Tuesday, March 6, 2018

India 2018

Two weeks ago I went to India as an invited speaker at several student-organized technology festivals. I had a great time in India (as usual) and really enjoyed the experience - except the flights around the world, which were pretty tough. India is a long way from the USA. But it's better than walking.

Photos: https://photos.app.goo.gl/y7L6YNcdOpvjsHnn1

Transcript of the talk: https://caseyexaustralia.blogspot.com/2018/03/footprintstrystpragyan-speech-transcript.html

This whole episode began when some students from NIT Trichy, a technical university in southern India, invited me to speak at their festival, called "Pragyan". I cleared the time in my oh-so-busy schedule and agreed. Then they asked if I minded going to a few other places too, and they could share the cost with other universities. I thought this sounded sensible, so in the end I was lined up to speak at three places: "Footprints" at MSU Baroda, "Tryst" at IIT Delhi, and "Pragyan" at NIT Trichy.

My flight left in the afternoon. The usual litany of complaints apply: My Lyft driver was scary. Check in took forever. Security was even more slow and pointless. The gate lounge was overlit, noisy, and crowded. The flight was delayed an hour. Eventually I found my seat, which was a window on the left side. As I had hoped, as we flew over northern Canada I was able to watch the aurora out the window for about 20 minutes. Unfortunately my phone camera wasn't able to capture it, even with fully manual control. The light on the plane wing got in the way, but it was still pretty cool. The only other time I saw the aurora was flying back from India on my last trip. Any flight in the northern hemisphere that will result in terrible jetlag, is conducted during the northern winter, and leaves at the right time of day will fly over the pole in darkness, which is a pretty good opportunity to look for the pale green washes of light.

The sun rose as we cruised past Iceland. We flew over the Shetland Islands and I saw a bunch of oil platforms in the North Sea, the coast of Norway, the edge of Denmark, and a bunch of gigantic windmills. In the haze of exhaustion, dehydration, and tiny seat compression I had a remarkably clear vision of how I could adapt the Australian parenting philosophy to my own questionable life choices. "First, we'll go to Australia to play with gigantic poisonous snakes. After, we'll decompress by hitchhiking to Siberian gulag." We flew over Turkey, and Iraq, where I saw the Tigris river. There's something special about the northwest corner of the Indian Ocean and early civilization.

Two days later we landed in Abu Dhabi, where my fully loaded long haul 777 flight on Etihad, the state flagship carrier, was forced to unload down a single mobile staircase. I had about 90 minutes to clear security and immigration for transit, and as usual it was complete bedlam. Of course the departing flight was sneakily delayed, so I did make it. The seat next to mine was filled by a very broad shouldered man who snoozed and leaned over, bracing me securely against the bulkhead, where I was able to doze.

In Delhi airport there was, of course, no signage anywhere in the gigantic terminal, but eventually I found a corridor next to another corridor with 6 different kinds of unlabeled immigration lines, handed my passport over, and had arrived. Delhi is a bit of a tough city to visit - though it is improving. I wasn't overwhelmed by the heat, pollution (which stings your eyes before the plane even lands), supposed scams, terrible traffic (still better than LA), but by a general feeling of institutionalized bureaucracy, which seems to affect every capital city I've ever visited. Delhi is just on another level in terms of scale.

Fortunately in Delhi I was met by a couple of the IIT students at the airport and transported to the connecting terminal for my next flight. It was about 5 miles away and had no formal connection system, just a sea of taxis. The security line had a bag X-ray, gender segregated metal detectors, and a frisking system. In practice this meant giant piles of baggage blocking the whole thing up due to multiple interlocking deadlocks. But what's the rush? I eventually found my flight, boarded, and had been traveling for just over 24 hours. The last flight to Vadodara was mercifully short, as the plane was full of mosquitoes and my repellent wasn't accessible. Let's just say I was ready to be out of planes!

Fortunately the plane landed and let me out, and the trip got dramatically better. I was met by three local students who took me to the hotel, where I was in my room by 8am. I thought the students might be tired by their early start, but they were so excited in the lead up to their festival that they, and about a hundred other student organizers, hadn't slept much for days. I took an incredible shower, changed my shirt, then attacked the buffet breakfast in the hotel dining room. By 10am I had met A, a student assigned to look after me. I like to walk around a bit in blinding sunlight to help the jet lag set in, so we walked to the engineering school, sussed out the schedule, and said hi to everyone. The level of preparation for the opening the following day was at fever pitch.

That afternoon we walked to Laxmi's palace, the closest monumental palace open to the public. It was built by the Maharaja in the late 1800s, has more than 500 rooms, and all the latest technology, including elevators, lighting, electricity, air conditioning, and a gigantic golf course. The armory, containing about a million exquisite Indian steel swords, was a particular highlight.

I had plans to go to dinner in the evening, but I was mostly insensible by about 4:30pm, then slept in until 6am the following day. I took the opportunity to write a few words for a new book, then got dressed and headed to the festival opening ceremony. There I met another speaker, the neuroscientist Dr Vaughn, the various deans, and the university Chancellor, Shubhangini Raje Gaekwad, who lives in the palace I visited the previous day. I spent most of the rest of the day taking photos, signing things, talking to people, visiting various booths, checking out fighting robots, and watching the talks by Dr Vaughn and also Vineet Mehta, Tesla's power train specialist.

The following day, I woke up early, practiced my talk, then traveled to the venue, a large auditorium in part of the local hospital complex. I was a bit nervous, but I got to the end with plenty of time for questions. The floor microphone failed, so I jumped down and ran my microphone to various people asking questions, which was a lot of fun! I felt like a TV reporter. After the talk, I bailed to the green room, changed into cooler clothes, and went to a sponsoring restaurant for lunch with everyone, which was amazingly good dahl and roti.

Back at the school, I checked out the robot fighting arena. A raised platform with a mesh screen to catch larger bits of shrapnel, the robots were sometimes direct DC drive remote controlled via thick cables. D:

My hosts asked if I would like to rest. I insisted I was fine, but they found an empty room, carried in a couch, and politely insisted that I take it easy. I guess a lot of their guest speakers are more distinguished people from colder climates who drop like flies in the early afternoon? I probably should have napped, but instead just read for a while, then took a car to the airport, performed the now familiar security contortions (don't put your boarding pass in the scanner) and waited for the flight. Back in Delhi, the students found me again, drove me to the IIT Delhi guest house, where I failed to operate the hot water heater, washed some clothes, and passed out.

