Tuesday, August 23, 2016

Artemis and Esteban wedding speech

To me, adventure is a setting out, with a degree of intentionality, to encounter the unknown and the inexplicable. A good adventure, like a marriage, has a good deal of mystery in the future, but most importantly, the guarantee of interesting things along the way.

That crystallization of intention, that first step along the adventurous path, is the one that requires the most courage. Today, you leave behind the comfort of the familiar and well trod paths, and set out into the wilds of matrimony.

Some adventures are solo journeys, which can present opportunities for self discovery. Other adventures are more familiar exercises. A close friend, or traveling companion, is a piece of home with whom you can contextualize your dramatic shared experience.

Obviously, one's choice of companion is critical. If you are very lucky, you may meet in your one lifetime, a person with whom you can produce that vanishingly rare hybrid adventure. One where you can self actualize, though without crushing loneliness. One where you can share the full spectrum of life's adventures, but without stifling over-familiarity.

Artemis and Esteban, I have known you both since my first days on this continent, more than five years ago. That you were meant to be together was obvious to most of us, even then. It gives me infinite pleasure to celebrate with you this phase change, this sublimation, of the inevitable.

Wednesday, July 20, 2016

90 hour weekend with B

Last weekend, my dear friend and antique house mate B finally decided to visit me in LA, and it was GRAND. Here follows a brief, blow by blow description of the utterly banal and forgettable weekend we enjoyed together. My primary mission was, by example and through song and story, to infect B with the Californian Dream.


On Thursday evening, B arrived from Seattle. Rather than head straight to hot pot, he dallied at the airport, so we were mostly full and about to admit defeat (after 90 minutes) when B showed up. He re-energized us and after only 3.5 hours stirring the soup we paid the bill and crawled away on our stomachs, snail style. 

The following morning, Friday, I apologized for not having any milk, so we enjoyed our breakfast in the traditional style. Depression flakes - cornflakes and tap water. A great way to start the day, if you like things to improve rapidly after breakfast, no matter what. I mentioned we could probably grab some milk later that day but - spoiler alert - milk was never obtained.

I took off for work, B's aunt C showed up and took him to Ventura beach, and we met again at 3pm at JPL. There we were joined by my friend D, who works on lab, and the four of us (B, C, D, and I) took off for a quick tour through the lab. I have, of course, taken the same tour numerous times but it's always a pleasure to look at the robots, visit the control room, look longingly at lucky peanuts, and kick rocks in the Mars Yard. It has mostly returned to normal since "The Martian" came out, but plenty of Juno-related paraphernalia is still in evidence.

B, C, and I headed back to my place, where recharging of phone and mind and body was called for. I took a quick call to Antarctica, while B and C jumped on my piano and played several four hands pieces they mysteriously carried the music for, apparently, everywhere they go. I came back out and we all sang some stuff together, which was grand. I miss the social creation of music. At this point the sun began to set so we gathered our peace offerings, farewelled aunty C, and headed off for a birthday party at my friend M's place. 

M is a paragliding astrophysicist polyglot, so we knew we would fit right in. M had only been in town for about 2 months, so it was a small gathering of her 50 closest friends, many of whom spoke mainly Spanish, and all had good stories. Later in the evening, round with excellent food, we set up a telescope to examine Mars, Saturn, and the Moon, before gathering around my printed copy of the SUMS song book and singing about 6 verses of Gaudete, a carol with improvised interstitial verses. Late in the evening we took in the guitar circle, faded, and headed home for some well earned rest.

The following morning was Saturday, so we decided to take it easy. By getting up early, travelling to a nearby workshop, and building me a dining table from scratch. After only 4 hours of finicky work, a couple of mistakes, and numerous design regrets, the assembly was basically done. Now only remains the finishing touches. We had pushed lunch back so we headed home, cleaned up a bit, and headed to a local restaurant where I enjoyed vegan (dairy free) pancakes.

Following this we headed to rendezvous with friends DA and L, with whom we enjoyed a second lunch. DA described the intersection of attractor theory and the microbiome. L ordered a vodka/grapefruit, but got the relative quantities reversed. B talked about materials with weird thermal and magnetic properties. I talked about spaceships, for a change. At some point we went for a walk, covered solar power, desalination, and the space nuclear imperative. Later, we got a ride in a fast electric car back to campus, where there were Pokemon to hunt. 

