Worst astrophysics cut and paste job ever.

OK, I know that people's perceptions of astrophysics can be a bit off at times, but this is taking things too far... Come on, use some common sense here. Never mind any fancy astronomical distances, the article itself points out that the difference in distance between the moon right now and at other more 'normal' times is currently 350,000 km, some 30,000 km less than the usual distance of ~385,000 km. This is a difference of around 7%! This means that the Moon is only 7% larger in the sky than normal. 7%. Unlike what's represented in the picture, from which you'd deduce that the Earth-Moon distance had suddenly shrunk to at least a third of its usual distance!

*wanders off muttering about science education and reporting these days*

Radio data reduction... How I love thee...

So this was going to be my procrastination from flagging RFI from my radio data; I was going to ramble on about the 'fun' that is radio interferometer data reduction, that is how you go from a bunch of numbers representing correlations between every antenna and every other antenna in your radio interferometer array to something resembling a decent image of your source at radio wavelengths with a resolution far far better than what you can achieve with just one dish. Instead, I actually flagged the data instead... Go figure, but hey, I'll start now.

So (assuming that one's actually got data from a telescope and the telescope was actually pointed where you wanted it to be pointed), how exactly does one go about going from 'bunch of numbers that represent a Fourier transform of the sky' to pretty image?

Well first you need to prepare the data. You start with having a source of known flux, and a source which is a point source so that the phase variation of the radiation from it is just intrinsic and not atmospheric. So before you start your calibration, you load up your data and look for evidence of RFI... Spikes of high intensity radiation at a given time and/or a given frequency channel. And you do this for each and every baseline (i.e. for each antenna correlated with every other antenna... There are 30 GMRT antennas... So there are 435 baselines to go through...) at two different polarisations (so 870 arrays of data to look at and its tedious... The data basically look like a load of white on black barcodes... I can see them in my sleep!), flagging anything that looks suspicious. And then you calibrate -- first the antenna gains for that particular observation. Then you calibrate for the phases, and figure out what your bandpass should look like. Then you apply all this calibration to the data of your source. Then you remove the noise spikes from the source (looking at 870 arrays of data again!).

Then and only then can you start to consider how to do an inverse Fourier transform of your data to create an image... A problem which is further compounded because your sampling of the Fourier plane isn't perfect or complete, so you can't actually do a proper inversion... The fun is endless...


And in case you hadn't realised... Do you really think I love this rigamarole? ;-)

A belated party post...

So, way back around a month ago, Chloé hosted a party at hers, just before I left Paris. It was a fantastic evening, and well, me being me, I offered to cook some things, including my oft-requested (but alas rarely made -- you try making a baked cheesecake in a toaster oven!) cheesecake. And well, seeing as I had access to not only a decent-sized oven whilst staying at Chloé's mum's place, but also a fantastic mixer, I decided that I'd give in to the repeated requests and make my baked cheesecake. And then go all out and make a fruit topping for it all. Amazingly, I managed to find all the ingredients in Paris, even if it did involve a wander down to Le Grande Epicerie for sour cream (and really rather amusing to see things that are classed as everyday essentials in the UK going for premium prices in Paris... ;) ), and so set about making cheesecake, with my own twists.

I'd decided to make two cheesecakes, for the party and one for the night before, and so, of course, tripled the recipe... However, events the day before being what they were, meant that I didn't get chance to make the cheesecake the night before, and me being the oh so highly organised astrophysicist I am, and not scatterbrained at all completely forgot about this when I went to pick up the ingredients on Saturday morning. And so ended up with enough mix for three cheesecakes but only enough biscuits for the bases for two. Which led to the experimental cheesecake pictured which has no base (but was yummy anyway!). Its got a blackcurrant sauce swirled into it, courtesy of Lil, (one of the others had a raspberry sauce with raspberries in it on top and the other had the rest of this blackcurrant sauce together with blackcurrants)...

