Costa Rica Alternative Spring Break Trip (part 1)

Last Thursday evening I had a sudden craving for airport sushi. By a lucky coincidence I was AT the airport. Eleven intrepid adventurers from Caltech were off to Costa Rica for a week to look at strange animals and do some volunteer work as a Caltech Y Alternative Spring Break.

As I munched my slightly stale imitation crab California role and stared across the cavernous check-in hall of the Tom Bradley Terminal, I made eye contact with a strikingly glamorous face. About 40 feet tall, she seemed to be spruiking diamonds or perfume or something. All at once, I was struck with a familiar feeling of 'forever again', or almost oppressive nostalgia for the timeless present. For some reason, airports are a really good place to feel stuck in a time warp. They have not changed as far as I can see in the decade or so I've been aware of them, and in that moment I could have been 100 years old, eating the same food, breathing the same air, wondering if I needed to purchase some expensive perfume.

Fortunately my tiny travel bag was already completely full, the feeling passed, and somehow I had slipped smoothly back into a travel frame of mind, and correspondingly became extremely grumpy as I realised I was once again in for disorientation, exhaustion, weird food and yet more experiences that are difficult to integrate into my own psyche, let alone anyone elses. Incidentally, that's why all my travel stories (this one included) are complete fabrications. ;P

That's not to say travel isn't overflowing with opportunities for amusement and hilarity. As an example, years and years studying science has allowed me to perfect the art of sleeping while seated, my head motionless while hovering uncannily in space. We scudded along the edge of a different sort of space as we followed the great circle south over Baja California and past a series of perfect volcanic cones. Sadly, none of them were erupting. 

After a short break at El Salvador, we reboarded the same plane. The previous crop of mainly hispanic passengers was replaced by a new bunch of mostly moneyed and liquored American holiday makers, new decor, and a new smell. If the television advertisement for the attractions of Guatemala had not lagged at precisely the same points as on the first leg, I might have been fooled despite being in the same seat.

Landing in San Jose (Costa Rica, not Silicon Valley), our token responsible adult C found his old friend and driver extraordinaire J, who pulled up in a shiny new Toyota minibus. The buses passenger door opened on the wrong side, however, so we loaded our luggage through the window. We requested a lunch sufficient to cancel out two previous airline meals and J did not disappoint. We parked by an unassuming ramshackle roadside diner in Alajuela, an affluent suburb to the west of the big smoke. We unholstered our Spanglish dictionaries and cast caution to the winds and were duly rewarded with an extraordinary selection of food, including some of the best beans I've ever eaten. 

The bus zoomed south towards the Pacific coast. The road twisted like a shoelace between impossibly lush fields, over crags, and through canyons. On one side, the 'old' road, one lane wide, was at least twice as wild and three times as narrow. On the other side, an old narrow gauge railway followed our progress to the surf. Later I was saddened to learn that the railways are largely defunct. The corridors, however, are still extraordinary. In between these sights paddocks were marked by a dense thicket of fence posts, all of which had sprouted. Unlike Pasadena, where a faulty sprinkler is the only difference between green and desert, tropical growth was everywhere. Locals shook their heads and said it was drier than it had ever been.

Friday afternoon, the banks close for the weekend, and some for the whole following week of Easter. We piled out of the bus in the perennially rough town of Quepos and went looking for a place to change our greenbacks. I joined a queue for an ATM and giggled hysterically as the Australian exchange rate poured colones by the thousand into my lap. With an exchange rate of 500 colones (ie Columbuses) to the US dollar, I anticipated spending somewhere between Vietnam and Mongolia. I was in for a rude shock. I rounded a corner and after smiling my ultra-innocent smile to two heavily armed guards was ushered into a spacious and air conditioned bank where a few of my companions were avoiding using their credit cards on dodgy foreign networks by exchanging cash directly.

We managed to dodge half a dozen glassy-eyed meth addicts (both local and imported) and drove a few more miles into the park, where a few pre-existing and quasi-pre-existing hotels existed to cater to the foreign and affluent domestic tourist market. We checked into our hotel, an expansive beach side low rise with an even more expansive fellow at the desk, and as one mind switched to beach clothes. For me this amounted to switching to my other set of clothes. When you have only two pairs of pants, choosing your clothing is really straight forward. The beach was a perfect arc of warm sand and warm water about 2km long. For whatever reason, the students in this trip were mostly fitness obsessed undergrads who immediately decided the best thing would be to run to some exposed rocks pummeled by the surf and to climb them. We spent the remainder of the day clambering on stuff, looking for crocodiles, and running along the beach until finally it was time for dinner.

The next day, C, with whom I was sharing a room, thoughtfully woke me at about 4 with the alarm-o-snore. Not wanting to lose a single minute of precious time, I went back to sleep only just long enough to get to the park entrance at the moment it opened. This day I went alone - the rest of the crew opted for horse riding on a ranch in the mountains. Walking into the park, I struggled to see the animals therein for the crushing presence of one particular 'advanced' species of monkey. Their distinguishing characteristic was a peculiar custom of wearing shoes...

Fortunately, they were organised into tribes of about 20, each arrayed around a sacred optical device. Each sacred optical device had a high priest, to whom tribute was duly and frequently paid. His job was to locate the sacred objects of desire with his telescope and then allow his acolytes a quick peek. In such a way I was able to spot the arm of a sloth a few hundred meters away before fleeing the noise. A side track branched to the left. I took it. It branched again, I took the less tracked one. Soon I was almost alone in the jungle. The humidity condensed on my eyelids. Not to worry - walk for a few minutes, then sit quietly until the cool returns. If you sweat too much, you'll ruin all the fun. Before long I came to a sign in Spanish that I think said "only fearless and highly competent hikers past this point". After checking over my shoulder I ducked onto a series of paths with a soft bed of leaf litter. Before long I was alone in the forest, with only the sounds of the surf and lizards skittering along the floor for company. At once I slowed down and relaxed. I opened my eyes and looked around. I followed trail after trail through the wilderness. In such a way I crisscrossed the park several times through the course of the day, while keeping contact with the maddening crowds to a minimum. I saw many, many awesome animals. Monkeys, sloths, a paca, a coati, innumerable lizards, geckos and iguanas, a bright green snake, dozens of birds, fish, frogs, hermit crabs, raccoons, and so on. 

In the heat of the day I made my way down to a beach with a family on it. After emerging from the brush, I took a group photo for them and then settled down to eat my balanced lunch of corn chips and water in the shade of a lemon tree. I counted the period of a seiche wave that periodically flooded the beach or else completely exposed it. From where I sat I could see a beach closer to the park entrance completely infested with people, though for the most part well behaved. A couple of American blokes showed up and one told me that this was the unofficial nude beach, especially in the off season. Noted. At some point I felt a few lemon leaves brush my perfectly coiffed hair and looked up to stare into the face of cheeky monkey who was just dropping in to share my lunch. Fortunately I understood that processed food is poisonous, only I had access to the sort of medical help necessary to survive eating it, and thus kept it all to myself. On my way out, I saw a family of monkeys drop in from a palm tree onto a branch and start grooming each other. Later I saw one catch a lizard and proceed to eat it.

Sooner or later the beaches emptied and I supposed it time to leave the park. I took a dip in the ocean and returned to the hotel to meet the rest of the crew, who had been horsing all day. We all rushed to take photos of the incredible sunset that shifted through an exponential number of shades of pink. B, K and I then exploited a small window of time before dinner to sprint back up the beach and, unable to read in the dark, sneak back into the park to look at some animal eyes with my flashlight. Just as B and I reached the part I knew there'd be raccoons scavenging stuff, we heard and saw some people through the dim light. I didn't want to get busted by rangers, so we slunk into the shadows and kept an eye out. They were speaking Spanish and walking our way. They didn't see us until they were right on top of us, at which point they thought WE were rangers, after which we had a good laugh. Turns out they were camping in the park to avoid paying a fee in the campground on the outside! I was surprised so few people did this, seeing as there was zero enforcement.

The next morning I had a look around town before breakfast and leaving. There was an alley full of tourist trap shoppes, stuffed to the rafters with caramel coloured wooden trinkets, epoxy sculptures of lizards, engraved stuff, and of course thousands upon thousands of pipes - nearly as much variety as Venice Beach, and considerably more tropical in aesthetic. I've seen a LOT of tourist souvenir shops but nowhere have I seen a greater disconnect between the wares (which clearly echo the expectations and preconceptions of the customers) and the actual lifestyle and aesthetic of a place. I nearly expected to see lizard themed babushka dolls. They would have been cool, actually.