We took it easy for an hour, enjoying a relaxed campus tour, before meeting friends J and C for dinner at the Caltech Atheneum Rathskeller Al Fresco, where I enjoyed bacon-wrapped meatloaf and B struggled to meet the demands of a nachos of truly biblical proportions. J and C regaled us with tales of boating down the Mekong river before bailing as the night chill settled over the desert we call home.

We headed west for the next event, but were waylaid by the intercession of an amazing music concert on the Beckman Lawn: Muse-ique. It turned out our friends N, R, and G were performing, so we sat with family and friends (D, C, etc) and enjoyed the incredible performance. Mostly 20th century jazz music in all kinds of varieties. 

When Muse-ique drew to a close, C, B, and I went to a karaoke bar in downtown, near where I work. The room was loud and full of friends, for dear friend H was celebrating her birthday, and all of us are huge musical theater geeks. In addition to numerous other positive traits, B possesses an exquisite tenor range and we "rocked out" until they closed us down. Friends K and T took a vote and decided that B was not to be allowed to leave for Australia. We headed home and quickly passed out, after a quiet, relaxing Saturday.

Sunday. Last full day of B's visit. Still so much to do! The clouds were clearing so we headed to the airport, clambered into the trusty Cessna 152 in which I did much of my training, and took to the skies. A quick jaunt south through the haze, over Long Beach, and across the channel to Catalina Island. A flight around the island, then up to the middle and, dodging scudding clouds, to land at the airport in the sky. 

Our first and biggest mistake was to assume it was too early for lunch, so we took a stroll around the airport, had a good chat, and returned to find we no longer had time to survive the queue, eat lunch, and get back on time. At least the plane was much lighter, we cruised back to El Monte in style, bouncing between mid afternoon bumps before executing a nice glided landing on the airstrip. 

Once home we did kick back for a few minutes. I did some laundry, we watched some silly videos, went shopping at Whole Foods (ever seen a vegetarian's eyes the first time they go there?), and cooked dinner. We finished our dinner, of sweet potato quesadillas, just in time to go to the local cinema and catch Ghostbusters with some of my former Caltech colleagues. B and I giggled and guffawed throughout, though I thought the spookiest part was how much the ghostbuster Erin looked like my fiance C once looked. Brown hair and MIT jacket. Uncanny!

On our way walking back from the cinema, I was livestreaming the SpaceX CRS-9 launch on my phone, when the internet cut out, mere minutes from liftoff. Fortunately we were walking past my friend T's house, so I gave them a call.

"Hi, Casey here, what are you doing?"
"Watching the SpaceX launch, duh."
"We'll be there in 3 seconds."

We caught the launch, including the incredible landing. Then B and T got stuck into a 30 minute discussion of the minutiae of knitting, before meeting a pet snake, sampling Indian food, and heading back. 

Time to sleep? Think again! We headed back to M's place for more guitar and music, arriving just in time to eat a bunch of apple pie and icecream, contribute some chocolate brownies, and leave again. We walked about an hour back to my place through Pasadena, then finally took rest!

Monday, last day. We took the train and walked into my work, a substantial hike with luggage in the hot sun. I gave B the "revolutionizing the manufacturing of transportation infrastructure" tour, fed him some of our amazing lunch, then sent him off to do a downtown LA walking tour and explore The Last Bookstore. Some hours later he arrived back, rather footsore. I called a Lyft, we said our farewells, then I got back to solving PDEs. 

Later, I heard he had successfully boarded an aircraft, because the Hyperloop still isn't built, and was on his way home. 90 hours had elapsed since he bounced into the hot pot restaurant and helped us in our hour of dire need. I think we shared a decent sample of what southern California has to offer, and I (and all my distraught friends!) can't wait to have him visit again!

