Sciency Words: Tau Level

September 14, 2018

Today’s post is part of a special series here on Planet Pailly called Sciency Words.  Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together. Today’s term is:

TAU LEVEL

I first came across this term in a press release from NASA’s Jet Propulsion Laboratory.  It has to do with Mars, and the global dust storm that’s been happening there these last few months, and that Mars rover that we may have lost.  But most of all, this tau level thing has to do with Beer.

No, not that kind of beer.

I’m talking about Dr. August Beer, a 19th Century German physicist who studied how light passes through and/or gets absorbed by various substances.  Dr. Beer is best remembered for Beer’s law, which (according to several papers I looked at… click here or here or here) is used to calculate how much sunlight makes it through the Martian atmosphere to reach the planet’s surface.

In those calculations, the Greek letter tau (τ) represents the amount of dust or other particulate matter that’s floating around in the atmosphere.  The more dust in the air, the higher the tau level.  And the higher the tau level, the less sunlight reaches the ground.

As you can imagine, you need to measure the tau level on Mars each day (or rather, each sol) and predict what the tau level will be tomorrow (I mean, solmorrow) if you’re trying to run any sort of surface mission on Mars that depends on solar power.  And in the future, when we have a well-established colony on Mars, don’t be surprised if the term tau level features prominently in the local weather reports.

P.S.: I had an idea that got too convoluted, but I really wanted to make a “don’t drink and drive” joke involving Beer’s law and our possibly wrecked Mars rover.


Lost Opportunity on Mars

September 12, 2018

Over the last few months, a global dust storm has been raging across the surface of Mars.  It started at the end of May and is only now beginning to clear up. It’s been suggested that this was one of the worst storms we’ve ever observed on the Red Planet

The Good News

If you’re worried about the Curiosity rover, don’t be.  The rover’s just kept on roving, and sciencing, and recently it sent back this selfie to let us know everything’s a-okay.

Just kidding.  Here’s a link to the actual “selfie” Curiosity sent back. It’s an interactive 360-degree panoramic thing, so click the image and drag it around to get the full experience.

The Bad News

While Curiosity seems totally unfazed by the bad weather, things are not looking so good for NASA’s other rover, Opportunity.  It’s too early for a eulogy, but based on what it says in this press release from NASA’s Jet Propulsion Laboratory, we should be prepared for the worst.

NASA lost contact with Opportunity in early June, shortly after the storm began.  Unlike Curiosity, which runs on nuclear batteries, Opportunity depends on solar panels for energy.  So the problem may simply be that Opportunity wasn’t getting enough sunlight during the storm.

Or it could be that something more serious has happened to the almost fifteen-year-old rover.  In the press release, Opportunity’s project manager is quoted saying: “If we do not hear back after 45 days, the team will be forced to conclude that the Sun-blocking dust and the Martian cold have conspired to cause some type of fault from which the rover will more than likely not recover.”

So fingers crossed….


Sciency Words: Garn Scale

September 7, 2018

Today’s post is part of a special series here on Planet Pailly called Sciency Words.  Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together. Today’s term is:

THE GARN SCALE

In 1985, Senator Jake Garn of Utah became the first sitting member of Congress to fly in space.  Florida Congressman Bill Nelson followed a year later.  I guess NASA felt it would be good for somebody in Congress to see firsthand how the money for the space shuttle program was being spent.

Senator Garn’s Wikipedia page quotes several astronauts. Apparently not everyone was thrilled about Garn’s mission, but some of them had nice things to say. Astronaut Charles Bolden, who would later go on to become NASA Administrator, said:

Jake Garn was the ideal candidate to do it, because he was a veteran Navy combat pilot who had more flight time than anybody in the Astronaut Office.

And Charles Walker, one of the astronauts who flew with Senator Garn, had this to say:

[…] I think the U.S. space program, NASA, has benefited a lot from both his experience and his firsthand relation of NASA and the program back on Capitol Hill. As a firsthand participant in the program, he brought tremendous credibility back to Capitol Hill, and that’s helped a lot.

Jake Garn may have had a lot of piloting experience before his mission, and afterwards he may have had a lot of positive things to tell his colleagues in Congress, but the mission itself… well, let’s just say weightlessness did not agree with the senator’s stomach.

As a result, Garn’s name has become something of a slang term at NASA.  The Garn scale is an informal, off-the-cuff system to quantify how space sick someone becomes while in space.  Apparently it’s not unusual, even for the most experienced astronauts, to get a little space sick.

A zero on the Garn scale represents not getting space sick at all.  If you do get sick, you’ll probably score a tenth of a Garn, or a quarter of a Garn—some fractional amount of a Garn.  It’s said that no one has ever reached one full Garn’s worth of space sickness, except of course, Senator Garn himself.

Hopefully the senator has a sense of humor about all this.