We left the Galapagos air and returned to the big city. For a country with 92% hydro electric power and a real shot at carbon neutrality by 2020, Costa Rica has a real problem with vehicle emissions, to the point where, taking a photo, you had to wait a few seconds after a bus passed before attempting to focus the shot through billowing clouds of smog. We were ushered inside the structure of our voluntourism organisation, Maximo Nivel (or Maximo for short). A slick operation that did a mix of teaching, teacher education, and volunteer organisation of all stripes, and a decent side of organising tours through their sister company Transleo, it seemed to be staffed exclusively by incredibly chipper foreigners from all over the Americas. One of them pointed out, positively bursting with excitement, the presence of not one but two staircases to the second floor.

After three hours of mostly pointless briefing we were ushered onto our courtesy bus for the 3k drive to our host families. Five of us were greeted by M, our host (grand) mother who ushered us into her guest wing, complete with laundry area, separate kitchen, and multiple bunk-bedded bedrooms. I inverted my bag and terrified my companions with the spontaneous generation of a full closet of clothes and gear. I took advantage of the distraction and fled to the bathroom with my towel and a supply of impossibly viscous shampoo that sometimes took hours to pour out. 

In a foreign country, one often has no idea what to expect when one enters a bathroom. In Britain, there is no such thing as a hotel with a functional hot water system. In Mongolia, there is no such thing as a bathroom. In Japan, you have to open the shower door to bend your knees enough to wet your head. Costa Rica seemed reasonable. Inside, the shower, however, there was only one tap. Looking upwards my slight trepidation at a week of cool showers was obliterated by the most visceral fear I've felt since breaking a hold while free-soloing on the 28th of December 2005. Armed with the knowledge that I'd since listened to the complete recordings of Enrico Caruso, and therefore had substantially less reason to live on, I took a deep breath and appraised the situation. A metal pipe jutted from the wall at head height. On the end of the pipe, a giant plastic pear covered in occult symbols had been attached. From the top of the pear emerged two thick electrical cables. These in turn vanished into twin blobs of disintegrating electrical tape, from which emerged another set of cables. These ran back down the metal pipe before disappearing inside a 110-240V transformer on the wall. I could assess the relative current because the number of windings was directly visible. The transformer in turn was wired into the lighting circuit. This fact I acertained when, standing outside the shower with one hand behind my back, I turned on the water. At this point the transformer's hum underwent an abrupt change in pitch, like a semi-trailer shifting gear. The lights in the whole house dimmed and flickered but, incredibly, stayed on. From the pear came a sound like a boiling kettle, and from its bottom dribbled a stream of luke-warm water. Seems legit. 

I got on with showering. At the point where I had completely lathered up, the water pressure dropped abruptly, the water flow cut off, and the heating element cut out to avoid boiling dry and catching fire. The lights went back up, the transformer went back to purring. This, of course, I figured out later. At the time, I was certain I had finally experienced the functional equivalent of electro-convulsive therapy and my only thought was whether patients in mental asylums were similarly covered in soap before procedures. Oddly enough, the following day I got an opportunity to find out.

To be continued...

(Photos: https://picasaweb.google.com/105494084231616659850/CostaRica2013)

Australia for Christmas

Prologue

I had to get up ridiculously early. In fact, it was only 90 minutes since I'd finally gone to sleep. I trundled over to my laid-out clothes, pulled on my suit jacket, pants, dress shirt, cufflinks, bow tie, belt, matching socks, and shoes, and snuck out into the winter air. A hulking blue whale of a van whisked me to the delightful LAX and before long I was coasting above snow-capped mountains and zooming between high rises in the city of sin. I spent the morning dozing in an abandoned wing of the Caesar's Palace convention center, before meeting my old friend D and getting lunch at the cheesecake factory. For a man with mere hours of unmarried life left, he seemed unusually calm and cool.

At last the appointed hour had arrived. We met in the foyer, and the six of us, D and his bride L, me, and three other friends clambered into a waiting limo. G had even flown out from Australia. L had also, thus ending the three years of long distance with D! 

We were dropped at the Little White Wedding Chapel on the Vegas strip and before long Elvis turned up and sang "For I can't help falling in love with you". Then the "I do"s and we all stepped blinking and teary eyed back into the sunny Nevada sky. A giant pink convertable whisked the newlyweds to the local landmarks for photos.

My photos: https://picasaweb.google.com/105494084231616659850/DeonAndLilySWedding

While I waited for my CSing friend C to pick me up, I checked out the adjacent drive-through wedding chapel tunnel of love! C and I drove out into the North East quarter to Frenchman mountain and paid our respects to the great unconformity. We checked out the Bellagio fountain, then met at Circo for dinner. I had to cut my antipasto short and flee to the airport, where my flight was only an hour late. 

Like Jonah I was spat out back on the Pasadena pavement a mere 14 hours after I'd left. Which was lucky, because the next morning I had to do it all over again.

---

I left my laptop plugged in until the last moment to optimise its juice concentration, then made a bolt for the airport, arriving with enough time to have dinner with an old USyd associate who I hadn't seen in about five years! Spending more time in the air than the entire door-to-door Las Vegas caper of the previous day, I watched sequentially Prometheus, Brave, The Bourne Legacy, Total Recall, and Cosmopolis. Of the five, the latest Bourne installment was probably my favourite. I also managed to get in enough sleep to land without jetlag!

Shortly thereafter I snuck into the carpark before my lift arrived, and while dodging cars driving on the left was greeted by my mother and sister, A1 and A2. The previous designation of A and a is no longer valid, as my sister had turned 18 during my years of pilgrimage, and was now all grown up!

That evening we went for a rejuvenating takeaway Thai meal at my uncle's new place overlooking the harbour. I savoured the 50s decor and peanut curry in equal measure as the sun set beneath a clouded sky. Thus I renewed my acquaintance with my first skyline and set about an (entirely unsuccessful) attempt to gain 10kg in 10 days.

The next engagement on my already bursting social calendar was a trip the next morning to my brother's university. M, despite a 17 month handicap, had by dint of hard work and more hard work (and ability, talent, and good looks), beaten me fairly and convincingly to the title of Doctor. I was incredibly proud to watch him walk across the stage and be recognised with first class honours and the university medal. Welcome to the club ;P. Even better, that night we all went to his graduation ball, where my cup runeth over with excellent food, fine dancing, and a LOT of doctors. For me it was bittersweet, as the realisation that this very cohesive class of about a hundred students were in the final moments of their physical and professional proximity, and would never ever be all together again reminded me of my own class and partial loss of friends and family following my own self-imposed exile.

Two days later, it was time to get my party hat on again as A2's belated birthday party required celebration. Like me, A2 had the good fortune to celebrate her birthday in the middle of the exam block, and thus I was able to attend the birthday party as well as everything else! A2 attends the same university I did, but with few exceptions there has been complete turnover of the people involved. About a hundred people of all ages and associations turned up to rock the house and play the piano and dance all over the floor hitherto concealed by now sequestered furniture. Admittedly my involvement in family life has been minimal since I moved out in 2006, so it was pretty cool to realise that in the meantime A2 had found a bunch of super nice friends and colleagues to do stuff with. We all gave speeches and told funny stories and partied until the tiny hours of the early morning, at which point nearly everyone went home.

We had a day to clean up and to catch up with other friends on their way through. Nearly everyone was busy with their own families, but in the meantime I was able to wander semi-lost through mostly forgotten fragments of my not too distant past and photograph the interesting stuff for later.

On Christmas eve M, dad and I were dropped on Pittwater by mum in the early morning. We applied sunscreen liberally. Sunglasses were obtained, and collars ceremonially popped. My grandfather's sailing yacht had been in for some repairs to the rudder, and after some minor confusion we set the sails into a stiff nor-easter and ploughed through the raging seas of Broken Bay. I did some sailing in high school, but all in high performance racing dinghies. It took some getting used to, but I loved the way the boat lifted over the waves and leaned into the gusts. (video: http://www.youtube.com/watch?v=7s08CmQZqwg - various time lapses are nearby). Somewhere near Lion Island we saw a fairy penguin swimming along. Eventually we luffed up into the lee of Box Head, dropped the sails, and motored up the channel. Narrower than I remember, the sandy entrance to Brisbane Water is only barely wide enough for two boats to pass. We were just barely pushing against the outgoing tide, swung wide around half-tide rocks, and cruised up past my old school at Pretty Beach. Spared a flogging by driving spray, I was now soggy with nostalgia. We cruised up to the mooring and rowed in. The small dinghy could hold only two at once, so I rowed back out to retrieve the doctor and returned him to the shore. There we careened the row boat, which had been growing stuff at the mooring for about a month, and gracefully accepted my grandparents' offer of an incredible lunch overlooking the bay, before driving back to Sydney. That evening M and I battled fading light and incredibly confined spaces to fix a leaky coolant hose in his car. Having only four hands between us it was amusing to juggle an umbrella, a torch, multiple screw drivers, and swat mosquitos. At last the job was done and it was time for to eat five consecutive dinners.