Monday, July 4, 2016

Illustrating Mathematics at ICERM

Last week it was my singular pleasure to be invited to a workshop on illustrating mathematics, an area that has been revolutionized by relatively recent innovations in 3D printing!
The conference was held in Providence, Rhode Island, at ICERM, a part of Brown. I flew into nearby Boston the previous Saturday, explored the city, caught up with friends, and acclimated to the new time zone. The following day I took the Amtrak to Providence, wandered through the town, and found my hotel.

By the time I booked my room, the conference hotel was full, so I was given a place at the Providence Biltmore. I was planning to couch surf, but it was part of the deal, so I had to deal with a 4 room suite. The kitchen seemed to lack mood lighting. Later, I found another 3 rooms and ordered some kitchen kit for cooking. They delivered about 6 saucepans, but had to go back for cutlery. Lucky I didn't ask for plates!

The next day I went and checked in. Surrounded by lots of unfamiliar people from unfamiliar places and all of them topologists of one form or another. I hadn't really done hardcore (sort of) algebra since undergrad days, so it took some getting used to. That afternoon I mapped a Rubik's cube, though, so I was back in the game.

There was an adjoining room full of everyone's 3D printed creations. Some people printed hinges, hyperbolic surfaces of every kind, non-orientable surfaces, and organic-looking surfaces. Some people had knitted non-trivial topologies, which was an interesting exercise in patching. My fiance C knew (only) 5 (of the 50ish) participants so I had fun meeting more people. One of them, F, had a successful kickstarter to buy a $100,000 knitting machine, with which she makes the most outrageous knitted stuff. My favourite was the cellular automata - networks governed by simple rules which can, in some special cases, do computation!

One evening, A and I were walking the streets of Providence looking for restaurants and we found Big Nazo labs, a creature/performance shop, full of all kinds of monster puppet type things! Quite strange but an interesting counterpoint to the day's adventures in pure mathematical thought. We also had an opportunity to visit the bio lab of RISD - the Rhode Island School of Design, which had an incredible collection of interesting forms used as inspiration for the architects etc in training there.

F, D and I explored the John Brown house, a museum on the site of one of the grandest mansions of the colonial/independence time period in providence, which had a great audio tour and all kinds of interesting stuff in there. The Brown family was, for the vast majority of the time, involved in the "Indian Trade", which is a euphemism for dealing in people - slavery. We thought it was interesting how the audio tour took its time to get to that aspect of the story, but when it did it went into some detail.

I live tweeted much of the workshop, never missing an opportunity to drop some terrible puns! On Thursday the non-speaking members of the conference were given an opportunity to speak for 4 minutes each. So I decided to focus on just one thing and do it well. I talked about the mathematics of music (1.5^12=2^7, roughly) and how you could encode single step transitions between chords into a biperiodic map, which can be printed on the surface of a torus, which I made into a ring. Amusingly, it was at about this point that Shapeways gave up on printing my often extremely finicky models and I had to switch to i.Materialise, something the audience found quite funny!

On Friday, I infiltrated the physics department at Brown, as part of a strategic job investigation strategy. Well, I made it to the foyer of the right building. On summer break it was pretty empty. I saw a fellow walking over and, not having any idea which department or type he was, asked where the physics grad students hang out. I took some pains to emphasize that I wasn't a crazy person, and it turned out to be one of the professors of the physics department, Savvas Koushiappas, who generously answered all my questions for about 20 minutes, at which point one of his recent doctors dropped by to hand over an autographed thesis copy. Savvas told me a bit about how Cooper, of superconductor and semiconductor theory fame, was at Brown, whose physics department dates from about the time of the inverse square law. Fascinating!

Friday afternoon the conference ended, we all anti-diffused back to our respective homes, and I to my hotel. The following morning I checked out and trained back to Boston, where I met yet more friends - this time a bunch of fellow expats, spoke my native tongue, and eventually wound up at the Boston Science Museum, where I spent a pleasant afternoon looking at frogs, spiders, and model ships. There's also some really cool Tesla coils there.

