Sciency Words: Shirt-Sleeve Environment

November 23, 2018

Welcome to another episode of Sciency Words, a special series here on Planet Pailly where we take a closer look at the definitions and etymologies of science or science-related terms so we can expand our scientific vocabularies together.  Today’s term is:


I’ve seen this term, or terms very similar to it, in a lot of different places.  It’s usually obvious what it means from context.  A shirt-sleeve environment is an artificial environment where humans can wear ordinary clothing in safety and comfort. The cabin of a commercial airliner is a good example.  So is the interior of the International Space Station.

In the early days of aviation, pilots were far more exposed to the elements than they are today.  They had to wear specialized clothing, especially for high altitude flights.  It gets really cold up there above the clouds, and the air is very thin. Pressure suits were often essential, and in some cases those early pilots needed to bring supplemental oxygen with them.

There were several experiments in the early 20th Century to create safe, pressurized cockpits.  I guess these were technically shirt-sleeve environments, but they still sound to me like tight and uncomfortable spaces.  Maybe you could have worn your normal, everyday clothing in those cockpits, but I doubt you’d want to.

So the first true shirt-sleeve environment (in my judgment) would have been the Lockheed XC-35, built in 1937 for the U.S. Army Air Corps.  It had a pressurized cockpit, crew area, and passenger cabin, so the crew would have had plenty of room to move around comfortably in their comfortable clothes.

Apparently the Army called this a “supercharged cabin,” not a shirt-sleeve environment.  Based on what Google ngram tells me, it seems the term supercharged cabin was replaced with shirt-sleeve environment by the end of the 1950’s, right around the time the American space program was getting started.

As this 1960 paper from Boeing Airplane Company explains, “The term ‘shirt-sleeve environment’ means that the crew would be comfortable in this environment without any special equipment such as pressure suits.” And according to this 1958 paper on the structural stability of spacecraft, “Shirt-sleeves can become the normal flight clothing in sealed cabins under [sea-level type] conditions.  In terms of human performance, the advantages of a sea-level atmosphere have been clearly demonstrated by the experiences of Ross and Lewis during the recent Strato-Lab High 2 and 3 flights.”

In modern space exploration literature, the International Space Station is typically cited as the most impressive shirt-sleeve environment yet constructed.  The term is also used to describe the kinds of habitats we’d like to build for ourselves on the Moon, Mars, and elsewhere in the Solar System.

So remember: when you’re packing your bags for space, you don’t have to be too picky about which shirts you bring.

My Favorite Moon: Io

November 14, 2018

Some of you may remember a post I did awhile back declaring Europa to be my favorite moon.  It’s a beautiful and mysterious world, a world that may have an incredible secret hidden beneath its icy crust.  Europa frequently tops the list of most likely places where we might find alien life.

But as I’ve learned more about the Solar System, I’ve developed a deeper affection for another moon, one of Europa’s neighbors, a world that is neither beautiful nor likely to support life.  I’m talking about Io.

Io is the innermost of Jupiter’s four big moons (Io, Europa, Ganymede, and Callisto).  As such, it gets pushed and pulled around pretty hard. Between Jupiter’s enormous gravity and the combined gravitational forces of the other three Galilean moons, it’s enough pushing and pulling to make anyone queasy.  And Io is a notoriously queasy planetoid.

Due to tidal forces, Io’s sulfur-rich interior is constantly boiling and churning.  And Io keeps literally spewing out its guts, making it the most volcanically active object in the whole Solar System.

Like Venus, my favorite planet, Io is a great chemistry professor, especially when it comes to sulfur chemistry.  Io’s also a pretty decent physics professor.  While most of the sulfur from Io’s volcanic eruptions settles back onto the moon’s surface, plenty of it escapes into space. The result: crazy dangerous games of particle physics in the vicinity of Jupiter.