While Christmas eve was a beautiful summer day with a warm sun and a cool breeze, Christmas day was more usual for Sydney this year. A series of thunderstorms dumped torrential rain incessantly from dawn to dusk. Family christmas was conducted at my uncle's place, where the table had been extended to the deck. Being young and vigorous, the under-30s were consigned to the deck, where biting winds served to augment our already voracious appetites. I ate until I couldn't move, and wasn't even hungry until 4pm! Meanwhile at home I'd scored a brand new electric shaver (thanks M!) and a rusty nail (thanks dad!). 

On boxing day we kept a close eye on the cricket and the Sydney to Hobart yacht race, and one of my teachers from high school R dropped by. Like many of my other awesome teachers, he'd just retired and was looking forward to some adventuring in the years ahead.

The following day I returned to the coast and spent an hour poking around the house my dad built just before I was born and the surrounding wilds where I spent much of my childhood. While there are now many more houses, some of the fundamental elements remain unchanged. In particular, the seashore, the smell, many of the same rocks and trees, places where M and I used to play. After yet another extraordinary lunch, in which my bread was mostly one-dimensional, A1's brother and I went for a walk around to Wagstaff, where I first went to school, and half-tide rocks, Lobster beach, and the intervening rock pools. We dropped in on some of my old friends from that time. N, who I remember as a 2 week old baby, is just about to finish school! I felt old.

The next day was, in many ways, the coolest thing I did all week. My old science revue friends C, M, and M's boy D met at central station and took the train south to Cronulla. We even made the connection to the Curranulla, a venerable old passenger ferry to Bundeena, a small town on the southern edge of Sydney. Although I had reasonably thoroughly explored this park during my undergrad years, this time we were going to try to walk the whole thing (28km, 18mi) in a single day. We were psyched and totally ready! A short walk took us to the trail head, and thence to the edge of the cliff, and the beginning of the Coast Walk. Stopping at the usual landmarks on our way south, we made it to Wattamolla by noon. Despite a complete lack of rain and dry waterfalls everywhere, the lagoon was crawling with people enjoying the beautiful weather. Above Wattamolla, however, we noticed a change in the wind and before long a southerly blew over with lots of wind and a few drops of rain. We clambered down the 'slot of doom', a steep canyon that cuts through a hundred metres of cliffs to the edge of the sea. Some of the most glorious rock hopping for miles around took us beneath the cliffs, over ledges, under boulders, and around the point until we smoothly entered the cove at Curracurrang. Here we walked up the nearly dry river bed to the waterfall and ate lunch on a rock in the middle of the pool, surrounded by hopeful looking lizards as clouds skudded overhead. We were making good time.

South of Curracurrang, the track winds around to Curracurrong, a twin waterfall next to eagle rock. I battled some wind gusts to get close enough to the waterfall to see it blowing up in the wind, something I had only seen there once before. We crossed the nearly always dry gully of Curracurrung and then traversed the Curra moors, although at times it was nearly impossible to make headway into the gale! Much to my amusement, C and M were blown backwards a few times. The trail tracks more or less directly south through the coastal heath, a wild, twisted, weather stunted forest of low shrubs and trees until it abruptly surfaces on the northern head of Garie beach. I ditched my sandals and we pushed on along the flotsam strewn beaches, skirting headlands just above the choppy sea and breaking waves, until it was time to summit the head above Era and descend to Burning Palms. For the first time ever, the group politely declined my offer of a water break on the saddle, keen rather to press on and make good time. At Burning Palms we opted to try and make it to the pools and then to the train station in about two hours, which seemed feasible. By this stage I'd stubbed my toe on a chunk of Australia and was leaking a little, so was pretty happy to leave the grassy path and return to rock hopping. By now we were pro and before long we reached the rock platform.

Between a towering, multihued cliff and the raging sea, with incredible views to both the south and the north, this particular rock platform harbours a secret. Close to the edge, the waves have carved a series of circular pools that are just big enough to swim in, and up to 10 feet deep. I don't get to go here very often, so I changed into my boardies and took the plunge, as thudding waves sprayed over the pools and bubbled everywhere. Peculiar erosional features channeled water away from the edge toward the cliff and eventually back out.

Opting not to climb the waterfall (and back way out) due to strong winds, we backtracked and hit the trail hard! Palm jungle never seemed shorter and without a break D and M led the charge to the top of the cliffs, after nearly a thousand stairs! After one last break to look at Werrong beach (though not too closely!) we redoubled our efforts and cruised along the cliff track towards Otford station. Without discussion we lifted our pace to an easy trot, and ran the last few km, arriving with minutes to spare. We were relieved to not have to wait another 2 hours for a train! Toe injury aside, there were no casualties and I at least suffered very little soreness the following day. There is something about wearing ridiculously wimpy sandals that encourages a gentle tread!

Photos: https://picasaweb.google.com/105494084231616659850/CoastWalkDecember2012

Nevertheless, I took the following days pretty easy, catching up with old friends and playing music, wandering through Newtown and checking up on all the old haunts. I even managed to pick up some mail for an ex-housemate at our ex-house, while being asked if I was interested in having multiple red-haired children with the current occupant's cousin. Needless to say, I politely declined.

Before long, new years eve rolled around and it was time to get into party mode once more. M invited some of his med friends, and I invited whoever I could find that hadn't already accepted a tastier invitation! As a result we had a terrific eclectic mix, consumed vast quantities of corn chips, cashew nuts, and smoked salmon, and managed to see both fireworks displays. C was keen to see the fireworks from a better vantage point at Blues Point, but last-minute road closures meant we had to run all the way around to the next point. We found a good spot seconds before the clock ticked over and the new year began. It was a pretty excellent display!

2012 was the most interesting year yet. Owing to time zone technicalities, it was a slightly short year, but 2013 will undoubtedly make up for it!

Next morning it was time to scoop all my stuff into a pile, consume it with a wheely bag, and head to the airport. I farewelled the family and got through the various circles of hell into the departure mall, only to be surprised by furious glass tapping on my way to the appointed gate. The family had snuck into a restaurant that faced the walkway and, hiding in wait, sprung their attack. One last round of smiles and waves and I was starting to think in destination time. I burned up some superfluous phone credit talking to the few people I hadn't managed to track down, boarded the plane, and took off. Sydney vanished beneath the left wing with airborne alacrity and I settled down to watch "Pitch Perfect", "Expendables 2", "Looper", write, read, and think.

---

Epilogue

It is fun to return home. At some point one becomes aware that although you're surrounded by a dimly familiar setting, the places you remember now exist only in your mind. Perhaps, they only ever existed there. Are memories images or feelings?

Photos: https://picasaweb.google.com/105494084231616659850/Australia2012

Space Elevator/Lift Physics

Recently I gave a lab talk on a topic that's always been dear to my heart - space elevators!

Here I will attempt to summarize my findings. Fortunately there are minimal numbers of equations!

The basic idea: A satellite in geostationary orbit completes one orbit every 24 hours, so thus remains at the same point above the Earth. If you unspooled a counter-balanced cable that was long and strong enough, it could touch the surface. Then you could climb up into space without using a rocket, like Jack and the beanstalk.

Question: How far above the earth must the center of gravity of the satellite be in order to be geostationary?

Answer: About 36,000 km.

Maths: In the geostationary point in a rotating frame the gravitational force is balanced by the centrifugal force. GM/r^2 = r w^2. The period of Earth's rotation is 86400 (-240*) seconds, giving a radius of 42,100 km. The Earth's radius is about 6380km, giving the above answer. *The sidereal day is only 23 hours and 56 minutes long.

Discussion: This is a long way - about 3 times the diameter of the earth. From the top, the earth would look smaller than the field seen inside a stadium. The cable length would nearly wrap all the way around the Earth. By comparison, a train line around the equator would be easier to make, but nowhere near as useful, and about the same length. Similarly, aiming for a travel time of 5 days implies a speed of 300km/h, about the same as a bullet train.

Question: How strong would the cable have to be?

Answer: Specific strength of 50,000 kNm/kg, which is about 100 times stronger than steel.

Maths: g(h) = GM/(r+h)^2 - (r+h)w^2. The acceleration is zero at the geostationary radius. 

dT = rho A g(h) dh, where rho is density and A is cross sectional area. Integrate from the surface up to any height H.

The peak tension is at the geostationary point, and is about 50,000 kNm/kg. This has the units of the sound speed in the material squared.

Discussion: One way of comparing the tensile strengths of materials is by their breaking length. Eg A-36 steel has a breaking length of 3.2km. That is, a cable 3.2km long would break under its own weight. Unfortunately this breaks down for really strong materials, because the Earth's gravity is not the same if you go up high enough! So we'll stick to specific strength as a unit of strength. Divide by 10 to get the breaking length in km. 

