Put all of your thrust ratings, nozzle theories, and degrees away boys. I've proven what I need to prove and no, it wasn't that Apollo 11 didn't land on the moon.

Ah, one of those wolves in sheep's clothing. You come here silently intending to determine that we're all dogmatic, concrete-headed buffoons who take things too seriously, and so you manage to wrangle a discussion that appears to you to have proved exactly that point. I said it before and I'll say it again: your methods are intended to convince people of a certain thing, not to determine whether that certain thing is the truth or not. This includes the notion of what our motives may be. You have exhibited no behavior to date that violates that characterization.

You would make a fine lawyer, but a very poor investigator.

If you look at my opening statements I spoke of how a person who opposes anything is likely to get trampled in a discussion on this site.

Of course. That's exactly the opening scene in the rhetorical script that you're acting out, which I see about four or five times a year in the various venues where I argue. You start out by saying, "I know you guys will beat me up for this." That predisposes an audience to attribute to our supposed hard-headedness and argumentativeness, any opposition we might offer. Then you lay out a case to which you know we will object. And you keep hitting on it, keep bringing out other evidence, in order to prolong the objection. The exact reasons for our objection are immaterial, because your plan all along is simply to elicit the objection. Once the objection is on the table you can invoke your a priori presumption of antecedent and attach it to the consequent you knew would be produced.

But of course in the real world -- not the isolated world of litigation -- an objection can come from many sources, not just the one you identify. The objection in this case came on the basis of quite a lot of applicable fact. You asked a question; we attempted to answer.

If you have the evidence on your side, why are you so defensive?

It takes two to tango; you deployed several arguments intended to support the same conclusion. The sustained refutation is in response to a sustained attack.

I thought I made it obvious in my opening statement I was walking in, in a humble manor into your home. Not quite, but almost instantly the condescending nature of a few of the board masters presented themselves like a car salesman on a used car sales lot.

Hogwash.

Astronot's contribution began with, "You’ve come to the right board, we don't treat posters that have questions rudely." There was even banter about sports and hobbies.

My first response was a brief summary of a determination I had made on the feature in question, and an outline of the scenario leading to it and a reference to the sources I had used as data. I made a followup to another poster who questioned me on some aspects of my findings. Both responses were factual and dispassionate.

The first time you mentioned me by name was to say

You simply dismissed my analysis by saying there were no "skid marks" (there are) and immediately suggested that my conclusion was based on some sort of preconceived opinion. Now that your ulterior motive is a matter of admission, I can see why you were so anxious to start down the path of personal arguments.

You continued, "(Jay, don't quit your singing job)". How can that be interpreted except as a personal attack?

Let's not bandy further: the ad hominem attacks started right there, with you, despite "olive branches" having been extended by me and by others. And I'm not the only one who feels this way. After I expressed my resentment of your approach, R.A.F. responded, "My thoughts about this, if posted, would certainly get me banned from here."

You came here with the intent to provoke a fight in which you would certainly get beat up, so that you could run home complaining about the bullies. Only we didn't bite; so you had to throw the first punch.

For what Jay claims to be true, not only would the triangular print be smeared

No. The bottom of the footpad is cupped so that it will ostensibly ride up on top of regolith rather than digging in. It is also covered with loosely-wadded insulation material (aluminized Mylar and H-film). The footpad will rotate in two axes on its "ankle" in response to underlying terrain. The insulation material will crush and deform in response to a load. Both of these will alter the profile of the portion of the footpad that is in contact with the regolith as the load varies.

I have seen exactly this type of compressive skidding on snow, which has many of the same mechanical properties as lunar dust (albeit for completely different reasons). In fact, if I had any inkling you were genuinely interested, and I had the ability to present it graphically, I could show you in step-by-step detail how one large crease in the insulation could be flatted into two creases by progressively heavier loads and produce exactly the triangular pattern of furrows seen in the compressed area near the footpad. You're dismissing the scenario simply because it doesn't jive with your simplistic impression of what a skid "must" look like.

but the displaced soil from the probes next to it would be flattened as well.

Only if the displacement occured before the flattening. As I explained in great detail, the displacement aft obviously occurred after the flattening and I proposed a scenario -- supported by multiple sources of data -- to explain just how that can have happened. The trench, in addition to being longer than the probe, is also wider than the probe. The regolith is displaced only on the rearward side of the trench, and the probe lies in the rearward portion of the trench. This absolutely telltale evidence that the probe was pushed backwards after having been embedded in the soil along most of its length.

The probe furrow is cut through compressed regolith because with the probe bent the way it is, it will continue to drag through it after the footpad has compressed it. There is evidence of compression on either side of the furrow.

I see that...

But you aren't an expert.

...an LA homicide detective see's that.

Anonymous authority. What makes him an expert on the Apollo lunar module? I am a recognized expert, and I have training in soil mechanics. Does your detective friend?

Further, I clearly refuted his rationale for dismissing the skid using nothing but dispassionate fact. You won't allow me to question him directly, and there's no evidence you transmitted my refutation back to him so that he could revise his opinion, if necessary. Once I pointed out that the "buckling" theory was not supported by the data, you dropped it altogether and moved on to something else.

I came here to see if anyone could adequately answer some of the question I have...

You came here expecting opposition to your questions. You got it. Now you seem to be complaining because you got what you expected.

You came here believing that your "underdog" conclusion had a very slim chance of being true. Now you seem to be complaining because that's apparently the outcome.

When you were presented with well-reasoned, factually-based, comprehensive answers using multiple sources of data, your response was not very consistent with someone who just wanted an explanation for an observation. People looking to be enlightened because they lack understanding generally don't fight that enlightenment tooth and nail when it's offered. From the very beginning you took up an argumentative position contrary to everything that was proposed. You cited anonymous testimony to confirm what you already believed. You sidestepped or simply expressed disbelief in all that was said. You ignored the items of data that directly refuted your assertions.

