Sunday, December 4, 2016

14 days to have a relaxing holiday.

2016 trip to New Zealand

Regular readers may note that of late my holidays have been somewhat compressed. In this blog I will describe how C and I filled 14 days away from Los Angeles.

On Saturday November 12 I woke exhausted. All I had to do was pack, complete a six hour dance rehearsal, eat dinner, clean the house, then go to the airport. The checking agent was in training and said "You're in seat F, which is not window, not aisle... it's nothing. Ooops." Said I "Did you accidentally upgrade me to first class?" Alas, it was not to be. Seat F, on this particular aircraft, was in the exact middle of the plane. I felt like the world was turning around me, noone climbed over me, and I slept like a baby.

The following day, Sunday, was my sister A's birthday, but thanks to the international dateline, I did not have to observe it. Instead, I landed in Brisbane on Monday, stumbled through immigration, and attempted to pick up my rental car. My credit card fraud division helpfully blocked my card, although (as usual) I booked the relevant flights with the same card. Get on it, people! Needless to say I couldn't recharge my Australian card with a broken credit card, but I eventually broke the cycle of endless pain, and drove at the ludicrously low speed limit south to the border. On entering NSW, I turned the clock forward one hour and 20 years, picked up some groceries, and made my way to one of the old family farms in Huonbrook. 

I was dismayed to find that all the chickens had been eaten by snakes, but I spent the next two days cataloguing everything, from the platypus pool to the spring to the solar power system to ancient photos going back to my grandmother's grandmother. The house belonged to my grandmother's sister R, who passed abruptly a few months ago. 

At about the same time, it wasn't entirely clear if my fiance C would be able to get out of the South Pole where mostly weather had trapped her. If she was delayed a week, I would cancel my trip to Christchurch and fly instead to Canberra where my brother is operating on people. At the very last minute I heard that one of the key flights made it to the South Pole, so I resolved that optimism would triumph and, early on Wednesday morning, headed back to the airport. 

On arrival in New Zealand, I saw the effects of various recent earthquakes, including one from a few days before. During my time in Christchurch I felt about half a dozen aftershocks, which is more than I've felt during my six years in LA. I checked into an AirBnB where my host was a 3D printing enthusiast with a pet talking parrot. Over the next day or so I explored the city, which has been mostly destroyed (and since very partially rebuilt) since my previous visit about 15 years ago.

On Thursday evening I headed back to the airport and, on Friday morning only one day after we initially guessed, C arrived! She only smelled lightly of jet fuel, and was beside herself with excitement, mostly at the prospect of unlimited showers and 24 hour internet. 

The earthquake had thrown our previous plans into disarray, so instead we picked up a rental and headed south into the remote and sparsely populated mountains of the South Island. Over the next few days we stayed at a series of gorgeous lakeside towns, including Tekapo, Wanaka, Queenstown, and even drove across the mountains to Haast for a trip to the beach. Our mission to locate penguins was defeated by sandflies, so we took out some kayaks and paddled through the wind and scattered rain for a few hours. 

We did numerous side trips to various lakes (for skimming rocks) and forests (for examining moss and waterfalls) and in general just had a bloody marvellous time. We checked weather forecasts for Milford Sound and tried to be clever, taking a plane from Queenstown. In the end we were defeated by low cloud, so settled for a quick zoom down the Shotover River gorges in the quiet, peaceful jet boats, followed by a haircut, trip to the laundry, and zoom up the hill to the Overlook Restaurant, where we ate dinner as the sun set over the lake. We followed this with a hike among the wildling pines, then finally got some rest.

The following day we flew to Auckland, drove to Parakai hot springs, checked out their local aerodrome, soaked in the geological water, made dinner, and got some sleep. The following morning we checked out as the police arrested someone else staying at the hotel, drove back to Auckland, and had an amazing tour of Rocket Lab, a New Zealand-originated company that is building the Electron, one of the world's cutest rockets. It got started as a backyard inventor (Peter Beck) building rockets for his motorbike and has now developed into one of the only surviving microlaunch companies. They're focusing on hundreds of launches of small sats to Low Earth Orbit, at $4.9m/launch, and it was really amazing to see what they were up to. One of the most interesting aspects of the Electron is that its turbopumps are powered by electric motors. It turns out that with current batterytechnology, this constrains the overall size of the rocket to smaller payloads. These days most satellites are getting smaller as companies try to iterate the technology more rapidly.

We found lunch, C did an interview, then we headed for our next hotel in the hills to the west of Auckland. I thought there might be a nice walk to a beach near Piha, and I wasn't wrong. The hike started as an easy stroll throught the coastal scrub, before it became a near vertical series of boulder problems which eventually deposited us on an empty beach surrounded by gigantic cliffs. A waterfall tumbled down and flowed into a dark cave, from which we could hear the roar of the surf. The hike back up was faster than the descent but rather hard going. Back at the hotel we had the most amazing dinner and explored the grounds rather thoroughly.

