Why one enlisted in 1917

One of my duties at the Monrovia Library is to take old newspapers on microfilm and scan them into electronic files. We anticipate this making them much easier for patrons to use, and it will mean less wear on the microfilm itself.

I’ve been working on scanning the Monrovia Weekly News from 1915-1917 lately, and sometimes my attention is caught by unusual ads or articles. This item, from May 26, 1917, definitely stood out.

For context, what was happening in 1917? That’s right, World War I (at the time, the Great War). The U.S. had declared war on Germany just seven weeks earlier, on April 6, 1917. Before it was over, we’d lose 116,000 U.S. lives.

And the straight-shouldered grandfather? He’d have possibly fought in the Civil War, 56 years earlier. A bit more complicated, that, to consider it an answer to the call of the Flag (presumably the North and nationalism, vs. the South and federalism).

Regardless, a sobering take on conscription and enlistment. Does our Flag have the same call today?

Hunting for exomoons

Finding planets? Old hat. What about finding moons?

It seems likely that planets around other stars might also be hosts to their own moons. In addition to just wanting to know what’s out there, detecting exomoons could have implications for the habitability of exoplanets. While gas giants themselves might not be habitable, their potential rocky moons could be, if the planet orbits in the habitable zone. Also, moons can help stabilize a planet’s orbital inclination over long time periods, making it easier for life to maintain its hold rather than experiencing dramatic oscillations in environmental conditions.

This video shows the expected effect that a moon could have on the light curves we observe remotely:

The Hunt for Exomoons – Lightcurve Demo from Alex Parker on Vimeo.

The effect here is quite noticeable because the moon is at high inclination (out of the plane of the planet’s rotation around its star).

HEK (the Hunt for Exomoons with Kepler) is a collaboration established with hopes of finding the first exomoon in Kepler data. They were successful in getting some crowdfunding from PetriDish.org to purchase a supercomputer for their search. Laudably, they plan to post numeric posterior results from their search as an aid to the community.

Exomoons are theorized to tweak the planet’s transit curve in a variety of ways, but they are subtle and in many cases can be confused with other causes (like interactions with other planets in the same system). The community is still working to develop reliable models.

So, no exomoons have yet been found — but it’s probably just a matter of time.

The Kepler orrery

If you haven’t heard by now, the Kepler mission has opened up a firehose of exoplanet (candidate) detections. We’re up to more than 2300 candidates found by the mission, with more to come.

I’ve just discovered an awesome animation that Dan Fabrycky created to visualize systems discovered by Kepler that have more than one detected transiting exoplanet. (Note: this includes unconfirmed planet candidates as well.)

“There are 885 planet candidates in 361 systems. In this video, orbits are to scale with respect to each other, and planets are to scale with respect to each other (a different scale from the orbits). The colors are in order of semi-major axis. Two-planet systems (242 in all) have a yellow outer planet; 3-planet (85) green, 4-planet (25) light blue, 5-planet (8) dark blue, 6-planet (1, Kepler-11) purple.

I could stare at this for hours. Wow.

Ticking mechanics

I love fixing things. So imagine my delight when today I finally tore open a wall clock that stopped running years ago and got it working again. This clock has been stopped for so long that I’ve lost the habit of even looking at it, yet I’m so fond of the thing that I haven’t had the heart to replace it. (It was one of the first decorations I added to my first grad school apartment.) I’d previously given up when replacing the battery didn’t do the trick.

This clock has a simple time piece stuck to the back of it. I examined its mount and then carefully pried it off, at which point the hands fell off their spindle and clattered to the bottom of the front of the clock (it has a plastic enclosure). I couldn’t tell if that had destroyed anything, but since I had nothing to lose, I pressed on. I pried the time piece apart so I could get at the inside, which featured a bunch of flimsy plastic gears, a tightly wound spool of copper wire, and a tiny circuit board. I pried this up to see the circuit board, at which point the gears exploded off their mounts and went flying.

