Category Archives: Science

Twitter is back (on probation)

Oh, hello. My last post was just over a year ago; I declared that I was taking a break from Twitter for 2018. So. How did that go?

Spoiler alert: I didn’t miss Twitter much, but I did miss you, kind reader.

I didn’t miss any news. I mostly rely on The Guardian because I can read it daily (and no more frequently), I can pay for it directly, and it has an outside-the-US perspective. Space news comes from, well, Space News, as well as TMRO.

I certainly didn’t miss the drama. My life was refreshingly free of fights over apologies for slights over comments about news. Oddly enough, those fights sometimes ended up as Guardian stories, and they sounded pointless by the time they did.

I did miss friends. Even the occasional photo from a vacation or a night out can be nice, or a quick update about a new job or a move. We had our own milestones this year, like moving into our first house, and we only shared them with the few people immediately around us. It felt like losing touch.

With that in mind, I’m goin’ back in. So what’s different now?

First, I don’t sit on a bus for 3 hours a day anymore. Twitter won’t get big blocks of my time, because I don’t have them. In 2018 I switched from obsessively scanning through Twitter to obsessively scanning through Discord (and Slack and a few subreddits), so it’s not like I’m a social media angel now. I just won’t have the opportunity, so I think it’ll be a bit safer.

Second, spending a year without 99% of Twitter reminded me that I don’t need all of it. I don’t even need most of it. My plan is to stop following a bunch of people (because it turns out no one really needs DM access to me) and stick to a few quiet corners of Twitter. Starting today I’m sifting through messages to separate out the ones that bring joy from the ones that only bring drama.

We’ll see how it goes. Until then, Happy New Year!

taking 2018 off Twitter

TLDR: I’m stepping away from Twitter for 2018, from January through December.

I’ve talked before about how Twitter is a communication service, not an entertainment channel. I resisted changes to the format, retreated to third-party clients, and relied on lists* to make sure I’m seeing what I want to see, not what Twitter wants to show.

None of that is why I’m taking a break, though. Twitter’s been good to me for over a decade. I met some of my favorite people there. SpaceUp owes its existence to Twitter. (Specifically to @cariann, but that’s another story.) I work at a rocket factory because of Twitter. (Thanks to @malderi, yet another story.) I still hold that if Twitter were to go away, we’d have to invent something to take its place. (Something with a bit more empowerment and a lot less abuse. I can dream.)

I’ve actually spent more time on Twitter this year than before. I commute on buses a few hours a day, and Twitter is a reliable stream of low-effort infotainment I can hold in one hand while hanging on with the other. I can get excited about an upcoming launch, get mad about someone doing terrible things, feel better about someone being noble, get weepy over one thing and resolved about another, and calm down by looking at photos of Earth from space.

And that’s the problem. Once it’s done, all that time on Twitter feels like a waste. A sink. A tar pit made of feels. It’s engaging while I’m in it, but I get off that bus feeling hunched over, worn out, and ultimately unenlightened. Never mind the fact that I’m also contributing to someone else’s stream of social-media dopamine with every retweet and comment.

It doesn’t help that every day the company is growing more Nazi-friendly and less user-friendly, spending more time defending silly new features than defending people from attack. It also doesn’t help that one of the most prominent uses of Twitter is destabilizing western civilization, whether by botnet, crowdsourced horrible behavior, or single-handed idiocy. My gut tells me that Twitter is one more garbage decision away from a mass exodus. (Don’t laugh. It happened to Patreon quickly enough.)

So for 2018, I’m going to try life without Twitter. It’s not a rage quit, but a pause button. It’s not intended to be a judgement on anyone else. I just want to see what days are like without that particular monkey on my back. In January 2019 I’ll reinstall Tweetbot and take a look with fresh eyes. Who knows what I’ll find?

I’m not on Facebook or Instagram, so if you’re curious how to find me internet-socially… I have to ask, why on Earth would you? In general I’ll still be in the small-circle social places, like the Orbital Mechanics blanketfort on Slack and the TMRO audience chat. Heck, you could even dust of the ol’ email and send something to chris at globalspin dot com. Who knows where that might lead.

[*] OK, a confession about lists. If you take a look at my account right now, I’m following 530-ish people. However, I never view my timeline directly. I have two private lists called “Daily Reads” and “Extended Reads”, with 60 people and 380 people respectively. That lets me see everything from the 60 people I don’t want to miss, and skim through the rest. I sometimes worry this is misrepresenting that “follow” idea, but then I realize how little anyone actually “follows” when they’re following thousands of Twitter accounts.

back of the envelope: daylighting on Mars

Sometimes I need to work out a rough calculation to check whether my idea of something science-fictiony has any basis in reality. It doesn’t need to be super-rigorous*, but close enough to tell if my conception is way off the mark.

In this case, I’ve been thinking about how it might feel to walk around a city on Mars. It’s likely to be mostly underground to help shield against radiation, but there should be as much daylight as possible to save energy. On Earth, that kind of daylighting comes from skylights, windows, and (my personal favorite) light tubes.