Up until this point we had been extremely lucky with the weather, mostly skipping town just as the rain came in. Finally, it caught up with us. The next morning, it thundered down. We went on a deceptively long hike to a nearby waterfall with one rain jacket between two. By the time we got back to the car I was rather soggy, but the waterfall itself was spectacular. 

The next stop on the agenda was the Auckland Zoo, where we spent most of our time exploring the exhibit on New Zealand animals. We saw a Kiwi! It was rather large, like a soccer ball with feathery fur and a spectacularly long beak. We also saw some little penguins, which were just adorable. 

That evening we checked into our last hotel for New Zealand, splashed about in their pool, tested the pillow menu against pillow fights, and got lost in a room considerably larger than my house. We ate yet another spectacular vegan dinner, closely followed by a spectacular breakfast, both at Hectors restaurant, then headed once more for the airport.

We had a 16 hour layover in Sydney, during which we found various Australian animals (kangaroo, quokka, platypus, echidna, koala, bilby, wallaby, etc) and ate a great dinner with my parents. The following morning we headed to the airport for the last time, found a friendly looking plane, and headed back to the states. The flight was uneventful, and I got through secondary screening in a record 13 minutes. We followed that with a Lyft back to Pasadena in a near-record 26 minutes. As I write this I'm surrounded by the detritus of unpacking and moving, as C and I are moving in together! 

That, dear reader, is how one can spend 14 days, six hours, and one minute in luxurious relaxation!

Thursday, September 29, 2016

SpaceX Mars plan analysis

Update: Try your own simulations of Mars EDL with my code:

On September 27, 2016, SpaceX finally revealed their Mars transportation architecture ( It was a very exciting moment. Regular readers will know that I have engaged in idle speculation on the topic, and I was gratified to see I got the details mostly right, though their system is a lot larger (up to 450T cargo!) than what I initially had in mind. If you're interested, see my best guess from 2015:
That said, I would be very surprised if the final product looks much like what we saw today, especially for the ship. The architecture presented is fairly conceptual, especially on some of the less mass-affected issues.
With that in mind, what SpaceX presented today can be broken down into a few different parts: a conceptual concept of operations (conops), a CAD draft and pretty animations, and most enticingly, early demos of core tech. Let's look at each in turn, and I'm going to assume familiarity with the presentation: .
The architecture is designed around the principle of "cheaper is better" which almost always drives "simpler is better". Yes, it is possible to get more mass (maybe) with less fuel if there is an intermediate stage or multiple cores, but the most overlooked handle is the size of the rocket. Mars requires a developing a new super heavy lift rocket anyway, so it may as well be BIG! The SpaceX booster, with a nominal 550T to LEO capacity, fits the bill. 
Having total reusability drives a big Mars vehicle that can fly from Mars back to Earth with a single stage, requiring about 8km/s of delta-V. Indeed both ship, tanker, and booster can fly single stage to orbit on Earth, albeit with no payload. The same Mars vehicle also has to perform entry descent and landing on Mars, and has enough fuel to fly from Earth LEO to Mars, and from a suborbital boost to LEO. This means it has to be refueled along the way: In orbit by 3-5 tanker flights, depending on how the masses wash out down the line, and on the surface of Mars. The rest of the presented masses and thrusts all check out. The engine clustering on the ship is an interesting approach, with 6 vacuum engines and 3 sea level engines (smaller bells). Thrust wise, sea level engines are only needed to land on Earth or under high dynamic pressure on Mars, and one is plenty. Three provides some redundancy, and may figure in some launch abort scenario. Mars is so close to vacuum that the vacuum raptors will work there too. Given that landing on Earth happens at the very end, it may even be possible to detach part of the expansion bell so that the vacuum raptor engines can function in the Earth's atmosphere.
Areas that were light on detail include the transition to powered flight during descent on Mars (or Earth). The video showed it nosing up indefinitely, though that would require terrific pitch authority and amazing anti-slosh fuel tank baffles. Downmass capability on Mars is driven by aerodynamic constraints, so I ran the SpaceX sizes and masses through my Mars EDL simulator:

(Click to expand) Left panel: Historical data from robotic missions, showing Mars entry profiles. Parachute descent typically commences in the bottom left at around 500m/s. Central panel: Results from my ballistic motion simulation reproducing behaviour of previous landings, validating the code. Right panel: Entry profiles of several hypothetical future Mars vehicles, with Curiosity for reference. LDSD levels out a little higher (depending on total loading), while Red Dragon needs a significant mass offset to achieve enough lift to not hit the ground. The three curves marked ITA (Interplanetary Transportation Architecture) represent different lift parameters for the SpaceX ship. Horizontal flight represents banked turns to prevent multiple skips out of the atmosphere. Their high lift and high entry speed compensate for their high mass, and they don't get too close to the ground. Mars' highest mountains are >20,000m tall.