50,000 kNm/kg is a lot stronger than Nylon, the polymer from which climbing ropes are made. A standard climbing rope is about as thick as your pinky and can lift a car, or (more importantly) absorb a large fall from a big man. If climbing ropes were made from something strong enough to make a space elevator, not only would they be even more expensive, they need only be as thick as a human hair. Of course, heat dissipation in descenders is already a problem with narrow climbing ropes...

Question: How much energy do you need to escape from Earth?

Answer: 62MJ/kg. This corresponds to an escape velocity of 11km/s. (REALLY FAST!)

Maths: U = Gm/r. The earth weighs 5.94*10^24kg. G is Newton's constant or 6.67*10^-11 in SI units.

Discussion: This is the MINIMUM energy requirement, assuming 100% efficiency. If you use a rocket with chemical energy (the current best method) typically you need at least 100 times as much mass just in propellant, and that is about 1/1000th of the cost of the rocket structure, as a rough proxy of how much energy is needed to build the metal parts of the rocket. So the attraction of a space elevator is a million fold increase in energy efficiency for operation. In comparison aeroplanes, bridges, and trains can consist of more than half cargo or payload, not less than 1%. Note that a space elevator does not get you to escape velocity, only to geostationary orbit. However, extending the counter weight with a tail out further into space can allow people to steal momentum from the rotation of the earth to be flung into space. Escaping the sun requires about the same delta-v again (30 km/s to 42 km/s). Such space elevator extensions could be readily added onto an existing space elevator as it is already in equilibrium, and would require an extension of 109,000 km and 260,000 km respectively. The tensional forces in the cable continue to decrease out until Earth escape velocity, then reverse direction. To obtain cable-flinging escape velocity from the solar system, the cable would extend 5/6 of the way to the Moon and need to be somewhat stronger: 200,000 kNm/kg if it were uniform, somewhat less if it tapered as the inverse of distance from the Earth. Tapering can also work on the Earth side, though practically speaking you still need stuff two orders of magnitude better than steel anyway.

Question: Material strength. What is strong enough to do this?

Discussion: 50000 kNm/kg is a really big number. Some other materials commonly regarded as strong, and their specific strengths (in kNm/kg) are:

A-36 steel: 32

A1S1 A11 steel: 694

Titanium: 209

Tungsten: 750

Glass fibre: 1900

Carbon fibre: 3540

Spider silk: 1270

Kevlar: 2500

Spectra: 3800

Bone: 80

Silicon (crystal): 3000

Diamond: 800

This looks a bit bleak. To get there, we're going to have to have to resort to using the words nano and meta. 

Carbon nanotube: 46000

This is the right ballpark. It's hard to imagine a stronger material than certain allotropes of carbon. 

Question: Just how strong can carbon structures be?

Answer: Graphene (the subject of the 2010 Physics Nobel Prize) is a remarkable material with a specific strength of about 450,000 kNm/kg. It is hard to imagine a material that could be stronger.

Maths: Graphene is a single layer of graphite, and consists of layered hexagonal lattices bound together by SP2 hybridized orbitals. The spacing between atoms is 0.142 nm and between layers is 0.335 nm, which is about a thousand times smaller than a wavelength of light. From this the density can be estimated at 2.272g/cm^3. The tensile strength can be ball-parked by dividing the first ionisation energy by a typical deformation energy, giving 7.5*10^-8 J/bond, which is a really big number considering these are just atoms! In a lattice, this gives a yield strength of 1 TPa, which is (not coincidentally) the laboratory measured value.

Discussion: It is hard to overstate just how miraculous graphene is. A one square meter sheet of graphene strong enough to support a cat would weigh less than one whisker! This is a far cry from 99% of a rocket's mass being not-cargo, which illustrates nicely the difference between the two regimes. However it is worth remembering that the longest nanotube ever made is 18.7cm. So there is a long way to go before we are able to bind a bunch of these together to make a strand that can wrap all the way around the earth. It is also worth noting that if the day were much longer or the Earth much fatter, a space elevator would be impossible.

Question: Architecture? How might you build one?

Discussion: Consider for reference value a cable strand 1mm across and 36,000km long. A very special piece of string! When spooled up it has a volume of 36 m^3, or roughly equivalent to my office. Its mass is 75 T, which is somewhat more than the mass of the occupants of my office. With a specific strength of 60,000, which has been demonstrated in the lab, it would be able to support a weight of 100 T, most of which is its own weight. The loaded space shuttle also weighed about 100 T, although it only barely got to low earth orbit.

Question: How might a space elevator system work?

Discussion: With departures every 15 minutes, a 5 day transit time and 2 directions of traffic, there are 1000 climbers in total. Each is structurally and functionally analogous to a train car or a mid-size commuter jet such as the A320, weighing about 50 T when loaded. Additionally, the cable has to support the mass of attitude rockets, shielding, power, escape pods, tracks, damping, and so on. Estimating a mass of 1.5 T/km, the cable has to support a mass of 100,000T. Estimating the structural ratio at 10%, or each kg of stuff requires 9 kg of cable, the total mass of the cable is a billion tonnes, or 1 Tg. Only in computing can you use giga, tera, and exa with a straight face! This would require something like 15,000 of the 1 mm model string-like strands, which all bundled together would be 15 cm across. So as of today, we can make a carbon nanotube long enough to span a space elevator cable, only in the wrong direction! Obviously in an actual cable, the fibres would be separated to avoid bulk failure and aid weight distribution. Note that this billion tonne cable needs a counter balance or counter cable above the geostationary point to prevent it from falling down!

Question: How do you build it?

Discussion: Good question! Wave a magic wand! In all seriousness, there are two possible approaches.
Send a nuclear powered robot to the asteroid belt, find an appropriate sized carbonaceous chondrite asteroid. We're talking ~300 m long. Have it mine water and blast it out to move its orbit to the Earth, inserting it in geostationary orbit. Construct a cable by extrusion, probably pointing away from the earth. When it's finished, rotate it into place above a suitable point on the Earth. Profit. Problems include possibly crashing said asteroid into Australia, and a slow rate of construction. Even if it built a cable at 1 km/day, it would still take 100 years to reach the required length.

Launch a seed cable to geostationary orbit. Currently the largest rocket available can launch 6 tonnes to geostationary orbit. This is more than enough for a clever communications satellite, so we'll have to make do. The satellite consists of a spool and other gizmos, and the cable can be paid out at the appropriate angle to compensate for Coriolis forces rather rapidly. The cable in question would be about a quarter of a mm thick, but capable of supporting a large car, in addition to its own considerable weight. Part of that extra mass could consist of attitude control rockets at the LEO altitude to help it avoid space junk, and possible laser systems for micrometeorites. Once the feeder cable was secured, additional strands could climb and fix themselves into place at an exponential rate. Finally, shielding, tracks, dampers, giant space lasers and other equipment could be fixed in place and the cable completed in as little as 5 years. Note that construction on a tail or counterweight could proceed at the same time. As multiple strands could be build on the earth at the same time, there is no bottleneck in this approach. Disadvantages include the cost of the initial launch, weight balance issues, and the vulnerability of the early cable to severing.

Question: What about vibrational modes?

Discussion: The math of this is left as an exercise for the reader. The sound velocity is given by the square root of the tension divided by the linear mass density, just like a guitar string. The sound velocity goes to zero near the ground, implying that the wavelength also goes to zero, and the amplitude necessarily increases. Fortunately the atmosphere provides some viscous dissipation, but ultimately avoiding harmful vibrations is a matter of clever design. Some transverse vibrations are probably an excellent way to transmit power along the cable and to enable it to avoid collisions with satellites at lower orbits.

Question: What might other hazards be?

Discussion: Corrosion, micrometeorites, lightning, attacks, etc. Most of these issues can be dealt with by covering the structure in a shield like the shield on the ISS. It consists of a ceramic layer which absorbs the impact by shattering, and a metallic shield layer which can absorb lots of small impacts. There are other valid approaches for absorbing smaller collisions as well. The tracks would also be covered, possibly by moveable hatches that open as the climber passes and close after it leaves. Tracks would be multiply redundant and would be able to be switched in case of damage or maintenance such that the overall system could continue to operate without breaks. Although the cable could be as narrow as 15 cm, it makes more sense to separate the strands in a weight-sharing structure to which the tracks and other stuff can be attached. That way the breakage of compromise of any particular strand is less likely to affect those around it.

Question: What would it look like?
Discussion: Not much. At any point along its length, perspective would disappear it out of sight within a few km. On the earth's surface, it would appear as a rope going up and disappear from sight before reaching the clouds. From the top looking down the earth would be the size of a basketball at arms' length. On the way down, the earth would appear to dominate the view with a horizon for the whole day, but only in the last half hour would you enter the atmosphere. For comparison, it has similar length-width ratio with a railway rail that stretches across a continent.