It's far too late for you to claim complete to be innocently asking questions.

Jay presented the soil around the pad as evidence and he has to expect that evidence to be required to be validated, not taken just at his word, no matter who he is.

I pointed out that there was a buildup of regolith which you and your detective friend had both apparently missed. You acknowledge that it was there and immediately launched into a secondary argument about why it shouldn't have been there. It took a few rounds of discussion before you were made to understand that it was intended to show, along with other bits of evidence, that the footpad indeed skidded.

You still have not dealt with the totality of evidence that universally points to the skid conclusion. You have taken a few potshots at pieces of it. You have followed a few related tangents. But you still have not explained how so much independent evidence can point so strongly to one single conclusion, and yet still be wrong.

And while he claimed he never said the soil was unaffected by the blast, he implied that.

I believe Jay wrote:

There is nothing in the fluid dynamics model of the LM exhaust plume that stipulates significant direct or indirect loading at the site of the footpads. You're simply handwaving here.

Yes, I said that. I can see where you might have been confused by that, and it relates to a part of the reconstruction that I didn't explicitly state. Sorry for misleading you like that, but let me go back and fill in a few gaps.

Let's hypothetically put the LM five feet or so above the lunar surface, hovering, and not moving forward, backward, left, or right. Where with the plume impact? Mostly on a spot directly beneath the nozzle, expectedly. You get the most velocity right in the center of the nozzle, so right under the thrust axis will be the strongest impact. As you move away from that axis, the downward loading decreases gradually until you get to the boundary of the supersonic portion of the plume. The vertical surface loading then falls off dramatically through the subsonic plume portion -- most of which disperses before striking the ground. Portions of it are even striking the bottom of the LM because they curl up around the lip of the nozzle. So if you go out to the diameter of the footpads, several meters from the thrust axis, there is no downward force at all.

So much for primary effects. But what happens to the plume as it hits the ground? It disperses, obviously, but not in a hemispherical pattern. And not in the pretty billows of smoke you see in earth launches. It goes out radially from the point of impact. As seen from above it would make a perfect circle of expanding exhaust products. But as seen from the side -- if the entire plume were made magically visible (as is done in our Fluent models) -- it would not be a hemisphere centered at the point of impact. In fact it would be a low, flat disk of material, with most of the gas departing the surface along an elevation angle of but a few degrees, and at fairly high velocity.

Thus, near the plume impact area you would expect the mostly horizontally moving gas to "scour" the surface, just as you hose the dirt off your sidewalk. But the farther outward you go, the higher above the surface is the densest portion of the reflected plume, since it's climbing at a shallower angle. It's still moving very fast, but it's decreasingly in contact with the surface and decreasingly able to scour it significantly.

The density of the exhaust plume is also decreasing at a rate proportional to the radius. This is the basic law of radial expansion. Plus, you have kinetic-molecular expansion into the vacuum. The plume, after striking the lunar surface, disperses rapidly. This does not preclude the visible dust seen in the 16mm films. After conversations with the pilots, I'm told the film overrepresents the amount of dust actually displaced. It is often assumed there is an opaque sheet of dust, when in fact the dust sheet was usually transparent.

Okay, so that's the general idea. The behavior of the plume simply doesn't lead us to expect a lot of scour near the footpads.

But what about the scour that is observed near the footpad in question? That's a good question.

As stated in my reconstruction, the LM was moving forward and to the left prior to touchdown. This means the bulk of the plume would have swept the right rear quadrant of regolith some seconds prior to touchdown. The streaking you see is the effect of the full brunt of the exhaust as it passed over that area, not the supposedly far-reaching effect of the exhaust as it fired from where it came to rest. This is amply evidenced by the total lack of streaking in any of the other quadrants.

And then later Jay wrote:

You're the one saying it's unaffected. I never did. Why do you keep trying to pin your assumptions on me?
God Jay, you crack me up. It looks like you the one doing the hand waiving here.

That statement was intended specifically to discuss the inboard regolith buildup. You imply that such a buildup should have been blown away by the exhaust. Its very presence in its current form seems suspicious to you.

Now I will admit here to having conducted a little rhetorical manuevering. I apologize if having done so has offended you or misled you.

Nothwithstanding the results of plume impingement models, I can't verify that the regolith buildup is, in fact, untouched. Nor can I verify that it has been eroded. There simply is no basis for making any judgement on that point. If it was eroded, it was eroded. If it went untouched, it went untouched. You seemed to want to polarize the issue: that if it wasn't totally obliterated then it must have been "untouched". My disavowal of the "untouched" hypothesis was not so much a retraction of my previous statements as it was an attempt to force the issue of suspension of judgment.

In a litigation setting, one outcome is usually presumed and the opposition is required to make a case refuting it. In criminal proceedings, innocence is presumed and thus a prosecutor carries the burden of proof. If he fails to satisfy it, the accused is found "not guilty". He is not found "innocent". To determine innocence one must make a case for innocence. The defense, instead, has merely to rebut a case for guilt. The two are most certainly not the same thing.

In an investigational setting, there are three outcomes to each hypothesis: "proved", "disproved", and "inconclusive". Litigation merely decides what to do in the inconclusive case. But in our mode we can let it stand as inconclusive. Litigation must have an outcome. Investigation need not.

That was the point I was hoping to make.

You never confront anyone with your knowledge on their turf or do you?

All the time. Most of the people with whom I associate here have "extracurricular" opportunities to share these ideas. Most simply don't have the time to do it as much as I do.

I honestly have enjoyed it.

Would it help if I took you less seriously from now on?

__________________
"Facts are stubborn things." --John Adams
Clavius Moon Base