IWSG: True Muses Never Leave

September 5, 2018

Today’s post is part of the Insecure Writer’s Support Group, a blog hop where insecure writers like myself can share our worries and offer advice and encouragement.  Click here to find out more about IWSG and see a list of participating blogs.

For last month’s IWSG, I wrote about a traumatic experience I recently went through.  It was a difficult thing to write about, and I’m sure it was a difficult thing to read as well.  Thank you to all of you who did read that post and left such kind comments. I realize this is an odd thing to say, but the love and support I received from “strangers” on the Internet meant a lot to me.

I still have some raw emotions about what happened, but I’ve gotten back to writing.  To be honest, I got back to it a whole lot sooner than I expected. I’m not sure how to explain why that happened, so I’ve asked someone else to write a post explaining it for me.  She’s written IWSG posts for me before.  At this point, I’m sure many of you know her well.  She’s the magical fairy person who helps me write: my muse.

My writer has been plagued by a secret fear. This has been going on for years now, but he’s been too afraid to talk about it or write about it.  He’s even tried to conceal certain dark thoughts from me (in case you weren’t aware, muses have mind reading powers). But of course I still sensed this fear stirring in the depths of the subconscious.

So what is this secret fear?  Here’s an easy answer: the fear that I would leave, that I might never come back, that maybe I’d go be a muse for someone else—some new writer who’s more disciplined and talented than the writer I already have. But like all easy answers, this answer is not the full truth.

What really frightened my writer was the thought that maybe, deep down inside, he didn’t really want me around in the first place, that maybe he didn’t really want to be a writer at all, and that maybe he’d be happier doing something else with his life, something that didn’t involve a muse like me constantly pestering him to do his writing.  No matter how much my writer insisted that he wanted to keep writing, there was always that nagging fear that whispered: “you’re wrong, you want to give up.”

Then came the traumatic events that occurred a little over a month ago.  My writer’s been through some painful experiences before—the loss of a parent, a nasty break up—but nothing compares to witnessing a murder.  In the aftermath of what happened, my writer lashed out at me and at writing in general.  He told me to go away.  He told me to never come back because the things I made him write about—death, violence, various other atrocities—suddenly hit way too close to home.

Of course I didn’t leave.  True muses never leave.  It’s not in our nature.  I guess my writer didn’t know that, but he knows it now.  And I didn’t have to wait long before my writer picked up the pen again and asked for my forgiveness (which was easily given).

To my surprise, my writer chose to dive straight back into the story we’d been working on before all this happened—one of those violence and destruction stories.  But that’s what he wanted to do, and with a renewed sense of urgency too, because the casual disregard for human life that would lead one person to kill another—my writer has some things to say about that, things that he only knows how to express in one way: through fiction.

And that’s the secret truth about writers: they may think they can give up on writing, until they actually try to do it. But writers need to write as badly as other humans need to eat or breathe.  It’s in their nature.  I guess my writer didn’t know that either, but he knows it now.

So much for that secret fear.


Hobbit Holes of Mercury

September 3, 2018

Scientists need artists.  This is especially true for those scientists who study the planet Mercury.  According to a convention established by the International Astronomy Union, craters on Mercury are to be named after famous artists, writers, and musicians. And it just so happens that Mercury is the most heavily cratered object in the entire Solar System.

So yeah… Mercury scientists need artists. Lots and lots of artists.

This brings me to one of my all time favorite facts: there’s a crater on Mercury named in honor of J.R.R. Tolkien. And it’s not just any boring old crater, at least not from the perspective of colonists who might one day be living on the first planet of the Solar System.

The best real estate on Mercury is near the planet’s north pole. Sheets of water ice have been detected in that region, within the permanently shadowed bowls of craters where the sunlight can’t reach them.  We recently learned there are similar ice sheets on the Moon, within craters near the Moon’s south pole.

Whether humans go to Mercury in pursuit of natural resources or for the purposes of scientific research, we’ll want to set up shop somewhere with easy access to water. Prokofiev crater (named after a Russian Soviet-era musician) is the deepest of Mercury’s polar craters, and thus likely the iciest.  But Tolkien crater appears to be pretty icy too.

We’ll also probably want to construct our habitats underground.  Underground habitats would provide us with some protection from solar and cosmic radiation, among other things.  Therefore I have to assume that in the distant future, the residents of Tolkien crater will refer to their underground dwellings as “Hobbit holes.”


Sciency Words: Space Adaptation Syndrome

August 31, 2018

While doing my recent research on hypogravity and its effects on the human body, I’ve seen the term space adaptation syndrome come up a few times. I figured it would make a good Sciency Words post. Then I discovered, to my surprise, that I’d already done this one!

So today I’d like to present to you, apparently for the second time:

SPACE ADAPTATION SYNDROME

Yeah, we could just call it “space sickness,” but this is Sciency Words, so we have to call it “space adaptation syndrome.” Because NASA has a rule that all space related terms must be turned into acronyms, we can also call it “S.A.S.”