I was pleased to see that despite the high mass (up to 800T) the high entry speed, generous cross section, and lifting body concept results in an entry profile that doesn't involve a compulsory crater. Thermally speaking, SpaceX claimed a maximum temp on entry of 1700C, which seems a little low. If PICA can endure 1.2kW/cm^2 heat load, that implies a peak heat shield temperature of about 3800K, given a sensible surface emissivity. A fully loaded ship decelerating at 6gs is dissipating more like 67kW/cm^2, but most of that turns into a very hot, shiny, pretty wake like a shooting star.
Similarly, the propellant farm was presented as a series of chemical reactions, without specifics on mass, efficiency or output rate. About a megawatt of electrical power, continuous, is required to refuel the ship on Mars is a single year (365 days). Most of this power is spent on electrolysis. A solar array capable of producing this (without tracking) would be around 10,000m^2, which is not impossibly large. Solar panels are virtuous, in the mass sense, since they can be made practically two dimensional. 

CAD Models
The CAD models look great, but clearly represent an early draft. The interior space of the crewed module is a bit spartan (needs bulkheads), while the oxygen feed lines to the 42 raptor engine cluster look a lot like a brain angiogram scan. Getting prop feed to 42 engines that are throttling and pogoing, across a giant thrust structure trampoline, while damping every instability and cavitation, sounds like a nightmare/worthy engineering challenge to me.
Similarly, I'm not convinced about the giant window or the downward facing aero strakes, but these parts are less important at this time. The long lead stuff is engines and tanks, and those parts in the CAD are nicely specced out. 

Core Tech Demos
This was the most exciting part by far. The reusable architecture calls for single stage return from Mars. It's all very well to draw spaceships (spaceship!) all day long, but when the rubber hits the road, the system requires a monster engine, as well as fuel tanks with practically imaginary mass. That's a good place to start, and that's what SpaceX has been working on.
I don't know enough to comment on their carbon fiber fuel tank prototype (though I liked the chandelier), so I'll focus on the engine. The Raptor engine has haunted my dreams for years. Unlike the rest of the architecture, here cheaper does not drive simpler, at least at the combustion cycle level. When it comes to high efficiency, the Raptor uses every trick in the book and probably a few that aren't written down yet.
These include full flow staged combustion, multi stage pumps, very high chamber pressure, and the latest in materials and manufacturing tech. Big moving parts in this engine have to withstand high pressure high temperature preburned (ionized) oxygen, which makes a lava-proof submarine look easy by comparison.
And to their credit, SpaceX designed and built the hardware, and showed a video of a short test firing, probably at around the 20% thrust level. Obviously, the engine is far from qualified. But a working demo is a long way from a paper study, it convincingly demonstrates that SpaceX has world leading vision and core competence in rocket engine design.
Final Thoughts
The SpaceX Mars plan is a compelling vision for moving lots of humans to Mars. A complete system will be much more detailed and probably a bit different, but importantly this lays a technical foundation and is a great starting point for future system discussions.
To read more about these and other technical challenges facing crewed Mars exploration, check out my book "How to get to Earth from Mars" at .

Sunday, September 25, 2016

Mars Society Talk: Confronting the Credibility Gap for Crewed Exploration of Mars

Confronting the Credibility Gap for Crewed Exploration of Mars
(Notes from talk on September 22, 2016, at the Mars Society Conference. YouTube video!)

Look at this amazing picture of Mars! I don't think I have to try very hard to convince you that it would be cool to stand in Gale Crater and look through the haze towards Mt Sharp. But to achieve our goal and send humans to Mars we have to convince a lot more people, and that's what I'm here to talk about today.

First, a bit of information about me. I did a PhD on gravitational waves at Caltech, and got an opportunity to sword fight with my collaborator. More recently I'm the levitation engineer at Hyperloop One, where we're building high speed vacuum trains. On Mars, I made this neat 3D printed ring and then later did some research into emergent flow networks using MOLA data. The Mars crust has deformed, the geoid has changed, and so the rivers don't always go the way you might expect. (arXiv:1606.05224)
So, I'm here to talk about a difficult issue, but I'm not here to criticize pointlessly. It's easy to be negative. I am overwhelmingly enthusiastic about Mars exploration and extended habitation. The credibility gap amongst Mars crewed exploration advocates is a serious issue that hampers that effort. It's vitally important to raise our profile among the general public, since ultimately they will foot the bill, and in general opinions on crewed space exploration range from ignorance to ambivalence to skepticism. And this is not entirely unwarranted. I'm going to talk about three different aspects of credibility, working from the outside in. First, I'm going to talk about public credibility, as mediated by an occasionally unreliable or sensationalist media. Second, I'm going to talk about mixed messaging within the space community, and reconciling authority with humanity. Last, I'm going to offer a couple of illustrative examples to point out that there are still serious unsolved problems relating to crewed exploration, namely entry descent and landing (EDL) and earth return. We have to be more internally and externally honest about confronting our ignorance in this regard.

