Follow the reluctant adventures in the life of a Welsh astrophysicist sent around the world for some reason, wherein I photograph potatoes and destroy galaxies in the name of science. And don't forget about my website, www.rhysy.net



Friday, 21 September 2012

The fault, dear Brutus, lies not in ourselves but in our software

That's right, it's time for another post about FRELLED, my very own FITS viewer. Well, I have been tinkering with it on and off for about a year. I spent a large fraction of the summer ignoring... avoiding.... I mean, encouraging my students to work independently to finish coding it. Was it worth it ?

YES.

Never mind the fact that looking at data in three dimensions is pretty (we'll get to that in a minute). Or that I strongly believe in doing thinks on the basis that they are cool, regardless of whether they suffer from such petty attributes as usefulness. Nope. in this case it was worth it for hugely simple pragmatic reasons. Namely that instead of spending a full month searching a data cube, I can now do it in a day.

Just to emphasise - that's a full working month, every day, doing virtually nothing else besides staring at images of static hoping that they might contain galaxies. That's actually not so bad. The problems start when you find something, because then you have to carefully record the coordinates and type lots of different parameters into another program to measure it. Not any more. Now you can just point to the source, click on it, and FRELLED will generate all the parameters for you. It also masks the source at the same time, so there'll be no more wondering whether you already detected something or not.

Typing in the parameters for one galaxy isn't all that bad. Typing them in for 400 is massively tedious, and with that many objects it would normally be impossible to guarantee that you don't miss any, or record some twice. Not any more ! It's not every day that you get a factor x30 speed increase with no loss of accuracy, so you'll have to forgive my repeated excited posts about this.

I've previously posted a few short clips trying to show how lovely HI data is, using more primitive versions of FRELLED. Now that it's more sophisticated, making nice videos of data is much easier. So I've decided to enter this year's National Science Foundation Science And Engineering Visualisation Challenge. Wish me luck !

Here's my entry. It's a 5min video all about hydrogen. Hopefully it stands on its own. I would have preferred to call it "Pimp My Hydrogen" but I suspect that wouldn't go down so well with the NSF types. If this doesn't convince you that hydrogen is pretty, then I may as well give up and go home, 'cos I got nothin'.



In other news, my second paper as first author has been accepted for publication. That finishes off my thesis research, which I first started in 2006 - a terrifyingly distant era. At last I can bid farewell to the Virgo Cluster and move on to shiny new data set. This time I won't have to spend weeks cataloguing the galaxies, only have to do the whole thing again months later because more data becomes available. Hurrah !

Tuesday, 4 September 2012

.glass

Readers should by now be aware that I work with 3-dimensional data and have a minor obsession with building a better FITS viewer. 3D rendering on a screen is all very well, but electronic data is sooo impersonal. Whatever happened to that bygone era when astronomers looked through telescopes and had no other option but to draw what they saw, or write poetry about it ?

Err, well, nothing, actually. Anyway my point, inasmuch as I ever have one, is that sometimes it's nice to have something good and solid that you can point to and, if necessary, bludgeon people with. Because laser pointers can only blind them in one eye at once. Or, if they're not trying to steal your research, you might just want to give them something to eat, and astronomical data may be many things, but no-one would ever describe it as nourishing.

For preference, I'd like all my data printed in .cake format. This would be something like a Battenburg cake (but with a better colour scheme). It'd be made up of hundreds and hundreds of little cubes of cake, each of just the right colour, so that the whole thing would be a physical model of an electronic data cube. As you slice through it, searching for galaxies, you'd also get a tasty snack. Of course, the resolution of the .cake format couldn't be much better than about 1cm per pixel. Which means that for a decent-sized data set, the cake would have to be about 7 metres long and 1.5 metres tall.

That's about right.
This of course is just idle fantasy. For now. But other approaches are yielding results. The .glass format offers the prospect of better data archiving (not being able to present your work because you ate it isn't normally a valid excuse), better resolution, and is much more shiny. Plus, when asked "what's a data cube ?" I can now just say "there's one on my shelf."


This cube is of HI data of the Virgo Cluster, which took 4 years of my life to analyse. Each blob is the gas in a distant galaxy. It measures approximately 14.5 x 14.5 x 6.5 cm. It looks somewhat better in reality, especially when properly illuminated. It doesn't photograph very well though, and owing to a lack of black surfaces I had to use a coat for a background. Here's what the data looks like electronically :

video


To create the physical cube, I converted the original FITS cube into a text file of x,y,z,v format using an IDL script I'd already written. Then I sent the data off to Bathsheba Sculpture. I stumbled on them having searched for custom glass etching companies. I couldn't find any that would just allow me to submit a model or text file, but I saw the astronomy section of the site and sent them an email - reasoning that since they'd obviously had prior dealing with astronomers, so were less likely to be thrown into a state of bewilderment.

Indeed they weren't. It took a couple of months to go from a state of raw data into a physical cube sitting on my desk, but this isn't very long considering the length of time I spent looking at this thing in its original format. Now all I need to do is find an illuminated base so that it's easier to see in daylight.