Nothing seemed obviously fried or broken with the circuit board, so I decided to try reassembling it. Because I hadn’t taken a picture of their arrangement, I then spent several minutes puzzling out the mechanical logic of the seven (!) interlocking gears (two are underneath in this shot). This is not the correct solution. This is the picture I took after reassembling them the first time (which I thought was correct). Everything fit together, and it started ticking (hooray!), and the little gears all started turning at different rates. But right after taking this picture, when I snapped the case on top, I heard a SNAP and then a little rattle when I moved the case. I was sure I’d broken some vital plastic bit. I opened it back up and found that one of the plastic stand-offs was broken. However, it didn’t seem vital, so I pressed on. The rightmost gear in this shot is the one that’s wrong. I finally figured out that it goes underneath the platform (it’s the gear that lets you manually set the time). The gear that drives the ticking is on the far left.

Encouraged, I snapped the case on, and it was still ticking. I then disassembled the front of the clock to get at the hands. I mounted the time piece to the back of the clock frame, took the battery out (it stopped ticking), stuck the three clock hands on the spindle axis in the correct order, and set them to point at 12:00:00. I twisted the dial to manually set the time, stuck the battery back in, and IT WORKED!

So basically, I didn’t learn anything about what was wrong or how to fix it, except that (as sometimes happens), just taking the thing apart and putting it back together did the trick. The fun part was figuring out how to get in, and then how to fit everything together. It’s possible that some dust had wedged in there or some of the tiny gears were just slightly not touching or the battery leads weren’t making the right contact. I favor the latter hypothesis since I couldn’t hear any ticking. But either way, it works now!

Runner’s Knee

Last December, I started training for my first triathlon, which for me primarily involved running. I’d never done any sort of regular running, but I soon found that I really loved doing it (far more than, say, swimming). In March, I successfully entered and completed the Pasadena Sprint Triathlon — what a high point! I’d worked up to 3-mile runs without any trouble. After the triathlon, I continued running, and kept increasing the distance until I made it to 5 miles. That run actually wasn’t so much fun, so I backed off from there to ~3.5-mile runs again.

By June, however, I started experiencing knee pain. Not while running, but at other times, like just walking around, and especially when going downstairs. The final straw was when I was hiking in Scotland and had to cut a hike short (one I’d done two years before with no trouble!) because it was just too painful. I took a couple of weeks off of running but still was feeling achiness in my knees. That’s right, knees plural — not just the one I’d injured skiing last year.

Today I visited my doctor and learned that I’ve developed runner’s knee, also known as “patellofemoral pain,” which often manifests as aching below the kneecap, most strongly when going downhill or downstairs. This can be caused by a variety of things including imbalance in musculature or mechanical problems with how your patella (kneecap) slides over the knee, but it’s very common in runners who increase their distance or speed too aggressively, and also twice as common in women as in men. Argh! I was being cautious, but I hadn’t really abided to the suggested “only increase by 10% each week” rule because I was feeling fine. In fact, my knees don’t hurt much or at all while I’m running. It’s afterwards (for days?) that I notice it. So this all points to the running aggravating the joint, and it means I need to back off, take it easy, and be more gradual in my efforts. As my doctor said, “Run for enjoyment, not for achievement,” and then chuckled self-deprecatingly before he segued into a story of his own over-ambition and series of injuries in his determination to run a half-marathon even if it killed him (or his knees). There are also some strengthening exercises for the quad muscles that can help, and I can go to a running shoe store to get an assessment and their recommendation for shoe styles (many friends have advised this). His other advice was to avoid running downhill (here I’d thought downhill bits were my chance to improve my average speed!) and online I’ve read that I should be running on a track or something softer than sidewalks/roads.

I hope to improve soon! I am really, really missing my running. The good news is that the doctor said there’s no reason someone my age shouldn’t be able to run 3 miles 3-4 times a week, so I should be able to build up to that pain-free. It was good to hear this confirmation of my own expectations, rather than a dim outlook and some dire words about the effects of aging. Bah!

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