The following morning I was woken by the strains of a brass band at 5am, so I took the opportunity to wander around the university incognito and try to get some context and detail for my talk later that day. I saw many peacocks, including some that were flying, which was pretty amazing. Also prominent at all the universities were multilingual signs explaining the zero tolerance ragging/hazing and sexual harassment policies - an encouraging sign!

I found the lecture hall and, the talks being sequential on a tight schedule, showed up in plenty of time. For some reason, the students ushered me to some separate room so by the time we got mic'd up and started it was 20 minutes late. So I cut the more depressing parts of my talk and then bailed out for lunch. I considered running away to Agra to see the Taj Mahal, but instead wandered around talking to some students, then decided to call an Uber and get out of dodge. I traveled to the nearby Qutub Minar, an 800 year old semi-ruined mosque. Particular highlights include the 72m tall minaret and the Iron Pillar of Delhi, a 7m tall iron post that is thousands of years old and rust free. It was pretty amazing. At the entrance, though, were two separate lines. A very busy line for Indians, and a short line for foreign tourists, who pay about 20 times as much to get in. It reminded me a bit of Cuba, which has separate currency for locals that is intended to provide cheaper goods and services for tax-paying locals, but in practice renders foreign money irresistible.

I found my way to the nearest metro station, then zoomed on the modern, efficient metro to Central Secretariat, in the middle of New Delhi. Here, I walked through a local park to the India Gate, and then up the road to Connaught Place, a very intense shopping district. All too soon it was time to return to the university by metro, grab dinner, and put my feet up. I walked about 17km that day, and I felt it. I think I must be getting soft.

The following day, I went into the festival again and saw Robert Metcalfe's talk. He invented ethernet, the lowest level of the tech stack that powers the internet. After lunch, we teamed up and traveled into town to visit the American Center, where UT Austin and the US State Department have teamed up to build Nexus, a startup hub that's focused on training various incubators to help bootstrap the local ecosystem. Apparently there are about 400 incubators in Delhi! The local contractor had lived all over the world and had some amazing stories.

We considered heading to the Red Fort in Old Delhi, but cut our losses and instead took an autorickshaw to the Lodhi Gardens, a landscaped park around 4 ancient tombs dating back to about 1500. Delhi is the site about about 11 ancient cities, many of which were partially or totally destroyed, built over, and left a variety of ruins, monuments, and other stuff. I found it fascinating how urban planners drew lines around the densest collections of monuments, which are now tourist sites. And, in the surrounding areas, unrestored tombs of often forgotten people lurk in people's backyards. Somewhat like Athens, one can't take a photo or turn a clod of Earth without hitting some aspect of 4000 years of history.

That evening, Robert and I were pretty wiped, but wanted to have dinner with the Tryst organizers. For some reason, finding a restaurant that wasn't an hour's drive away was impossible, so we piled into the guest house dining room, had a quick chat, then beat a hasty retreat. By now I had applied my decades of catastrophic over education and activated the hot water system, so had a decent shower before going to sleep.

My flight left in the mid afternoon of the following day. Robert took off for the Taj Mahal, but I packed up then took a car to Humayun's Tomb, built a couple of generations earlier and, in some sense, a prototype. The wild traffic sharpened slightly as my car clipped a motorbike! For a place where accidents are reasonably common, few riders wear helmets. Accidents are much less common than you would think, though. It's not unusual to see trucks, autorickshaws, cars, bikes, pedestrians, dogs, cows, and even amputees on wheeled skateboards all sharing the same highway.

I arrived about an hour before the tour busses and hordes of people all trying to take exactly the same photo. The complex has a large Persian style garden, about 10 tombs in varying states of repair, and a never ending scheme of conservation and restoration. It must be difficult to do, since the original construction was never documented and even obfuscated. The centerpiece is the tomb of Humayun, which looks similar to the Taj Mahal, but made of red sandstone rather than marble, and was monumental in every sense of the word.

I headed back to the guest house, ate some lunch, then headed to the airport. There were two connecting flights to get to Trichy, with a layover in Chennai. As usual, the layover involved buses, passing back through security, navigating the airport without signs, and a boarding zone order of 1, 4, 3, then 2. All I'm asking for is door-to-door super hypersonic suborbital transportation. I don't see what's so hard about it.

I got a nasty headache on the flight, but fortunately was well met at the airport and taken to a very nice hotel in Tiruchirappalli, where I dosed up on Malarone and Tylenol, then had an incredible mushroom dish called "kulcha" and bread. I washed some clothes again and had precisely zero difficulty falling asleep.

The next morning my gracious hosts apologized and asked if I would wear long pants, since we were going to visit some local temples. The first one was Ranganathaswamy Temple in Srirangam, an ancient temple to Vishnu on an island near Tiruchirappalli. We cloaked our shoes and then walked in through the first of seven concentric gates and walls around the central deity. The complex contains about 20 towers, was mostly built about a thousand years ago, and has several cloisters and halls with thousands of monumental exquisitely carved granite columns. The tallest tower, completed in 1987 after 400 years of intermittent progress, is 73m tall. The gate beneath, which is part of the original structure, is so tall it has powerlines routed through it.

Following this we visited a butterfly park and an ancient water control feature, used to supply irrigation, before overheating and getting some lunch in the hotel. That afternoon, a different pair of students appeared to take me to the Rockfort temple, right in the middle of the city. This is actually a set of temples built around and inside a monolithic granite hill, with over 300 (mercifully shaded) carved stairs to get to the top. There was a great view over the surrounding area from the top, with a decent breeze and many brightly colored buildings. Once back at street level we went to a few different shops, full of all sorts of things I couldn't fit in my bag! That evening I once again skipped dinner to sleep, and did not regret it.

The following day I caught up with Robert Metcalfe at breakfast, then drove to Brihadisvara Temple, another famous, ancient temple (among hundreds!) in the area. This one is devoted primarily to Shiva, and is most famous for its giant gopuram, or tower, with an 80T monolithic globe on the 60m tall peak. Noone is quite sure how it was built, but it is believed the entire complex was completed in only seven years. The structure was built without arches, and I'm really impressed by how the lintels were built without (mostly) cracking. It manages to be both enormous without being overly oppressive. One other detail which stuck in my mind was that in Hindu temples, most deities are also depicted with their "mount" nearby. Shiva's mount is a bull, so there's an adjacent shrine containing a very large carved bull. Like the Lascaux paintings, this animal depiction is stylized and contains a compelling animal character, almost like movement. I generally don't buy arguments that ancients knew more technical information than we do - in particular claims that modern engineering couldn't reproduce, say, the pyramids are quite silly - but I am always impressed by the artistic finesse of ancient art right back to the earliest known examples.

