Sunday, March 30, 2008

Telescope Wrangling

So far, I've tried to stay away from discussing my actual work in these posts. As I settle in to the ebb and flow of life down here and things become routine, I'll probably have to include occasional posts about work to fill the gaps. First up, a bit about the less-cerebral work of a cosmologist.

Most of the time, my job is a desk job. Generally speaking, I sit at a computer and analyze data, then try to fit the results into a larger picture of how the universe operates. I also spend a fair bit of time working on equipment, trying to improve stability or performance. Up north, that would mean time in lab, developing and testing new detectors. Down here, that means keeping the telescope going.

Most of the sensitive equipment in SPT is located in the "receiver cabin", a large room-sized box held on the end of the boom, into which the primary 10m mirror focuses light. To work on anything in the receiver cab, a large 3 ton section of the roof rolls back and allows the telescope to "dock" the receiver cab against the control room. The roof was supposed to be motorized, but people are more reliable than motors, so we use a pulley instead.

Some tests we have been doing lately required moving the telescope by hand. It's a half-million pounds of steel that has to be moved, so hand-driving isn't the easiest task under ideal conditions. Actual conditions require you to wedge yourself into small spaces and work around sheets of metal so cold they burn at a touch.


Any large and complex system will invariably have failures or problems in one of its many many subsystems, and figuring out which one failed and how is actually one of the joys of this work. Of course, sometimes it requires you to wedge yourself into cracks not quite wide enough to let you inhale, 30' above the floor, while you disassemble and rebuild a motor with a blown coupling, but that's all part of the job.

Physics (cosmology at least) can be a surprisingly physical field of study.

Friday, March 28, 2008

Dusk

The sun doesn't rise or set very quickly at the poles. Even after it dips beyond view, the world stays well lit for weeks. Sort of like an extended evening.


It's still easy to tell time by the sun, just by finding the brightest portion of the sky. Opposite that, the earth's shadow is growing daily, a sapphire blue band against the still pale sky. A slight rainbow persists on the edge of the earth shadow, adding the only touch of color in our world.

Not to say that things are drab now down here - far from it. Everything has now taken on one shade or another of blue, and the world almost glows with a thin, cold light. It's an enormous contrast to the glittering, white, shiny world of the day, but just as beautiful.

No longer warmed by the sun's rays, every surface now accumulates frost and wind-driven snow. Whereas in sunlight that accumulation would sublimate away, it now simply sits and builds. Everything is becoming encased in ice crystals, lending an eery, untouchable, end-of-time sort of feel to the world.

Everything here continues to amaze and delight. I can't wait for the stars.

Monday, March 24, 2008

Twilight

I awoke the Sunday after sunset to find patches of clear sky visible through the clouds. The prospect of clear skies, even two days after sunset, was tremendous.

The sun is pretty big, and "sunset" only refers to the moment when its center crosses the horizon, while assuming there is no atmosphere to bend the light. The upshot of that is that part of the sun can appear to linger above the horizon for days after the official sunset.

Through the day, clouds continued to clear, and some amazing colors began to resolve themselves. Opposite the sun (which was still obscured by low clouds circling the horizon), the Earth's shadow was creeping up, a dark blueish-purple band just above the ground. Above that, a swathe of purples and pinks, topped by a nearly full moon.

From DSL, the station was backlit by the mostly-set sun, which threw up a rainbow of colors as a backdrop.


The temperature had soared to a record high, -38C. We haven't seen temperatures like that since station close, and it left us free to take pictures outside for hours, developing admirable eye-frost.

Saturday, March 22, 2008

Sunset

I set my alarm for 5:45 am Sunset Day. There was a bubbly giddiness about the station - like we were a community of 6-year-olds on Christmas morning, not a pack of young adults living at the end of the earth about to see the sun for the last time.

All day, people were dashing to and fro, making preparations for the evening's festivities. Most employees at pole work 6-day weeks, with a special 2-day weekend scheduled once a month. (I say most, because beakers - scientists - don't get days off, ever.) March's 2-day weekend was scheduled for sunset weekend, so in addition to the general celebrations, there was a short vacation for everyone else to look forward to.