Io’s ionized sulfur has a lot to do with controlling the intense radio emissions coming from Jupiter.  It’s also a major factor contributing to Jupiter’s insanely dangerous (to both humans and our technology) radiation environment. We recently learned that Jupiter has a third magnetic pole, located near the planet’s equator; while I haven’t read anything yet to back me up on this, I have a feeling Io is somehow responsible for that.

And lastly, Io’s ionized sulfur is partially (mainly?) responsible for the magnificent auroras that have been observed on Jupiter. And that’s my favorite bit about my favorite moon.  I love the idea that Io—the ugliest ugly duckling in the Solar System—plays such a crucial role in creating something beautiful.

But of course picking a favorite anything is a purely subjective thing.  Do you have a favorite moon?  If so, what is it?  Please share in the comments below!

I collect stamps now. Stamp collecting is cool.

November 12, 2018

Well, I cannot deny the truth any longer.  I’m a stamp collector.  Or at least I am a person who is in possession of a stamp collection.  So how did this happen?

It started with those “Pluto: Not Yet Explored” and “Pluto: Explored!” stamps.  Those particular stamps have an interesting history, which I wrote about in a previous post.

I bought the “Views of Our Planets” stamps at the same time as the “Pluto: Explored!” set.  And then just recently, I saw some Star Trek stamps at the post office.  Naturally, I had to get them.  And the nice man at the register mentioned they had commemorative Sally Ride stamps as well.  Naturally, I had to get those too.  What kind of space enthusiast would I be if I didn’t?

To be clear, I originally meant to use these stamps as stamps.  You know, for postage. Mainly for paying bills.  I wasn’t looking to start a new hobby. But I figured what’s the harm in buying an extra sheet of Pluto stamps to keep, just for fun?  Or an extra sheet of planets?  Or now an extra sheet of Star Trek and Sally Ride?  It’s not like I’m sinking that much money into stamp collecting.

Fast forward to me ten years from now when I have huge albums full of space and Sci-Fi stamps.

Sciency Words: Clarke Orbit

November 2, 2018

Welcome to another episode of Sciency Words, a special series here on Planet Pailly where we take a closer look at the defintions and etymologies of science or science-related terms so we can expand our scientific vocabularies together.  Today’s term is:


So I was once again flipping through my copy of Brave New Words: The Oxford Dictionary of Science Fiction when I discovered a small fact that gave me a big surprise.  It involved Arthur C. Clarke, the legendary science fiction writer who’s best known for co-writing the screenplay of 2001: A Space Odyssey, but who was also a prominent thinker, futurist, and inventor.

In 1945, Clarke wrote this article for Wireless World describing a method for transmitting radio and television signals to the entire globe.  Clarke’s idea involved placing artificial satellites in a very specific and somewhat peculiar orbital arrangement.  Clarke explains:

It will be observed that one orbit, with a radius of 42,000 km, has a period of exactly 24 hours.  A body in such an orbit, if its plane coincides with that of the equator, would revolve with the earth and would thus be stationary above the same spot on the planet.

Clarke admits that this idea may sound a little too fantastical to some, but he argues that it’s entirely plausible to do this using current (as of 1945) technology.  His only concern was whether or not radio transmissions would be able to penetrate Earth’s ionosphere, though he was confident that at least some radio frequencies would work.

And of course Arthur C. Clarke was right (he usually was about these sorts of things).  We now know this orbital arrangement as a geosynchronous orbit, or to be more specific a geostationary orbit.  A geosynchronous orbit allows a satellite to move around in Earth’s sky, so long as it always returns to the same positions at the same times of day. A geostationary orbit does not allow a satellite to move at all in Earth’s sky.

And according to Brave New Words, these kinds of orbits are also known as Clarke orbits.

So which term should we be using?  Personally, I’m not sure.  I like how the term Clarke orbit honors Arthur C. Clarke for inventing the idea.  On the other hand, I appreciate how the term geostationary orbit helps define itself, thus making verbal communication a little easier.