That afternoon, we drove to the main campus to look around, look for animals, meet people, check out the robot construction lab, and attend the opening ceremony. The highlight of the inauguration, for me, was a terrific talk by Dr BN Suresh, former director of ISRO's Vikram Sarabhai Space Center, who spoke about the Indian space program. I was also amused by someone videoing the ceremony from a drone, flying inside the auditorium. Back at the hotel I prepacked by bag, practiced the talk, and fell asleep again.

The next day was already my last day in India. I had two breakfasts to smooth a logistical issue, then traveled to NIT Trichy. I was dressed, shaved, combed, and I had a busy schedule of talking to student journalists, a couple of classes of mostly mechanical engineering students (I learned a lot!) and then gave the talk in an capacity lecture hall. After the talk I took a lot of questions, took the obligatory photos (selfie production line), received some lovely gifts, and then returned to the hotel to eat, shower, and pack.

All too soon I was stepping off India back into a plane for the first of four flights, over 36 hours, back to the USA. Once again, my grumpiness was well induced. I had lactose free cheese sandwiches. I had gate lounges with inscrutable whistling covers of insipid Andrew Lloyd Webber. I had bad air quality. I had numerous frustrating interactions with unhelpful uniformed bureaucratic loafers. I spent many, many hours in various lines waiting for nothing to happen. I went through layers of security to access elevators that went nowhere.

And, as usual, I somehow ended up seated in a section of crazy people on the long haul flight. There was the guy playing games on full volume on his phone, and then setting alarms that would go off throughout the night, waking everyone except him. There was the usual croaking chorus of tubercular coughing types. There were the chronically uncoordinated who insisted on shaking every chair as they staggered endlessly up and down the aisles, when they didn't grab a handful of hair by accident. There were the trash hoarders who somehow filled the underseat space with a mixture of half crushed water bottles, used wet wipes, unlabeled medicinal herb containers, and sputum. But the piece-de-resistance was undoubtedly the domino of people in my row who, as soon as I got up to go the toilet, immediately annexed my seat and fell into an unrousable horizontal sleep. And, when they got up, the next one in line annexed all three seats, same deal. I ended up standing by the exit door for about 5 hours, reading and looking out the window for polar bears.

One person sitting next to me, after trying to treat their randomly targeted endless coughing and strategic sleep-destroying poking with some inscrutable mix of tea leaves, which mostly ended up on me, asked about an hour into the flight "Are we nearly there?" On arrival, 16 hours later, they asked if I would call their spouse to let them know we'd landed, but it transpired they didn't know their phone number. They always find me! How do they find me?

The plane came down into LA, miraculously smog-less after a week of rain, I headed for the exit, and miracle of miracles one of the eight security screens ("Please remove your cash, shirt, belt, laptop, shoes, loose change, pancreas, IN THAT ORDER") in Abu Dhabi was pre-immigration, so they let us right out into the airport. I was home after only 40 minutes of terrifying driving.

India! What an amazing place! I feel like I could spend a lifetime in a single state and still not scratch the surface.

Monday, March 5, 2018

Footprints/Tryst/Pragyan speech transcript

In late February-early March, many Indian universities hold student-organized technical festivals, and in 2018 I was fortunate to be invited to speak at three of them: Footprints at MSU Baroda, Tryst at IIT Delhi, and Pragyan at NIT Trichy. The talks I gave had about 70% commonality and will eventually be uploaded to YouTube. Below, then, is a "final version" with a mix of local material.

(Don't speak too fast.)

Sound check! Could the people in the back row please wave?

Gujarati - Kem cho
Marathi - Sub prabat
Hindi - Namaskaar

Hindi - Namaskaar
Urdu - Assalamu alaikum
Punjabi - Sat sri akaal

Tamil - Vaṇakkam, eppidi irkreenga


Good evening, ladies and gentlemen. I am humbled and privileged to be present among such brilliant people, and to be given the opportunity to share some thoughts. Today I am going to talk about my experiences developing technology including the Hyperloop and how that meshes with a yet grander scheme - the bold, experimental invention of an improved, more just world enabled by innovation.

If I have not yet had the pleasure of meeting you one on one, my name is Casey Handmer. Is anyone here on Quora? Excellent.

I was born and raised in Australia where, like you, I was attracted at an early age to the purity and truth of scientific exploration. I didn't really have access to scientific equipment or technical libraries until early adulthood, so I gravitated towards theoretical and mathematical studies. Later in life, I discovered many other mathematicians, like Ramanujan, who had taken a similar path, albeit much more brilliantly than I. Indeed, the experience of some intellectual isolation and technical frustration is known to have inspired the ancient greek mathematician Archimedes, responsible for very early treatments of calculus and also super weapons. Aren't we lucky to live in a place and time where it is possible to have colleagues! Isn't it great to enjoy the company of like-minded people?

I completed my undergraduate degree at the University of Sydney. Sydney is an incredible city on the edge of the world, and I've always felt fortunate to be able to call it home. But in 2010, it was necessary to find the toughest PhD I could, so I applied to numerous programs in the US. I was rejected from two thirds of them, including MIT and Stanford, but someone at Caltech admitted me and so, within a year of discovering that Caltech was even a place, I had moved there. Big Bang Theory wasn't a thing back then.

At Caltech, I switched fields again and performed research into gravitational waves as part of the broader LIGO effort that culminated in detection in 2015, the year I graduated, and a Nobel Prize last year. To be clear, my doctoral work had nothing to do with the detection or Nobel Prize. I did meet my wife at a party at Kip Thorne's house, though.

Actually, this seems like a good time to talk about gravitational waves, the subject of the most recent Nobel physics prize. As you know, our sun is a star like the hundred billion stars in our galaxy, which is one of the hundred million galaxies in the observable universe. Our sun burns hydrogen, which mostly formed during the big bang. When stars get old, they exhaust their fuel and puff up into red giants, which will one day consume the Earth. After that, the glowing white hot remnant becomes a white dwarf star. About a century ago the Indian mathematician and physicist Chandrasekhar computed that if a white dwarf weighed more than 1.44 times the mass of our sun, it would collapse to form a neutron star. Neutron stars are so dense that a single teaspoon would weigh as much as the hill upon which the Rockfort temple is built.

