OK, got me there…didn’t mean to imply that a college-level physics education is
required.
I guess that what gets me is that these folks think that in college we all just
read this stuff (like you can on the Internet) and believe it. They then equate
reality with belief. What happens in college-level physics, however, is that we
all did experiments to demonstrate the concepts and to actually make the math
fit reality. It’s really powerful to actually do this stuff yourself and get
the same mathematical result as the folks that described the reality 400 years
ago did. That’s understanding, not belief.
I tell folks the following: “I understand that we landed on the moon.” or “I
understand that the Earth is a sphere (an oblate spheroid, to be more
precise)”. I don’t believe either of those things.
OK, time for some beers...
Allen
--------------------------------------------------------------------
Allen H. Farrington
http://www.allenfarrington.org
818-653-2284
On May 27, 2018, at 4:17 PM, Brian Home (Redacted sender "bsuttonh97" for
DMARC) <dmarc-noreply@xxxxxxxxxxxxx> wrote:
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
<mailto: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 ;<http://www.allenfarrington.org/>
818-653-2284
On May 27, 2018, at 1:33 PM, Troy Monroe Stacey <tstacey001@xxxxxxxxxxxx
<mailto: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
<mailto: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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