Moon Rocks and the Absence of Regolith

[JayUtah]

The two articles that you quoted in another post refer to plasma clouds...

It looks to me like the articles refer to actual dust, and are using the word "plasma" in its more general sense of a fluid affected by electromagnetic (and here, possibly gravitational) effects more than by Newtonian or Eulerian fluid dynamics.  The gist here, of course, is that these are not particulates entrained or suspended in a separate fluid.

[JayUtah]

What do you have to say about the regolith on Tracy's Rock which Gene Cernan disturbed with his gloved hands?

I believe this was raised early in the thread -- at least the notion that one cannot look at a photo of the lunar surface and determined from that alone whether there is any substantial amount of regolith on it.

[gillianren]

No, EVERYONE here is using science to try to explain to you why you are wrong.

To be strictly fair, I'm not.  I'm just asking why "I'm wrong" isn't the more likely explanation.

[mako88sb]

Thanks Smartcooky and your Angle of Repose study. Atleast someone here has attempted to use some science to explain things.
 

Well, in regards to me asking you to come up with plausible explanations for the Apollo 16 House Rock video, there's the science of kinematics and how experts in that field can examine the live TV broadcast footage to validate the fact that those astronauts and lunar rovers interaction with the regolith is in a vacuum and a 1/6th G environment. Plus there's the science of telecommunications and the experts in that field will tell you that it would have been impossible to fake hours of live TV broadcasts that clearly shows them in a vacuum and 1/6th G plus video footage of what is obviously taken from some much higher elevations during the 3 J-missions. If you take the time to verify this info and find you can't come up with plausible explanations on how to fake it all, then maybe you won't waste anymore time with your pet little theories that have you convinced the missions were hoaxed.

[jr Knowing]

Hi Guys, What you guys are saying is correct but mainly not relevant. (I also question posters suggesting that the speed an object goes up is the same speed it comes back down at. I believe (and I could be wrong ) if you shoot something straight up off the moon (less than escape velocity) it will eventually fall back to the moon surface at the rate of gravity which may or may not be as fast as its original speed (especially since there is no terminal gravity velocity on the moon).

As far as the relevance goes, I am not quite sure why no one seems to suggest there will not be a localized debris/dust field from an impact. Posters seem to suggest that any dispersion of an impact results in either no localized debris field or the debris is carried back into to space to once more rain back on the moon. What some posters are suggesting is almost like a never ending loop of impacts. The moon gets hit, debris is shot back into space, eventually falling back to the moon creating an impact which would then send more debris into space which would then fall back to earth causing an impact to repeat the process etc... If that was the case, the moon would be raining micrometeorites continuously. But that doesn't seem to be the case, otherwise the LM would have been swiss cheese.

The issue I am trying to address here is why there is a layer of regolith on the surface but not on top of a five inch rock (for instance) in which its base is completely buried in regolith. Suggesting that moon impacts are akin to "sandblasting" or "machinegun fire" does not solve for this. (in fact, the idea of "sandblasting" sort of proves my concern not dismiss it). Perhaps there is a reasoned answer, but because moon impacts can be very violent doesn't necessarily account on how the regolith is disbursed in such a way that it will bury the base of a rock but leave the top of the rock regolith free. Thanks.   

 

[bknight]

<snip>
(and I could be wrong
<snip>

This is the heart of where you err in both of your threads.
Let's see "if it doesn't look right" it must be faked, if I don't understand, it must be faked"

[JayUtah]

To be strictly fair, I'm not.  I'm just asking why "I'm wrong" isn't the more likely explanation.

Strictly speaking in the terms of applying specialized domain knowledge, no you aren't "using science."  But the principle of parsimony you allude to is perhaps more important to scientists.  Deference to longstanding, well-established tenets is a pillar of scientific reasoning.  If a scientist obtains a result that seems to challenge a bedrock principle (no pun intended), then the most likely explanation has always been, "I'm probably wrong."  Exercises like peer review help practitioners discover in what precise ways they might be wrong.  Of course this doesn't mean that new findings can never overturn long-established precedent.  It means simply that parsimony holds throughout the entire process.  A single contrary finding isn't parsimonious.  Multiple consilient contrary findings might eventually become the parsimonious answer that revises known findings.