It turns out that if a neutron star weighs more than 1.8 or 1.9 times more than our sun, it too will collapse further into a black hole. Who here has seen Interstellar? The black hole in that was called Gargantua, and at one hundred million times the mass of the sun, it is similar in size to the black hole at the center of the Milky Way. We know of black holes that weigh almost a thousand times as much. But the LIGO detection was focused on black holes that weigh about as much as our sun. Imagine a pair of such black holes. Each has an event horizon a few kilometers across, about the size of this campus. Each is separated by a few tens of kilometers, about the distance from here to the airport. They orbit each other at nearly the speed of light, emitting energy and angular momentum in the form of gravitational waves, spiraling inwards. They orbit so fast, they complete hundreds or orbits a second, which means that gravitational waves, if transformed into sound waves, are in the human auditory range. They sound like this.


And you might be surprised that at the end of that long process of inspiral and collision there is no final gigantic crash. In their final moment as separate black holes, each event horizon stretches out like two elephants high fiving with their trunks and then merge, all in about a thousandth of a second. That final gigantic crash occurs but the black hole event horizon grows and swallows almost all of it before it can escape. They swallow even their final scream.

The gravitational waves propagate outward through the universe at the speed of light forever, eventually passing through the Earth. When they do so, they stretch and squeeze the Earth by about the width of a hydrogen atom, which is significantly less that the deformation induced by stepping here to my left. But the LIGO detectors, one of which I think will soon be built in India, are able to filter out the noise and detect these incredible events. So, that's gravitational waves. I hope you were paying attention. There will be a short quiz next period.

I went to Caltech to learn about physics, as in the rules of the universe. What I was not expecting was to learn about physics, as in the way humans go about discovering, the rules of the universe. At 23 I was pretty sure that academia was a unique and privileged calling, and exempt from the mundane issues that plague any other attempt to get large numbers of people moving in the same direction! Well I have been wrong about many things, and I was wrong about that too! Management is non trivial and a skill that must be learned. The "academy" is not just a building that contains ideas. It also contains people.

By the time I finished the PhD, I had seen enough of the way that research works in the US to decide that I would rather spend my time contributing to the wellbeing of humanity in a more direct way. In 2013, Elon Musk and his team put together the "Hyperloop Alpha White Paper" technical document discussing his idea for a high speed surface transportation system that combines the speed of airlines and the convenience of cars, while outcompeting high speed rail.

As you know, the idea behind hyperloop is to adapt the concept of high speed maglevs and reduce air resistance by operating inside a vacuum tube. The advantage of the scheme is that the vehicle does not have to carry all its fuel, like a jet, it only has to carry the cargo, and can operate more efficiently on a given route.

I thought the document was pretty interesting, though even in 2013 I knew it was a long way from being technically complete. In particular, I was worried about how to route the tube over mountains. This geographic constraint was dramatically illustrated by the success of the Burma airlift, or "The Hump," over the Himalaya mountains in 1942. While obviously some parts of the world, like the Ganges plain, are relatively smooth, other parts, like the Tibetan plateau, are incredibly rough. How fast can vehicles travel while being close enough to the surface to avoid miraculous feats of civil engineering?

2013 was about the time that gradually made an important transition in academic life. If you haven't already encountered this, you will soon. Up until this point, my preoccupation had been with getting 100% on every exam, and thus demonstrating total mastery of the sum total of human knowledge in my discipline. But at some point, you reach the edge of the known and emerge into an area where there are no known solutions, and sometimes even the problems are very poorly defined. In such a case, 0% is the default grade, so if you spend a month or a year or 10 years on a problem and raise the state of knowledge to 1%, that is a huge improvement.

Likewise, I was tiring of the perception, probably developed while being raised in Australia, that technology and engineering is done by other people, and that if I wait long enough, cool stuff will eventually come to me. This is surprisingly common - how many otherwise competent and well-resourced people are waiting around for Elon Musk to take some time out of his busy schedule and solve their problem for them?

So I didn't need anyone's permission to run the calculations myself. Many cities are built near or between mountains, and my home town of Los Angeles is no exception. I wrote some basic code to try to optimize a route over the mountains. Today, four years later, I still use a descendent of that code to find terrain-optimal routes.

And, in the meantime, all kinds of adventures occurred! On the back of that analysis I was hired, initially as an intern, at Hyperloop One in September 2015. If you've followed the news, you know that we've had a lot of excitement since then. It's certainly helped me learn a lot more about how large scale organizations with a diverse range of personalities, experiences, and skills can still work together to accomplish a common goal. I suppose the act of government is preoccupied with similar concerns though on a yet much larger scale.

My primary responsibility at Hyperloop One was development of the devloop tech demonstrator levitation system. Most of the devloop systems were more conventional and had large teams of experts already hard at work. But we were trialing a few new kinds of levitation system and needed someone who could do the difficult quantitative analysis. And, by some crazy chance, I happened to walk through the door that very same day.

Step one was to get a handle on the underlying physics - electromagnetism, bulk currents, induction, and other stuff only just beyond a second year level. Step two, and for me the more unfamiliar step, was to interface with other teams, understand requirements, and get channels of communication up and running. This was followed by preliminary and more detailed design. After design, it was time to go back to analysis and thoroughly characterize theoretical performance. This is a good start, but since we couldn't test the levitation system before the first flight, we needed multiple lines of reasoning to prove it would work before we finally pushed the big shiny red button.

So I started again from scratch, this time using finite element analysis methods. On the first try, the simulation disagreed with the analytic result by more than a factor of two. This would be great in astronomy, but not great for a flight system. We had about six weeks to sort it out, so over the next six weeks, we identified about half a dozen errors, mostly sneaky ones hiding in the simulation system, and harmonized the results. Then we moved on to new projects while the downstream processes of fabrication and assembly turned our dreams to reality.

Within a year of starting out, the finished vehicle was sitting in the loading dock, its assembly getting one last quality check, before putting it on a truck and moving it to the test site in the desert about four hours drive away. The test technicians loaded it into the tube and, like everyone else on the team, I held my breath and hoped that, if something horrible went wrong, it would at least be someone else's part. But it worked. The test pod flew down the test track, and over the coming weeks, the team pushed the speed up to 107m/s, which is about 380km/h. This is the fastest hyperloop demo yet performed. We could have gone much faster, but we were running out of track!