First up, let's talk about the role of media. Mars One is a perfect case study. More publicity than any other human Mars mission has gotten in years, and also completely vacuous. I googled "Mars One credibility" and got 189,000 hits. The first 6 hits include how Bas Lansdorp, the CEO of Mars One, whose only job is to know everything about putting people on Mars and keeping them alive, got absolutely smashed here in a debate with MIT students last year. "Do you realise the astronauts will run out of nitrogen on day 59 and die?" So Mars One isn't really funny, it has probably set back the credibility of the movement by a decade. Hype, opacity, haste, are all hallmarks of counterproductive media strategy. There is a dark side to publicity.

Let's look at a few examples of imperfect media coverage. Here are two cases from the recent, and highly flawed study suggesting that space radiation caused heart disease in the handful of Apollo astronauts who already died - at rather advanced ages, given their lifestyles! What blew my mind here is that there is not one, but two different stock photos of depressed astronauts in space suits. The ultimate slow news day is hand wringing about radiation or wishy washy psych factors.

The other major kind of shonky coverage covers mythical propulsion. The idea is that spending 6 months getting there is too long, so we can't go until we have warp drive. And so we have articles about actual warp drive. I did my PhD on this sort of thing, not only is it complete garbage, even if it wasn't, it would still be extremely inefficient. Yet these articles have images where we know how many windows the spaceship has! We also have "Mars in three days", from 1g acceleration the whole way with lasers a million million times more powerful than any existing laser, and no mention of how to slow down, how to get back, or how to handle the thermal issues of being shot with the death star. And then you have the EM/reactionless drive, which is less efficient than a Hall effect thruster, and also impossible. Not to mention the VASIMR thruster, about which no-one ever mentions the need for gigantic gigawatt scale space nuclear reactors. Sure, it's cool and an interesting propulsion system to research, but the full picture should be available.
Of course, it's not all bad. A lot of these articles are actually pretty good, the headline just refers to the most controversial aspect of the article to be click baity. The writers aren't bad people, to be writing about Mars already they're one of us, maybe they just need some expert help. I reached out to the writers of the articles I referred to and one of them has already gotten back to me. Which leads me to a deeper point - it's easy to sit in the ivory tower and criticise, what I'm trying to do is show that communication between the general public and the experts is mediated by the media, and we can collate the information better. Sometimes they even get it unbelievably right - how good was The Martian? The first step is to take the Socratic approach (no longer punishable by death) and ask questions. Search Google, Quora, or even the Mars Society Facebook page. And, if you want to be told you're wrong by a thousand people, you can try Twitter.

So, what are warning signs an article is probably bullshit? Does it violate laws of physics? Does it promote transit times of less than 90 days? Does it involve warp drive? What about content-free hand-wringing over psych factors? No-one is saying that psych factors aren't an issue for crews in space for years at a time, but there's a gulf of credibility between the typical slow news day and some actual serious stuff backed by real data. Does the article have no quotations or endorsements from recognized experts? Does it have no reference to peer reviewed papers? Does it have a naked agenda, or uncritical reporting? Lastly, does the headline ask a rhetorical question to which there is an obvious answer: No!?

What can we do to help? Reach out and if you're an expert, make sure your local writers have you on their rolodex. If you like working with writers, consider joining the Science and Entertainment Exchange. Many of my colleagues have consulted on Marvel Movies, and it's always a lot of fun getting a whispered phone call at 2am saying "you're a physicist, how can I destroy the world?" "well, strictly between you and me…"

So we can help improve media coverage, and our problems are solved, right? Well, not really. It's easy to criticise, but it's unfair to do so without also taking a hard look at our own internal messaging. Even the pros make mistakes, and we need to be honest and circumspect about it. To what extent are we responsible for the credibility gap? We should know better than anyone that there are real challenges that can't be wished away, that Mars is hard, and that "all you gotta do" doesn't really cut it when human lives are on the line. Yes, humans will die in space, and on the ground building space machines, but I'm sure we can all agree that we want to minimize people dying for stupid reasons. And so, as a couple of illustrative examples, I'm going to look at the titans of the movement and nitpick for a bit. First, Elon Musk's suggestion that space radiation can be solved with a column of water between the astronaut and the sun. This only works if the column is of a comparable size to the gyroradius of protons in the solar magnetic field, which is a few thousand km. So, the pros sometimes make mistakes, as we saw with SpaceX's last attempted launch. And then the original slides for Mars Direct, I saw as a kid when the Mars Direct book tour came to Australia, which suggested a first launch in 1997. We earn no credibility by pushing optimistic or aggressive timelines. Or, for example, our own Robert Zubrin's oped in 2012 in the Washington Post, suggesting 3 Falcon Heavies to fly 2 humans to Mars, a mission plan that no expert I know hasn't found a problem with. The Dragons are too heavy to land on Mars, and too crowded for people to live in, once all the provisions are also added, like Gemini but for 150 weeks instead of 2. It doesn't pass the sniff test - it smells of desperation. Falcon Heavy is a terrific rocket, but it's not for humans to Mars, or back.

