Well, here's the graph I promised in my last post. It took so long because I intended to take some features from the graphs I produce at work, but kept forgetting to copy the relevant code for perusal at home. As it turned out I only needed a little bit, and the graph was pretty easy to make once I sat down to do so. Anyway, here it is:
Click for larger version.
It's interesting to see the patterns that emerge. The early high count steadily drops around the middle of 2012, then after a little more variability seems to have settled into a surprisingly consistent alternating series of 2–3–2–3.
I really enjoy making graphs like this, iterating over and over, often dozens or scores of times, to get a graph that's both informative and aesthetically-pleasing (to me, at least). According to my terminal history, I ran the command to generate this graph sixty-two times, though of course a decent number of those time something threw an error and no new version of the graph was produced. And I'm reminded once again just how happy I am to have a job where I get to make interesting and beautiful plots—perhaps I can share some of them in the future.
Today marks six years to the day since I started this blog. Why is this the first such anniversary post on this blog, you ask? Because I thought it was only five years and had decided to write a nice “happy five-year anniversary, me!” post and only discovered it had actually been six years when I sat down to write it. (I suppose it's also a great demonstration of my normal facility for dates in general.)
I had an idea to make a plot showing the number of blog posts per month over the run of this blog, which in fact is what prompted this post in the first place. At the beginning of this blog I was putting out multiple blog posts per week; over time that ratio has flipped to several weeks per post frequently, and I'm curious to see exactly how and when that happened. Part of that is simply circumstances. Back when I started, I was a student, and despite a brutal scholastic schedule I could still find both the time and motivation for post-writing fairly frequently. Two years later and I've graduated, but taken a part-time job at the Mauna Kea Visitor Information Station. Due to the binary nature of that job (days completely off vs. days spent entirely at work) I still had a lot of free days to think up and compose posts. Finally, a year later, at the beginning of 2013, I took my current job with the James Clerk Maxwell Telescope. This was (and still is, thankfully!) a full-time job with regular hours, but the downside was that it left me less time in general for post-writing and fewer days where I wasn't already tired from working.
Now, I mentioned a plot in the previous paragraphs, but alas! there are no plots gracing this particular post due to technical difficulties and a missing python-tkinter package that doesn't want to install. I really want to see what it would look like, however, so expect a post showcasing it in the near future. So check back soon, and a hui hou!
Merry belated Christmas and happy early New Year, everyone. It's a quiet Christmas holiday for me so I haven't had much to talk about. My big excitement for December so far was attending a Messiah sing-along for the first time.
I'd never been to a Messiah sing-along before so I didn't know what to expect, but I ended up having a lot of fun. The four voices of the choir were split up around the church and I ended up sitting in front of my choir director, who coincidentally also sings bass. This turned out to be very helpful as my ability at singing unfamiliar music can be summed up as “tempo, lyrics, pitch—pick any two!” (and while I'm intimately familiar with the solo parts of the Messiah, I get lost in the dense melismas of the multi-part choruses).
Ultimately, I had a great time with it (we didn't perform the entire work, just Act I, the Hallelujah chorus, and the final two choruses) and I hope to participate again next time I get a chance. A hui hou!
I don't know how much coverage it's getting outside Hawaii, but here on the Big Island of Hawai‘i we're having the largest outbreak of dengue fever in a U.S. state since World War II (though there have been much larger ones in Puerto Rico and American Samoa). The number of confirmed cases passed a hundred and forty this week, with no immediate signs of slowing down. Dengue fever, if you don't know (as I didn't), is a mosquito-borne viral disease endemic in more than a hundred and ten countries, which can have potentially life-threatening effects.
This isn't the first outbreak in the island chain; the most recent outbreak happened on Maui a few decades ago, though only a total of eighty-seven cases were reported before it was contained. It remains to be seen if it can be similarly contained here on the Big Island, or whether it'll become endemic. Rather unnervingly, up to 80% of people who contract the virus are asymptomatic, so there could potentially be a lot of people on the island who've had it (and are [or were] potential spreaders) but don't know it.
The bright side (if you can call it a bright side) to all this is that the virus comes in five strains, exposure to any one of which grants lifelong immunity to that strain and is likely (as mentioned above) to cause no major problems. So far I don't think there have been any fatalities directly tied to it, despite the large number of reported cases. The problems really begin, however, when someone who's had it once contracts a different strain; then you start to get much higher chances of very dangerous complications.
The outbreak hasn't been confirmed to any particular location, and cases have been reported all over the island, so officials are warning people that infected mosquitoes could be anywhere. If you, gentle reader, are thinking of visiting the Big Island (specifically the Big Island, it hasn't shown up elsewhere yet) in the near future, you'd do well to investigate how things are going and how much progress is being made in the containment process, and take care not to get bitten. Stay safe! A hui hou!