Despite some setbacks, a few misunderstandings, and the constant stream of pessimism in the press, our team had taken a vision from imagination into the real world, and in only a couple of years. It is easier to criticise than to compliment. It is easier to destroy than build. So, it is always a struggle to innovate, to fail, and to try again, and again, and again, and eventually either succeed or die of old age. But it is worth it.


Enough about me. This is my first visit to your city, and I already can't wait to come back. I'm always happy to visit India, I'm not sure why. People told me the traffic would be bad, but honestly it's more scary in Los Angeles.

(MSU Baroda)

I arrived in Vadodara the day before yesterday and the student organizers have just been terrific. I used to participate in student organizations but I've never seen anything like this! At the inauguration yesterday it was great to hear about the beginnings of the Footprints festival, now in its 18th year and going strong. Footprints are such a powerful metaphor for deliberate progress.

And Laxmi's Vilas Palace! To be honest, I had no idea what to expect here in Vadodara, but isn't it amazing to have such heritage and world-famous architecture in your backyard? I walked there.

There is one other thing I saw that I would like to comment on. Yesterday I visited the Mechanical Engineering department. Who here is studying MechE? When noone was looking I peeked into the Heat Engines Laboratory because I saw the aeroplane engine and I like planes. And then, tucked against the wall, I saw the machine shop tools, lathes, mills, saws, and so on. They were remarkable for me in two ways - and I've seen a lot of workshops. They are the oldest looking tools I've ever seen. Older than stuff I've seen in a museum! But, more importantly, they are the best-cared for looking tools I've ever seen. As you know, a half hour of carelessness on any tool can destroy it, and I think it's a great testament to the respect I've seen here for technology that these tools have trained maybe five generations of expert machinists and engineers, and could easily train another five. Sorry, I'm getting a bit emotional here. Technology is the gift we produce for the future, and love for technology is, along with aerodynamics, the thing that keeps planes in the air, factories working, and the rest of us clothed and fed.

(IIT Delhi)

I arrived in Delhi late last night and stayed here on campus. Isn't it a beautiful place you have here to work. I walked through the gardens in the east part of the campus and encountered *herds* of peacocks who were friends with the local cats. I didn't even know peacocks could fly.

Walking through IIT Delhi, it seems clear to me that this is a very prestigious, very well resourced, very honorable, and very rigorous school. We are lucky to be the beneficiaries of such heritage, it will help us and our careers for the rest of our lives. I like to think about ways that I can take my good luck and pay it forward, to help to enrich this generous and powerful tradition.

(NIT Trichy)

I arrived in Trichy the day before yesterday and I've had a great time exploring this ancient city. At MSU Baroda, they assigned one student to accompany me and help out, at IIT Delhi they left me to my own devices, but here it seems all the organizing students take it in turns to hang out with us guest lecturers, presumably so you still get a chance to enjoy this great festival!

I have many Indian friends in the states, and when I mentioned I was going to Trichy, they said that it was famous for its temples. Well I had no idea what to expect, and then you took me to see Sri Rangam and Thanjavur. I have to admit they both kind of blew my mind. What I really liked was the juxtaposition of the eternal and the ephemeral. I walked through a gallery of ancient granite pillars, essentially unchanged since its building more than a thousand years ago. And then a cute toddler stared at me and offered me a bite of their snack - a singular moment, swamped immediately by the ongoing hustle and bustle.

I've enjoyed the sunny weather, which reminds me of home in California, and the cooling breezes, which we could do with more of! And finally, I got a chance to walk around the campus yesterday evening before the inauguration and check out all the new buildings and my favorite, the robot development lab. I've never seen so many robots being built so close to each other, it was practically a robot nursery!


Who remembers the launch of the SpaceX Falcon Heavy rocket two weeks ago? How good was that? StarMan is going to Mars! Let's talk about space for a bit, then move onto technology more generally. If you were at the inauguration last night, I have to warn you that Dr BN Suresh (former director of ISRO launch site) stole all my best lines, but I'll do what I can.

71 countries have space programs. Only six of them have the ability to build, launch, and operate robotic satellites and deep space probes. Those countries are China, Europe, which isn't even a country, Japan, Russia, USA, and of course India. Australia has more kangaroos than any other country, but we do not have a space program. Arguably, North Korea has better space technology than Australia. I may live long enough to see Australia get a space program, but I would have to be very lucky indeed to see one anywhere near as good at India's!

I think it's a big deal that India has such an excellent space program. In 2014 I had the pleasure of meeting Dr Koppollil Radhakrishnan when he visited Caltech, during his tenure as the director of ISRO, the Indian space agency. He was as aware as we all are that of the six countries that do space robots, India is arguably the poorest. From time to time, we hear criticism of space exploration on the grounds that it's expensive and there is no shortage of worthy uses for money here on Earth. Dr Radhakrishnan explained that India's space program is largely focused on Earth observation, and that the unique insights produced by the "eyes in the sky" help India predict, understand, and cope with natural disasters, unpredictable harvests and, more pressingly, climate change. In other words, the question is not "How can India afford space?" The question is "How can India not afford space?" How can we all not afford space?

To this I want to add that the expense of a space program is small compared to other government programs of similar technical complexity, which are usually oriented toward secret weapons development. Furthermore, money spent on space technology isn't just put in a gigantic pile and burned - it employs us. Ten or hundreds of thousands of highly trained technical experts whose knowledge and abilities build wealth - the fundamental mechanism for alleviating poverty through technology.

With that out of the way, let's talk about why the Falcon Heavy launch, and space more generally, is so exciting. ISRO has a deep space robot, the Mars Orbiter Mission, or Mangalyaan, which I just discovered is on the new 2000 rupee note. India is the fourth nation to send a probe to Mars. It is also the first to succeed on the first try! This is a big deal. Mars' hobby is eating robots for breakfast.

While rather tiny compared to NASA's rovers, I think Mangalyaan is also very cute! Yes, robots can be cute. In fact, my favourite photo of Mars was taken by the Mars Orbiter Mission last year. It shows the planet about ¾ full, with clouds, ice, dust storms, mountains, craters, and canyons all visible. This volcano, Elysium Mons, is so tiny noone ever talks about it. It's twice as tall as Everest. This is Olympus Mons, which is three times as tall as Everest, and about as wide as India. This is Gale Crater, where NASA's latest rover lives. Even better, there is a tiny black speck to one side - the silhouette of a moon in front of this world!