Question: So how much does it cost?

Discussion: This is impossible to estimate! The cost of a launch to geostationary orbit is about $150m, but this would be a trivial expense compared to the materials. If each climber cost the same as an A320, then they would cost $100b, including a few spares. If the cable cost the same as steel, the materials would cost $300b. Cable would likely be made from coal or oil, or possibly atmospheric CO2. What you lose in material construction costs you might make back because of the lack of refinement needed. At a billion tonnes, the cable represents about 10% of the current annual carbon output, so could be viewed as positive carbon sequestration! Including development costs and peripherals, a cost in the trillion dollar range seems possible.

Another way of estimating the cost is the cost necessary to be competitive. If there was a demand for 4000T or 600 launches a day, which is the projected capacity of the cable in the above discussion, the cost of doing that over 30 years using rockets is about $2*10^15. However there is an excellent chance that rockets will gradually become fully and rapidly reusable, bringing the cost down by a factor of a thousand to only $2t. By comparison, this is the cost of 10 years of war and a national reputation. This is also roughly equivalent to the cost estimate above, indicating that with enough demand, space elevators could be competitive. While 600 launches a day might seem ambitious now, especially considering that each has a payload of 6 T, consider the history of aviation.

One hundred years ago, a plane that could carry 6 tonnes, let alone the demand for 600 flights a day seemed impossible. Today, there are more than 5000 A320s (just one type of aircraft) built. The US has an average of 28,000 commercial passenger flights a day, each carrying an average of 20T of cargo. Similar narratives apply to the history of mass rail. If today a million tonnes of people and stuff gets moved by air every day in the US, a country with a mobile population of about 200m, then 4000 T/day into space implies an off-world population of less than a million. As crazy as that seems today, it's only a tiny fraction of humanity.

The purpose of this blog post was not to predict when, but to demonstrate feasibility. Jules Verne and Leonardo da Vinci both knew that flight was possible, just not yet technologically available. There is no physical law that prevents space elevators from being possible. I cannot say for sure that by the time they become competitive, there won't be a better or more awesome way to get to space. Hopefully involving warp drives. But what I've shown is that it's nearly economically feasible too. 

If I were to hazard a guess for when it would be likely to build one? 15 years to put people on Mars. 5 more to set up a permanent base. 5 more to begin mass migration. 20 more to move half a million people there. At this point continued migration would be cheaper by space elevator, even if people were only going one way. So 2055, which is in my lifetime, hopefully. A space elevator on Mars could be built much more easily due to its reduced gravity.

Pushing the limits of the possible with respect to space telescope design

The next generation of ground-based optical/Near IR observatories, including the 30 meter telescope, will have the capability to perform spectroscopy on "close" extra-solar planets. When results of these observations demonstrate a signature for life on Earth-like planets, I won't be holding up a sign saying "I'm so surprised". What then? Life is one thing, but radio or laser communication capability is another. Let's say that radio transmissions from close extra-solar planets can be ruled out by SETI as of yesterday, but pesky scientists want a closer look. 

In my day job, I study details of fundamental gravity theories, many of which suggest the possibility for faster-than-light travel, given infinite energy or money or both. Assuming that doesn't become possible, and no-one gets around to building an antimatter or fusion powered space ship like the one from Avatar, getting closer to get a better look (like we do with the outer planets) isn't really an option. 

So... we need a telescope. A REALLY REALLY big telescope. Just how big are we talking here? Rayleigh's resolution limit is a wonderful piece of physics I do not have time to expand upon here, but the basic equation is:

(distance to feature)/(size of smallest visible feature) = (number of wavelengths you can fit across your telescope). 

If we have a telescope of a given size, a smaller wavelength would seem better. This is the reason, for instance, that computer chips are produced with ultra-violet light, and that electron microscopes have higher resolution than visible light microscopes. However, the highest resolution telescopes are actually radio telescopes. How can that be, that a telescope with a wavelength of about 10cm can have a better resolution than a telescope with a wavelength of 10^-7m, a million times smaller? Simple answer: the telescope is a million times wider. Ultra-wide baseline aperture synthesis, such as those fancy dish radio telescopes you see in the movies (in Bolivia, I think), and even using remote space probes like the STEREO spacecraft. In the next decade or so, the square kilometer array will be built in Australia and Africa, further emphasizing the utility of this approach.

For the purposes of this discussion, I'm going to assume that the rapidly developing field of optical aperture synthesis has reached maturity, and that a cable of optical fibres is sufficient linkage between non-adjacent telescopes. In truth this glosses over the bulk of the technical problem, but similar systems have been developed in the mid-IR band, and all-optical signal oscilloscopes currently in development will eventually give rise to a thousand-fold increase in the resolvable frequency of signals. In short, while existing optical aperture synthesis requires fancy clean rooms and alignment and mirrors and stuff to ensure the optical paths are of the same length, and thus to achieve analog interference, future systems will be able to be designed digitally. 

How large, then, must this system be? The distance to the nearest exoplanets is of order 10 light years. That is 10 years * pi * 10^7 seconds/year * 3 * 10^8 m/s = 10^17m. Further than the average afternoon stroll. The full moon subtends an angle of about half a degree in the night sky, which means that the naked human eye can see about 100 features across its face, or ~10000 features in total. The smallest such visible feature is about 30km across. Rayleigh's equation for telescopes applies to the eye too. If your pupil is 5mm across viewing the moon, then you can fit about 10^4 (10,000) wavelengths of visible light across it. The inverse of this is the angular resolution of the eye. To convert to degrees, multiply by about 60, giving about 200 'pixels' per degree, though real-world results may vary (100 is a more reasonable figure).

But I digress. We want to view exoplanets with as much detail as the naked eye can view the moon. The number of wavelengths needed in the aperture is 10^17/10^5 = 10^12, or a million million. Choosing 1 micron light for the nearest of the near infra red (and very close to optimal wavelengths for optical fibre and chalcogenide-based instantiations), this gives a telescope aperture of about 1000km, the size of a small continent. Trained on planets in our own solar system, the power of such a system is incredible.  At Mars' closest approach, individual treads left by the Curiosity rover would be visible. Indeed, the field of view would not be much larger than the rover itself!

Where on earth to build such a monstrosity? Speaking bluntly, nowhere. There are not enough tall mountains to build telescopes on to get the appropriate baselines, and even if there were, the aberration introduced by the Earth's atmosphere ruins the whole party. Fortunately there is another 1000km canvas nearby with no weather or atmosphere to speak of. Getting there is a little technical, but compared to the cost of freezing out Earth's atmosphere, it's comparatively easy.

Bear with me, as this is where the fun part starts. Basically copying the SKA's plan for radiating spirals of telescopes to maximise the number of different baselines available for aperture synthesis, a plan begins to develop. First and foremost, the moon is a terrible place to live. No atmosphere, a month-long day night cycle, baking/freezing temperatures, lots of radiation, lots of granite and SiO2 and not much else. Very little water. If humans ever live on the moon, they'll live somewhere near the poles and do so only furtively.

What is the best way to build a telescope capable of imaging continents, seas, and mountain ranges on planets around other stars? I do not know for sure, but a few ideas come to mind.

1) Autonomous nuclear powered self-reproducing robots.

2) Lots of humans on the moon drilling stuff.

3) Build them on earth and fly them up there.

I'm going to focus on option 3, as it could work with existing technology. Several hundred telescopes with folding capability based on the James Webb Space Telescope architecture, with an integrated landing system and mobile shade are individually launched from Earth, flying to lunar orbit and landing a few days later. This is proven technology, and the numbers involved mean that a small failure rate would not be the end of the project. Each telescope then unfolds itself and deploys a rover vehicle equipped with ~50km of fibre cable, which then drives to the next closest and already deployed/linked telescope and plugs in. Each rover can then perform a secondary exploration mission. If based on the versatile architecture of the MSL, a wide variety of experimental payloads are possible.

While built at an equatorial location on the far side of the moon, the array would depend on a relay satellite, likely in polar orbit to transmit data back to earth, though Lagrange points might also be possible.

Price tag? Based on similar projects undertaken by NASA this decade, the cost of such a project would certainly be rather large. In rough figures, I estimate about $5b on development, $2b on manufacture (mass production), and launching? Well... 

The JWST will be launched on an Ariane V booster (assuming all goes to plan...), which costs $120m a shot. To launch 400 telescopes would then cost $40b or so, though you might get a bulk discount. However, SpaceX is developing a reusable launch vehicle capability. For this launch, however, that would only apply to the first stage. Nevertheless, the total cost might be reduced by a factor of 2 or 3.

Total cost would then be $20-50b, or roughly the cost of a manned (series of) missions to Mars. Equivalently, this is the cost of a few months of war in the middle-east. For a telescope powerful enough to deliver detailed optical images of planets we may never be able to visit, this is a bargain.