This week I learned of a volcanic island about a thousand kilometers south of Tokyo named Nishinoshima (“western island” in Japanese). Prior to 1973, Nishinoshima was a tiny islet comprising the northwest ridge of an underwater caldera about a kilometer across and about a hundred meters beneath the ocean surface at its deepest. No eruptions at this volcano had ever been recorded in the historical record.
Starting in May 1973, however, the volcano began erupting, ultimately forming a new island to the east of the old one. The volcano fell silent a bit less than a year later, after which wave action joined the new and old islands (the new one being composed of a lot of cinder doubtless helped).
There things rested until November 2013 when the volcano began erupting again, creating another new islet off the southeast coast of the old one. This eruption continued vigorously until it had created an island larger than the one already existing. The Japanese government (which claims the island[s]) was reportedly waiting for the eruption to stop to give the new island a name, but this was rendered moot soon thereafter when the still-growing island connected to the old one, making a single island a bit over two square kilometers.
The eruption continues to this day (as far as I can tell), though it's become a lot less vigorous and may be dying down. Here's what the island looks like on Google Maps at the moment: the older part of the island is the north-western part in the lighter tan color (it's clearly recognizable in an image from December 8, 2013).
I thought it was a neat look at what the Hawaiian islands must have looked like at one point, breaching the surface of the ocean and building up to the towering edifices they became. The base Nishinoshima volcano already rises nearly three kilometers from the ocean floor and is nearly thirty kilometers across at its base, so it could presumably get a lot taller. All very interesting. A hui hou!
This week I peeled a ripe breadfruit for the first time. It was quite an interesting experience!
I've cooked breadfruit before—I've even written about it on this blog—but looking back on it I realize now those breadfruit were unripe. Peeling a ripe breadfruit is a very unique experience. The closest I can liken it to is to trying to peel a lump of soft, sweet, bread dough encased in a skin something like a pear's, or perhaps a potato's—and I can definitely see where the name breadfruit comes from now! The taste is also difficult to describe. The closest thing it reminds me of is bananas, but it's very definitely its own unique, mildly sweet taste.
I've been having a rain of fruit going on in my backyard this past week, which prompted the breadfruit peeling. The avocado tree lost a small branch loaded with fruit a week ago (in addition to other ripe fruit falling), and there's been a steady stream of small earth-shaking thumps from the intermittent rain of breadfruit.
I peeled the breadfruit in order to cut it up and make a sort of hash out of it, with sautéed onions and diced Spam, but I suspect a less-ripe fruit would have been better (unripe breadfruit is kind of like a potato in texture, although it also bleeds an extremely sticky latex-like sap, so there's a lot of washing involved). I'm still trying to figure out how to prepare one best; I cooked an unripe one in the oven, but it came out looking extremely unappealing. I cooked a ripe one on the advice of a coworker, but forgot to peel it first leaving it somewhat difficult to separate from the (sap-covered) skin (it's still in my fridge while I think how best to eat it). I'm thinking of just peeling a ripe one and eating it raw at this point, but if I can find a good recipe for it I may put it up here in the future.
And finally, on a different note, happy belated Thanksgiving everyone! I spent a very relaxing Thursday topped by dinner with friends remembering all the things I'm thankful for, such as trees dropping seemingly-endless amounts of fruit in my backyard. Hau‘oli Lā Ho‘omaika‘i!
In the confusion surrounding attending the International Astronomical Union session just a few days after getting home from vacation this summer I only recently realized that I had some pictures lying around on my hard drive that I'd intended to post. I put up some panoramas I'd made soon after getting back from the IAU, but forgot about some other, single pictures I'd taken. So here they are!
These pictures are from Shore Acres State Park in Oregon—once the estate of pioneer lumberman and shipbuilder Louis J. Simpson, now the site of a five-acre formal garden overlooking the Pacific Ocean. Looking over my pictures I don't seem to have been feeling like taking any wide-angle photos, as most of my pictures are more focused on individual things. So nothing showing the large-scale structure of the gardens, sorry.
These aren't real birds, they're just statues—but very nice-looking ones.
Slightly-wider view of the pond they reside in.
Do not adjust your monitor! This picture is not upside down—it's a reflection showing the lovely conifers surrounding the park.
The park had a small greenhouse full of various flowers and plants. This particular one caught my eye for its spiral leaf patterns. (The text says “rex begonia 'Escargot'”.)