Saturday, 1 September 2012

Why Star Trek Is Clearly Better Than Battlestar Galactica

I've just finished re-watching Battlestar Galactica for the second time, and Star Trek : The Next Generation for the ten millionth time. They're both very, very good shows and I've no doubt I'll watch them both again. And again. And again and again, eventually. Now it must be said that while BSG is far superior in terms of special effects, plot, dialogue, acting, storytelling, character development, political intrigue, costume design, sound quality, lighting, props, sets, hairdressing, and cinematography, TNG will always be the better show.

To be more specific, in terms of political drama BSG kicks donkeys. That's because it is a political drama. One that just happens to involve mystical forces in space with explosions and killer robots, which are pretty much guaranteed to improve anything.



Trek never tried or even considered being a commentary on contemporary American politics. Where it exceeds BSG is as a science fiction show. That's because it's got actual fictional science in it. Like phasers and photon torpedoes and warp drives and holodecks.

Spaceships not good enough eh ? Fine, add dinosaurs.
Neither show would benefit by gaining what the other lacks. Suppose Saul Tigh decided one day that instead of drinking to solve his problems, he'd go for a chat with Councillor Troy. Or that Gauis "Frakking" Baltar just got on with quietly scanning nebula all day like a good little scientist. Or that Captain Picard, instead of throwing the aliens a buffet reception, decided to shoot them all. Or that Dr Crusher found that treating patients was a waste of time and that she'd rather go and have sex with a nymphomaniac ghost.

I figured people would rather see this than Dr Crusher having sex with a ghost.
Err, well, ok, forget the last two - TNG actually featured both of these. But my point still stands. BSG is no more a science-fiction show than Star Trek is a political drama. In fact, comparing the two on equal terms is a complete waste of time, because it's impossible.

HOWEVER, the underlying psychology of the shows does not escape so lightly.  In fact that's where it gets interesting. While BSG is not really about cool tech in the way that Trek is, technology in the show is conspicuous by its absence. About the only ways in which the human civilisation in BSG is more advanced than our own is the use of FTL and cybernetics (although, importantly, Caprica did remind us that the Colonials were rather further ahead than this before the holocaust).

It also reminded us to beware of killer emo teenage robots. Very few shows do that.
The story of a great civilisation brought low by its own hubris and arrogant technological prowess is one of the oldest stories of all time. While the Colonials may have once prospered thanks to their advanced tech, ultimately their abuse of that technology becomes self-destructive. In the form of a bunch of angry robots, who were probably sick of having to spend every evening being miserable and alone in their black-painted bedrooms, in accordance with their emo progenitors.

There's nothing wrong with warning about the dangers of abusing technology. But Star Trek showed us what happens if we use it properly. Sure, it didn't come with anything quite as out-and-out cool as a lightsabre, but it did have holodecks, replicators, transporters, force fields and... iPads (they even called them pads, and this was 1993 for heaven's sake). It was also undoubtedly the inspiration for Google's decision to call their phone-based operating system "Android".

Star Trek was so utopian that even iPads and Androids could coexist.
While the Enterprise is basically a techie's flying holiday resort, you'd have to be stark raving mad to want to live on the Battlestar Galactica. Terrible food, squalid conditions, highly aggressive (though sexually insatiable) crewmates, and the prospect of a horrible death by killer robots / irate crew members / terrorists / the ship falling apart / summary justice / Adama's steely gaze each and every day. Worst of all, unlike Star Trek, I've never seen a single damn one of them drink any tea*. Actually, that probably explains why they're all so very, very angry. That and the genocide, of course.

* Caprica Six claims she does, once, but I don't trust her, on account of being a psychopathic anorexic killer robot.

What worries me is that Star Trek, by its very nature with a happy-clappy, "YAY TRIBBLES !" attitude, is a proven source of inspiration for legions of today's scientists and engineers. Battlestar Galactica isn't going to inspire anyone, because it doesn't contain a single piece of technology anyone either doesn't already have, or would want to invent. Unless you count - like many strange people - Caprica Six, but if anorexic genocidal robots are your thing then you can keep them to yourself, thanks.

"LOOK ! The monitor is too small. We need a viewscreen !"
In fact, I'm not so worried about BSG itself any more than I would worry that Yes Minister didn't feature enough zombie dinosaurs with lasers for eyes. What concerns me is the total lack of inspirational sci-fi shows around at the moment. Even Stargate made an attempt to jump on the "oh let's all be incredibly ANGSTY !" bandwagon, which it did with all the masterful control of a sheep trying to herd a bunch of rabid cats.

Perhaps we don't really need science fiction for inspiration, and this meandering rant hasn't achieved anything. All I know is that Star Trek is one of the two reasons I chose my career (the other is that nebula are goddamn pretty), and this is true for a lot of other people as well. Scientists are by no means Trekkies by definition, and vice-versa. And no doubt some scientists became Trek fans after discovering science, rather than the other way around. Just don't come running to me in twenty years when today's young BSG fans grow up and the hordes of angst-ridden robots start nuking the place.