(Credit: ISRO)

Today, there are 7.6 billion humans on Earth, of which 1.3 billion are in India, almost a whole world in itself! Perhaps 100 billion humans have ever existed. Let me be perfectly clear, there is no physical way that any but the tiniest fraction of today's 7.6 billion will ever fly to space. To this day, 315 rocket launches have flown humans to space. In total, 536 people have been launched into space, some of them up to eight times, which seems excessive. And only twelve of those have walked on another world, the moon. Of those twelve, only five are still alive - it happened a long time ago.

Even if all of our dreams, and all of Elon Musk's dreams come true, maybe one in ten thousand humans will ever go to Mars. Maybe only one in a million. Correspondingly, most of our concern and technological effort must address the reality that humans must keep Earth habitable. But while billions will remain, perhaps some will go to build another city, another branch of humanity on other worlds. Making life multiplanetary is a worthy challenge and, along with preventing our own extinction, probably the most important evolutionary milestone since oxygen breathing life first evolved. I see no reason why India could not contribute its proven expertise and spirit to this enterprise!


I want to tell one more story about the very real dangers of apparently politically neutral technology. This story is a bit of a downer, but I chose it because it has an important point. Many technical people like to think of themselves as politically neutral, or apolitical. Afterall, a plane or a valve or a computer program is an idea that exists independent of ideology, except perhaps the basic philosophy of empiricism. In particular, no-one could describe a tool like a power drill as having a political party affiliation! How preposterous. Yet this attitude is not accidental. It is very unusual to find an academic mentor in the sciences who is even prepared to admit that they have political views, let alone specify what they might be. Why? I can understand why public servants employed by taxpayer money would be careful to avoid accusations of partisanship. Political policy does materially affect the wellbeing of our fellow humans, so there is something here that's worth thinking about.

In about 2010, the Defense Advanced Research Projects Agency, or DARPA, started up a program known as Nexus 7. DARPA, founded in 1958, is a secretive US agency whose mission is, to paraphrase, "no surprises." That is, anticipate and develop secret technology so that, in the event of a future world war, the US could not be blindsided by a secret weapon. Many of DARPA's inventions have subsequently made it into public view, including the internet, street view, graphical operating systems, GPS, voice recognition, holographic displays, TOR, and stealth technology. To be clear, I only know about this project through reading newspaper articles!

At this time DARPA, under the leadership of Regina Dugan, was aggressively pursuing academic partnerships to modernize its outlook in machine learning, and wanted to find ways to help fight and ultimately end the war in Afghanistan. Some of my colleagues at Caltech, motivated by pacifism, signed up to go to Afghanistan and help develop these projects. One of them was intended to try to understand the flows of money. In particular, variations in prices of food seemed to predict local unrest. If you can predict unrest, you can prevent it, and that begins the process of trying to break the cycle of violence that has persisted in some of these places for generations.

Further, perhaps half a dozen bomb makers producing roadside IEDs were obviously being paid somehow. But cash transactions are hard to track in a cash-based economy with electronic espionage. In essence, there are a huge number of unknowns and a few constraints. Traditionally, solving this linear algebra problem would use least-squares, since in engineering this helps to minimize the energy. But in this particular problem, applying least squares doesn't work because it would assign small payments by nearly every citizen to nearly every other citizen - something that doesn't occur in reality.

The insight was the development of compressed, or sparse, sensing, now used for all kinds of things, including image enhancement in every phone camera. Most people never interact financially with most other people. Take the same data and close it with the L1 norm rather than the L2 norm, and a remarkably accurate picture of the missing information emerged. This project was deemed successful, the people I knew rotated off the project and resumed their PhD work in the US.

Ultimately unrelated extrinsic factors led to the loss of Jalalabad and an escalation of violence, despite best efforts to solve it. Sometimes despite perfect moves you still lose the game.

Fast forward a few years. Although my former colleagues have long left, the projects continued to be developed, and related algorithms were applied to mobile network data. Again, most people only routinely call or text a handful of other people, so analysing the network topology can help determine the identity of the users of various mobile phones, even if their names weren't known or confirmed through more traditional James Bond-style spying. For reasons I don't know, this method, which worked quite well for financial data, was pitched as being a terrorist-finding tool with mobile data, despite a lack, to put it mildly, of peer review. The US forces proceeded to drone a bunch of phones, and the people standing near them, in Pakistan and Afghanistan that had "terrorist patterns of use." This is the sad part. It turns out that there are other user profiles who also have sporadic bursts of activity calling dozens of people: Wedding planners.

This story isn't intended to discourage technical innovation, because there's always a chance that something you touch will end up being used to hurt someone, and most people won't get any sort of say in how their widget is deployed after they deliver it. It's merely to illustrate that even the lowest ranked engineer does get a say in the future they are building, as they build it.


For the last part of this talk, I would like to zoom out and take a broader view of technical efforts in general. When we look at the gradual, incremental achievements of the past, the fruitless careers, the backwards steps in progress, it is easy to become discouraged. How can I be sure that what I'm devoting time and effort to will have any lasting effect? Well, the short answer is that on a long enough time scale, everything averages out to zero, even for Elon Musk or Steve Jobs. This can seem a bit depressing.

(Credit: Wikipedia)

But I had a thought yesterday, when I visited the Thanjavur temple. Consider the gopuram, that 80 tonne monolith at the top of the tall tower, and our confusion and uncertainty about how the builders put it there, a thousand years ago. There will, inevitably, come a time when our knowledge, identities, and methods are just as mysterious to people then as the builders of Thanjavur are to us today. But consider the present day. If the builders of Thanjavur could build all that in only seven years, what can we, with our internet, mechanization, computers, and science build in seven years?

Further, as far as we know, humans are the only entities in the universe capable of self contemplation and progress through technology. And we are fortunate to live in an era where we are already beneficiaries of so much painstaking progress. We can live long, peaceful lives relatively free of deprivation and pain. What I am trying to say is that there is an art, a performance art, to practicing science and living a technically contributive life. This is optimism in practice. A belief that our children will inherit a better world, and a belief that it's worthwhile to expend our blood, sweat, and tears to ensure that we leave this world better than we found it.

So why be technical at all? Why not let other people invent cool stuff? I will tell you a secret. Technically literate people have a special advantage. Through the practice of technology, we actually have a magical power, the ability to imagine a better future, and then to bring the rest of humanity forward with us. In fact, you can think of technical ability as a special kind of democratic power, a power that naturally comes with a level of responsibility. In addition to the vote you cast every few years for your own government, every code commit, every drawing release, is another vote for a particular type of future.