Here we have a collection of thousands of high-definition photographs that have been accepted by generations of well-trained, highly-motivated professionals as accurate and authentic depictions of the lunar surface.  They have been corroborated by photographs from other landers operated by interests that have nothing to do with the typical reasons by which conspiracy theories are entertained.  It has been challenged by a claim that rests on a poor theoretical foundation.  The notion that parsimony suggests the challenger is almost certainly in error is eminently scientific, whether proffered by a scientist or a layman.

[JayUtah]

I also question posters suggesting that the speed an object goes up is the same speed it comes back down at.

That's basic Newtonian ballistics.  We teach this to students generally at the seventh to ninth grade level.

...and I could be wrong.

You are certainly wrong.

What some posters are suggesting is almost like a never ending loop of impacts.

No one is suggesting that.  That's a consequent you are formulating based on your ignorance of elementary physics.

The issue I am trying to address here is why there is a layer of regolith on the surface but not on top of a five inch rock (for instance) in which its base is completely buried in regolith. Suggesting that moon impacts are akin to "sandblasting" or "machinegun fire" does not solve for this.

Yes it does, but you are simply dismissing the explanations as "irrelevant."  You do not have a good track record at knowing what scientific principles are relevant to your claims and which are not.

Perhaps there is a reasoned answer...

Start by trying to figure out how your "endless impacts" theory is wrong.

[benparry]

Hi Guys, What you guys are saying is correct but mainly not relevant. (I also question posters suggesting that the speed an object goes up is the same speed it comes back down at. I believe (and I could be wrong ) if you shoot something straight up off the moon (less than escape velocity) it will eventually fall back to the moon surface at the rate of gravity which may or may not be as fast as its original speed (especially since there is no terminal gravity velocity on the moon).

As far as the relevance goes, I am not quite sure why no one seems to suggest there will not be a localized debris/dust field from an impact. Posters seem to suggest that any dispersion of an impact results in either no localized debris field or the debris is carried back into to space to once more rain back on the moon. What some posters are suggesting is almost like a never ending loop of impacts. The moon gets hit, debris is shot back into space, eventually falling back to the moon creating an impact which would then send more debris into space which would then fall back to earth causing an impact to repeat the process etc... If that was the case, the moon would be raining micrometeorites continuously. But that doesn't seem to be the case, otherwise the LM would have been swiss cheese.

The issue I am trying to address here is why there is a layer of regolith on the surface but not on top of a five inch rock (for instance) in which its base is completely buried in regolith. Suggesting that moon impacts are akin to "sandblasting" or "machinegun fire" does not solve for this. (in fact, the idea of "sandblasting" sort of proves my concern not dismiss it). Perhaps there is a reasoned answer, but because moon impacts can be very violent doesn't necessarily account on how the regolith is disbursed in such a way that it will bury the base of a rock but leave the top of the rock regolith free. Thanks.   

 

I believe I am right on this but i'm sure if I am not I will be put right.

The rigolith will not fall at the rate of gravity because gravity doesn't affect speed directly. it affects acceleration. therefore the object will accelerate at the rate of gravity on the moon and will not stop accelerating. this is because no terminal velocity exists due to the lack of air resistance.

[JayUtah]

...the object will accelerate at the rate of gravity on the moon and will not stop accelerating. this is because no terminal velocity exists due to the lack of air resistance.

Yes.

Ignoring lateral velocity and assuming a vacuum, a particle traveling vertically upward from the lunar surface starting at velocity v will be slowed by acceleration -a.  The signs on the variables are different because velocity and acceleration are vector quantities, and we've arbitrary set "up" as the positive direction in this example, and gravity accelerates downward.  The acceleration -a is that imposed by lunar gravity and is (essentially) constant.  The particle will reach a prescribed altitude, the point at which v becomes zero.  That altitude is then the distance over which gravity will act to accelerate the particle.  The acceleration in this instance is the same -a as before, and the final velocity reached will be -v.  Distance and time for the two legs of the journey are the same.

