On the normalization of PRFs Yesterday I said that the PRF for a map in Jy/beam (or similar) should be normalized so that that peak is 1. But this is true only for an idealised (not...
Estimating the flux of a point source You have a map and you know what a point source looks like. How do you filter the map so that the value of each pixel is now the most likely flux of a p...
How to vote ethically I know nothing about politics. Okay, I know what I think about a few controversial moral issues, but the rest - the other 99% or so - is a complete myst...
Evangelicals Now: singing and tweeting Well, it's been almost two months since my last update. I suppose if this were a blog, that would be unacceptable. Anyway, I still don't have anything i...
Simon Singh sued Chiropractic is all about manipulating the spine to cure various ailments. It's all over the news at the moment because of something Simon Singh wrote i...
Visualizing noisy images You have an image. Each pixel has a value with some uncertainty. How do you visualize the uncertainty in each pixel?
Six days and counting Herschel (on the left) and Planck (on the right) are scheduled for launch at 2.12pm UK time this coming Thursday... At Sussex we're busy getting ready ...
Python, FITS and DS9 Here's an easy way to display FITS images (or any array) in DS9 using Python (with PyFITS, NumPy and Numdisplay, which is part of stsci_python). First l...
David Robertson on secular belief and society David Robertson, author of The Dawkins Letters, is due to visit Brighton in June/July. Yesterday he was on Premier Christian Radio's Unbelievable? progr...
PSFs in IDL Two methods of approximating a point-spread function in IDL: 1. StarFinder seems to do a great job at finding point sources in crowded fields. It includ...
The eclipse of IDL 7 I've finally made the transition from IDL 6.4 to IDL 7. Here are my handy hints... IDL Workbench rocks! (This is because it is basically Eclipse, which...
Film discussion: Iron Man (2008) Just back from a film discussion at my church, at which we watched Iron Man (2008) and then used the following questions to delve under the surface of t...
Are we alone in the Universe? After “Do you want to be the next Patrick Moore?” and “I’m a Capricorn”, the most common response I get when I tell people I work in astronomy is, “Do...
Peter Hitchens on equality and diversity Commenting on the scandal of nurse Caroline Petrie offering to pray for a patient, Peter Hichens made this observation: After an earlier incident she wa...
Is atheism compatible with belief in evolution? Perhaps not. Have a read of this extract from Alvin Plantinga's entry on Religion and Science in the Stanford Encyclopedia of Philosophy (dealt with at...
The government shall be upon his shoulders NT Wright, speaking on Christmas Eve: ‘Unto us a child is born; unto us a son is given; and the government shall be upon his shoulders.’ [Isaiah 9] Unl...
Simulating the Universe Astronomers spend a lot of time making computer simulations of the Universe. Some discussion on The e-Astronomer's blog has set me thinking about why.....
All religious beliefs are equal … ... but some beliefs are more equal than others. At least it seems that way when "equality" legislation is applied to justify the withdrawal of funding ...
Dawkins on rape Presenter of Premier Radio's Unbelievable? programme "Justin Brierley spoke to prominent atheist Richard Dawkins after his debate with Professor John Le...
Herschel Space Observatory PhD now submitted, I've just started a six-month contract working at Sussex on some software for the Herschel Space Observatory, which is due to be laun...
Mike Reeves on the Trinity (2) God is love So if the Christian God is entirely different to whatever God anyone else worships, then what - or who - is this God? Mike Reeves, part 2 (with a bit of...
Mike Reeves on the Trinity (1) Do you believe in God? Yes? Whoa, hold on a minute! Which God are we talking about? Sorry? Which God do you believe in? You see, the assumption is that...
The science of galaxy formation… ...is the title of a provocative article by Gerry Gilmore(*) on today's astro-ph. There's a bit about the scientific method, such as: The appropriate sc...
Confirmation bias Professor Aardvark has a theory. His theory predicts X. So he does some experiments and presents a tentative scientific result, suggesting that X might ...
Papers: your personal library of science Looking for a piece of software for your Mac that will allow you to: keep track of PDFs of academic papers, search for papers using Google Scholar, ADS...
UKIDSS paper submitted Well, the deed has been done, and the paper has finally been submitted to MNRAS and to astro-ph. You can read it if you really want to: Luminosity and s...
Galaxy Zoo: the independence of morphology and colour Galaxies come in two types: red, elliptical galaxies that reside in high-density regions, and blue, spiral galaxies that reside in low-density regions. ...
Evolution of Schechter function … so? This is some work in progress: K-band luminosity function from the UKIDSS Large Area Survey (LAS, black dots), showing the number of galaxies per unit ...
Religious exclusivity and world peace What is the main barrier to peace in the world?</p> asks Tim Keller in the first of a series of talks related to his new book, The Reason for God....
A galaxy being emitted by a star Why is the universe so crowded? This kind of thing is really messing up my data! Makes me want to work with simulations...
