Re: why people pretend that the moon landing was for real

Koobee Wublee wrote:
"Paul B. Andersen" <paul.b.andersen@xxxxxxxxxxxxxxxx> wrote in message news:d6qm7f$etq$1@xxxxxxxxxxxxxxxxxxx

The power radiated from a body with temperature T is:
Pe = E*sigma*A*T^4
where:
E is the emissivity
sigma = 5.67*10^-8 W/(m^2*K^4)
A is the surface area of the body.

The power absorbed by a body 1AU from the Sun is:
Pa = E*So*Ac
where
E is the emissivity
So is the solar constant = 1.37*10^3 W/m^2
Ac is the area of the cross section of the body
   perpendicular to the direction to the Sun

The body will be in thermal equilibrium when Pe = Pa
E*sigma*A*T^4 = E*So*Ac
T^4 = (So/sigma)*Ac/A = 2.42*10^10*Ac/A  K^4

The ratio Ac/A depend on the shape and orientation of the body.

For a sphere Ac/A = 0.25
T = 279K or 6 deg C. Chilly, but not freezing.

For a cube Ac/A = 1/6 = 0.167
T = 252K or -21 C. Freezing!

For a cylinder with length 4 radii:
Ac/A = ca. 0.25 if its length axis is perpendicular to the Sun.
T = 279K or 6 C.
Ac/A = 0.1 if its length axis points to the Sun.
T = 222K, or -51 C.  Freezing indeed!!

So what temperature Apollo 13 would approach depend
on its exact shape and orientation. But it would
most probably be below zero degree C.


Excellent post. Thanks for correcting me. 

Nice to see you can learn.

> I had no idea thermal radiation
could be that high. I thought it was only limited by black body radiation. 

I strange statement.
Black body radiation IS thermal radiation.

The following is from the other post.

"Paul B. Andersen" <paul.b.andersen@xxxxxxxxxxxxxxxx> wrote in message news:d6qmc8$etq$2@xxxxxxxxxxxxxxxxxxx

1. The Apollo mission is a hoax because the radiation in and beyond
  the Van Allen belts is so high that the astronaughts would have died.


Do you have a better explanation? I don't. 

A better explanation for why the astronauts didn't die?
You will find that explanation in the reference I gave you:
http://www.lunaranomalies.com/rad.htm
The command module was quite well shielded, and they
didn't stay in the Van Allen belts for long.

2. The high radiation in the Van Allen belts is a hoax made by
  the manufacturers of communication satellites.


No, communication satellites operate beyond the Van Allen Belts in the geosynchronous orbit. The article I presented has not referenced to Van Allen Belts as a
consideration of radiation source. 

Sure GEO is beyond most of the Van Allen belts,
but the belt is still a major source of radiation.

But solar storms is a greater concern.
A satellite has to take what comes when it comes.
If the peak intensity is high enough to damage a satellite,
it doesn't help that it can withstand the average radiation.

Got any better ideas? 

For what?
Why the satellite manufacturers build unnecessary much
shielding into their satellites?
I don't believe they do.
Why should they put themselves out of business by
making their satellites too expensive?

Paul
.

Relevant Pages

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