Anyway, all three cheesecakes were really rather well received, and the party was an absolute blast and involved such antics as the boys (well Guilleme and Arnold) dressing up as Mario and Luigi and doing quite silly things like well, see for yourself... Its not like the Wii was on at this point... ;-)


And for those of you who've read this far and who are probably going "come on woman! give us the cheesecake recipe damnit!", here's the cheesecake recipe. Scaled back down for one single cheesecake... ;-)

Baked Cheesecake:

for the base:

• About 3/4 of a large packet of ginger nut biscuits
• 25-50 g of butter (maybe more)

for the cheesecake itself

• 450 g cream cheese (like Philadelphia)
• 110 g fresh sour cream
• 170 g caster sugar
• 3 eggs
• grated rind and juice of a lemon
• good teaspoon vanilla extract

for the topping:

• 2 punnets of blackberries/raspberries/strawberries/soft berries of your choice
• 2 - 3 tablespoons of sugar
• 50 ml water

Method

• Make the base first
• Pound the biscuits to a medium-ish crumb, some larger bits are fine in it though.
• In a saucepan, melt the butter over a low heat
• Add the biscuits to the melted butter and coat the biscuit crumbs thoroughly in the butter
• Place the mixture into the bottom of a greased, non-loose bottomed cake pan (20 cm diameter), pat into the edges making sure you have a uniform layer of biscuity goodness.
• Place in fridge to chill.

For the cheesecakey bit:

• Take a roasting tray and fill with water, such that the water will come up to about halfway up the cake tin.
• Put this into the oven which should be set to gas mark 4/180 C
• Beat the cream cheese with the sour cream
• Beat in the sugar
• Add in the eggs one by one
  
• Add the lemon rind and juice and vanilla and mix well
• Take your base out of the fridge, and pour the cheesecake mix onto the base
• Place the cheesecake into the bain marie in the oven and bake for 35 mins
• When done, switch the oven off and leave the oven door open so that the cheesecake can cool.

Whilst the cheesecake is cooking, make the topping:

• In a saucepan heat the water and sugar till all the sugar dissolves
• Add half the berries and reduce down till the berries have broken down and you have a berry syrup
• Taste and add more sugar if needed.
• Just before topping the cheesecake, put in the rest of the berries and coat them in the syrup.
• Or you can just swirl the syrup through the cheesecake like in the pic
  

Transcontinental moving...

So, the main reason I've been quiet on here for a while has been mainly cause I've been running around like a headless chicken sorting out plane tickets and a visa for India. Well I've been in India for a week now, as a 'visiting scientist' at the National Centre for Radio Astrophysics in Pune, doing data analysis of the data I took when visiting the radio telescope, GMRT, in July and interacting with students, other postdocs and staff here. And well they are proving that one really needs a sense of humour to be an astrophysicist! ;-)

Culturally, I'm loving the laid-back attitude here, and its actually proving conducive to getting a lot of work done, though I may, by the end of it, I'm either going to love or hate AIPS... I'm already starting to see residual maps when I close my eyes.... :S

I haven't had chance to explore Pune yet (hey, I've only been here for a week!), but I'm hoping I will... If nothing else, I need to do some shopping for gifts for people back home (and I may take requests... ;-) )

Will post more when its not quite so close to dinnertime!

Watching the US Election...

OK, so I haven't updated this blog in a while, I have to blame work, more work, and packing up to leave France. Luckily, have arrived back at my parents' place in the UK (fully equipped with internet access and CNN ;-) ), just in time to watch the coverage of the US Presidential elections... And yes, like most of the rest of the world, I have my fingers crossed for an Obama win, and so far, its looking interesting with polls in Indiana and Kentucky having just closed. Preliminary results seem to suggests that Kentucky will go to McCain, though Obama is catching up... Indiana is close... Very close... Come on Obama... This is getting nailbiting...

Freeing the airwaves... Hmmm... (And other geekery)

OK, time for me to get a little geeky today, I'm afraid, and have a head-desk moment about "Free the Airwaves". Simply put, this is a campaign to get the FCC to allow unlicensed use of "white space" in-between tv broadcast channels, i.e. at frequencies between 54 and 700 MHz, and indeed, once the digital switch-over happens, to allow unrestricted use of frequencies in this band, particularly for things like mobile broadband. Which all sounds great and peachy and "oooh we can open the internet up to more people and make it easier for people etc. etc.". Unless you're a low-frequency radio astronomer. Probably working with the VLA (or indeed the GMRT, but as that's in India, its not 100% relevant!), at frequencies in the 330 MHz and 75 MHz ranges where radio interference from TV and mobile phones is already pretty bad...