But what about on Mars? Mars is farther from the Sun than Earth is, so it gets less light on the surface, but how much less? Is walking down a Martian street destined to feel like a gloomy overcast day?

First I had to get a grip on how to measure daylight. An obvious comparison is solar radiation, measured in Watts per square meter. Depending on time of year, Mars gets between 1/3 and 1/2 as much solar radiation as Earth, because it’s about 50% farther from the Sun. That’s handy for figuring solar power output, but the human eye isn’t so linear.

Another way is illuminance, measured in lux. Though the exact conversion factor between solar radiation and lux is a bit tricky due to the eye’s reaction to different wavelengths, I gather that the relationship is linear. Thus, using some standard Earth values and scaling them:

on Earth on Mars (min) on Mars (max)
direct sunlight 110,000 lux 38,000 lux 55,000 lux
indirect daylight 20,000 lux 6,800? lux 10,000? lux
clear sunrise/sunset 400 lux 130 lux 200 lux

(I’m assuming that indirect daylight is scattered as well in Mars’s pink sky as it is in Earth’s blue. Something to check later.)

Filling in a few other Earthly values for comparison:

bright overcast 25,000 lux
dark overcast 10,000 lux
studio lighting 1000 lux
office lighting 500 lux
cloudy sunrise/sunset 40 lux

So it looks like daylight on Mars wouldn’t look too different from daylight on Earth. It’s orders of magnitude more light than during “golden hour” on Earth, which is plenty to get around by. It would probably feel like a partly-cloudy day, since there would be more light than even the brightest overcast day, with sharply-defined shadows.

For daylighting, this probably means that Martian interiors would need twice as many Solatubes to get the same level of illumination, but we’re still talking about a fraction of the available daylight. In other words, using Earth-style lighting techniques should keep a Martian city street from feeling gloomy.

*Note the use of Wikipedia sources. Kids, don’t use Wikipedia as a source if you want anyone to take you seriously.

three rules to put more science in your fiction

I won’t start an argument about the definition of “hard SF” or the state of scientific accuracy in fiction, but here are a few handy rules for science-fiction writers who want a quick test of real-science groundedness.

I call them Joi’s Laws, because SF writer Joi Weaver put them so well. (The headlines are her laws; the rambling context is mine.) Each one is a challenge: avoid this common crutch when starting your own story. Think of them like the Bechdel Test for solid science.

No FTL Travel

Space is big, and ships are slow. Thats the reality for at least another century, so embrace it. Faster-than-light travel lets your characters hop from star system to star system, but what are you really gaining? How is a rock around Epsilon Eridani inherently more interesting than a rock in the Main Belt?

Even if your story is set in the far future around a far star, FTL travel is dispensable. Joss Whedon didnt need it for Firefly, and his (solar-system-sized) universe was packed full of interesting locations.

No Aliens

Everyone knows it: aliens in most stories are just humans with funny foreheads. Even the most unusual aliens in the most mind-bending stories turn out to have mostly human attributes, because a) it’s hard to imagine anything truly alien, and b) it’s harder to relate to truly alien aliens. So stop trying. Humans and animals have bizarre enough variations to fill a century of stories.

My own corollary: No Monsters. Monster stories are great and all, but 99% of new sci-fi is already cluttered with zombies, mutant viruses, and killer robots. Next time you need something terrifying, how about the interplanetary DMV instead?

No Artificial Gravity

This one is tough even for me. I’m obsessed with gravity, and I honestly believe we’ll be a second-rate spacefaring species until we learn to control it. Still, no one is close to controlling gravity even a little bit, so spaceships with a solid one-gee field working at all times are still pure fantasy.

Besides, fifty years of astronaut hijinks teach us that weightlessness is one of the best things about space travel, and we haven’t yet explored the spectacle of low-gravity sports. The only reason your characters would actually choose to be in a one-gee field (occasionally) is due to health concerns, and a treatment for bone loss is much more believable than gravity control.

It’s more a guideline than a code.

Good stories can still be told if they violate Joi’s Laws. (I’m going to see the next Star Trek film just like everyone else.) They’re not a guarantee of a good story, either. If you want to tell a *new* story, though, keep these in mind to give yourself a bit of a real-science challenge.


on life and its sources

Tonight I read the geeklet a story at bedtime, the kind of thing that’s designed to be restful with a hint of mind-broadening moral reassurance. As I finished, he looked thoughtful.

“We wouldn’t be here without this.” He tapped on the floor. “I don’t mean the floor, or the neighbors downstairs. I mean the ground underneath us.”

“That’s right.”

“We also wouldn’t be here without this.” He held up is palm, and this time I wasn’t sure what he meant. “We wouldn’t be here without the sky.”

“That’s also true.” I stood up and turned out the light. “Good night.”

He wasn’t done, though. “The sky wiped out the dinosaurs so we could take over.”

“Mm hmm,” I said, without even a pause. “Good night.”

“Good night, daddy.”