Canyoning near Caltech

Many adventures, not all adapt readily to the blogging medium. I think this is a function of how much talking goes on. When I travel by myself, most down time is spent in quiet introspection and narrative building, whereas on a family adventure most time is spent talking and chasing, carrying on, etc! ;P

To begin with, last Friday Tesla Motors launched their all electric (all singing, all dancing) Tesla Model S luxury sedan car. It looks quite nice - I saw one at Caltech a few weeks ago. It's interesting to look at the pricing model. For most cars, buying a bigger petrol tank would be a small additional charge. For electric cars, the fuel tank, or battery system, is the single most expensive component, so each additional 120km or so of range costs you another 10k at the showroom. Prices for batteries are coming down, as energy capacity slowly increases, so likely this won't be the case forever. For the time being, however, the energy capacity of the best batteries per kg or per volume is about 1% of petrol, at least in the re-usable, non-Dell laptop sense. This necessitates a large battery, but you can get away with a motor that fits inside the wheel, with only one moving part. In the Model S, the battery pack is about 10cm thick and forms the floor of the car and part of the chassis, transforming this technical constraint to terrific body stiffness and a great deal of freedom with interior design. I think it's a rather nice car, though I'll have to clip my coupons for a while to afford it. Some reviews: 

http://news.yahoo.com/blogs/lookout/tesla-model-first-drive-electric-sedan-change-world-220709669.html

http://content.usatoday.com/communities/driveon/post/2012/06/first-drive-teslas-model-s-electric-is-spectacular/1#.T-fpibVSSuJ

To the main news. There was some unpleasant noise in various online climbing forums a few months ago as Caltech Alpine Club was incorrectly accused of trashing a climbing route in the Sierras. To mediate the PR situation, we decided to publicise one of our cleaning up trips much more widely this time, which resulted in yesterday's activities. Meeting at 7am, a hardy bunch of climbers and their friends set off for Eaton Canyon, one of the nicest canyons in the San Gabriel mountains and also one visible from Caltech. I was kitted out in shirt, board shorts and vibram "creepy toe shoes". Later I swapped my shirt for my harness, thus maintaining the size of my clothing arsenal. Some other, much more experiences canyoners wore wetsuits and very sophisticated belay systems. But I digress...

The trip began with a swift walk up the Mt Wilson Toll Road, originally a mule track by which large telescopes were brought up to the peak piece by piece about 100 years ago. Later it saw use as a death-defying car race track, though this morning it supported bikers and runners. It's about half of the Caltech-Mt Wilson-Caltech marathon, an unofficial route used by people who really really like pain. Though some improve it slightly by appending another 42km to get to the beach. About 2/3 of the way up we turned off the main trail and began an increasingly steep, slippery, and overgrown descent down into the canyon. My shoes provided a unique insight into the degree to which old dirt roads and tracks become very very rocky. Having got the canyon floor, most people harnessed and helmeted up and proceeded down stream. At this point I realised I had forgotten my trusty bike helmet, so resolved to avoid having my brains dashed out by an unseen rock plummeting from above. Reader ==> I got lucky this time!

I set off down the canyon, and quickly came to a double natural waterslide. Popping out the bottom, drenched utterly, I removed a persistent string of green goo from my hair and grinned from ear to ear. This canyoning business is awesome!

As one of the more experienced members of the CAC who were there that day, I was positioned manning a rappel (abseil) station, basically to ensure that people who were rustier than I put the ropes through the descender properly. The first waterfall, however, was easily downclimbed by any of several different routes, so I talked nearly everyone through them instead, taking time between groups of people to explore the area. I found a snake, a few frogs, an extensive cave system (beneath fallen boulders) with unexpected chimneys I used to surprise passing canyoners. Some hardy souls also fireman poled down a tree to bypass the drop. Some years ago it was in fact possible to pass all six major waterfalls by jumping, but subsequent floods infilled the bottomless pools to the point where I could touch the bottom in all but one.

Soon enough all the canyoners had passed me, with J and a rather determined woman in her 70s bringing up the rear. I put my gear back in my waterproof stuff sack, put my dried shirt back on, and promptly got it wet again. It was rather cold, so I took it off and went shirtless for most of the rest of the trip. I had another dry shirt in my pack that I wore during the longer breaks from getting drenched. The canyon walls slid by as I skidded on smooth river sand over boulder after boulder. Below my rap station was a series of larger and terrifyingly awesome waterfalls. I clipped onto the rope and threw myself into the abyss. I had found that my dominant right hand was more useful for fending off the wall than locking off the ATC, so I usually descended left-handed. This also helped to equalise the wear on my gear! From below, each waterfall was a unique combination of curved, watercut lines tracing back in space and forward in time to the current chute, often green with algae and moss, and forming very sleep water slides. Canyoners with more sophisticated belay devices, such as figure-8s or piranhas were able to slide these waterslides and check themselves before plummeting into the cave and pool below. Every now and then I walked beneath an enormous tree trunk, wedged between both sides of the canyon far overhead by a past flood. One of the last waterfalls in the upper section required a tight squeeze between a boulder and the wall, just wide enough for me to fit through. I threw my bag into the pool below, probably bursting the waterproof bag containing my (old) camera, with inconvenient results...

Meanwhile, I'd managed to feel my feet onto two slippery ledges below and out of sight. My body, wedged in the narrow space, left just enough space to pass my left hand through and tie into the rope. Meanwhile a very petulant frog sat on a rock 10cm from my face and stared at me the whole time I was fumbling the ropes. At last I was tied in, and began to descend. At this point the anchor was above my head, which necessitated some creative gyrating. The very height of gracefulness, I can assure you. Not long after that, a fallen tree provided a nice tightrope to avoid a swim down a short waterfall and across a pool. Here I caught up with the first of some of the people who'd already passed me. Wire brushes and squirters in hand they were undoing in 20 minutes what some spray-paint wielding vandal had done to some perfectly respectable granite in about 10 seconds. I stopped to scrape with a convenient rock until shivers set in and I kept moving. Between the two sets of falls, there is about a mile of more-or-less flat river to traverse, which is not dissimilar, though somewhat less tracked, than the canyon between the bridge and the first waterfall. I proceeded down until we came across a second group of trash collectors and graffiti removers a short distance below the third-last waterfall. It was at this point that I discovered that my camera and waterproof bag weren't, so I salvaged the batteries and memory card before proceeding. A rope had not been set on the second last waterfall, as there was an easy track to bypass it. Unlike the first waterfall bypass track, which killed two people last year and injured a few others---one before my very eyes. He escaped by helicopter with two additional "knees" between his hips and the original pair. 

Below the second waterfall was a large open area with a lot of trash and graffiti. By the time I got there, most of the work had been done by the second team, who had come up from below. Also enjoying the surroundings was a group of about five youths, who kindly took it upon themselves to see if alluvial action had yet deepened the pool below the waterfall to re-enable jumping. The first guy took the waterslide, falling about 8m into the pool, and didn't die. His friend decided to climb up the wall another 4 or so metres, and after a few minutes of deliberations, jumped. All but one of his foot bones survived the fall. Initially in shock, they began to walk back down the canyon towards the first waterfall, and presumably their transport. After a few hundred metres, however, it became clear that walking was not really an option, let alone climbing the track back down. For a while it looked like we'd have to harness him up and lower him over the first waterfall on one of our lines (how's that for an exercise in liability?!). Well before he got anywhere near the last drop, however, two helicopters had flown in and winched him to safety and probably a stern talking-to. On our way out we saw the usual 15 members of the fire brigade with their one-wheeled stretcher, impressively far up the very rugged canyon! So in the end, the only stuff I lowered over the last waterfall was some rubbish. Soon after I lowered myself down the final slippery and extremely cold/wet waterfall to the pool below and greeted some friends sitting at the bottom, including my Australian friend S, who helpfully pointed out that my bare chest was traumatising members of the general public. Again. I pulled my dry shirt out and threw it on, to general grunts of approval. Stowing my harness, I looked once again like a normal person, though by the time we'd walked back to the car, the pound or so of sand in each of my shoes had managed to displaced a lot the skin with which it competed for primacy. This was not a problem while walking in the water, or while my shoes were wet, which I found interesting.

On the way back to Caltech we passed my friend J (of the European adventures a year ago), who was off to summer research in points East for 6 months, so I jumped out and gave him a hug moments before he boarded the airport shuttle. Back at the ranch I cooked about 100 kilos of pasta before arranging my surviving photos and hitting the sack.