Now, ok, radio astronomy's not like finding a cure for cancer or something like that, but it is an interesting and important tool in furthering our understanding of the universe, how the universe evolves, how galaxies interact with and shape their environments, and provides a window on the universe that shows a truly amazing richness of beautiful phenomena, and has allowed tests of relativity, and deepened our understanding of the universe. And low frequency radio astronomy has been instrumental in telling us about the history of interactions between galaxies and their environments, helping us to further understand the evolution of these environments and ultimately our universe. I don't know about you, but I find this fascinating (well, I'd have to really, wouldn't I, else why would I do it?).

But, its difficult. Really difficult. Mainly because of all the man-made radio frequency interference there is at these frequencies. The signal we're looking for can be at least thousands of times fainter than the interferences, and we end up having to bin loads of data to get rid of contaminated channels. Which means our sensitivity is reduced and observing time and money (a limited resource) is wasted. And the faint signals we're looking for become even harder to find. And so science gets even more difficult, and more obstacle strewn than it already is. :-(

I'm sure that there'll be "protected" bands where devices won't be allowed to broadcast, but in reality there'll still be large amounts of leakage into these protected bands which will contaminate observations and make science that little bit harder. *sigh* Anyone fancy a trip to the far side of the moon with a radio telescope array? ;-)

And in other geekery, I've had to fix my MacBook Pro with a bit of post-it note and sellotape. Yep folks, a €2000 computer fixed with office stationery. What was wrong with it? Well, the keyboard and trackpad would just stop working randomly, for no rhyme or reason. Sometimes it'd come back, sometimes it wouldn't. I was confused as hell. So I Gooogled. And Googled some more. And it turns out that there's a known problem of a bowed ribbon cable that connects the keyboard/trackpad to everything else. Applying pressure on the ribbon cable makes everything work fine again, so, 10 minutes later, with a bit of post-it note folded over a few times to apply sufficient pressure sellotaped into place, everything works fine again. And touch wood, there won't be any more problems. I swear I'm cursed with laptops or something!

New digital camera!

Yay! After a couple of months of searching, debating, trying to find a good deal on a decent camera, I come home for a week, and within 24 hours, with the aid of my brother, I manage to find a decent digital camera at a decent price! Woo! Ended up with a Fuji FinePix J50 (from the store linked to), which being a mere 15 miles from Burnley, meant we went to pick it up, rather than paying extra for packaging etc, and meant I didn't have to wait either... (Not that I'm impatient or anything like that. Delayed gratification is good in some scenarios after all. ;-) ). Haven't been able to play with it yet, as the battery needed charging, but hopefully tomorrow I'll be able to have a play, post pics, and see just how good my new toy actually is! May be interesting to try the night mode (or play with the brother's camera) to see if pics of astronomical objects are possible. Though it seems a bit redundant given the multi-million dollar telescopes I get to play with anyway... ;-)

And well, once the camera's sorted, and I'm back in my own kitchen, I'll have to make a start on some illustrated recipes too... :-)

All new blog!

So yeah, new blog (can't use LJ any more as the ex has that address and I don't particularly want to be posting stuff there any more... ;-) ). So yeah, what's going on? Its been a hectic summer, conferences in the US, friends getting married, observing at the GMRT in India, and yes, breaking up with David.

That one was really a long time coming; lots of problems since I moved out to France really, stuff that he wouldn't really admit to until things were over, but the bottom line was that there was an expectation that my career was secondary to his, I wasn't "supposed" to succeed or indeed carry on in academia after this post in France (get it all out of my system I guess... ;-) ), and he expected me to give it up, find a job in the "real world" and move to London. Oh well, sucks to be him... ;-) Does mean this weekend's going to be interesting -- it'll be the first time we've seen each other since I broke up with him, hopefully it shouldn't be too painful to give his stuff back and get mine back from his. And well, I have a good network of friends I can run too if things do get too painful!

On the plus side, I get to see my parents and family for a whole week (someone remind me of this around this time next week! ;-) ), and generally chill as work is closed for the entirity of next week. Explains the miserable weather then!