.No, because the fundamental underpinnings of those hoax-related hypotheses are being questioned and you refuse to answer the questions. You just claim they are putatively equivalent. You won't explain how. I did not answer the "hard questions" because I did not have a chance to examine evidence which is not available online.There are hard questions on the table that relate to your methodology and are not affected by what data you have or don't have. I have asked you numerous times to address them, and you ignore my requests. Why should I have an opinion or address something that I never saw before.Because an honest approach to your questions requires you to obtain and address it. I do not feel a need to become convinced or to start believing or not believing in the reality of the Apollo missions.So do you intend to remain "undecided" regardless of whether the data really do support a conclusion? You've done nothing but trump up one absurd conjecture after another to buttress the notion that the footage in question was filmed in an atmosphere. How can anyone escape drawing the conclusion that you prefer to remain undecided? For me, this is purely a logical work which is interesting from analytical point of view.But you dislike the logical analysis of your work and you are unfamiliar with the best practices in this type of analysis. You emphasize the technical details until those who disagree with you prove to have a more extensive understanding of the technology. Now you emphasize the logical analysis when just an hour earlier you made a snide remark about my logical analysis of your work. When may we expect something from you that doesn't amount to dodging, feinting, and changing horses? It would be nice, anyway, to perform a similar experiment on the Moon one more time in the presence of a meter and a millisecond watch being held by a NIST representative. It would be nice if you could provide anything substantial that supports your insinuation that we should not respect the evidence that already exists.
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