At the end of the day, though, Elon or Bob miscommunicating some small aspect of a hypothetical mission is not the end of the Earth. It's easy to be critical, let's be constructive. Let's go one level deeper and look at two giant issues which are recognized but mostly unsolved, that of EDL and Earth Return. Rob Manning (JPL chief engineer of Pathfinder, MSL, and LDSD) held a series of conferences at JPL starting in 2004, recounted in Chapter 5 of his enjoyable book. At these conferences, the EDL challenge was recognized, defined, explored, and even now, 12 years later, there is no dominant, obvious solution architecture. A lot of the proposed solutions will be covered in the following talk by Kshitij Mall, so instead I'm going to describe only the problem. A great book if you are looking for a description of the state of the art is (MSL's EDL lead) Adam Stelzner's "The Right Kind of Crazy".

What is the EDL problem? We don't know how to land more than about 1T on the Martian surface. We obviously need to land 10-100T for human missions. Existing solutions do not scale. Without >10T landing, we have no Mars ascent vehicle, we have no ability to return to Earth, so we have no program. This is a serious issue! Entry, descent, and landing is composed of 3 parts. The entry part is where a heat shield is used to slow down from 5.7km/s, which is escape velocity, to terminal velocity, which is around 500m/s or Mach 2. This procedure burns off more than 99% of the kinetic energy, and the limiting factor is that Mars' atmosphere is really thin. The ballistic coefficient is a measure of surface density, or 'thickness', defined as the mass divided by the heat shield surface area. For all successful landers, it has been very very low, between 60 and 150kg/m^2. If we imagine a heatshield as big as the biggest payload fairing we can imagine, maybe 11m diameter, then we have a vehicle on the surface of perhaps 11T, which is really too low. This methodology, a gigantic flat flying saucer, has no headroom. Blunt bodies do not scale to 10T-100T range - there is simply not enough atmosphere to slow you down before you hit some tall mountain. There have been a few attempts (ADEPT, LDSD) to increase the size of the heat shield, but they are marginal, structurally problematic, relatively unguided, and have poor scaling characteristics. We need a new approach to entry. Bi/triconic hypersonic lifting bodies are, in my opinion, our best hope.

The good news is that landing, under subsonic propulsion, does scale extremely well. But there is still the descent problem. At 500m/s, the vehicle is still supersonic, which complicates propulsion. Heritage solutions use a gigantic supersonic parachute originally developed for Viking. The key issue is that parachutes also don't scale. They don't scale on mass, on timeline, or peak structural loads. On mass, it's pretty clear that the shroud cross section scales with vehicle mass, as does the canopy area, so the mass has to scale at least as vehicle mass to the 1.5. For 10T-100T payloads, we're talking a parachute the size of a stadium, since the Kerbal approach doesn't work where parachutes are made of fermions that obey the Pauli exclusion principle. A parachute of this size, mass aside, can't inflate fast enough to catch the vehicle before it makes a rather small but deeply unfortunately crater. And last, even if these scaling arguments were acceptable, all of LDSD's parachutes, at only 26m diameter still broke, for reasons we do not fully understand. There are potential solutions, SpaceX seems to be serious about supersonic retropropulsion, but nothing that's understood for certain, and it does our movement no favours to pretend that every problem, including these problems, are trivial.
The second major unsolved engineering issue to cover is Earth return. Of the three phases of a crewed exploration mission, outbound, surface, and return, return is by far the hardest. Deep space life support, razor thin margins, tiny mass allowances, long term machine reliability, completely unsupported launch ops, no indigenous industrial capacity whatever. Broadly speaking, there are two potential Earth return architectures. One is a tiny, even LESS-sized vehicle to fly to Mars orbit and rendezvous with a vehicle big enough to contain humans for 6 months to get home, which has to carry a lot of fuel and generally be a battlestar galactica. The other approach is direct Earth return from the surface of Mars. While on the one hand you need a much larger vehicle, you can't get away from 30T landings anyway. So you have to solve the EDL problem. And on the plus side you don't have some orbiting autonomous platform, orbital rendezvous, and Mars is the easiest place to get return fuel, by far. That said, even in Mars Direct, the Earth return vehicle (ERV) architecture is not explicitly sketched out, though clearly the vehicle is a lot smaller and the margins a lot tighter than the outbound voyage. On the plus side, it may be just possible to fly back from Mars with a single stage, which greatly simplifies vehicle architecture.

There remains a substantial credibility gap in crewed Mars exploration, but I hope I've sketched a set of ideas for improving the discourse going forward, both on a public and internal messaging level. I've been writing a (free!) book on these and other as-yet-unsolved crewed Mars mission engineering challenges and I encourage you to read it, leave comments and questions, and help us get specific! It can be found at .

Tuesday, September 13, 2016

Returning to Russia for the Eastern Economic Forum

Last week I returned to Russia, albeit briefly. It was very unexpected and under odd circumstances, but I got sent there for work! Last week was the Eastern Economic Forum, an effort by the Russian government to encourage foreign investment. Because I was taking a detour from the China trip, my sister A got to come along too!