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

In other news, T, S, and I explored Anza Borrego Desert State Park a couple of weeks ago. It was pretty rad, though the adventures are best shared in the visual, rather than textual, medium: https://picasaweb.google.com/105494084231616659850/AnzaBorrego2012WithTAndS

Spring 2012 Geology field trip

It was time for another trip with the geologists. My most avid reader(s) may recall a trip to Baja California about six months ago, or to the grand canyon, this time last year. These field trips are like a breath of fresh air and new ideas. This time, the trip had been timed and placed to coincide with the annular eclipse of May 20. Being my first eclipse, I was rather excited, and brought all manner of solar filters, cameras, tripods, binoculars, etc.

We jumped in the tiny 9 seater extended expanded Ford Expedition and headed for the Owen's Valley, site or route of many previous adventures, as it is on the way to MOUNTAINS. First up was the Vasquez rock, once thought to be much more geologically interesting than it in fact is, but still rather tall and a good place for lunch and some mild bouldering exercises. After lunch we drove across the San Andreas fault, visible in the side of the road cutting as fabulously twisted strata. Set the steering wheel and take a snooze across the Mojave desert, through red rock canyon, and into the Owen's valley. At its head is a fossilised water/lava waterfall, caused by a series of eruptions moving the river around. Dry now for a long time, water carved hollows like Somersby Falls (inter alia) remain carved into the basalt. Again, set and forget as hours of your life vanish before getting to the top of the Owen's valley, where the road follows a water course (long dried up) through the Bishop ash deposits and up to the crater lake called Mono Lake. Many volcanoes in this region along a hot spot, though today the active part of the Cascades is far to the north, where various microplates are still being subducted under Washington state. California was obviously hungrier, because it's already finished. 

We stopped at the Mobil Station restaurant in Lee Vining, apparently set up by a celebrity chef escapee from San Francisco, and ate our reasonable fare looking out over Mono Lake and watching the sunset. We drove to the south to find our campsite, passing large patches of bare ground; the forest killed by gas seeping up from below. Won't sleep there! S and S and co had already set up a nice campfire for us, I located a cot bed, and spent a few minutes freezing my toes away from the fire to get a good look at Saturn's rings through my binoculars. After a few hours of fireside chat, I settled into my sleeping bag to sleep, watching a shooting star streak overhead as I did so. Unfortunately, my feet had already got so cold in the sub-zero temperatures that they didn't really warm up until the morning, which made for a cold, uncomfortable night.

Next morning I woke up, dragged myself metaphorically kicking and screaming from the warmth towards some breakfast, packed the car, and drove down to Mono Lake's shoreline. Once the site of an army testing base, now a scrubby beach, the lake's falling level has exposed a large number of tufas formed by precipitation of calcium carbonate from fresh water springs below. Mono lake is much saltier than the ocean and has a pH of 10, making it inadvisable to drink. Surrounding the lake a few local mountains still had snow, which made for a pretty view. Next stop was Walker Lake, a remnant of a much larger lake, and even now, dropping more than 25m in a hundred years, since water diversions for irrigation. Formed by the usual half-graben process, it was possible to assess rates of fault slippage by examining the movement of alluvial fans down the valley as the shoreline receded. Also visible was a large 'bathtub ring' of deposits from a much older paleo-shoreline, far above the current road line. Similar deposits are also visible 11m above the present Salton Sea. We discussed whether it was miromictic (mixing layers once per year) or not, and the provenance of stromatolites on rocks around the shore. Since they had formed in MUCH deeper water, it was thought that they formed through inorganic accretion processes, though the area is still somewhat controversial. Like Mono Lake, it was also salty and alkaline, though not quite as much. Some fish were even present. One interesting thing I took away was that mobility of sediment is actually U shaped as a function of water velocity. Sand is the most mobile sediment. Larger pebbles, rocks, and boulders require faster water to move, which makes sense. But apparently smaller grains of silt, sediment, and clay stick together so well that they also require large water velocities to shift. This was an important point in understanding the progression of alluvial fans down the exposed valley.

The next stop was the Pumpkin Hollow copper exploration site near Yerington, Nevada. Some geologists have been working the site thoroughly for five years, though the history of the site is much longer than that. The basic idea of metals deposition is that a big bubble of hot rock (a pluton) breaks free of an underlying batholith and slowly rises through the surrounding rock. If it reached the surface, it would likely cause a cinder cone volcano, but normally that doesn't happen. Instead, the rising rock stratifies, and certain insoluble minerals float to the top - normally copper, tungsten, gold, silver, iron, and other useful things. When the pluton reaches lower pressures closer to the surface, it tends to fracture rather than melt or deform surrounding rock, often through the agency of steam, and the concentrated metals in its nose then leak through these cracks, forming dykes of highly concentrated deposits. The cool thing about the Yerington deposit is that normal faulting has gradually tilted this rock column, originally about six km deep, completely onto its side. This can be seen here: https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirQmhyM4JLNsYgEIPubAr1J9ZF1vw9V8Sy8MRKO3-LoWKGi9BHwK_hHIp5ZA4yKnHpeLrqTvy7pqv0UYvuRT_LotS8NrB3ja4uKiOpca-mL7POaQcImOTpq-gh37oFiL_4QoF6WIco_fQ/s1600/IMG_3799_5_1.jpg

The deposit is rich enough that the metal can be seen in the rock, somewhat reminiscent of computer games. Dozens of cores have been drilled to assess the size of the claim. Then comes the fun part - how to get it out. Also present in the deposits are garnets, which are pretty cool. Garnets are rocks that formed near the surface, sunk into the mantle, then came back up. As a result, they've undergone chemical changes that enable study of the route they took. A transverse geological map of the area shows lots of sequential faulting associated with the land here (as in the rest of California and Nevada) being stretched by a factor of between four and six. (https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkF2Ftl05Tlc7QET7R_LC4GjzA6Q7E8keaJKfASqSnZppICq_YJ72Qh7wmm4aYAlUE_K1aVANJtbiZfW7_Id58_O-osSDS6rlna2Go8kJXE4-X4o4aq-IWy-EBLLFEGnrd2A5jGYbtYzk/s1600/IMG_3797_3_1.jpg) So one of the local geologists decided to take a digger and uncover one of these faults! We drove to the site and found the fault marked by a line of black rock about a cm thick! It slanted into the ground about 5 degrees from horizontal (which is pretty flat for a fault), and, it seems, has about a mile displacement between opposite faces of the fault. Given that a really big earthquake moves a fault by 2 metres, and such earthquakes only occur every hundred or thousand years, it would seem that the fault took between 100,000 and a million years to achieve its degree of displacement. But that's nothing on a geological scale. Plates move past each other at a rate of mm/year, and most of the continents have already performed at least one circumnavigation. Before long, the fault trench was filled with excited geologists!

Next, our DJ started up a podcast called the Bugle, a satirical comedic current affairs radio show, which was highly amusing. On we drove to Lake Tahoe. We camped near Fallen Leaf Lake on the southern shore. A few brave souls went for a swim in the snow-melt-fed waters, while I contented my aging frame by skimming a couple of rocks. Later that night we sat around the campfire comparing the size of our head torches, shining lasers at smoke, and telling crazy stories from past field trips and/or quirky people in the department. Particular highlights included a recounting of the extremely wet experience in Baja last year, wherein everything washed away, including the road. Another story recounted the phantom of Arms building, sneaking into the fridge at the dead of night to eat other people's carefully stowed sandwiches, sometimes in front of them. At long last I found a place surrounded by plenty of undergrads to distract the bears, set up my stretcher, and went to sleep. This evening I had taken the precaution of warming my sleeping bag by the fire, so was toasty warm all night.

Next morning we packed, I munched some stuff from my "Casey friendly food bag", and we drove north to Emerald Bay, where followed a walk to Eagle lake, several interesting talks about faulting in Lake Tahoe, earthquakes, tsunamis, seich waves, and glacial deposits in the area. It was particularly nice to sit by an idyllic lake nestled in a cirque and have someone point to a rocky outcrop hundreds of meters above and say "during the last glaciation, that arete was the only thing around here not covered in ice". On the way back we found several exposed rocks with striations left from glacial grinding. More exciting, perhaps, was reading the geological history of the granite's formation with the help of a few layers of partially broken mineral deposition, indicating that the rock was still moving when it was partially molten.

We drove back to Nevada and north towards Genoa and the eponymous Genoa Fault, which was exposed at one point by an old gravel quarry. One of the most important faults (of a few dozen in the area), the Nevada/California stateline roughly demarcates the boundary between the North American Plate and the Sierra Microplate, which accounts for about a quarter of the 27mm/year difference between the pacific plate and the american plate. The remainder is taken up by the San Andreas fault. The difference in structure between the two regions is accounted for by the fact that the Sierra Microplate is moving about 7 degrees closer to the pacific plate, leading to compression in the west and extension in the east. It's also gradually tilting towards the pacific ocean. On the exposed face of the Genoa Fault, we searched for slickensides, or micro/macroscopic features which can be used to deduce the movement direction of the fault, something like scratches. While it was not too difficult to find evidence of normal faulting, this fault apparently used to also move in a right-lateral fashion, though I'm unclear if anyone was able to find evidence at this location. We noted with interest that the paleomagnetism vandals had struck here too, with 4 neat holes on a vein of pseudotachylite. This mineral fills fissures on fault faces and is formed by the pressure of a fault slip during an earthquake. Thus, if the earthquake can be dated, then the magnetic field at that place and time (wherever the rock was at that time) can also be determined, or vice versa.

