Sciency Words: Fault Tree

October 21, 2016

Sciency Words PHYS copy

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 all expand our scientific vocabularies together. Today’s term is:


The Future

The chief engineer marched herself up to the captain’s ready room, saluted, and stood at attention. The captain leaned back in his chair, reading the chief engineer’s report.

“So the starboard engine pod just exploded?” the captain said. “For unknown reasons?”

“Yes, sir,” the engineer replied. “I cannot explain it. My team has no idea what happened. The circumstances of the explosion are so unusual that we don’t even know where to start.”

“Well, couldn’t you start with a fault tree analysis?”


The Present

I first encountered the term “fault tree” in an article about the recent Space X rocket explosion (click here, it’s an interesting read). I then read more about fault tree analyses in NASA’s Fault Tree Handbook for Aerospace Applications (click here, but I’ll warn you it’s pretty dull reading).

Basically, a fault tree analysis is a method of evaluating all the things that could go wrong to produce an undesirable result (like your engine pod mysteriously blowing up). Fault trees are sort of like flow charts, and they look something like this:


As I understand it, you start from the bottom of the chart are work your way up. Which subsystems failed? How did those subsystem failures affect the main systems, potentially leading to the “top event” on your chart?

One of the key advantages to using a system like this is that it can show how two or more seemingly unimportant problems can combine to cause bigger problems farther up the tree.

According to NASA’s Fault Tree Handbook, fault tree analyses have become fairly standard for space flights ever since the space shuttle Challenger disaster in 1986. A good, well thought out fault tree can not only help figure out what caused an accident, but it can also help determine what might go wrong before an accident even occurs.

The Future

“Oh, right,” the chief engineer said, chuckling at her own foolishness. “A fault tree analysis! That’s been standard procedure since, what… the the 20th Century?”

The captain nodded.

“Sorry, Captain. Sometimes I forget I’m a real engineer and not a character in a science fiction story.”

“Happens to the best of us,” the captain said. “Carry on.”

P.S.: I have been having a really rough writing week this past week. I wonder if writer’s block can be diagrammed with a fault tree.

Sciency Words: Shadow Biosphere

October 14, 2016

Sciency Words MATH

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 all expand our scientific vocabularies together. Today’s term is:


Crazy Talk

We are not alone on planet Earth. There are aliens among us. Their existence has gone unnoticed and unsuspected for millions of years.

Truth be told, I shouldn’t call them “aliens.” They evolved here on Earth, side by side with what we, in our arrogance, call “organic life.”

They’re everywhere. There’s a whole biosphere of these weird creatures sharing our planet with us. It’s called the shadow biosphere.

Not Crazy Talk

I first heard about the shadow biosphere on an episode of SciShow, and I’ve been seeing the term more and more lately. It seems like some sort of astrobiology buzzword at the moment.

The idea is that an alternative form of life could have evolved here on Earth, and we just haven’t discovered it yet. Maybe it lives in areas totally inaccessible to us, like deep beneath the Earth’s crust. Or maybe it’s so different from us that we don’t yet recognize it as a life form.

Personally, I take this as more of an astrobiology thought experiment than a serious hypothesis about life on our planet. It’s a way of reminding us how limited our understanding of life is and show how difficult it might be to identify alien life should we happen to find it.

You see, to determine if something is alive, we must try to identify ways in which it is similar to other living things. Does it move? Grow? Reproduce? On a more fundamental level, is it cellular in structure? Does it have a carbon-based biochemistry? A DNA-like genetic code?


Little did the humans suspect that their “pet rocks” were in fact silicon-based life forms.

But all these questions presuppose that newly discovered life forms will be similar to life forms we already know about. What if we’re dealing with a life form totally dissimilar to life as we know it? What if they’re non-cellular, non-carbon-based organisms that don’t have anything resembling DNA?

Why, such organisms might be so strange to us that they could exist all around us, even right here on Earth, and we wouldn’t know it. Or so this type of thought experiment may lead you to conclude.