Another picture of a second plant of the same type, showing off those radical foliage helices.
This week on my way home from work I decided to stop at Rainbow Falls on a whim. Since I moved last year the falls are a lot closer to my house, so it's not very far out of my way. About four days earlier we'd had a powerful thunderstorm all day, and while we get many days of rain here in Hilo thunderstorms are pretty rare—perhaps ten or fewer a year. The large amount of rain from upstream had swelled the falls to a thunderous roar, and with the sun going down but still above the horizon I decided to shoot some photos in the picturesque light.
This one's from the outlook spot just a short walk from the parking lot:
And this is from the path that climbs up to above the waterfall's head—if you look you can see someone silhouetted in the previous picture, standing very close to where I took this next one:
Fun fact: my profile photo up there was actually taken at Rainbow Falls! Though it's been cropped so you can't actually see the falls in it. And it's about six years old at this point...maybe it's time for me to think about updating it (not that I look vastly different or anything).
Yesterday I went to see The Martian with my friend Graham from work. Overall I had a pretty good time with it, and I liked the happy ending. I can't really talk about what I want to without spoiling the plot, so consider the rest of this post one big spoiler warning.
If you saw a trailer for The Martian, you probably already got the gist of the movie. The Ares III mission (third in a series of five manned mission to Mars) encounters a mission-scrubbing sandstorm only twelve days into their mission. During the emergency evacuation one crew member (Mark Watney) gets lost in the sandstorm after getting hit by a flying communications antenna and is (quite reasonably) presumed dead after his suit reports a suit breach, leading the rest of the crew to abandon Mars and head back to Earth. Mark turns out to be alive, amazingly (the blood from where he got impaled having sealed the small hole in his suit), and most of the rest of the movie deals with his attempts to survive until he can be rescued. Luckily, as this was a series of planned missions, Ares IV is already set to land 3800 kilometers from his position in a few years, leading to the idea of getting there to meet it when it arrives. The rations left behind in the evacuation won't stretch that long, but a serendipitous discovery of viable potatoes among the rations leads to him growing them and giving hope that he can survive long enough to modify the rover (also left behind) to be capable of traveling to the landing site.
It takes a few months for anyone to notice he's still alive based on satellite photos of Mars, but when they do they manage to get communications up and running between NASA and Mark. NASA fast-tracks sending the scheduled pre-delivery of food for the Ares IV mission in order to get it to Mark faster, especially after a freak explosion blows up his growing habitat and destroys his potato crop, leaving him with the unenviable prospect of running out of food in a very definite amount of time.
Meanwhile, the rest of the crew of the Ares III are still on their several-month journey back to Earth in the Hermes crew vessel. An astrodynamicist at NASA realizes that the Hermes could potentially slingshot around Earth and get back to Mars fast enough to save Mark as a backup in case the food shipment doesn't make it. (Turns out the Ares IV ascent vehicle has already been landed at the proposed landing site on Mars, since it could be launched ahead of time and means the actual Ares IV mission doesn't need to bother with bringing it along; Mark could take it up and rendezvous with the Hermes as it slingshots again around Mars on its way back to Earth.) This idea is floated in a secret meeting, but is rejected for putting the rest of the crew in additional danger (not to mention several more months of spaceflight time). However, when the rocket carrying the food package explodes during launch the Ares III mission director secretly sends the crew details of the maneuver, whereupon they unanimously vote to mutiny and perform the maneuver against NASA's orders.
Ultimately, the Hermes makes it back to Mars in time for Mark to make it to the Ares IV ascent vehicle before starving, where he strips a frankly ludicrous amount of material out of the ascent vehicle in order to make it light enough to reach the speed necessary to rendezvous with the Hermes (as in, he strips out all of the manual controls leaving it controlled remotely from the Hermes, and even the windows and airlock, performing the ascent in his spacesuit with a tarp over the windows). After a climactic rescue scene Mark is saved, and in the epilogue it's shown that everyone made it back to Earth safely and Mark has taken up teaching future astronauts.
Think Apollo 13 meets Robinson Crusoe.
Now, most of the time, the science was quite good, as you would hope for a movie where almost all of the tension comes from butting up against the laws of nature. Things like burning hydrogen to get water (and causing an explosion due to unaccounted-for excess oxygen), space scenes shot in zero-g conditions (although the Hermes also has rotating sections where people can walk around normally due to centrifugal force), and a homemade bomb made of sugar mentioned as being “four times more powerful than a stick of dynamite” (which is entirely believable, given the vast amounts of energy in food; thankfully, it doesn't easily burn fast enough to explode under normal conditions). The shots of Mars were also particularly gorgeous, especially in the 3D version I saw, which worked well; the 3D was used to good effect rather than being a mere gimmick, and was never used to “in your face” type things.
