Moon Landings: why is there no dust in the lander pads?

[QUOTE=tagos]
As everybody is trying to tell you - you are credulously falling for the oft-refuted ranting of charlatans with books to sell and loons with no knowledge of, well frankly, anything.

Who do you think took all the pictures of the Earth from the moon? Or was Apollo 8 a hoax as well. Who and what did countless amateur radio hams as well as scientists around the world track, along with the distance/time delay of the radio signals consonant with the distance, there and back? Or were the civilian scientists at Jodrell Bank also in on this?

Who put the laser reflector on the moon? Where the hell did Apollo 11 go if it didn’t go to the Moon? It went up and it did not go into orbit. Why in hell’s name would america’s enemies, including North Vietnam who they were at war with, go along with it?

Why has no-one broken ranks and exposed it? This is not like the UFO thing where many allegedly ‘in the know’ from military to the odd astronaut have broken ranks. No one has. That should tell you something.

Darwin didn’t give you a brain to waste it on arrant nonsense without even the slightest scintilla of evidence to back it up. For your own future self’s sake, stop making a fool of yourself because one day you are going to look back on this beleif and your toes are going to break curling with embarrassment.
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Do you see the wink emoticon at the end of my statement? It means I am not entirely serious with my suggestion.

But as for the laser reflector, that wouldn’t have necessitated an actual manned landing, would it.

[QUOTE=ivan astikov]
Isn’t there actually film footage of the moon landings that don’t show up the stars either? This Phil Plait's Bad Astronomy: Bad TV part of the BA article only seems to address still photographs.
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If there was any film of a lunar module landing that would be proof of your position. Have a guess what has the greater ability to capture low light stuff like stars - still or cine-film? I expect Bad Astronomy have failed to address the question of whether Mug-wumps hid the stars too. They can’t address every still-born of raging ignorance question.

[QUOTE=ivan astikov]
Do you see the wink emoticon at the end of my statement? It means I am not entirely serious with my suggestion.

But as for the laser reflector, that wouldn’t have necessitated an actual manned landing, would it.
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It would have necessitated some mission and that would have been spotted. It’s turtles all the way down.

Without an atmosphere, there’s no such thing as clouds of billowing dust. Clouds only exist because there is something (random air currents in the atmosphere) that cause forces in many directions. The only forces in the situation where a rocket is landing on the moon are gravity (pulling the dust down) and the bouncing of the exhaust from the rocket after it hits the ground (pushing the dust up and away from the spot where the rocket lands).

[QUOTE=Left Hand of Dorkness]
If I understand, the dust was thrown up and behaved in a fashion similar to how pebbles behaved. WHen the lander’s rockets were just starting to affect the dust (because it was still pretty high up), the dust was thrown in little arcs, up and away and down. As the lander got closer, those pebble-like arcs grew larger. At some point, the arcs were large enough that it was as though pebbles were being tossed outside the landing area of the lander (that is, if the lander’s pads were 10 feet from the engine, the dust particles were being tossed pebblelike 11 feet). As long as that happened before the zenith of the arc was still below the landing pads, then nothing would land on the pads. As the lander came in, those arcs grew bigger, and nothing landed on the pads themselves.

That’s pretty cool; I had no idea! Consider ignorance fought.

Daniel
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Hiya Daniel
doesn’t seem like it’s any mystery to you! While you’re here, what’s your thoughts on who killed JFK? :slight_smile:

Seriously, I don’t see it… and I have found 1 major flaw in your reply: these are talc sized ‘pebbles’, not anything with great mass in them. I agree a lot of dust would be blown but not all. The dust would ‘billow’.

Best to you

[QUOTE=where’s the subscription info?]
I agree dust in the strong jet of the rocket would be blasted away and away… but what about around the edges to that rocket flame wheer the thrust decreases to zero. That will 'kick up a cloud that has nostrong direction.
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Without an atmosphere, there is no cloud - particles move in ballistic trajectories, regardless of whether they’re dust or boulders. Dust would hang in the (absence of) air in exactly the same way a brick does.

[QUOTE=where’s the subscription info?]
Seriously, I don’t see it… and I have found 1 major flaw in your reply: these are talc sized ‘pebbles’, not anything with great mass in them. I agree a lot of dust would be blown but not all. The dust would ‘billow’.
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The flaw is in your understanding of the motion of bodies in gravity in a vacuum. Billowing is entirely a function of atmosphere upon fine particles. Without atmosphere, fine particles will drop exactly like a stone.

[QUOTE=Mangetout]
The flaw is in your understanding of the motion of bodies in gravity in a vacuum. Billowing is entirely a function of atmosphere upon fine particles. Without atmosphere, fine particles will drop exactly like a stone.
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Give it up. Joe Haldeman has written about shorter wars than the ongoing War on Ignorance.

[QUOTE=Mangetout]
The flaw is in your understanding of the motion of bodies in gravity in a vacuum. Billowing is entirely a function of atmosphere upon fine particles. Without atmosphere, fine particles will drop exactly like a stone.
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Are scientific replications of these effects online anywhere?