At the end of the China (previous) blog, we had eaten lunch in Seoul. There we got extra security screening, found a transfer desk, a bright green plane, and took a flight to Vladivostok, in the Russian Far East.

Vladivostok is a remarkable city, on the other end of the trans-Siberian Railway. It overlooks the Pacific from a series of gigantic hills which are still not quite overwhelmed by rapidly developing high-rise buildings.

We took a taxi from the airport, found our hotel, and checked in, all without incident. Then we found a nice restaurant just across the road and settled in for a series of small dinners.

I first traveled to Vladivostok about 10 years ago, then again 6 years ago. On both trips I made many friends all over the enormous country, but the very first one I had lost touch with. And there, in the restaurant, was someone who looked just like them. But wasn't, as it turned out when I asked their name! Still, that would have been cool.

We had 5 days in town, due to flights being booked out for the Forum. So we had most of a free day before having to Suit Up and Look Serious. I thought that walking through the whole town was a sensible substitute for breakfast so, raincoat in hand, that's what we did.

It was the first day at school, so the streets were covered in children with flowers for their teachers and bows in their hair. It was rainy and there were puddles everywhere!

We saw most of the town's sights, including cats in Sportivnaya Harbour, the mall, the submarine, and a little church, where the poor babushka couldn't decide to yell at my sandals or Annie's hair first.

We hailed a cab and ventured out of town to my friends place. A2 and A3 I had met 6 years (to the day) previously during a previous trip, and it was cool to find old friends again! They had a daughter, Z, who was very entertaining. A2's English took about 5 seconds to get warmed up and we were back to making rhyming puns, just like old times. They gave us some dumplings and some perspective on how Vladivostok had changed over the previous decade, certainly a lot had changed.

At length it was time to return to the hotel, get dressed for the governor's reception, and take a cab across both bridges to Russky Island, skirt security, and find our way to where the good food and 30 piece Jazz band was. It was a pretty good view, surrounded by all the buildings of the venue, looking across the bay to the main bridge, with a span exceeding 1km! 

The following day it was time to earn our keep so we made our shoes extra shiny and headed back to the venue, sampled the luncheon, watched some sessions on cargo transportation, and met one of the Hyperloop venture capitalist guys. We were ushered into another room where I took a seat next to the Russian transport minister and the head of Summa Group, a major Russian logistics/industrial company. A few deals were signed and we took some questions on the Hyperloop. I got to say a few words, alas not in Russian, and said something about how we looked forward to a combination of Russian steel and American technology to show the way in moving ship volumes of cargo at aeroplane speeds and ship prices. Fortunately, no-one asked any really difficult questions!

Duty discharged, we breathed a huge sigh of relief, borrowed some bikes and explored the campus. We found a fish market, some chatty volunteers, more dumplings, and our complimentary show bags, which contained lots of books, a (locked) tablet, and various Siberian teas. Eventually it was time to bail out so we headed back to the hotel, grabbed some dinner, and passed out.

The next morning, not all of my washed clothes were dry, so I hung them on a heated mobile drying apparatus - me - and went to the forum anyway. A and I found a session on attracting investment but began to suspect that the formal sessions were a screen for the real deal making that goes on in other, unadvertised, rooms, and decided to get into position for the plenary session. Starting only an hour late, I live tweeted it (, but it was quite fun. It featured Vladimir Putin, Park Geun-hye, and Shinzo Abe, moderated by Kevin Rudd, the former Australian prime minister. Most of the talk seem directed at each leader's respective domestic television news, but Kevin seems more keen on the UN top job. Shinzo seemed super keen to resolve the Kuril Island dispute and to sell Russia a bunch of tech, while Park continued to publicly ask the UN to enforce sanctions and resolutions against their recalcitrant northern neighbour. Putin was his usual self, keen to point out that Russia will only act in its national interest.

In particular, I thought it was interesting that in the context of the Kuril Island dispute, Putin was at pains to point out that there needed to be a face saving resolution, but that Russia would not trade territory for economic assistance. Of course, since 2014 and imposition of sanctions by the US and EU, Russia has been in dire economic straights. Putin complained about the fickle nature of the international community, in particular (though not explicitly) that the annexation of Crimea was not so different from the formation of Kosovo, but the outcome was rather different. Well, in real politik, Russia's actions in 2014 traded 10+ years of economic stagnation, particularly in the Far East, for some tiny scrap of territory on the Black Sea. So the trade does exist, in one direction, at least. More generally, the Far East's biggest deficit is in human capital. Putin pointed out that for the first time, ever, the Far East birth rate exceeded the death rate. But the emigration rate is still 3.5% per year. The population has halved in the last 25 years. I couldn't help thinking there's a lot of Syrians looking for a fresh start. Why have immigration controls at all, if you want to make up for 200,000 people leaving a year?