Advice to an archbishop So in a lecture Rowan Williams, admittedly in a display of "political ineptitude", makes some carefully reasoned and apparently reasonable (if obfuscato...
pIDLy: IDL within Python Now Python and IDL can talk to each other (okay, Python talks to IDL and IDL does what it's told), using pIDLy (pronounce as you please). I experimented...
IDL code miscellany IDLdoc 3.0 (more info here) gives my badly-written bits of IDL the deceptive appearance of being well designed, useful and user-friendly. So I've made a...
Opto ergo sum (4) free to choose To be free to choose is to be free from commitment ... because to be committed means you've chosen already. To be free to choose is to be free from bel...
Moving files to trash from the Mac command line Ever wished you could move files to the trash from the command line on the Mac? Here’s how. First, buy a Mac. Then Option 1 (uses bash): add the follo...
UKIDSS at ESO Just back from my first visit to Garching (near Munich). ESO, to be more specific. The reason for the visit: a three-day workshop on Science from UKIDSS...
Filtering astro-ph with CosmoCoffee One of the things mentioned in Sarah Bridle's talk at YAM last week was a filter for arXiv.org provided by CosmoCoffee. I decided to sample it this week...
UKIDSS poster Last Friday was the RAS Young Astronomers Meeting up in Edinburgh. I presented a poster, ‘A census of K-band galaxies from the UKIDSS Large Area Survey,’ which I’ve just put online on my (very short!) publications page.
Nothing worth reading This is the first entry in the new Research Blog [update: tagged under astronomy and computing], reserved for posts of a tedious, technical or boring na...
New category for boring posts Tedious and technical posts related to my research in astronomy are henceforth to have a home on this blog (update: they are now tagged under astronomy ...
Opto ergo sum (3) you are what you listen to You're at a party. Talking to someone new. It's someone of the opposite sex. Thought goes through your mind (again): maybe this could be the one? Who k...
Stellarium If, like me, you know virtually nothing about astronomy, wouldn't know which way to look through a telescope, but would quite like to be able to identif...
Galaxy Zoo Galaxy Zoo is a project to get ordinary people (that's you) to help look through pictures of a million galaxies, labelling each one as a spiral galaxy, ...
Tolerance, equality and diversity Tolerance, equality and diversity: three words that reflect the core values of our culture. But what do they mean? Listen carefully, because these wor...
Recitals in May I'll be trying my hand at singing a couple of solo recitals this month, with James Lloyd Thomas accompanying me on the piano, and with a guest appearanc...
Questions for the standard cosmological model ...it seems probable that most of the grand underlying principles have been firmly established... The words of Albert Michelson, Nobel Prize-winning phy...
Good Friday Bach What better way to spend Good Friday evening than at a live performance of possibly the most profound piece of music ever composed? I'm referring, of co...
A cappella Bach This Saturday (17 March) I'll be singing (as an extra) with the Brighton Consort for Bach and the German Tradition, featuring two of Bach's glorious mot...
Does God exist? Six-minute mini-debate on the Today Programme this morning, featuring William Lane Craig and Lewis Wolpert. I'm hoping to get to the real thing this eve...
Does Richard Dawkins exist? For a novel take on this perplexing question, read this, or listen to this:
Freecycle Got something you don't want any more, but it would be a shame to throw it away? Or is there something you want that someone else might be trying to get...
HIV statistics Earlier this week I sang in a choir for a Christmas concert to raise money for treatment of HIV patients. I thought I'd do some research. It is often tr...
On faith and reason Religious knowledge is about faith, but scientific knowledge is about reason, right? Well, no. At least, not according to this talk (MP3) by Andrew Fell...
Opto ergo sum (2) I choose therefore I am I've been thinking lately about what it is that makes us tick. There has been plenty of discussion in the media about what makes a person British - in t...
Nothing out of the ordinary It's official: today, Tuesday the 17th of October, 2006, is an "ordinary day much like any other of no particular national significance". Bloggers are ...
Opto ergo sum (1) six choices before breakfast We're surrounded by choices. Here are six I was compelled to make before breakfast. Should I get up? I'm not a slave or a child. No one will force me t...
Sorry, Zidane? Zidane is reported to "apologise" for his "inexcusable" headbutt in Sunday's World Cup final. But he added, "I can't regret it". Huh?
Firefox or Safari? I've been using Firefox for a good while now as my web-browser. It's been the obvious browser to use on Linux and I've found it much better than Interne...
Structured Procrastination Found the key to organizing my life: Structured Procrastrination. Now, what was I trying to avoid doing...
Ceci what? For those of you still in the dark, René Magritte, a Beligan surrealist artist, painted La trahison des images (The Treachery Of Images) in the 1920s. ...
Blogging: good or bad? A weblog, or blog, is well described by Dilbert.com: When I see news stories about people all over the world who are experiencing hardships, I worry abo...
Ceci n’est pas un blog Thanks to WordPress, K2 and ColdMedia, I've been able to give this site a new feel. I hope you like it. I don't want to start writing a blog (I'll expla...