Tuesday, 11 February 2014

It came, it went, it didn't really conquer...

Lame Latin puns aside, the snow did actually come for a few weeks and it was amaaaazing! Well, mostly. Most days were a balmy -5 but there were a few scary nights where the temperature plummeted to -15, and that's not fun anymore.. (those days it feels like you're wearing a t-shirt under your third layer and winter jacket.. brr).. However, I did manage to convince my wife to go on a pulka with me (a pulka being a small, fairly cheap and crappy sledge that children and easily amused adults adore). This is exactly the one we used, 100 SEK in Clas Ohlson: http://www.intersport.se/Root/inRiver%20Resources/135426682783768214.png

For those not in the know, Sunnerstabacken is where it's at, where all the cool kids go (literally, our combined ages were larger than the cumulative sum of all kids) and the funny thing is, all of them, from the youngest (like 2) to the oldest (like 2 + x, where x is an integer in the bounded interval [0, x'], and x' is some constant given by the subjective definition of youth ... in reality, like 12 or something...), were utterly fearless. Maybe it's the fact that their lower mass equates to lower maximum acceleration, maybe it's the fact that children think themselves indestructible, I don't know... But one thing is certain, we certainly weren't. Those things go fast! But that's the best part. Or even better is hanging your legs out as brakes and not realising that despite being effective, it also sprays a ridiculous amount of snow in your face, and as most are well aware, snow is known as a "cold substance", and cold things hurt my face... I have some pictures on my phone, I look hilarious and very very cold. So we did that for an hour or two, until of course, we took it too far and went on the big and scary and icy slope and nearly killed ourselves (I saw nothing the whole way down and was mid-air more than once... Ana broke her back for a few days... Overall, it was awesome...Seriously.)

But then it left :( About a week or two ago, it gradually became milder and slushier and greyer.. (I've always wondered why during winter the weather is, on average, better when there's regular snow then when there isn't... Maybe something to do with the conditions that give snow are also favourable to clear skies and calm weather? Not always, of course, but I did notice a lot of the snowy days were also sunny... Now it's just wet and grey and depressing... I feel like I'm back in Ireland, but with dearer beers :P)

But enough about snow, let me talk a little about a project I just started in the Astrophysics division. It's regarding the Sloan Digital Sky Survey (SDSS), a "major multi-filter imaging and spectroscopic redshift survey" (Wikipedia). Basically, they take a bunch of measurements of many different quantities interesting and useful for astronomers/astrophysicists/etc, and catalogue them in a massive database which can be accessed freely (there's even a bunch of tutorials on the site to get you up and running). Every now and then, they come out with a new data release which usually provides many more objects than the previous one. The current release is 10 but we're currently using 7, meaning all our graphs, results, and so on, could look a lot better and be a lot more informative if we were using 10.

However, the database is queried using SQL and unfortunately they have a tendency to change the names of all the objects in the database from release to release (meaning to get the same thing in two different releases can have completely different code). So my task is to determine the new code for each release and compare the results from release to release. Do I get the same results as everyone else in release 7? Do I get similar (but "better") results in 10? And so far, I've had really great success, which makes me very happy. I hadn't used SQL before but I really enjoy it now. The whole interface is a bit of a mess (some releases use different sites, servers, many things are duplicated in "old version/new version" fashion, which is a little frustrating) and the SkyServer for Data Release 7 (DR7) went down yesterday, forcing me to use a different separate server just for DR7 and below. However, that one needed me to make a new account to access (though it looks almost identical) but became upset when my queries returned too many results (I expected around 20,000 -"too many" in this context means around 20 million....). So my account ran out of storage space but wouldn't let me delete the database (it was very upset). So I had to create another account (bear in mind, these all required different email addresses...) and finally got everything working perfectly :)

Except not. Why? Because while the general trend has been DR7 = one set of code, and DR8-DR10 = equals another set, for these particular sets of queries, DR9 and 10 had the same code but DR8 was different. Completely different. So different we couldn't get it to work and have lost faith that it can be done in DR8.

But having it in the newest release is pretty good, right? Yes, of course, except (there's always an except, isn't there?!) what we want to do in the previous releases can't conveniently be down in DR10  - the entire underlying structure has been changed. We wanted to deal with quasars and low redshift galaxies, and instead everything is mixed together so our results are sort of like this:

DR7: 13 000 objects (galaxies, low redshift quasars)
DR8: ????
DR9: 17 000 objects (niiice, same order of magnitude, a few more, very very good)
DR10: 600 000 objects (wtf? That makes no sense.)

But we're working on it and we're well ahead of schedule, so that's great to hear :) Also, it's my first time being "promoted" to a full-fledged access-card wielder, and I'm so happy. I get to sit in a fancy department which has a ridiculously fancy espresso maker and coffee bean grinder and free fruit and a fika data on Monday's and every second Thursday and "AstroPub" on Fridays (lecturers, researchers, students all meet in a random pub for a beer to relax after the week).

I tell ya, "easily-impressed" doesn't even cut it with me ;)

So that's the story so far.. Will update more how this project turns out, it's becoming very exciting now that this underlying work is mostly finished. Now the "interesting" stuff appears (though I'm too damn curious for my own good that I already found this stuff extremely interesting).

Oh wait! I almost forgot. I saw the TandemLaboratoriet last week, Uppsala's very own particle accelerator. Really cool because it's the one and only I've ever been so close to! (I did go to CERN a few years ago but they don't let us mere mortals near the actual machine itself... thank god, actually!). I met some lovely researchers and prospective Master's students, while being fed and given far too much coffee, an all-in-all, productive day :) I also saw a presentation by a previous PhD. student, now working in Stockholm University, who is working on Sweden's first and only SETI project (SETI being the Search for Extra-Terrestrial Life, like Star Trek, sort-of, but we stay here and nothing has happened so far...). It's a tough field to work in by the sounds of it, very difficult to get papers published or be taken seriously, which I think is really unfair :( Definitely one of the fields that if (or when?) they discover something, everyone will say "Well, don't I feel like a jerk now..."

Good luck SETI PEOPLE!

P.S. A bunch of interesting lecturers are happening on Thursday & Friday, people should go:


  1. So unfortunate that because of weather Vikingarännet 2014 (Uppsala-Stockholm ice skating) was cancelled :( At least walked on frozen lake before it softened, now I think it wasnt wise decision:)) But we (students) can try signing for boat race for Valborg :)

  2. Definitely! Really want to do that at least once, seems like an amazing experience :) the lake was so cool! I had never experienced that before, completely frozen :)