Allen, I have to disagree with you on one point. You start your third paragraph
with “A college-level understanding of physics or more specifically,
thermodynamics.” Well as a theater major and elementary school teacher with a
mild interest in science, I can attest that you certainly do not need a
“college level” understanding of the topic to understand that material.
In other words, I believe that someone has got to be pretty “dense” to think
that a few really hot molecules in a vacuum are going to vaporize a spacecraft.
On May 27, 2018, at 3:18 PM, Allen Farrington <allen.farrington@xxxxxx> wrote:
OK, in all seriousness…
This guy reminds me of 15-year-old debate team stuff…he takes imprecise
language and statements from a variety of NASA folks locks onto the
inconsistencies as if they reveal some deeper, hidden truth. My favorite
phrase is that “NASA has an answer for everything we think of as moon-landing
deniers”…well duh, reality is full of truth and an unyielding bitch.
The truth is that Technology is a lot like muscle, use it or lose it. That’s
what it means when NASA people say we don’t currently have the technology to
fly to the moon. We lost it and just rebuilding the systems we had back then
presents a currently unacceptable risk to the astronauts. So here we go…
A college-level understanding of physics or more specifically,
thermodynamics, teaches you that temperature is simply a measure of the
average speed of molecules of the surrounding medium. To equate the concept
of temperature at altitude with the atmosphere’s surface capacity of heat
transfer that we intuitively understand is flawed. Yes, the temperature at
the stratopause may be same as the temperature on the surface, but you’ll
still freeze your fingers off if you take off your glove. That’s because that
there’s effectively no air there to help you retain your heat, so while the
molecules are moving just as fast as they are on the ground, there’s not very
many available to do heat transfer. The loss of heat due to it just radiating
away at infrared will chill you pretty quick. So…things in space get cold,
but if you prevent the radiation of the infrared heat with something shiny,
like tin-foil, then you can stay warm. Amazing how all those spaceships are
made of tin-foil…that’s to retain the heat from the astronauts and the
internal heaters. In fact, when properly operating, we worry more about
things getting too warm in space. Another way to think about it is like
this…isn’t 60 degree water a lot colder to humans than 60 degree air? In
fact, 60 degree water will kill you fairly quickly while 60 degree air is
tolerable for a long time. Why is this? Is it our perception? No, it’s simple
heat transfer. Water is about 800 times more dense than air at the surface
which means that it’s a whole lot more effective in conducting heat away from
you than air.
OK, so don’t get me started on the radiation bullshit…during Gemini and
Apollo, we flew through the Van Allen belts exactly twice on each trip. Ever
been walking down the street and pass by one of those propane heaters that
restaurants use. You feel warm as you move by, but you don’t cook internally,
do you? Of course not because damage from radiation, whether it be thermal or
ionizing depends on several factors including, flux (how dense is the
radiation), exposure time, and target cross-section. We have to design our
spacecraft to be shielded from radiation and to shield humans from
radiation…again, due to the nature of the particles, tin-foil does quite
well. For Apollo, the duration of the trip through the belts was minutes to
an hour. That would be the same today, but we’re designing systems to keep
astronauts in space to and around the moon for weeks. That means that it’s a
more challenging task to shield them for a longer period.
For more, I need a campfire and some beers…see you all at ROCStock!
Allen
--------------------------------------------------------------------
Allen H. Farrington
http://www.allenfarrington.org
818-653-2284
On May 27, 2018, at 1:33 PM, Troy Monroe Stacey <tstacey001@xxxxxxxxxxxx>
wrote:
Anybody?
In all seriousness though: What was that one guy talking about saying we
used to have the technology then to visit the moon and now we don’t anymore?
Best,
Troy Monroe Stacey
-------------------
On May 26, 2018, at 9:44 PM, Troy Monroe Stacey <tstacey001@xxxxxxxxxxxx>
wrote:
In all seriousness though: What was that one guy talking about saying we
used to have the technology then to visit the moon and now we don’t anymore?
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