The Milky Way from DA

Not much to report this week. It has been cold and dark, enough that our scheduled station safety drill got pushed offuntil next week. The pressure has been super low for the past week and a half, so the physio elevation has been right around 11,000 ft, with the highest being about 11,300 feet. The side-effects of that kind of elevation were some head aches (at least for me, although they’ve gone away for the most part), and some grumpy people suffering from lack of sleep. The high elevation also made working out harder, especially intervals.

The cooks just switched shifts last week, so we’ve gotten some different styles of cooking for breakfast and dinner. We also got this:

The cake is a reference to this video: Honey Badger

One of the scientists on station has been doing Monday night astronomy classes, and this last week he took us outside to take a look at the sky.

Robert showing off his fancy green laser

Iridium flare

He used a green laser to point out various constellations, and Carlos got some pretty cool pictures.

Tuesday, the trauma team had another little drill. This time we were trying to get our patient out from underneath the floor of the station.

Our friend, the dummy, got into trouble again

Kind of a tight spot, but we got him out on a backboard without hitting his head too many times, and we were fast about it that with Shawn last week.

This weekend was our two-day weekend for the month of May, and we kicked it off with appetizers down in the green house on Friday night.

Joceline crushing lemon balm and mint from the green house,
to add to the home-made hibiscus spritzer

And even thought the cooks had the weekend off, we still got two hot dinners. On Saturday, Shawn, Jared, and I did a burger bar and showed “Two Lane Blacktop” in the galley. Jono made shakes/malts, which were great, and added to the ‘50’s feel of the evening. It went well enough that we are planning another burger night, with a summer theme, for August or September. Tonight Dale, the weather guy, made a Greek dinner, which was delicious, especially the baklava. 

A Little More Science

MAPO under the moon

The last couple of weeks I’ve been making the kilometer long hike out to MAPO pretty regularly to check on some of the other science I’m taking care of this winter. MAPO, or the Martin A. Pomerantz Observatory, is another one of the buildings in the dark sector, and houses the machine shop, a couple of CMB experiments and AMANDA (Antactic Muon and Neutrino Detector Array). AMANDA is pretty cool in that it uses the entire Earth as a detector. Basically, high energy neutrinos passing through the Earth sometimes interact with the Earth in just the right way to create a bit of light. AMANDA has an array of phototubes sunk deep into the ice to look for this light.

Anyways, the two projects I’m looking after over in MAPO are RICE4/AURA and the Gattini-UV South Pole Camera. AURA (Askaryan Under-ice Radio Array) is a new experiment which is utilizing the work begin done for one of the other telescopes down here (IceCube). The goal is to create a large scale (100 – 1000 cubic km) radio array to detect neutrinos. Where I come in is running RICE4, which was a precursor to AURA, that is now being used to calibrate and check the new array.

The electronics for RICE and AURA.  Kind of a mess.

 Basically, I check to see that things are running properly (ie. data is being taken), start a new data run when the old one is done, and send the data along to folks back in the States to look at. Lately I’ve been working with one of the scientists back home to set up a pulser, in order to calibrate the equipment, since we were getting some very noisy, unhelpful data a few weeks ago.

The other project, Gattini-UV South Pole Camera, is being used to study the UV properties of the night sky above the South Pole in an effort to evaluate the site for possible future optical and UV telescopes. So far, all I’ve had to do is check on it once a week to make sure that we don’t have drifts building up over the window of the camera.

Gattini-UV with SPT in the distance

And looking the other direction, the MAPO dish

Other than work, life has been pretty quite of late. Doc has taken to having the trauma team do weekly drills for our training, rather than lectures/powerpoints, which has been fun, and probably better for us than more talking, now that we’ve covered the basics. Last week we found Shawn in the heavy shop like this:

Katie and I, trying to figure out how to get Shawn out.

He is in between one of the big snow plows and its blade, with a big gash on his forehead and a piece of rebar “through” his leg. Katie and I also found bruising on his chest and ankle. We were pretty slow about getting him out of there and back to medical (it took about 45 minutes, meaning he would probably be dead in real life). But we did eventually get him out and up to the clinic.