So which of these terms would you prefer? Clarke orbit or geostationary orbit?

My Favorite Planet: Venus

October 31, 2018

I’m thinking of doing a few of these kinds of posts, if people are into it: my favorite planet, my favorite moon, my favorite asteroid… that sort of thing. Today I’d like to tell you a little about Venus, my favorite planet in the Solar System and also the best chemistry teacher I’ve ever had.

Venus has been my favorite planet for a long time now.  I used to say to people, “It’s because Venus has the most personality.  It’s the personality of a serial killer, but still… so much personality!”

It’s true that Venus is excessively, unreasonably, incomprehensibly hostile toward life.  I mean, all the planets are dangerous (even Earth is a dangerous place in its own ways), but if you ever go to Venus, Venus will try to kill you at least a dozen different ways before you touch the ground.  And when your crushed and crispy remains do reach the ground, Venus will try to kill you again in at least a dozen more ways.

No other planet is so creative and so gleefully enthusiastic about murder.  As a science fiction writer, one of my goals in life is to set a novel on Venus or a Venus-like planet, because no other setting makes for such a deadly antagonist.

But upon further reflection, I think there’s a better reason why Venus holds such a special place in my heart.  I’ve done a lot of space-related research over the years.  It’s all part of my ongoing quest to become a better science fiction writer.  Venus was the first planet to really challenge me intellectually.

Why is Venus so deadly?  In many ways, Venus is Earth’s twin.  The two planets are about the same size, they have almost the same surface gravity, and their chemical compositions are similar. Venus is slightly closer to the Sun, but it’s still within our Solar System’s habitable zone.  So what gives?

It was hard work getting the kind of answers I was looking for.  Venus forced me to learn a lot of new things.  In particular, I had to learn more about chemistry, a subject that I despised in school and had really hoped I could avoid.  But in struggling to understand Venus’s sulfur chemistry, and later its carbon chemistry, I was rewarded not only with a deeper understanding of one planet but of how planets in general are put together, and how they each end up with their own distinct “personalities.”

Picking a favorite anything is obviously a subjective thing. For me, studying Venus was an eye-opening experience in ways I never would have expected.  For that, I’m forever grateful to the planet Venus, and Venus will always be my favorite planet.

So what’s your favorite planet?  If you say “Earth, because I live there,” I’m going to be a little disappointed.  But whatever your favorite planet is, and whatever your reasons for that, please share in the comments below!

Which Planet Has the Weirdest Magnetic Field?

October 23, 2018

When I did my yearlong Mission to the Solar System series back in 2015, the planet Neptune stood out as having the weirdest and wackiest magnetic field.  Here’s a totally legit photograph from 1989 taken by the Voyager 2 space probe.  As you can see, Neptune is really confused about how magnetic fields are supposed to work.

But since 2015, science has learned more about the other three gas giants in our Solar System.  Neptune’s magnetic field is still really weird, but it’s no longer clear that it is the definitive weirdest.