Does anyone need this proven by actual math, or is it a commonly-enough known principle?

[jr Knowing]

Hi Jay,

With all due respect, you have not once attempted to answer the question I posted. I get it, because the moon landings are real, what I am asking is obviously wrong and stupid.

And you know what, you are probably 99 percent right that the moon landings are real. But to dismiss others with contempt because it doesn't fit your view of things is not right. I think I have asked a reasonable question and have been courteous. But I don't believe anyone has came up with a reasonable answer to why there is an absence of regolith on rocks and boulders. It makes sense, if the photos are real, there should be a logical explanation. Using Chinese photos or a "sandblasting" analogy as answers really doesn't explain this phenomena despite what people might think. Respectfully JR.

[mako88sb]

I don't think it's been very courteous of you  to blatantly ignore requests made to you by some, including Jay to go back to your "Apollo 11 Lunar Lander Pre-Launch" and wrap that one up. You just come across as someone incapable of admitting you were wrong about one of your pet theories.   

[onebigmonkey]

Hi Jay,

With all due respect, you have not once attempted to answer the question I posted. I get it, because the moon landings are real, what I am asking is obviously wrong and stupid.

And you know what, you are probably 99 percent right that the moon landings are real. But to dismiss others with contempt because it doesn't fit your view of things is not right. I think I have asked a reasonable question and have been courteous. But I don't believe anyone has came up with a reasonable answer to why there is an absence of regolith on rocks and boulders. It makes sense, if the photos are real, there should be a logical explanation. Using Chinese photos or a "sandblasting" analogy as answers really doesn't explain this phenomena despite what people might think. Respectfully JR.

Yes, it does, despite what you think.

What you think doesn't matter. What you can provide evidence for in support of what you think does.

Furthermore it's a little disingenuous to complain about dismissive answers when you dismiss out of hand reasonable explanations.

[AtomicDog]

Jay has been nothing but courteous. Mistaking being firm with wrongness for discourteousness tells me that jr Knowing has never taken a science course.

[jfb]

What some posters are suggesting is almost like a never ending loop of impacts. The moon gets hit, debris is shot back into space, eventually falling back to the moon creating an impact which would then send more debris into space which would then fall back to earth causing an impact to repeat the process etc... If that was the case, the moon would be raining micrometeorites continuously. But that doesn't seem to be the case, otherwise the LM would have been swiss cheese.

Energy is lost with each impact.  Initial impact sends debris far and wide, and assuming it didn't achieve escape velocity, that debris hits the surface with less energy, bouncing or kicking up debris with even less energy, until all the energy of the initial impact has been dissipated (like billiard balls on the initial break).  Since impacts are random, debris is eventually evenly distributed over the surface, but in an intermittent, energetic fashion, and not at like a snowfall. 

The issue I am trying to address here is why there is a layer of regolith on the surface but not on top of a five inch rock (for instance) in which its base is completely buried in regolith.

That rock is part of the regolith, ejected by an earlier impact.  Regolith isn't just dust.

Suggesting that moon impacts are akin to "sandblasting" or "machinegun fire" does not solve for this. (in fact, the idea of "sandblasting" sort of proves my concern not dismiss it). Perhaps there is a reasoned answer, but because moon impacts can be very violent doesn't necessarily account on how the regolith is disbursed in such a way that it will bury the base of a rock but leave the top of the rock regolith free. Thanks.   

Imagine a low-energy impact near an exposed rock - the finer particles will hit the side of the rock and slide down.  Some particles will hit the top of the rock, some percentage of those will simply bounce off. 

Again, without an atmosphere, nothing "settles" like snow.  The dust acts more like water getting splashed (not exactly like, obviously, but it's the best visualization I can come up with at the moment).