That afternoon we headed for the cafeteria, found a talk on the eastern Siberia spaceport, then wandered through all the exhibits picking up all the pamphlets we could ever need. Except from the Crimea-related tents, though they were by far the best funded! That evening we found a restaurant that specialized entirely in dumplings. By this point we realised every restaurant in Vladivostok sold small, cheap dinners, so you could serialize every meal, like Tapas, but with more walking. Dumpings are just a natural extension of this principle. We had to have every dessert on the menu.

The following morning was September 4, the 29th anniversary of my existence, so we spent the morning taking calls from various family, to the point where we missed our usual breakfast of 3D quantities of pancakes and Russian depth. We decided instead to feed the mind and wandered through slight drizzle to a museum nearby, a house which once belonged to Arseneev, a wanderer/adventurer/explorer type who lived there 120 years ago. His whole family died at one point or other from bandits, fires, or post-communist purges, but the house preserves a lot of detail from that period, and some very interesting stuff from his various explorations in the Ussuriland area, as well as some nice furniture.

Pancakes cannot be canceled, only delayed. We found a cafeteria devoted to them and proceeded to uphold the newly formed tradition of gluttonous consumption, followed a mere 30 minutes later by lunch at Zuma cafe, a very upmarket place with a modern Japanese bent and tasty sushi. We enjoyed a conversation with another local couchsurfer, called A(4!), before surveying some of the local shops in town. Soon enough, A2 and A3 showed up (sans Z) and we headed down towards the lighthouse, climbed a building to look at the view, skimmed some stones, and wallowed in nostalgia. It was the place I spent my last day in Russia 6 years before too. I have always liked wild shores, grey skies, slate seas, wind, mysterious sea birds, ambiguity of purpose, and lots of spikey rocks. A good place to celebrate a birthday!

Back in the center of the city we hit the regional museum, though I was saddened to see all the really cool exhibits on La Perouse and bears fighting tigers had been removed or replaced. Last time I checked there was a genuinely awesome museum in Khovd or Olgii, in Mongolia, I hope they haven't been 'updated'! We decided to go on one last walk through town, found the footings of the enormous bridge, examined various fixtures, got blown around, then back to the hotel to pack. 

That evening we had built up an enormous appetite so we returned to Brothers Bar and Grill and ordered 7 (tiny) dinners, then ate the lot. The table was already tall and the chairs short. After the meal, our eyes were level with the silverware. 

The following day I woke up early to call my fiance C, still at the South Pole, on the occasion of our anniversary. Really inconvenient that I wasn't born a day later, all things considered. A and I did one last walk down to the ship terminal to check for souvenirs, without much luck, and then checked out and headed for the airport. Given how long it took for the cab to show up, he drove extremely fast and cost quite a lot of money - perhaps $20 for the hour long trip. 

The airport was new since my previous visit, but the baked-in process disasters were familiar. Two lines for check in, neither able to handle Chinese speakers on a flight to Hong Kong, neither able to handle excess baggage, requiring a detour to two other counters to make sure everything was legit. And some local officials scratch their heads and wonder why it is that the rest of the world goes out of their way to avoid doing business there! The Russian Far East is an amazing place, contains amazing people, and harbours incomparable treasures in mineral, timber, etc, but bureaucratic inefficiency is like a gas, it expands to fill the space in which it is allowed to exist.

The flight to Hong Kong was uneventful. Immigration was swift and painless. We met our cousin A5 at the taxi rank, then went to his 3 story beach cottage on Lantau island, on impressively windy roads. We met A5's lovely wife R, and baby F, which I made sure to steal for a while. We had a terrific dinner, played with the dogs, and headed back to the airport.

At the gate, there was more than the usual trouble as 4 Cathay Pacific agents attempted to determine whether my EAC (temporary green card) was a thing. After 30 minutes, the aircraft was ready to depart, they decided to phone a friend, after which I was ushered onto the plane. On the flight I watched Steve Jobs, XMen Apocalypse, and Batman vs Superman, and managed to cry in all of them. Plenty of Michael Fassbender! Cathay has much nicer screens than American, but they use the in-armrest headphone jack, which gets damaged every time someone slides by, so basically doesn't work. Such a shame!

Back home in LA, I get to go to secondary immigration screening, as is usual. It's pretty late, how bad could it be? The room contains 65 (I counted) other people. Phones are strictly forbidden, I see 8 other people have them confiscated after trying to text panicking relatives. The agents say they can't be sure how long it will take. Some people take days. They just can't tell without looking at the documents, which are right in front of them. If their families are worried, they can get in touch via their embassy, they try to respond within 48 hours. People effectively disappear. I open a travel book to Kamchatka and day dream about running with the bears down rivers alive with salmon. An Indian woman with limited English is accused of lying about her financial resources. The agent threatens to take her 10 year old son into protective services. The guy one window over is trying to explain to his agent that he served 6 months for domestic violence somewhere in Indonesia, but it was 8 years ago. The agent has to check with his supervisor. When/if my green card is ever approved I'll write a detailed blog on the whole process. For all Russia's faults, there's a standardized fee for a business visa, with basically complete freedom of work and travel. 