In the US, and Australia, and maybe in India, there is an unaccountable and irrational nostalgia for a simpler time back in the distant, and imaginary, past. Back when things were supposedly simpler and life was slower and we all lived healthy agrarian or even hunter-gatherer lives. Well if you've ever had a toothache you know just how shallow this romantic fantasy is.

In 2018, the human species faces all kinds of truly daunting challenges. These include, but are not limited to, resource depletion, climate change, poverty and greed, food security, internet security, energy security. Regressing to an agrarian way of life is not an option. Mass starvation is not an option. Zombie fantasies are not an option. Mass death is not an option.

The only way forward is up, meaning emancipation through technology. We need every brain  working on these problems. Not just US brains, or Australian brains, or Indian brains. Not only white brains, male brains, christian brains, or rich brains. And not just physicist or software brains. We need them all. I challenge each and every one of you to think about how much more we can all do. What we can do to promote the diversity we desperately need to transcend the human challenges of the 21st century. There is no one way to be a scientist, engineer, or technician. In particular, please don't try to duplicate my poor example and numerous career mistakes! There are an infinite number of paths to technical enlightenment.


Finally, what can we look forward to in 2050, now only 32 years away? Here are some things I would personally like to see. This is in some sense a fantasy, but it's not forbidden by the laws of physics. I feel they are very achievable.

  • Zero humans living in poverty. A sufficiency and dignity for all.
  • And yet, all humans treading lightly on this one Earth we share.
  • Ecologically conservative and restorative industry.
  • Renewable, clean energy and recycled resources.
  • Zero humans dying in war.
  • Zero humans suffering oppression or injustice.
  • Security, safety, and freedom on the internet.
  • Access to affordable, efficient mass transportation. Shoutout to hyperloop!
  • Humans living and working in space, on the moon, and on Mars.
  • Things we haven't even dared to dream of yet.

It's not enough to wish for these things. As technical people, it is our responsibility to build this future. We can, and we must, do everything we can to see these better futures brought about. I look forward to seeing you there!


Alright, let's move to some questions. I want to get through as many as possible, so please keep them short.

I am sorry if we didn't get to your question. Ask me on Quora or Twitter? Thank you!

Wednesday, February 21, 2018

Science fiction short story - That Final Moment

I wrote this in 2016 and finally decided to publish it on this blog. It was my first written foray into the mechanics of deep space industrialization.

by Casey Handmer

"I am Sita." She could write a monologue of thoughts, organized by each activity at the moment of ideation. Identity and thresholds seemed to go together. She ran the flow check necessary to use the Mars surface airlock safely. Open valves to dump lock atmosphere into the air processor. Close valves. Check pressure on both gauges. Check the spacesuit was, in fact, not pajamas. Well sealed. Comms, temperatures, smell, pressure holding. Ears didn't pop--always a good sign.

She reached for the external door locking wheel and put her weight behind the mechanism. It ran smoothly enough. With practiced motion the door unlocked, opened inwards. A tiny puff of dust, cut by slanting rays of faded sun. She stepped through the narrow portal, like a submarine bulkhead door. Like a birth canal, no wider than it had to be, at least for people. Their machines birthed through a different door.

Vivid memories of her former life on submarines surfaced and just as suddenly faded into the depths. Between this outpost and those underwater islands of humanity, there was something fundamentally insular about society. Sita was here, now. She stretched towards the open sky for now there was no roof over her head. A few light steps over the trampled ground and, with intake of breath, a staring at, an acknowledgment of the horizon. If a problem is spherical, it is hard to see all of it at once.

Sita's problem was Mars. The outpost behind her looked no more worn than it actually was. Sita had accepted the mission with eagerness. Go to Mars, live there until something breaks beyond repair, then bail out. If you could. Sita had not flown with the exploration missions. She had waited on Earth and then flown with the outpost. She herself had explained it many times. "How do you solve the problem of machines eventually breaking more frequently than they can be fixed?" On Earth, all machines would eventually be retired, but on Mars, the very air was produced by a machine.

Therefore, an outpost on a dusty plain where humans lived indefinitely, with resupplies of parts and sometimes crew, every other year. Sita and a few others lived in this experiment. Or the experiment lived in them, since the blood and toil that kept the concern operational was the sheer dexterity of human ingenuity, their own capacity for biological regeneration, far better than any machine, and occasionally a liberal dose of the will to not-die-that-day.

And, she mused, a gigantic nuclear reactor. Every machine, every light, every pump, every vehicle, every robot--they all needed power, and their nuclear reactors provided it. She could see a heat shimmer beyond a nearby hill where they operated and quietly irradiated the surrounding area. Heaven help them if it ever broke down!

She scuffed the ground. How many years ago had they trenched the ground here, laid the power cables deep enough that frost creep and spring blow and wheels couldn't damage them? That tractor had been trouble from the start. Like every other machine, they could and did completely disassemble it with basic tools they had in their inflatable workshop. But, like nearly everything else they had back then, it had broken too frequently to be worth repairing.

Sita had dragged it out to the boneyard of orphaned machinery, a place of sculptures, metaphorical monuments to industrial ambition and too much clever complexity. There, with dozens of other unloved machines left by parents too busy to keep them alive, they waited only for oblivion. Which was worse? Gradually harvested for scrap, whittled away to nothing, and yet pieces living on as parts of other, more valued equipment? Or forever neglected, until sun and sand and aeons abraded the paint, wore away the shell, the chassis, and scattered every molecule in a wide, flat, glittery sand dune that ever so gradually slunk downwind from the outpost in shame?

Of course, Sita reflected, being recycled in some sense only delayed the inevitable for obsolete machinery. And indeed, explorers had passed, their bodies unretrieved, sometimes. Caught out at night, perhaps, and frozen to death. Or fallen and breached their suit. Or broken bones. Or poisoned by bad air. Or burned. So many abrupt paths to the end.

Sita had found one once. Kind eyes in his frozen, perfectly preserved face stared up through his wind abraded helmet, right into the void. Right into Sita's own black eyes. His peaceful expression reflected none of the ambition that must have driven him to Mars, to die out here alone. Her suit's profile, a hemispherical head with burning flashlight eyes, reflected in the glass of the deceased. The yet living and the dead superimposed in imago, like one hand covering the other. They placed him in the burial ground, opposite the boneyard and obscured beneath the crumbled surface.