Everyone showed up for the celebratory dinner dressed their best. The galley had been rearranged by a small army of volunteers, with lighting dimmed, white tablecloths throughout, and candles spread across two long banquet tables. The food was exquisite, the company outstanding, and the conversation practically sparkled. Everyone was in the highest spirits, there was a wonderful feel about the room, and the evening was a delight. Really one of my happiest times so far at pole.

Following dinner, people maneuvered into smaller groups for coffee, tea, or - for those who fancied - Scotch. There are 3 major celebrations through the year at pole - sunset, midwinter, and sunrise - and people pull out all the stops on those three nights. Half a dozen bottles of excellent scotch (which had been carefully hoarded in closets so far) made their way into public, and everyone relaxed, laughed, drank, and talked for a couple of hours. That was followed by a fantastic party - think of a REALLY good New Year's party, minus any worries about the New Year or anything else, with 60 of your closest friends, and you're getting close - which went until the wee hours of the morning.

Saturday, people slowly filtered into the galley all morning. The station was quiet, people were smiling and calm, and a quiet mellow atmosphere hung over the place. Through the station, they sat, sipped mimosas, and just enjoyed life in the slow lane. I had to go to work, but the general feeling of peace was wonderfully rejuvenating.

Of course, not everything could be perfect - the weather didn't hold. When I awoke early Friday morning, it was to catch every possible minute of the sunset. Instead, I woke to find the world covered in thick cloud, the temperature up above -40 for the first time in a month, and a diffuse white light which had replaced the pinks and purples of the sunset. It even snowed that afternoon - a rare event here. We ended up missing the actual sunset completely.

Still, I can't wait for midwinter and sunrise.

Thursday, March 20, 2008

One Day

There is now one day left until sunset, and excitement is certainly mounting. The sun is diving ever lower in the sky, but so far, the weather has been cooperative, and the band of haze which usually circles the horizon largely dissipated yesterday afternoon.


The world is now distinctly tinged with pink, the wispy clouds overhead positively glow, and everywhere you turn another sight makes your breath catch. The 15-minute walk to DSL took me over an hour today, with my camera making an appearance every five paces.


Exhaust plumes emanating from every building occasionally envelop the world in thick fog, making the view eerily reminiscent of a foggy morning up north. So far, the sunset hasn't disappointed.

Yukimarimos

Last Friday, we here at pole were treated to one of the rarer weather phenomena in Antarctica. We woke to find the landscape littered with little spherical puffballs. Dana (the other SPT winterover) had been telling tales of the strange cottonballs which mysteriously turned up one day four years ago, then disappeared just as mysteriously the following day, and he was thrilled to see them again.

This time, though, they showed up during daylight, and that made all the difference. The temperature had dropped suddenly, and the ground was covered in hoarfrost. Looking across the plain, dozens - hundreds, probably thousands - of little balls were tumbling in the wind. Think tumbleweed - natural snowballs made of the fine frost covering the ground for miles around were rolling along, almost jovially, without a care in the world. It was actually a pretty comical sight, the whole landscape suddenly alive with motion.


The little balls are called yukimarimos (formed from the Japanese word for snow and the name of a small globular water plant from Hokkaido), and form when a light wind follows a sudden drop in temperature to below -60C (-80F), rolling the frost into snowballs. The yukimarimos collect in any little crevice or hollow, forming into large piles until a gust of wind disperses them, or they sublimate back into the atmosphere. They rarely last more than a day.

Yukimarimos were described for the first time in 1999 in the Journal of Glaciology, after almost 50 years of continuous inhabitation of the antarctic interior - that should give some idea of their rarity. Oddly, they have the consitency of cotton candy, almost exactly. Nothing like a hand packed or rolled snow, they're disctinctly fibrous, virtually weightless, and dissolve almost instantly if you take them inside.

I'm running out of words to describe how amazing and unique the world down here is. Incredible, surprising, and always novel.