As an astronomer, however, several details stuck out to me while watching. At least twice, the Martian night sky is shown with a small crescent moon hanging in space. While pretty, it's also unrealistic because Mars' two moons Phobos and Deimos are both tiny, and far too small to be seen as anything other than star-like points (they're also irregularly shaped like asteroids, so they wouldn't have a nice crescent like the Moon does here on Earth). There was also a beautiful shot of a Martian sunset…which looked suspiciously like a sunset on Earth, with a blue sky fading to red around the Sun. Interestingly, it's almost the exact opposite on Mars: the sky is normally red due to ever-present dust in the atmosphere, while fading to blue around the Sun at sunset and sunrise. The atmosphere on Mars is only about 1% as thick as Earth's at ground level, so it's usually too thin for there to be enough Rayleigh scattering to produce the blue skies here on Earth. However, at sunrise or sunset the Sun's light passes through enough of the Martian atmosphere to create a pale blue color, as seen in the picture below. (On Earth the extra atmosphere at those time scatters so much blue light out that what's left appears red or orange.)
Another thing I noticed is that the movie tries to have it both ways with regards to how thick Mars' atmosphere is. In the first few minutes of the movie, the sandstorm that kicks everything off both rips off a communication dish and takes out Mark with it, and presents a credible threat of blowing over the ascent vehicle. Yet near the end of the film as Mark is preparing to ride an Ares IV ascent vehicle that has had even its windows and airlock removed in order to lighten it, it's pointed out that the Martian atmosphere is thin enough that you could feasibly pull such a thing off due to air resistance being essentially non-existent. I'm not familiar enough with the fluid dynamics of the Martian atmosphere to say anything myself, but I've read that in reality even a fierce sandstorm on Mars would feel like a light breeze and wouldn't be able to tip over a large metal ship. The highest atmospheric density on Mars is only 0.6% that of Earth's, so I believe it. Mars' famous planet-wide sandstorms work because of the lower Martian gravity, not because the wind is so strong. And speaking of gravity…
…as a physicist, I couldn't help but notice how Mars has Earth gravity the whole time. The surface gravity on Mars is just 3.7 m/s², a mere 37.6% of Earth's 9.8 m/s². Obviously the movie was filmed on Earth (Wadi Rum in Jordan standing in for Mars), and it'd be to impossible to change something like that, so this isn't a fault of the movie in any way—it just wouldn't be possible to make it look realistic. The fact that something so minor is what I kept noticing really says something about how good the rest of the science was.
Interestingly, during the part where the crew on board the Hermes votes to mutiny and perform the maneuver to return to Mars against NASA's orders to save Mark, the commander says something to the effect of “if we do this, none of us are likely to ever fly again.” This may sound like mere dramatic oratory (although it's justified in the context), but it turns out this has actually happened: in at least two cases crews of astronauts (on Apollo 7 and Skylab 4) have mutinied while in space, and both times no one on the crew ever flew in space again, as eloquently explained in the videos below.
Overall, as I said, I found it a pretty good film, though I couldn't watch the early scene where Mark performs self-surgery to remove a bit of metal from his abdomen from where a spike on the communication array impaled him with nothing but local anesthetic (queasiness is why I'm an astronomer and not a doctor!). I laughed at the part where, in the secret meeting to explain the maneuver for the Hermes, the guy who came up with the maneuver calls it “Project Elrond” and while one of the people in the meeting is trying to figure out what “Elrond” means the normally staid and stoic director of NASA pipes up from the background to say “If this is the council of Elrond, I want my code name to be Glorfindel.” And I especially winced in sympathy at Mark's line “I ran out of ketchup seven days ago” said while eating a potato. Surely that would have to be the worst thing about being stranded on Mars: running out of ketchup. A hui hou!
When I put together those pictures of Saturn I used to illustrate the scale of Saturn's ring system last month I went to a lot of trouble to make all the rings consist of two mirrored halves, with the intention of using them to make the illustration in perspective (by hiding one set behind Saturn, then squashing both sets symmetrically inwards vertically, if you're curious). Along the way I decided I liked the straight-on overhead view better and ended up not doing it, but the capability remained, so today I decided to blow the virtual dust off the file and see what I could make of it. I had to make a new radial gradient for Saturn, but I think it came out looking pretty nice:
(Despite the title, this is just a plain old PNG image, as Blogger unfortunately doesn't take SVG images directly. But the original is SVG, anyway. See how many of the rings mentioned in my previous post you can spot here!)
