Originally Posted by SpitfireIX
Indeed, I struggle to see where any of these geologists have any experience transporting
a milled and graded aggregate.
This is the classic conspiracist tactic of misplaced expertise. Gravel, rocks, and finely-powdered dust are all made from rocks, right? And who knows more about rocks than geologists, right? So here's a geologist offering his untried opinion that you can haul rocks in trucks or conveyors without generating dust. And since he's an expert in rocks, his opinion should be respected, right?
Unfortunately we're not talking about the use of aggregate particulates for some specific practical purpose, something that engineers are far better at than geologists. It's also something we've been doing since, oh, Roman times. If we start from the macadam roads the Romans built and trace everything forward to modern high-strength concrete, the need to prepare a precisely proportioned mix of precisely graded aggregates is a well-worn problem (pun intended). Specifically, we need particles of a particular shape and mix of sizes, so that they sift together in the mix and create a matrix that offers the best of both worlds -- the strength of the aggregate plus the ability to assume the formed shape.
The problem is that when we attempt to transport the coarser aggregate elements from the grading mill to the site, we end up with too much fine aggregate because what started in the truck or conveyor as particulates of a proper shape and of a given size, +/- 0.X%, arrives with a whole bunch of smaller particles produced as the aggregate rubs against itself during transport. That's the reason precisely proportioned aggregate mixes can only be prepared onsite in very small quantites: they simply cannot be subsequently handled very much without destroying the proportions.
Geologists aren't typically experts in this -- the practical handling of particulates. This isn't a matter of "Well, geologists speculate this might happen." It's a matter of, "Engineers know
this happens because they experience it."
Originally Posted by mrbusdriver
If any of these geologists discussed the chemical cementation properties of lunar soil, I missed it. That affects how well it will take a print. Those properties were discussed briefly in the Apollo 11 Preliminary Science Report
and at length in the remainder of the relevant literature. I'm not saying these guys don't know their stuff; I'm just saying that a proper discussion of whether a particulate would take a print has to include that chemical factor.
There is also physical cementation. Above, I mentioned proportional mixes for high-strength applications. We also consider dry-aggregate cementation, which is the matrix that forms when you compact an aggregate composed of particles of a particular shape. We know that a weak form of mechanical cementation occurs when jagged particles are poured into a crevice or gap and then allowed to settle either by gravity or accelerated by compaction. This cementation can achieve surprisingly robust results.
Originally Posted by rambaldi
And that's the real story. As you've guessed, FatFreddy88 is all about proving Jay wrong about something, at all costs -- not about finding the answers to his hoax claims. Back where I first debated him and we first discussed fake Moon dust, he was simply unable to deal with the opinions of experienced experts and the objections they raised. So he turned to trying to impeach the expertise. He did this first by saying that no one could be considered an expert unless they agreed with him about other conspiracies. That is, he proposed a litmus test that said unless you were a conspiracy theorist like he was, your "expert" opinion couldn't be trusted because you were otherwise just a government shill.
Predictably he was banned
. And I have to say it's a little disturbing to see that five years later he's still trying to impeach my credibility by trash-talking me to anyone who will listen.
Five years later he's still making dishonest and unproven claims of this ilk:
(Google it, since we're not linking for the time being). He has provided zero evidence for it. This has become a personal vendetta for him, and I'm sorry to see him join a very small, very exclusive club of people with a sort of sick, obsessive fixation on me personally. Naturally it's not healthy, and I do not intend to indulge it here, although I will courteously engage others.