Shawn, with IVs and the EKG hooked up

After we got done with him, Shawn spend the rest of the day walking around like this:

Shawn of the dead

The Dark Sector Lab

As you already know, part of my duties down here involve delivering helium to BICEP2, one of the telescopes in the dark sector. The main rules for entry into the dark sector are no white lights (only red), and no keying your radio, unless it is an emergency. Both those rules are to reduce interference with the science that goes on out there. There are four telescopes in the dark sector, MAPO, ICE CUBE, BICEP2 and SPT (South Pole Telescope). Both BICEP2 and SPT are located furthest from the station, in the Dark Sector Lab (DSL), so that is what I know most about.

DLS: SPT is blocking the sun, and BICEP2 is to the far right

SPT is a 10m telescope (the largest every deployed at the South Pole), designed to do large-scale millimeter and sub-millimeter wave surveys of faint, low contrast emissions, making it idea to observe primary and secondary anisotopies in the Cosmic Microwave Background (CMB). As an aside, anisotropy is the property being directionally dependent, as apposed to isotropy, which suggests identical properties in all directions. One example of anisotropy is light coming through a polarizer. In one orientation, a certain component of light will be transmitted, while another component will be absorbed and/or reflected. An example of an anisotropic material is wood, which is easier to split along the grain than against it.

In this case, no light will be transmitted through the second
polarizer, much like if you orient the lenses of two pair of
polarized sunglasses perpendicular to each other, no light
will get through.

In the case of the CMB, anisotropy is used to describe its uneven temperature distribution. By carefully mapping the CMB, the scientists working with SPT are able to find clusters of galaxies and determine their sizes. The hope is to use this to confirm the existence of Dark Energy, one of the main components of the universe (matter makes up only about 4% of the universe). DE pushes things that are far apart, even further apart, the opposite of gravity, which pulls things togeather. If it exists, it will have an effect on how galaxy clusters, the biggest things in the universe, grow over time. By tracking how many large-massed clusters have developed during different periods in the history of the universe, they can probe the opposing forces of gravity and DE.

The CMB. The different colors represent different temperatures.
The coldest areas are dark blue, while the warmest are red. The circle
highlights a particularly large and cold region that was studied at the
UofM

BICEP2 is also a millimeter/sub-millimeter telescope studying the CMB. It this case, however, BICEP2 is looking at the CMB in order to explore the conditions in the universe in the earliest times after the Big Bag. The CMB is the result of photons produced when the universe cooled enough to allow electrons to combine to form hydrogen (~380,000 years after the Big Bang), making the CMB the oldest light in the universe, and thus, a very powerful tool for probing the universe at these early times. One of the theories of what happened immediately after the Big Bang, is that the universe underwent a period of rapid expansion called Inflation. If this did in fact occur, it would produce something called the Cosmic Gravitational-Wave Background, which in turn would have left a faint signature in the polarization of the CMB. It is this signature that BICEP2 (512 detectors), and its predecessor BICEP1(98 detectors), are searching for.

The optics and detector of BICEP.  The 4-tile focal plane unit is where
the detectors are located. The 512 detectors of BICEP2 are divided
amongthree of these BICEP2/Keck inserts.

My role in all this is delivering the helium that keeps the optics and detectors on BICEP2 cool. The optics are kept at a temperature of 4K, four degrees above absolute zero. The detectors are kept evern cooler, at 250mK. This reduces the amount of electron noise in the detectors, allowing them to more sensitively and accurately detect that signature they are looking for.

In the case of both BICEP2 and SPT, they were built at the South Pole for a very specific reason. It is extremely dry here. Water vapor in the atmosphere absorbs millimeter and sub-millimeter wave lengths, making it difficult to observe the CMB in most places. The combination of altitude (almost 11,000 ft) and cold temperatures make for a very dry atmosphere. As an added bonus, night lasts for months here. The lack of daily sunrises/sunsets make for an extremely stable atmosphere, and allow for extended observations that would otherwise be interrupted by the sun.

A couple more pretty pictures of DSL

If you'd like to learn more about BICEP2 and SPT, these are some good places to start:

BICEP2

South Pole Telescope