Next we drove out to Soda Lake, a much smaller version of Mono Lake in terms of water chemistry. Water table changes as a result of irrigation actually caused the level of Soda Lake to increase, and subsequent tufa formation on the shore occurred extremely rapidly, forcing theories of its formation to be reexamined. Meanwhile, the eclipse had started. I fitted the solar filters to my binoculars and got cracking with the timelapse. Unfortunately we then drove back to Fallon before finding a field somewhere to watch the rest of the event. As a result, my time lapse was somewhat stop-start, as a lot of the photos were taken out the window of a moving car. Since I returned I was able to process them somewhat to reveal the sequence more fully. Luckily, we stopped in time to hand out eclipse glasses etc and watch. It got quite dark, birds went to sleep, and trees cast very peculiar shadows, effectively forming a pinhole image. I gave my talk on eclipses, stalling to run out the clock on the time lapse as long as possible. During 'totality' (or 'annularity'), the moon was visible in perfect profile, and light could be seen shining through valleys on the surface. Before and after the eclipse, a couple of sunspots joined the party. It was my first solar eclipse and it was awesome!

After that we drove west back to Reno, dropped someone at the airport, then proceeded to Stampede reservoir, near the north end of Lake Tahoe. To the relief of our desperate-to-pee driver, we arrived just in time. I headed down to the shore to make a time lapse of the stars rotating, then we once again set about burning things in the fire and eating a delicious dinner of pasta, once again magicked into existence by S and S.

Next morning we packed back into the cars and drove off. After stopping at the Donner Pass for a few talks on volcanism and an impromptu from me about cannibalism, we drove for about 10 hours down highway 5 all the way to Los Angeles. It was a VERY long way. Eventually we got back to Caltech, unpacked the cars, and headed off. I had more than a thousand photos to sort out!

Photos: https://picasaweb.google.com/105494084231616659850/Ge136Spring2012

San Francisco with T and S

Last weekend I was lucky enough to have yet another adventure with two rather special people; T and S. This time, T had occasion to be in San Francisco, so what should have been a surgical fly-by-night conference visit quickly transformed to an eclipse-class zeppelin behemoth of awesome.

On Thursday, we somehow managed to pack the car with everything we needed and an equivalent mass/volume (=density?) of optional extras, and took off for the airport. Parking, transfer shuttles, checking in, security! Wonder of wonders, travelling with a 4-year-old gets you waved past the cancer-testicle-blaster-of-doom, and for the first time in my life I missed out on being 'randomly selected' for additional screening. Racial unprofiling, I believe. We settled into our luxurious sofa-sized chairs (for S) and egg-carton seats (for T and I), and before long were in the air, over California, and plummeting back to earth. With a budget for travel-related expenses to enjoy, we took a cab to the Hyatt Regency Santa Clara, a miniscule boutique bed-and-breakfast 20 floors high just next door to the old Hewlett-Packard headquarters, now looking for a viable company to enclose. Within minutes of checking in we had already swum laps in both pools, sorted out all the tiny soap, failed to hack the entertainment system, allocated beds according to nationality (northern hemisphere on top, southern hemisphere under the bed, of course), and organised dinner. T went with a few co-conspirators to her Women Achievements in Science conference, while S and I met my Silicon Valley inclined friends D and R at Tomatinos, and ate our own weight in pizza. S also brought his toy hippopotamus, which turns into a complicated 3D puzzle if you ask it nicely. D is doing well since his move to the states 3 years ago, and looks forward to the impending arrival of his fiance, L. R, who I met through CSing in Sydney, is doing absurdly well and seems happy and fit! Soon S and I retired to bed, reading a few books while we waited for T to return and, ultimately, sleeping.

Next morning we stumbled to the hotel restaurant for a rather pricey breakfast, then took the VTA tram downtown to the San Jose convention center, where I met E, my former office mate of 2009, with whom I tracked down my ex-adviser MdS. We found him hiding in a local cafe, and he looked rather surprised to see me! Meanwhile T and S checked out the Children's Discovery Center next door, featuring a mammoth excavated in the adjacent park. With a quick detour to possibly the grottiest urban creek/drain I've seen all week, we headed for the Caltrain station. Beneath the blazing sun and burdened with luggage and unused child-sized legs, we were picked up by an uncharacteristically helpful bus driver and dropped much closer to our destination. We caught the train with minutes to spare, and quickly snuggled down between our bags for a well deserved nap. Once in SF we took another tram to our hotel on Market St, the Edwardian San Francisco Hotel. In a narrow building with seven rooms per floor (originally perhaps twice this number!), and subsequently retrofitted for electricity, lifts, and running water, it was sufficient for our purposes. So, after a quick break to freshen up we took to the streets to meet T's friend K, with whom we successfully located and consumed dinner, as well as chatting rather a lot. In the meantime S constructed Pleistocene Park between the plants surrounding our table, ate yet more pizza, and engaged several other customers of Arlequin diner in happy chitchat. I walked K home, then set out once more to find contact solution for T, since her supplies were aircraft incompatible. My initial guesses for locations of open chemists proving unsuccessful, I engaged an expanding spiral search until I bumped into the hotel staff dude, who pointed me in the right direction. Dodging clouds of magic purple smoke emanating from several establishments I located a safeway, obtained my product, and returned home triumphant.

Next morning, after a slow start, we began a highly convoluted journey across San Francisco to the Exploratoreum, next to the palace of Fine Arts, via a sushi restaurant, a bagel shop, a few climbable trees, an impromptu lecture on sailing by yours truly, some nice views of Alcatraz, etc etc. Once inside, T and I vied for S's attention on behalf of our respective disciplines, split roughly between electricity and stuff that dies. In the end we pronounced it an honourable draw, since the real winner was both of us, reliving our respective childhoods discovering science. For me, this was the Questacon in Canberra, which had some similar-looking experiments. We walked back from the Exploratoreum toward the city, eventually catching a series of buses, all the while entertained by half a dozen or so variously incoherent vagabond types, until we met my friend J at Lers Ros, a rather nice Thai place somewhere near Civic Center. In due course, we were joined also by T's friends M and L. The six of us had one of the most tremendously erudite conversations in which it has ever been my pleasure to take part. All too soon, however, I had vacuumed up my Pad See Iew with Beef (still not as good as Thai La Ong's) and J and I set out for the Davies Syphony hall, at which we were set to see a concert. I had planned to see it, since one of my favourite musicians, Cameron Carpenter, was performing. In truth, I did not even know the program's theme before the show. It turned out to be a collage of musical moments from the history of the "Barbary Coast" region of San Francisco, the region between the Embarcadero and Market St, between the gold rush in 1850-something and the exhibition in 1915, celebrating the recovery of the city from the 1906 earthquake. The music was terrific and the stories were even better. I was sorry that S was too tired and wriggly to enjoy it at the time. Soon!

I headed back, and fortunately was able to sneak into the hotel, since T had fallen asleep after locking herself in!

Next morning, we packed, checked out, and headed into SoMa to visit some more of T's friends who live in warehouse conversions in a rather sketchy part of town and consume waffles. Sadly we were unable to visit the group who went to live on an icebreaker, but these ones (at least the ones who weren't in LA for the Mindshare conference) were pretty cool too. On the street, we dodged litter and dangerously incoherent types. Inside, we walked past a collection of bicycles, photos, and maps reminiscent of places I once frequented in Newtown. A warehouse conversion with centralised kitchen and living space, indoor trees, and an alleged boat in case of sudden flooding, it was a fine place to while away a few hours in interesting chit chat. At one point we went down the road to the Sight Glass Cafe, where I ran into non other than A, an ex-Pauline who has since made his way in VC in the states. We spent a good 20 minutes catching up on news that I hadn't had updated since the day I moved out of college!

All too soon it was time to once again lift our luggage skyward and begin the long trek to the airport. After applying our combined 42 years of education, T and I managed to deduce how to buy tickets to get on the BART to SFO, though as it turns out we messed up the amount, and had to reapply our exceptional computer skills to get off at the other end. Once more we settled in for our short flight home. By 10pm we had dropped S and K's place and found something to eat - the end of a long adventure, though only a taste of what's to come.

Photos are here: https://picasaweb.google.com/105494084231616659850/SFWithTAndS