[QUOTE=ivan astikov]
Are scientific replications of these effects online anywhere?
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I doubt it because nobody since Galileo and Newton has felt any need to question what the rest of the world has understood for several hundred years. I don’t think anyone capable of using a computer without trying to talk into a mouse could even ask such a thing. I’m filing you under ‘T’ and backing out of this thread.

[QUOTE=where’s the subscription info?]
Seriously, I don’t see it… and I have found 1 major flaw in your reply: these are talc sized ‘pebbles’, not anything with great mass in them. I agree a lot of dust would be blown but not all. The dust would ‘billow’.

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Again. No, it wouldn’t. Dust particles, regardless their size, would move according to old Newtonian physics, just like they teach it in primary school: they would go by perfect parabolic trajectories affected only by gravity and - small number of them - by collisions with other particles.

[QUOTE=where’s the subscription info?]
But you make my point better stronger. I’m thinking it’s ‘1/6th of a heli’ and you’re saying ‘no, the dust is 3 times worse than that’. I know ithey have different type of ‘thrust mechanicals’ but in terms of energy expended, it’s still ‘3 times more’ with 3-times more dust, agree.
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Well, but it would impart the vast majority of that energy in a direction away from the lander, meaning there’s actually less dust expected to ‘stay behind’ at the lander site the more thrust you apply.

At all points where the thrust is zero, no dust will be kicked up, except through knock-on effects from dust particles hitting other dust particles. At all points where the thrust is not zero, the dust that is kicked up will have a vector pointing away from the lander.
Besides, the lander’s thrust is essentially a directed stream of hot gas, which will expand under its own pressure when shot into a vacuum, further removing dust from the landing site.

In all fairness, I am simplifying things here, and yes, there are competing effects to the direction of the dust – multiple collisions of dust particles, rebounds of the material of the lander, stuff like that. But compared to the thrust from the lander, those effects are nearly totally negligible, and certainly won’t amount to a dust buildup noticeable in the photographs.
Besides, your argument works far better against the conspiracy hypothesis – on Earth, no matter the circumstances, you’d certainly expect a far bigger dust buildup, so what’d they do, wipe the thing clean between shots? For what reason, if your argument is right and you should expect dust buildup no matter what?

[QUOTE=tagos]
I doubt it because nobody since Galileo and Newton has felt any need to question what the rest of the world has understood for several hundred years. I don’t think anyone capable of using a computer without trying to talk into a mouse could even ask such a thing. I’m filing you under ‘T’ and backing out of this thread.
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Yes, because righteous indignation is definitely the only way to confound ignorance, isn’t it!

[QUOTE=where’s the subscription info?]
Seriously, I don’t see it… and I have found 1 major flaw in your reply: these are talc sized ‘pebbles’, not anything with great mass in them. I agree a lot of dust would be blown but not all. The dust would ‘billow’.
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Do you understand the physics that allows dust on earth to billow? If so, please explain it. You don’t need a high-tech definition; layman’s terms are perfectly fine.

Daniel

[QUOTE=where’s the subscription info?]
But not ALL of it. There’s no way that that mini-hurricane of dust under that lander would not have left even a teeny-weeny touch of dust on a pad. I’ll grant you the rocket would have blown a good 90-95% of it away as you say… but what about the edges of the rocket where the thrust isn’t as strong.

Do you not think there would have been ‘clouds of billowing dust’ around it? Don’t forget, it’s ‘talc-like’ dust, not sand, grit or the like.
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No, because there is NO ATMOSPHERE to resist the flight of the dust particles, no matter how tiny. No resistance, no cloud, no way for the dust to drift back to the landing pads.

[QUOTE=ivan astikov]
Are scientific replications of these effects online anywhere?
[/QUOTE]

Yes.

[QUOTE=ivan astikov]
Are scientific replications of these effects online anywhere?
[/QUOTE]

You can watch a feather and a steel ball bearing being dropped in both atmosphere and a vacuum here. (YouTube link)

EDIT Beaten again! And it’s even the same video…

And here’s the same experiment performed on the moon:

[QUOTE=puppygod]
Thing is, there really wouldn’t be clouds as you know them here, living all your life in atmosphere. Only dust that would go toward the lander would be particles that bounced from other, heavier particles. That would be very, vary small number of them. Certainly not enough to see on the photo of such resolution as linked.
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You clearly think like me. Not all of the ‘dust’ would be sub-sonically blasted away and therefore, the particles that aren’t under such propulsion would… maybe bounce around, maybe go straight up vertically past the lander.. maybe hit rocks lying on the floor just outside the perimiter of the 4 pads where they’d ricochet back.

Of all those billons of particles, the pads don’t even end up with a fine mist of a covering containg your ‘small number’?

Deleted - the previous posts said exactly the same thing only with video clips.

I gotta start typing faster or talking less.