Sita never found the other bodies. In her mind, they gradually transmuted from cogito ergo sum insularity to landscape. Wouldn't they all eventually find themselves blasted to smithereens by the passage of time, condemned to wander the northern latitudes by seasonal winds? Perhaps, given the risk of explosive decompression, that was why thoughts of identity and more importantly its willful continuation pervaded during airlock operation.

Sita's mind and eyes wandered the landscape as she stared into the horizon. Their outpost was spread out over a large area, a perfect island of solitude within a world that was, for now at least, empty. Positioned in a broad valley between distant ranges, their faded peaks in the distance. A tiny speck, a blemish, precarious in a nonsense landscape that told a garbled saga of dust and ice and wind and countless ancient impacts.

Her booted heel scratched at the ground as she turned to take in the view. She felt the sun's weak warmth through her pressurized carapace, her inner reptile took a second breath. In the distance, beyond the greenhouse, beyond the burial ground, she spied their return vehicle. The rocket sat there, inert, waiting to take them back to Earth. It had waited a decade. Four times, Earth had swung across the sky, daring them to cease their foolishness and fly home. Four times, they had duly performed the procedures to wake the sleeping behemoth and prepare it, just in case. Four times, Earth had passed out of range, its pale blue dot fading amongst the rest of the stars, and their loyal rocket had been put back to sleep. Sita wondered if the rocket could tell that Earth was no longer really home. That morning, something had changed. Everything had changed.

Sita felt she could have been happier. Against the odds, that same morning her mission had been deemed successful, by the squints up on the big world. Her team had proven the design methodology that could keep them alive indefinitely. Now, humans could come. Humans would come. First by the dozens, then the hundreds, then the thousands. An unstoppable rain of humanity from the sky. And her maintenance protocols would keep them alive, most of them, while they built their mines and refineries and foundries and factories and farms and cities, until humans could live on Mars without continuous resupply voyages from Earth.

Industrial autarky. Involuntary industrial autarky, necessitated by the hundred million miles of space between the nearest money and her. At least until someone made a warp drive or something. Then people would come by the million. Sita felt numb at the prospect. For a decade, just her and a handful of others under the Martian sky. Long rover traverses, endless testing, breaking, and repairing. Blue dawns to red days to blue dusks to black nights. Nothing but a planet and a mind, her mind, in it. Building Field Camp 18 in the next valley, confirming the aquifer. Building out a farm, growing food. A lifetime of learning and building and fixing and learning all over again.

They had one hundred days left. A message from the pale blue dot, confirming launch after thundering launch sending cargo and passengers to Mars. One hundred more days of relative solitude, before the new Martian hordes landed at the field camp aquifer, unfurled a gigantic tent over the barren plain and made the frozen desert bloom. There would be so many new faces. What does a face even look like? From the outside?

Sita didn't have to wait around to find out. There were still tasks to complete, systems to check, failures to diagnose, procedures to document. And Sita still had one hundred days of solitude to tread the rocks beneath her feet. Some were dark, scattered, their faces faceted and scored by wind. Some were rounded, perhaps some ancient alluvial disaggregate. And beneath them all, more rocks. Rocks on rocks, all the way down, enough rocks to hold a person to the planet's surface with a gentle, forgiving force. Sita could jump right over a rover in the three-eighths gravity. Not such a good idea, she thought as she eyed the dozens of patches holding her pressure suit together. It would be thought exceptionally bad form to leave the ranks of the living just before things got really interesting.

Sita stared beyond the return vehicle, right out along the almost featureless plain until the horizon's pastel browns and reds smeared ground right into sky. The horizon on this tiny world was never that far away. She could walk over it before lunch, find the outpost completely out of view. She could even make it back without running out of air, probably. Her helmet's glass fogged slightly with each breath. It was never warm outside. She checked her gas and power levels, then sat down on what had once been a voice command mainframe interface, its little silicon brain zapped by a cosmic ray. It had been a slow death, rambling ceaselessly in idiomatic Esperanto while Sita attempted repair before it, too, succumbed. Now it was a bench outside the airlock.

Sita leaned back and looked up towards the zenith, where the sky is always white. Why does the universe contain introspection? Why so little? Why at all? Her eyes looked through a few inches of air, a millimeter of polycarbonate visor, the pitifully thin Martian atmosphere, and then infinite space, where the very first photons were stretched beyond the limits of human eyes. If you look far enough in any direction the view is deepest red.

Metal robot oblivion dust is probably more glittery than the scoured remains of dead Martian explorers. Sita wondered how glittery she'd end up. If she lived long enough for the new city to get its biosphere up and running she'd request they recycle her remains. Nitrogenase and tyrosine are hard enough to come by without dumping them onto the frozen, ultraviolet blasted surface. But how was being eaten by worms any different from her recycling parts of broken machines? Were not humans machines themselves? Thinking, feeling, self-repairing and optionally self-replicating machines, but machines nonetheless?

Sita could cut off her oxygen supply with trivial ease. She could purge her suit's fuel right into the dirt. There would always be new ways to die a pointless death on Mars. But nothing could stop the new ships bringing new people to their new world. Sita's mission had shown that humans could live on more than one planet. Her identity was now part of the tapestry of human destiny. Something to mull over.

Sita stared at the sky and remembered the site as it was before they had built the outpost. She liked its design, a central hab connected to a variety of satellite structures by cylindrical tunnels. Against the odds, a tiny patch of human-habitable volume in an unlikely corner of the universe. Her project, her refuge, her home, her triumph. As much as she empathized with her ragtag family of machines, only flesh and blood could rebraid itself into humanity's raging torrent. More than her physical constituents would survive her passing. The contribution of her life's labor to the pool of human achievement might even someday enable her to find meaning despite the inevitability of both death and self pity.

Sita once more looked into the distance, where together they would all build their new city. In her mind's eye she saw their arrival on Mars. They would come, just as the previous cargo resupply missions had come. One by one the ships streaked across the sky. They came as a bright dot, then an expanding fireball, each brighter than the sun. Then the crack and jolt of the sonic boom, the roar of engines felt through her feet. The sun careened off the panels of each ship as they hovered, descending suspended on point-like engine glows and fat columns of dark, rushing smoke. And when the last of the ships had landed, their engines cooling but their effervescent contents not yet disgorged, Sita alone would savor that final moment of silence.