Tuesday, March 18, 2008

Commute

As I mentioned in an earlier post, the telescope I work at/on/with is about a kilometer from the station, connected to the Dark Sector Laboratory. Every day, I hike out to DSL and back, usually twice. That puts me outside for an hour or so each day - not a lot, but enough to get a good feel for the weather and environment.

To repeat the obvious, it's cold down here now. Spending fifteen minutes outside takes a little bit of preparation, mostly donning half a dozen pieces of Extreme Cold Weather (ECW) gear. I still haven't worked my way up to the heavily insulated Carhartt work overalls, but am otherwise pretty well decked out. Blue boots, Big Red, and gauntlet mittens are the major pieces, complemented by some long undies, a second pair of gloves, a balaclava/hat/gaiter combo, and a pair of goggles. Together, all that keeps me pretty warm outside, to the point that I sometimes overheat when the wind dies down.

Because some of the science projects are light sensitive, outdoor lights aren't allowed here. Once it gets dark, all the windows get blacked out, and buildings become pretty much invisible from any distance. Add to that the occasionally thick ice fog and enough wind-driven snow to cause a whiteout even in direct sunlight, and finding your way to work a kilometer across the frozen plain can get a little tricky. There's a flagline to show the way, and a well trod path has grown alongside it.

Saturday, March 15, 2008

Late Afternoon

It's now late afternoon in the South Pole's yearly day.

There is less than a week left now until sunset, and it shows. The sun just circles on the horizon, and shadows extend ridiculously far. The temperatures have continued to drop, and the windchill broke -80C (-115F) the other day.

It's cold enough now that the power plant gives off an impressive plume of steam, extending for (literally) miles downwind. For hours in the middle of each day, it blankets my entire world - station, flag line, and DSL - in shadow.


The snow has begun to take on an orangey-pink tint from the setting sun, and the landscape is filling with color for the first time since I arrived. Someone commented yesterday that the fields of snow now look like an ocean, only frozen in time - I think that describes them nicely.

This time of year, every day is more beautiful than the last here at pole.

Wednesday, March 5, 2008

Sastrugi

The winds here don't just pile snow up, they also carve it away, and they do so in a particularly strange manner.

High winds tend to pile snow up into large drifts. Any obstacle (lump of snow, building or even a flag post) will rapidly develop a large complex drift downwind, complete with peaks and valleys caused by eddies in the wing passing over it. When the wind dies down, it also tends to lie closer to the ground, and instead of building drifts, begins to eat away at them, bottom first.

This leaves the tops of some drifts poking off unsupported into space, their bases having been eroded away beneath them. These funny sideways spikes in the snow are known as sastrugi, and are absolutely amazing to see.

So far, most are only a couple of inches high, but through the winter, they should grow up to a foot or so. Just large enough to catch your boot and trip you, and because of both the lack on contrast in the snow, and the lack of sunlight for the next six months, all you can really do about it is get used to the idea of falling on your face several times each time you go outside.

While they only grow to a foot or so here, further inland, they can be 4-5 feet high, meaning 10 foot long spikes, which most people travel on top of, and risk breaking off or falling through. Sastrugi - another beautiful environmental factor that'll try to kill you in Antarctica.

Sunday, March 2, 2008

March

It's March now, and things down here have begun to change. The temperature has been dropping for a week or so, people have started to settle in on station, and the sun is getting dangerously low in the sky.

It's now cold enough outside to hear your own breath. Not your breathing, your breath. The moisture freezes out and it contracts with sufficient force now that it makes sound. Exhaling without a balaclava or other covering sounds a bit like a fire extinguisher, only deeper and sharper. It kind of looks like one, too.


You may have noticed from some of the pictures lately that shadows are starting to get very long on the ground. Every little ripple in the snow now casts one, and the landscape has changed from brilliant white into a mottled grey.

The sun is down to about 6 degrees above the horizon, but it's getting hard to imagine life here without it. Since I got here almost 2 months ago, I've had sun 24 hours a day, 7 days a week, and I've completely internalized it. In my mind now, the sun is supposed to be up all the time. That adaptation, along with the fact that after two months I've never seen any of my surroundings in the dark, is making contemplation of a dark life here difficult. I guess I'll see for myself soon enough.