Most astronauts experience space adaptation syndrome at some point, usually during training or during their first few days in space. Relapses are also known to happen. As you can imagine, NASA really wants to figure out what causes S.A.S. and how to prevent it. This is one of the reasons they recently left an astronaut in space for almost a full year.

Mr11 Year in Space

This is totally how the year in space mission happened.

At present, S.A.S. seems to be similar to motion sickness. It is also sort of the exact opposite of motion sickness. Think of it this way:

  • Motion sickness: your inner ear senses motion, but your eyes do not (because you’re playing with your phone in a moving car, for example). In this case, your eyes are feeding your brain false information.
  • Space adaptation syndrome: your eyes see that you’re moving (or not moving), but in the absence of gravity, your inner ear hasn’t got a clue what’s going on. So in this case, your eyes are trustworthy; it’s your inner ear feeding false information to your brain.

The good news is that we humans can adapt. Our brains learn to rely less on our inner ears, allowing the business of human space exploration to continue.

The bad news is that once we humans adapt to space, returning to Earth becomes a problem. I’m not talking about bone loss or muscle atrophy. I’m talking about balance. All of a sudden, your inner ear is working again, and your brain has to relearn how to do this balancing and walking stuff.

There is also a concern—and I’m not sure how seriously to take this concern—that the human body might adapt too well to space. You might spend so much time up there, becoming so acclimated to zero-G, that your brain and inner ear will never function properly together again. You’ll never walk again. You’ll never be able to come home. You’ll be stuck in space for the rest of your life.

That would suck.

Or maybe it wouldn’t. To be honest, if I ever get to go to space, I probably won’t want to come back anyway.

P.S.: Here’s a bonus Sciency Word: lead-head. Lead-head is what astronauts call immunity from space adaptation syndrome.


How to Walk in Hypogravity

August 29, 2018

As a science fiction writer, I really wish I knew what it’s like to walk on the Moon or Mars or any other low gravity world.  It would help a lot with that whole “writing from lived experience” thing.  Of course there are ways I could experience hypogravity for myself, but I don’t have that kind of money.  So instead, I’ve turned to medical research papers like this one from Frontiers in Physiology.

First off, let me just say this: I’ve read some really complicated stuff over the years, but I don’t think I’ve ever read anything as complicated as a scientific paper trying to describe how we humans walk.

But if we want to understand what it would really be like to walk on another planet, we have to start by understanding—in meticulous mathematical detail, apparently—how we do this walking thing here on Earth.

Gravity Makes Walking So Much Easier

The mathematical relationship between walking speed, leg length, and gravity was determined back in the 1870’s.  It was later used in what sounds like a rather whimsical research paper about the walking pace of the Lilliputians from Gulliver’s Travels.  And then it was used for more pragmatic purposes to estimate the running speeds of dinosaurs.

For those sorts of calculations, the force of gravity would have been treated as a constant, but gravity can easily be treated like a variable, and that’s when things get interesting.  You see, when you walk, your body uses energy to complete the full arc of a footstep, especially at the beginning when you’re lifting your foot off the ground.  But gravity helps you (perhaps more than you realize) when your foot comes back down to the ground.

So if you reduce the force of gravity, gravity provides you with less assistance, and you end up having to expend more energy to complete each step in your walk cycle.

Walking-Mode vs. Running-Mode

The muscle actions involved in walking and running are different enough that there’s no real grey area between “walking-mode” and “running-mode,” as that paper from Frontiers in Physiology calls them. These two “modes of locomotion” take advantage of gravity in distinctly different ways.  Walking-mode ends up being more metabolically efficient at slower speeds, and running-mode is the more metabolically efficient way to travel at higher speeds.

So what happens when you alter the force of gravity?  The transition point where running-mode becomes more efficient than walking-more changes too. Lower gravity means your body will naturally want to switch modes at a lower speed.

On the Moon, for example, walking-mode only works well when you’re moving very slowly.  To achieve what we might consider a normal walking pace, you’ll have to switch to running-mode.  And if you want to reach Earth-like running speed, you’ll probably have to try hopping-mode or jumping-mode—modes of locomotion that we don’t use often here on Earth except under certain specialized circumstances. Skipping-mode also seems to be more metabolically efficient on the Moon than it is on Earth.

Moon-Walking or Mars-Walking in Science Fiction

I’ve read plenty of Sci-Fi stories set on the Moon or Mars. For the most part, I feel like science fiction writers just mention the reduced gravity thing in passing and then move on with the story as quickly as possibly.  I don’t blame them.  It’s really hard to imagine what hypogravity must feel like, and even harder to communicate that feeling to readers.

But one of my highest ambitions as a writer is to write something that makes you feel like you’re there on the surface of a hypogravity planet like Mars.  I want to capture that experience of “running in order to walk” and “hopping in order to run.”  Hopefully this line of research will someday help me pull that off.