From there I walked to South Station, got to the airport, worked, ate, boarded a plane, and set off for home. The flight back was notable only for containing about 95% of the most antisocial fellow passengers I've ever encountered. I couldn't quite believe the extent to which about 20 passengers somehow managed to get up during take off, "crutch" off every seat as they constantly traipsed back and forth to the bathroom, took up space, time, made their discomfort everyone else's problem, and even shook the seats of sleeping (and previously screamy) children, even when asked specifically not to. The one next to me waited 4 hours until I fell asleep to wake me up to go to the bathroom, pissing off the flight attendant, waking up a sleeping family, and then doing it all again on his way back 10 minutes later. I couldn't wait to jump into LA traffic! How do we create a cultural meme of not being terrible at air travel, and enforce it? It would be 100x more pleasant for everyone if people just followed some basic guidelines, summed up by "be mindful about not being a selfish jerk". I wrote a script that performed surface minimization, then realized that what I really wanted was curvature minimization. Whoops! I will have to normalize by volume.

Fortunately I was back home safe and sound by about 1:20am, unpacked and asleep shortly thereafter! I never had any idea that my little hobby work with 3D printing work would ever lead to anything quite this exciting. But, overall, it's led to quite a lot of interesting stuff, including this incredible opportunity to meet and collaborate with so many amazing people! So my advice is to follow your interests and see where they end up!

Wednesday, June 22, 2016

Mars future hydrology

Some years ago, on a long flight to Australia, I first tried to solve the problem of modelling catchments. I'd been aware of this issue since my mid teens, and thought one method might be some kind of fall-line integration to determine the addressable catchment area of any particular point, and extrapolate flow from that. 

Full paper: http://arxiv.org/pdf/1606.05224.pdf

Of course, the obvious place to apply this concept was Mars, which might not have traditional multi-scale catchments, so I needed a more robust algorithm. It seems pretty obvious that a pile of water will spread out. Indeed, during the development of this project, I saw this effect first hand when my apartment flooded. Things that spread out with time, or bunch together, can usually be modelled with the diffusion equation, and there I got stuck. Imposition of topography caused my depth parameter to misbehave, losing stability and frequently going negative.

Fast forward a few years and one night I sit bolt upright in bed, I have figured out a way to make this work. The trick is to use the diffusion equation but apply the brakes before it gets out of hand. You don't need to write an algorithm that solves dozens of special cases or does some kind of filtering or any of the usual tricks. You just have to check what water is going where and compare it to how much there already is. Perhaps the blockchain could solve this problem, but I didn't think of it then.

After a few hours of work it was essentially complete. I threw in a maximally simple precipitation model and ran it to equilibrium. I tried a variety of different water depths and precipitation levels, eventually settling on a dataset which showed a broad variety of underlying behaviour.

The central question I wanted to answer was inspired by Kim Stanley Robinson's epic Mars terraforming novels, in which one character casually imagines that the southern region of Mars is poorly drained, like the Canadian shield, and would probably just mostly fill up with water, which would become ice, reflect heat, crash the climate, and use up a lot of Mars' limited water supplies which are more useful at lower altitudes. The southern region is, of course, mostly made of craters. I later discovered that the presence of the high altitude Tharsis massif on the Martian equator basically guarantees a icebox/snowball instability anyway, but our gigantic orbital mirrors will have to be used for something. 

If the southern craters filled with water, some may overflow and cut channels through their rims, substantially draining them. If this could be done quickly enough, perhaps the planet wouldn't turn into a snowball of sadness. Fortunately, flow rate and underlying topographic gradient is a pretty good indicator of erosion rate, so I prepared this figure showing the best rapids/waterfalls in bright red. 


Whoever engineers the greenhouse effect that gets Mars THIS warm and wet can basically have the whole planet - I'm that impressed. Because I was running this in a slow, memory inefficient language, my resolution was fundamentally limited. If anyone is interested, datasets with literally 1000x more pixels are available, I would love to have a poster-quality version of this figure, but don't currently have the time to develop it myself.

My original idea was to zoom in on a region of interest, freeze the boundary conditions, find a higher resolution map, iterate, and then subtract material as though erosion was occurring, and see how drainage patterns shift. Instead, when I checked the high resolution data, I found that the erosion had already occurred. Spooky, I know!