Back to Crazy Talk

It’s not just a thought experiment. The shadow biosphere is real. It’s real, I tell you! Wait, where are you taking me? No, I don’t want to take my medicine. Are you working for them? Did the pet rocks send you?

Science in the Chronoverse

October 13, 2016

Here on Planet Pailly, I write about real science, or at least I try to. That’s not so much the case on my other blog.

Today on the Tomorrow News Network website, I’m starting a series of posts about the “science of the chronoverse.” It’s basically the made-up science I use to justify time machines and faster-than-light travel in my stories.


The first post is on primitive science. Although actually, “primitive science” is just classical physics, so I guess I’m not making stuff up yet. But I will be soon!

All These Worlds Are Yours: A Book Review

October 11, 2016

In his book All These Worlds Are Yours: The Scientific Search for Alien Life, author Jon Willis gives you $4 billion. How many authors do that? Okay, it’s imaginary money, and you’re only allowed to spend it on astrobiological research. But still… $4 billion, just for reading a book!

If you’re new to the subject of astrobiology, All These Worlds is an excellent introduction. It covers all the astrobiological hotspots of the Solar System and beyond, and unlike most books on this subject, it doesn’t gloss over the issue of money.

There are so many exciting possibilities, so many opportunities to try to find alien life. But realistically, you can only afford one or maybe two missions on your $4 billion budget. So you’ll have to pick and choose. You’ll have to make some educated guesses about where to look.

Do you want to gamble everything on Mars, or would you rather spend your money on Titan or Europa? Or do you want to build a space telescope and go hunting for exoplanets? Or donate all your money to SETI? Willis lays out the pros and cons of all your best options.

My only complaint about this book is that Enceladus (a moon of Saturn) didn’t get its own chapter. Instead, there’s a chapter on Europa and Enceladus, which was really a chapter about Europa with a few pages on Enceladus at the end.


I agree, Enceladus. On the other hand, Enceladus is sort of like Europa’s mini-me. So while I disagree with the decision to lump the two together, I do understand it.

In summary, I’d highly recommend this book to anyone interested in space exploration, and especially to those who are new or relatively knew to the subject of astrobiology. Minimal prior scientific knowledge is required, although some basic familiarity with the planets of the Solar System would help.

P.S.: How would you spend your $4 billion? I’d spend mine on a mission to Europa, paying special attention to the weird reddish-brown material found in Europa’s lineae and maculae.

Sciency Words: Conan the Bacterium

October 7, 2016

Sciency Words BIO copy

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 all expand our scientific vocabularies together. Today’s term is:


Meet Deinococus radiodurans, a species of bacteria found in truly unexpected locations all over the globe. It’s said to be the toughest bacterium in the world. It’s so tough that it’s earned the nickname Conan the Bacterium.


Don’t panic. Conan the Bacterium is nonpathogenic and does not represent a threat to humans.

Some microorganisms are referred to as extremophiles, because they’ve adapted to survive in some specific extreme environment. Conan is a polyextremophile, because it has adapted to survive in a wide variety of extreme environments. Among other things, Conan can endure:

  • Highly acidic environments
  • Airless environments
  • Waterless environments
  • Extremely cold environments
  • Extremely radioactive environments

Frankly, it sounds like this little bugger is perfectly adapted for life on Mars, but according to my reading, its genome suggests that it did in fact evolve here on Earth.

Conan’s resistance to radiation is of particular interest to science. It seems that whenever radiation damages Conan’s DNA, even if the DNA is shredded into tiny bits, Conan can stitch its DNA back together again in as little as twelve hours.

Lots of organisms, including humans, have some ability to repair their own damaged DNA. Conan is just a whole lot better at it than the rest of us, and no one’s sure why.

I first learned about Conan the Bacterium in a book called All These Worlds Are Yours: The Scientific Search for Alien Life. I’ll be doing a book review early next week.

IWSG: When’s It Ready?

October 5, 2016

Insecure Writers Support Group Badge

Each month, the Insecure Writer’s Support Group gives us a question to answer. I usually forget about the question, or I choose to ignore it because there’s something else I want to/need to talk about. But this month, the IWSG question gets to the heart of my chronic insecurities.

