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In the first two parts of this response to Guillaume's video, Pseudonautics -
Episode 3, Soft Landing, we lost count of the number of math errors we found in Guillaume's calculations.
We discovered that Guillaume blindly used numbers from a rocket simulator without really
understanding what he had in his hands.
And then we looked at the dynamic pressure, and corrected Guillaume's equivalent earth
wind speed, which he thought was important.
Then we asked, "What's the worst thing that could happen?"
This is what could happen...
17.7 MW!
Whoa Nelly!
That's BIG!
That's HUGE!
That's...
What is it exactly?
Well, Guillaume took one-half of his flow rate times his effective exhaust velocity,
squared, to get the kinetic energy in each second of exhaust.
The first time you were probably exposed to this equation was in the sixth grade.
And the example probably had something to do with a car running into a tree.
Here, for example, a 3200-pound automobile, traveling at 30 mph, has a kinetic energy of
96,800 ft lbs, upon crashing into a tree, that doesn't move, the tree has to expend
96,800 ft-lbs of energy, in order to STOP the car.
Another example is one that Guillaume uses.
An astronaut weighing 200 N on the moon...
Ha!
Subtract the mass of his suit and PLSS, and there's not even a 98 pound weakling left.
While this astronaut is walking on the moon, at the apex of his step he has 20J of potential energy.
After falling 10 cm in 150 ms (my stop watch gave 600ms), he has 133 W of kinetic energy
(which is actually wrong on so many levels, but) then he takes that and divides it by
0.06 m-squared, the total area of the astronauts feet...
Ha!
The astronauts wore OVERBOOTS on their EVAs.
If they wore size 7-1/2 overboots, then their PGA boots couldn't be larger than a size 5-1/2 [shoe].
Pigmy astronauts on the moon?
Again, we shouldn't be surprised.
He made the astronauts look too small so he could make some comparison to make the LM look even more
powerful that it really was.
Anyway, this is the only way I can figure you can get a number close to his 2,170 W/m-squared.
This is actually a bad example.
But, what he's showing is that the moon had to push back with 133 W of energy to STOP
the astronaut's fall.
In both cases the moving object STOPS.
So, dividing 17.7 MW by 1.75 m-squared, gives you 10 MW/m-squared, for whatever that matters.
So, how much damage are all those mega-watts going to cause on the lunar surface?
Well, look at this picture.
Where are all the kilograms of energy-depleted nitrogen-tetroxide?
If a tree can stop a car, and the lunar surface can stop a pigmy astronaut from falling, then it
must be true that the lunar surface can stop the propellants being thrown at it.
Right?
There should be dozens of kilograms of propellants lying on the lunar surface directly under the nozzle.
Where are they?
Is this me being condescending again?
No.
Not yet.
Obviously, the gases did not loose all their energy when they hit the lunar surface.
For the most part, they bounced off and went in different directions, carrying some of
the lunar surface with them.
We'll look at that in more detail later.
I'm going to blow through this Phoenix lander comparison.
Like the XCOR example, this shows that a very small thruster, focused on a very small area,
can push less than an inch of dust around.
Duh?
Most of the rest of his video is the same type stuff - useless analysis of hover jets
and hand waving.
But, I don't want to pass up the most fascinating part of Guillaume's video.
That is this journal article from a Dr. Gromov that shows that the top four to five inches
of the lunar surface could be disturbed by the dynamic pressure from the lunar module's exhaust.
Why this fascinates me is the fact that Guillaume is using data
from recorded measurements
of lunar core samples
brought back by the Apollo astronauts
to build a case
that the astronauts didn't go to the moon
to collect those core samples.
And so it goes.
If Guillaume doesn't believe these core samples came from the moon, then how can he use the
data from them to discredit the landings?
This is like standing naked in room full of people and thinking that by closing your eyes,
nobody can see you.
It's ridiculous.
I guess that's a privilege of being a conspiracist.
You can use anybody's data you want to, even if comes from the source you're trying to discredit.
So, how bad a job did Guillaume really do?
What do the correct numbers look like?
Well, assuming worst case, on the later J-series missions, the LMs landed with a little more
than 13 kN on board.
The main disturbance area, half a foot under the nozzle, was 2.14 m-squared.
The static pressure model says the absolute pressure in that area was 1.4 kPa.
The equivalent velocity of the descent engine was 486 m/s.
To remain at hover, the propellant mass required to push through the nozzle was 27.4 kg.
The kinetic energy in these gases was about 6-1/2 MW.
Now, if you consider that about 3 inches of regolith is missing out by the landing pads,
then probably 4 to 6 inches is missing from directly under the nozzle.
Although, we can't prove that easily from the photos.
The span of the landing pads was 31 ft, tip-to-tip.
Subtract 3 ft for each pad, and we can estimate the disturbance area, just inside the pads,
was about 494 sq ft.
Assuming the missing regolith was 3 in deep throughout this entire area, that's
3,474 thousand-cm.
Lunar regolith at the surface is usually quoted to have a density of 2.3 to 2.6 g / cm-cubed.
Taking the conservative end and multiplying by the volume, we get 7,990 kg of missing regolith.
Wow!
That's a bunch.
That's almost nine earth tons of missing material.
If you assume an elastic collision of the gas into the regolith, then the gas molecules
bounce off, loosing only 7 ppm of their original momentum, while the entire mass of regolith
assumes a velocity increase of 3 mm/s.
That's average, per bombardment.
It also tells us that it would take the equivalent of 300 seconds of bombardment to give the
entire mass a velocity of 1 m/s.
Since the gas looses almost none of its momentum, it will bounce around and continue to collide
with everything it can.
And the regolith directly under the nozzle, of course, will pick up the most momentum
and move the farthest.
The effect would feather off as you get out to the pads and probably continues out well
beyond the immediate landing site to some extent.
That's it.
It's more a strip mine than a crater.
In conclusion, I must say that I am impressed that a moon hoaxer would attempt any mathematical
analysis to prove a point.
I want to encourage Dr. Guillaume to try again,
and again.
But next time,
SHOW YOUR WORK!
Dr. Guillaume?
Doctor of what I wonder?
Obviously, it's nothing to do with math or science.
Otherwise,
God save the French!
Try as he could, Guillaume failed to make a convincing case for his craters.
Pointing to old conceptual drawings, an XCOR methane rocket, the Phoenix lander,
hover jets - all that was irrelevant.
Over 90% of the video had nothing with the lunar module.
His major evidence of sizzling propellant velocities and mega-watt energy pulses got
deflated considerably when we redid his math.
His math, flawed as it was, did nothing more than suggest that the hot gasses expelled
from the LM descent engine were moving relatively fast, but have very little density.
So what?
No matter how fast the gases are moving, the total pressure on the surface, dynamic plus
static, caused by a LM at hover, cannot exceed the WEIGHT - that's mass times gravitational
acceleration - of the LM itself, or it wouldn't be able to land.
Why?
Why is that so hard for you moon-hoaxers to understand?
I'm done.
Another conspiracist's video debunked.
A thousand more to go.
Ciao moon hoax conspirators,
wherever you are.