This was super cool, because it meant my model had just become predictive and was potentially publishable. Time will tell in that regard. As far as I can tell, it's the first quantitative speculative hydrology simulation of another planet under a terraforming scenario. Mars is also the only planet where doing this makes sense, because we have both high resolution data and it could (and has) had liquid water on the surface. Titan and perhaps Venus are also possible, but we await laser mapping! And some day, extrasolar planets!

So, rest assured, even though Mars looks like a hydrological disaster, most of it will drain sensibly to one of three oceans or seas, visible in the image above!


Flying through Death Valley

Last Sunday my friend G and I crawled out of bed at 3:30am. For summer mountain/desert flying, the early bird gets the worm.


By 5am we were on our way, 6am refueling at the 'last services' at Daggett airport. Not long after we turned left at Baker and proceeded to fly through every single valley in the Eastern Sierra Fault Zone. Our route took us up the Amargosa valley past Tecopa, Shoshone, and Death Valley Junction, cut down over Zabriskie point, Badwater, and Furnace Creek, passed Salt Creek, the Mesquite dunes, Stovepipe Wells, Scotty's Castle, Ubehebe Crater, Tea Kettle Junction, and Racetrack Playa. Here I demolished a Clif Bar as we dropped into Saline Valley. 

We flew over the Chicken Strip and hot springs, cruised up the Eureka Valley, turned left into Deep Springs Valley, and saw the remains of the Alma radio telescope. Before us the Sierras loomed to 14000 feet, and the Wacoba lake beds shored up the Inyo/White Mountains. We passed Bishop, Hamill, and crossed over to the Mono Basin at 10,500 feet above sea level. We continued north until Bridgeport and Bodie were in view, then turned back south into the only headwind of the whole flight, crossing into the Long Valley Caldera with the Mono craters on our right, checking out the various hot creeks and landing at Mammoth Yosemite Airport, right beneath the awe inspiring Convict Lake roof pendant.

We watered the thirsty bird and once more took to the air, passing Lake Crowley and Bishop, then cruising down the Owen's valley past Big Pine, Independence, Manzanar, Lone Pine, and Owen's Lake. Here we turned left, crossed the Darwin Plateau, and flew the length of the Panamint Valley. With a quick diversion to check the state of the road connecting to Death Valley south of Telescope Peak, we popped over into the Trona valley, cruised past the pans and the pinnacles, before climbing up over the Edwards AFB restricted area and setting course for home. Once over Santa Anita racetrack I idled the engine and practiced a glide back to the airport, landing just a few minutes after 2pm, with 16.8g of fuel remaining.

I have been planning to do this flight for more than a year - finally the weather was just right: clear, and calm, to do the entire thing in one go. All I need now is a faster plane!

Tuesday, May 24, 2016

Gliding adventure

Photos: https://picasaweb.google.com/105494084231616659850/6287271869386479233

A couple of weeks ago, my friend S suggested we go a-flying together. So, ready for a nice, relaxing weekend with nothing too stressful or tiring, I woke up at 5am on Saturday, went to the airport, jumped in a plane, and flew to Hayward airport, near San Francisco.

The >3 hour flight up was uneventful save for some bumps at 6000MSL over Pasadena which neatly resorted all my gear in the back. At HWD, I refueled, S jumped in, and we motored off low and loud over some large houses on inconveniently tall hills. We managed to overtake a helicopter before landing at Williams gliderport, a little haven of peace and quiet amongst the fertile fields of the central valley. 

I relaxed in the shade between comatose dogs, ate some food, and then in the afternoon took a quick gliding lesson. S also flew a couple of times, and was dangerously close to going solo! That evening we managed to find a diner with theoretically optimal decor, went for a quick run, then passed out gloriously.

The following morning we were considering driving to Willow, just down the road for breakfast. Says me, "why drive when you can fly?" and of course mine was the only plane that could seat S, me, and our CFI. So off we went, and 20 minutes later were tucking into some tasty tasty food. 

Dodging crop dusters we headed back to Williams where the wind pushed me down the runway not quite as far as my brakes were able to stop us, parked, and prepared for the next lesson. S clambered into a trusty ASK 23, prepped for tow, and disappeared into the distance. Her CFI and I stayed on the ground, suffering terribly in the spectacular weather (Mt Shasta was visible on the horizon) while S circled and, eventually, brought the plane in for a textbook landing.