When do you know your story is ready?

Short Answer: As soon as I have a story that’s ready, I’d be happy to tell you.

Long Answer: My Tomorrow News Network short story series has been “ready” several times now. The first time, my stories were ready because:

  • I’d set self-imposed deadlines for each story. When a deadline came, whatever I had had to be good enough because I needed to move on to the next story.
  • The problem was that most of my stories were rush jobs. They felt amateurish to me. Even though I’d created my own world populated with my own characters, at times my stories read like bad fan fiction.

So I worked with an editor and did a lot of studying on my own. I learned a bunch of writing rules and editing techniques (remove adverbs, avoid the verb to be, cut your manuscript’s length by 15%). After all that, my stories were ready because:

  • I’d fixed the specific issues my editor had identified, I’d cut my manuscript’s length by the recommended amount, and I’d conformed my writing style to the rules I’d learned. My stories definitely felt more polished, more professional, but….
  • I realized that my stories now suffered from something that I now call generic narrator syndrome. I can’t put my finger on what defines a generic narrator, but I know it when I see it. I think it happens because when everyone follows the exact same writing rules, we all end up having the exact same narrative voice.

So my challenge now is to establish a unique J.S. Pailly narrative voice for my stories. Not sure what that means. Don’t know yet what differentiates my voice from everyone else’s. But I think I’ll know it when I see it.

At that point, my stories will be ready. I hope.

* * *

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.

Who’s Eating Titan’s Acetylene?

October 3, 2016

The first Monday of the month is Molecular Monday, the day I write about my least favorite subject from school: chemistry.

Molecular Mondays Header

I’d planned to write something about ammonia today. Ammonia might (might!) serve as a good substitute for water in some alien biochemistry.

But then I was reminded of something. Something important. Something I’m kicking myself for not covering before. So once again, let’s turn our attention to Saturn’s largest moon: Titan.


Making Acetylene on Titan

As we’ve discussed previously, methane gas and other chemicals break apart in Titan’s upper atmosphere. This allows carbon, hydrogen, nitrogen, and possibly other elements to recombine in new ways. The result is a mishmash of organic chemicals collectively refered to as tholins.

Tholins tend to be sticky, yucky, and orange. They slowly fall to Titan’s surface, covering the moon with sticky, yucky, orange sludge. One chemical in the tholin mix should be acetylene (C2H2). In fact, acetylene is a fairly simple molecule compared to the rest of the tholin gunk on Titan, so we should find lots of it.

But we don’t. We’ve detected little to no acetylene accumulation on Titan’s surface. Maybe this means there’s something wrong with our detection techniques. Or maybe some as-yet-unidentified chemical process breaks up acetylene molecules as they fall through Titan’s atmosphere.

Or maybe (maybe!) something eats the acetylene as soon as it touches the ground.

Eating Titan’s Acetylene

I first read about this a few years ago in Astrobiology: A Very Short Introduction. It came up again, in greater detail, in the book I’m currently reading: All These Worlds Are Yours. The case of Titan’s missing acetylene is a hot topic for astrobiologists.

There’s a rather simple chemical reaction that might (might!) explain what’s going on.

C2H2 + 3H2 –> 2CH4 + energy

That’s one acetylene molecule reacting with three hydrogen molecules to produce two methane molecules and some energy. The kind of energy that weird Titanian microorganisms could use to survive (maybe).

In my opinion, it still seems unlikely that life could have evolved on the surface of Titan, if only because liquid methane (Titan’s “water”) is not a good solvent for amino acids. But unlikely is not the same as impossible.

It’s worth noting at this point that a few other weird things are happening on Titan. Hydrogen gas seems to mysteriously disappear near Titan’s surface, and no one has adequately explained how Titan replenishes its atmospheric methane (all the methane should have turned into tholins by now).

If Titan does have an acetylene-eating, hydrogen-breathing microbe that expels methane as a waste product, that would conveniently solve three mysteries at once. I can’t help but think, though, that this might be a little too convenient to be true.