Apollo 11 Lunar Lander Pre-Launch

[JayUtah]

For just a fleeting moment, I thought he was talking about the Vehicle Assembly Building, which could actually have been referring back to the original topic of this thread, after all.

And once we get some closure on the issue of the lunar module stability with the plume deflectors, I would love to talk about operations in the VAB and on the pad.  I even went up to the attic and got the definitive references on the subject, not just for this debate but because they're legitimately fascinating engineering topics.  Rocket science isn't just about the bit that flies.

[Jason Thompson]

Hi Jay,

I surrender.

Except you clearly don't. Stop trying to weasel out of owning your mistake and actually answer the questions put to you.

But to be clear, that MIT paper

How many more times, do you understand that is a memo, which is NOT a 'paper'?

states plume deflectors can and will create serious stability issues under certain circumstances

Yes, but you presented it without including those circumstances. Why?

to the point it will go into "an uncontrollable spin".

To the point where the stacked CSM/LM spacecraft configuration will go into an uncontrollable spin under automatic control and IF one of the opposite jets has been disabled or has failed.
 

Yes, the MIT paper

MEMO!

deals with a different situation but I think it can be apply to other situations too.

I don't care what you think. The mathematics of the situation were presented in that memo along with a graph that allows you to see that the situation actually cannot possibly apply to the LM in solo flight, which was your original contention.

Having said this, this is only one paper by one person. They could be dead wrong on his conclusions.

Pathetic. THere is no other word for it. This memo was a document YOU brought to the discussion in support of YOUR argument. Now it is painfully clear you don't even comprehend what it actually says you dismiss it. That is pretty much a textbook example of intellectual cowardice. You can't even stand by your own presented evidence.

But that is not the point.

No, it isn't. The point is you have been asked some very simple questions and have demonstrated you are unable to either substantiate your views with anything approaching significant rigor, and unwilling to concede you do not know and are in fact wrong. You started this post saying you 'surrender', then tried to defend your stance again.

Case in point, I can dredge up numerous papers

I doubt that, since you still refuse to grasp there is a difference between a paper and a memo.

(I am not looking to go down the VAB, religion, government, health rabbit holes. These are just examples to show things are not always black and white)

Mathematics is. The simple equation in the memo you cited is. But you can't actually grasp it enough to use it even when being spoon fed can you?

[JayUtah]

Yes, but you presented it without including those circumstances. Why?

If memory serves, he actually redacted the quotes to omit the references to special circumstances.  Am I getting that right?

[Jason Thompson]

Yes, but you presented it without including those circumstances. Why?

If memory serves, he actually redacted the quotes to omit the references to special circumstances.  Am I getting that right?

Yes. Here it is:

To be clear it states

"Due to the presence of jet plume deflectors on the LM descent
stage, the use of +X thrusting LM jets for pitch or roll attitude control
of the CSM-docked configuration will"  "cause a
serious control instability"

This is what it actually states, and I have highlighted the bits you failed to quote:

Due to the presence of jet plume deflectors on the LM descent stage, the use of +X thrusting LM jets for pitch or roll control will, for some mass loadings, cause a serious control instability if any -X thrusting jets have failed off or been disabled.

[JayUtah]

Yes.

Thanks.  For me that materially changes the moral calculation.  It suggests a deliberate attempt to mislead.  It's one thing not to understand the technical details and therefore not understand what conclusions can reasonably follow.  It's quite another thing to recognize the conditional statements that must be excised in order to convert a specific warning to an illusion of general applicability.  That's not different thinking; that's just lying.  Jr Knowing isn't being oppressed because of his different view; he's being rightly held accountable for deliberate attempts to deceive.

[raven]

Yes.

Thanks.  For me that materially changes the moral calculation.  It suggests a deliberate attempt to mislead.  It's one thing not to understand the technical details and therefore not understand what conclusions can reasonably follow.  It's quite another thing to recognize the conditional statements that must be excised in order to convert a specific warning to an illusion of general applicability.  That's not different thinking; that's just lying.  Jr Knowing isn't being oppressed because of his different view; he's being rightly held accountable for deliberate attempts to deceive.

Reminds me of video from some of our equally morally and intellectually bankrupt old 'friends' which claim the Earth in the  spacecraft window was a cutout or transparency, but juuuust manage to leave out parts where it slips out of view of the window, something a transparency or cutout simply couldn't do.

[Jason Thompson]

Yes.

Thanks.  For me that materially changes the moral calculation.  It suggests a deliberate attempt to mislead.

I agree. Worse, the fact he also included the original memo with the text and calculations intact suggests either he is totally unable to actually comprehend it and assumes we are as well, or he knows damn well it does not support his conclusion and is just trolling. Consistently misrepresenting it as a paper is not helping his case.

JR, I took you through the mathematical equation and its significance earlier. Either admit you don't understand it, use it to prove your point, or concede that it shows you to be in error. This is physics, not opinion, not debate. It is applying literally centuries-old knowledge of force and rotation to the (then) new spacecraft systems.

[Abaddon]

jrK is not posting so much because of some other commitment. He is posting less because his goto tactic of Gish galloping and starting a new, unrelated topic as a fringe reset has been removed from him. As a result, he doesn't know how he might proceed. He can't sustain his position in this thread, and he can't divert attention by starting a new one.

Whatever shall he do?

[JayUtah]

Whatever shall he do?

Clearly saying, "Huh, I must have been wrong about that; thanks for clearing up my misunderstanding," isn't on the table either.  Which bodes ill for anyone wanting to engage him on other topics.  In a friendly debate, which is what Jr Knowing insists this is, one states a concession on points that one feels he would otherwise have won, for the sake of preserving the friendliness over the need to be right.  Here the need to be right -- even just a little bit right -- overcomes everything.  There is no reason to believe Jr actually considers this a friendly debate.

[JayUtah]

JR, I took you through the mathematical equation and its significance earlier. Either admit you don't understand it, use it to prove your point, or concede that it shows you to be in error.

That's why I pared away all the other issues raised in this thread, including the titular one, and focused on LM stability.  In this case it comes down to simple mathematics, the declaration and use of it being supplied by his own sources.  It is an issue on which there can be no factual question of his error, no credible impeachment of the source, and no wiggle room in the math.  He is as wrong as it is ever possible to be.  Hence on the one hand it could be a test of his mathematical skill.  Failing that, it becomes a test of his honesty.  Failing that, he should expect little in the way of further serious attention on any  topic.

This is physics, not opinion, not debate.

His approach really is quite insulting.  It's not enough for him to indicate an inability to understand the math.  He has to suggest that no one else can either.  He's so desperate to promote his beliefs as somehow still reasonable that he denies the ability for there to exist a conclusive answer.  If he cannot admit error when the question is so very black-and-white as this, then there is little hope for honest debate on anything else.

It is applying literally centuries-old knowledge of force and rotation to the (then) new spacecraft systems.

Correct; this simply as straightforward as angular momentum gets.  The effect on moment arms of a shifting center of mass is the introduction to the science, such as would have been taught in Newton's time.  We have developed it to a fine degree of precision in the intervening centuries.  There are no shades of gray on this particular point.