We distracted her with a photo while the gliderport operator snuck up behind with a bucket of water and performed the traditional baptismal rite.

Not long after we packed the plane, clambered in, and headed off to Davis via Sutter Buttes. At Davis we skipped lunch to talk with my friends V and N(A?) and their adorable tiny human S, before heading back to Hayward, refueling, and setting course for home.

I climbed to cruising altitude, set the trim, and turned on radio-sing-all-the-songs-I-can-remember, starting with Pirates of Penzance. With a strengthening tailwind I was over Pasadena in barely 150 minutes, whereupon I idled the engine and glided out of 9500MSL to land. 

Back on terrafirma I tallied my logbook and had surpassed 210 hours as PIC. I didn't fly for another 4 weeks to make up for it - some time the following day my brain finally stopped buzzing around my skull. 

Gliding is terrific. I would like to do more of it, and may well head in that direction in personal piloting development. But that evening I went home and packed my stuff - I was moving the following weekend!

Wednesday, April 13, 2016

J visits LA

My cousin L recently married his wonderful ex-fiancee N, and L's brother J dropped in to visit me in LA. Now that I'm a full time grown up, I don't have quite as much flexibility to destroy guests as I enjoyed in grad school, but I did my level best.

J took the red eye, arriving Friday morning. Chilled in Venice, then headed over to my office in the LA Arts District in the afternoon, just after SpaceX successfully landed their rocket on a boat.


We toured Hyperloop, ate some snacks, cleaned up a bit and took a Lyft to Hot Pot, where we were eventually joined by no less than five members of the Nerd Brigade, C, T, C, J, and V. J later remarked that he'd never been the company of so many PhDs before. He was well into his second wind, fighting back jetlag with oodles of noodles. The conversation ranged the gamut, including a discussion of shark week vs primate month. Eventually we staggered from the restaurant (which sadly lacked mermaids and mariachi bands on this occasion) and returned home. 

The following morning, after a slow start, we did some house hunting for me, as I have to find a new place to live in the relatively near future. On the way, we saw a shiny Tesla Model X, which was the second most exciting Elon Musk-related thing to occur that weekend. 

The Tesla Model X is an incredible technical achievement. I don't have scope here to describe it, but it's as far beyond the S as the S was beyond all other cars.

That evening we went to Yuri's Night LA, a space themed party under the Endeavor Space Shuttle at the local science museum. Buzz Aldrin was going to be present, which mandated that we wear suits. I spent whole minutes finding the optimal bow tie.

The exhibit is new and a bit sparse, but that didn't stop us from finding some storm troopers and catching up with lots of space nerd friends.

Before the dance party (featuring numerous Kerbals) got underway, we took a stroll through the conservatory and found Buzz Aldrin himself. A quick bit of legit social engineering and he was kind enough to spend about 20 minutes telling us about his take on using lunar resources in halo orbits for refueling. His manager C managed to get this pic of us examining my 3D printed Mars ring. The yellow jacketed fellow is the CEO of Virgin Galactic, another space-tourism and launch oriented company.

We danced for a bit and then headed for home. 

On Sunday, we were at a copious loose end, so we decided to fly to an island to get some lunch.


It was quite nice. A bird flew over to eat some crumbs.

And we decided to bail out before the clouds got any lower. We cruised back towards my home airport, when the weather radio told us the runway was closed. We flew past for a close look - there was a plane stuck in the middle surrounded by vehicles. We landed at a nearby airport instead, clocking 200 hours as PIC somewhere in the middle there. Took a Lyft back to the main airport to retrieve the car, and while we were there decided to have a sticky beak.

This is an example of a classic and very common mistake of landing with the wheels up. In this case, a crane had lifted it up to drop the wheels out, but the prop is destroyed and the engine totalled. Will likely spell the end of this plane's life too - $50,000 unlikely to be had easily. Plane occupants almost certainly unharmed, save for facepalm injuries. Before the airport manager chased us away, I snapped a selfie - one doesn't often get to walk out on the runway!

On the way back, we saw some crazy peacocks.

Sushi for dinner, before J headed to LAX, properly exhausted!