About 75 minutes later, I'm called. What sort of visa am I? Self sponsored, national interest waiver. Very good, welcome home sir. I'm out. Back in the world, where people don't just disappear, where human dignity seems to exist, at least for people like me. I climb into a lyft and, despite it being 1am, get stuck in traffic for over an hour. Welcome home!

Here's where I usually write a summary paragraph of a trip. 6 days in Vladivostok was too long. The world is too big and yet not big enough. It was a mistake to go to the Russian Far East but not into the wilderness. It took 4 days of 12+ hours a night sleep to feel normal again. Still, it was very cool to be able to help push a project which embodies the hope of technology to make peoples' lives better.

Monday, September 12, 2016

A quick jaunt to China

Last week, I went to China for a couple of days! I woke up dazed and confused, put my rings on the wrong fingers, and headed for the airport. I saw the new SpaceX booster outside the factory on the way, got to LAX, checked in. Everyone seemed to have a terrifying quantity of luggage, including in some cases living creatures. Maybe I was still dreaming.
My flight was half full, so I immediately staked out three seats and then slept for the entire flight, waking only to eat. I felt that this was a good omen. I watched Captain America: Civil War, which was a real tear jerker. I always cry in films on planes.
Once on the ground I took the maglev into town at 301km/h, found my sister A at the Astor Place Hotel, and immediately headed back out of town to find the Hongqiao High Speed Rail station, which was extremely exciting, as it contained trains, which are some of my favourite things. Here we also found our parents M&D, went back to the hotel, wallowed in history for a bit, then headed out to an extravagant hotpot for dinner, on East Nanjing Road. Conversation was at least 60% how hard all the beds are.
The following day we got up and took a taxi to Fudan University, where A had been studying Chinese for a few weeks. We ate pancakes for breakfast, A checked out of her accommodation, we got some cash from a convenient ATM, and indulged in terrible puns. A took us for a tour of the campus, including a view from the tallest towers, a large statue of Mao, and some excellent beef noodles.
Not far from the university we found a gigantic shopping mall, which D and I attempted to catalog completely while the women conducted a shoe hunt. We wandered until we had lost all concept of space or time, then we wandered some more. We found the male bathrooms on the 6th level to be unusually clean, possibly because they'd never been used.
Next on the agenda was the silk market. Here the mission, I eventually determined, was to greet earlier vendors and conduct second fittings, to find new vendors, to discover new types of things to buy, to negotiate prices and a settlement to middle east conflict, to thoroughly audit every kind of cloth ever invented, twice, and to obtain a new lower bound for the radioactive lifetime of the proton.
At length we found the exit, wandered through a historical portion of "old shanghai", then headed back to the hotel, where I was still coming to terms with the Great Firewall of China. That evening we found one of the "old" "French" districts, located a place that did Peking duck, investigated fancy houses and a Tesla showroom, and then passed out on an approximately horizontal surface.
The next morning we discovered hotel breakfast in the Peacock Room, which was all you can eat 20 kinds of dumpings, then took a relatively terrifying taxi to the bus station. Here we found a robot that spun on its balls (see photos if you don't believe me!), then took a bus to Nanxun water town, a strategically important town on the grand canal that had existed in some for or other for over a thousand years, with its most impressive architecture dating from the very late 19th century. At one point it had one of the largest libraries in the world, and still retains a few canals, though is surrounded on all sides by the modern city. It is one of the smaller, less frequented water towns. Later that afternoon we took the bus back into the city, ate dinner at the Drunken Seagull or some similar venue, featuring many different kinds of pork. D, A, and I checked out the Peace Hotel Jazz Bar, which is like a time warp except for the price. I washed some clothes and passed out.
The next day a point of considerable anxiety was alleviated as A managed to get her visa to Russia, so she and M headed for the pearl market. D and I walked the streets looking for tetanus and answers. We found an ancient hutong district a few blocks to the north, dating from perhaps 1986, which included several interesting shops, a church, and so on. We headed back down through the city and the bund, specializing in the narrowest of streets, until we managed to home in on the cloth market. Did you know that GPS in China is off by about 1000m, relative to google maps? At the cloth market I found my successfully commissioned bowtie, bought a bunch more stuff, and went to the other French area for dinner. We ate enough to make us the wrong shape, then walked back to the hotel through insane crowds. We packed and passed out.
The last day, we woke early, walked to the metro and found it shut. So we took a taxi to Shanghai Pudong Airport, eventually found the right terminal, and got ready to check in. A ate a biscuit with indescribable gusto, which was (easily) the most entertaining thing that hour. At length we found our Asiana flight to Seoul. During take off the airframe creaked audibly, while loose debris rattled as it rolled to the back of the plane behind the ceiling bulkhead. On landing, it all rolled back to the front. The approach, between dozens of thunderstorms, was bumpy and twisty but we eventually landed with an amazing splash, wandered into the terminal, and found free wifi that was faster than my "best that money can buy" internet connection back home.
Of course, we were en route to Vladivostok for the Eastern Economic Forum, but that will be told in a separate entry!

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:

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


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!