  • Jupiter: Based on data from the Juno mission, it looks like Jupiter has three poles instead of two.  There’s a north pole, right about where you’d expect it to be.  Then the magnetic field lines emanating from the north pole connect to two separate south poles.  The first south pole is about where you’d expect a south pole to be. The other one is near the equator. Click here for more about Jupiter’s “non-dipolar” magnetic field.
  • Saturn: As Sherlock Holmes says in one of his many adventures, “Depend upon it, there is nothing so unnatural as the commonplace.” According to data collected during the Cassini mission’s Grand Finale, Saturn’s magnetic field is almost perfectly aligned with its rotation.  At first blush, that might seem quite normal.  Commonplace, even. Except no other planet’s magnetic field is so perfectly aligned.  Not even close.  Apparently planetary scientists didn’t think such a thing was even possible.  Click here for more about the “negligible tilt” of Saturn’s magnetic field.
  • Uranus: The planet Uranus is tipped over sideways, and its magnetic field is tipped over further still.  According to recent computer simulations, these two factors combine to cause Uranus’s magnetic field to tumble over itself “like a child cartwheeling down a hill,” as one researcher put it. This leads to a “periodic open-close-open-close scenario” where the solar wind can flow in toward the planet then suddenly be blocked, then suddenly flow in again, and then suddenly be blocked.  If these simulations are correct, the Uranian aurora may flick on and off like a light switch. Click here for more about the “topsy-turvy motion” of Uranus’s magnetic field.
  • Neptune: In 1989, Voyager 2 discovered that Neptune’s magnetic field is lopsided. The magnetic field doesn’t run through the planet’s core. Instead it runs through a seemingly random point about halfway between the core and the “surface” (by which I mean the topmost layer of the atmosphere).  Also, only one of the poles ends up being near the planet’s “surface.”  The other pole is buried somewhere deep in the planet’s interior.  For more about Neptune’s “badly behaved” magnetic field, click here.

If I had to choose, I’d probably still give Neptune the award for weirdest magnetic field.  But the competition is a lot tighter than it used to be.  Maybe the real lesson here is that gas giants in general have wild and crazy magnetic fields.

So if you had to pick, based on all this new info, which planet do you think deserves the award for the weirdest magnetic field?

P.S.: Also, the Cassini mission discovered there’s an electric current flowing between Saturn and its innermost ring.

Putting STEM into the Arts

October 17, 2018

I thought I was done talking about the whole STEM vs. STEAM debate, but then it occurred to me that there’s one point that nobody seemed to be talking about.  This debate is often framed in terms of how the arts can benefit STEM.  No one ever seems to mention how STEM can benefit the arts.

About a month ago, SpaceX announced that Japanese billionaire Yusaku Maezawa will be going on a tourist trip around the Moon. Maezawa is an art collector, and he’s decided to take six to eight artists with him on a mission called “Dear Moon.”  According to the Dear Moon website, “A painter, musician, film director, fashion designer… Some of Earth’s greatest talents will board a spacecraft and be inspired in a way they never have been before.”

Art is meant to reflect the world we live in. Therefore artists have a responsibility to understand, as best they can, our increasingly scientific and increasingly technological world.  It sounds to me like Maezawa gets this.  But aside from seeking out new sources of inspiration, there are also craft-related reasons why artists might want to be exposed to sciency stuff.

As an artist, when you’re thinking about how light and shadow play off a three-dimensional form, you’re sort of thinking about physics. When you’re mixing paints, trying to make sure they’ll adhere to your canvass, or trying to make sure the colors won’t fade over time, you’re dabbling in chemistry.  And obviously when you’re drawing a figure study (nude or otherwise), knowing a little about anatomy and biology will help you a lot.

None of the art teachers I had in school, and none of the art tutors my parents hired for me outside of school, really made this clear to me.  As I said in my post on Friday, young me came to understand that the arts and sciences were totally different, unrelated things.  There was a long period of time in my life when I felt artistically stuck. I was unable to improve, and I didn’t understand why.

It wasn’t until I attended a seminar taught by James Gurney, the author and artist behind Dinotopia, that my art began to thrive again.  Why?  Because Mr. Gurney got me to start thinking scientifically about my art. I guess you could say he got me to stop thinking of myself as a left-brain-only kind of guy.

I can’t speak for every artist out there, but I know for me personally a more interdisciplinary approach to education would have done me a world of good.  And with that, I think I’ve said my peace about STEM and STEAM.  In my next post, I’ll move on to some other topic.

P.S.: While drawing that artist in space cartoon for today’s post, I thought of several reasons why painting in space like that would not work.  For one thing, I imagine those paints would do the whole freezing-and-boiling-at-the-same-time thing that other liquids tend to do in space.  If you can think of other challenges my artist/astronaut would have to deal with, please share in the comments!