Monday, April 29, 2002
I don’t know if I am more relieved or frightened to discover that astronomers have even less clue than software engineers on how to describe their subject to beginners.
I borrowed The Moden Amateur Astronomer, ed. Patrick Moore, from the library. It’s one of a series with the general title Practical Astronomy, and according to the blurb,
If you already own an astronomical telescope and want to know how to use it to the best effect, or if you are thinking about buying one and are wondering where to start, then this is the book for you.
The four pages of Chapter 2, Buying a Telescope, by Patrick Moore himself, are clearly written and left me with a clear picture of the pros and cons of different kinds of telescope and what to look for if I was buying one, but every other chapter gets bogged down in details that I (as a beginner) don't understand rather than explaining general principles, and shows no awareness of what I need to hear and what order I need to hear it in if I am to make any progress.
In a section on photography in the chapter on Auxiliary Equipment, I read that “…the most important features to bear in mind are the accessibility of the focus and the vignetting of the light cone.” Vignetting of the light cone, eh? What is that exactly? Is it something I should be avoiding like the plague or something I can’t do without? I read on and discover that it is “one of the most irritating problems in deep-sky photography and can easily ruin an otherwise excellent photo.” Yes, but what the hell is it? How will I know whether my pictures suffer from it? It turns out that I can avoid it if I buy “a low-profile focuser with a draw tube of at least 2 inches in diameter.” So all I have to do to clear up the subject is find out what a focuser is (and where I get one), and how I recognize a low-profile one. (As opposed to what? High-profile? Low-fullface?)
I searched in vain for a straightforward answer to these questions, though I did learn that “to determine the optimum focuser and secondary mirror size for your system, a simple ray diagram, showing the light cone, needs to be drawn,” (so simple that there is no need to supply an example).
Turning to Chapter 9 on Astronomical Spectroscopes, I read in the first paragraph that “75% of all our knowledge in astrophysics derives from observing spectra.” This sounds exciting, but the rest of the chapter has little to tell me on what this 75% is made up of. It provides me information like the following:
The wavelength shift of the observed stellar lines when compared with their rest wavelengths gives the star’s radial velocity via the Doppler formula
v = 3 × 105((λ0 - λ1) / λ1),
where v is the radial velocity in km s-1, λ0 is the observed wavelength of a line and λ1 is the rest wavelength of a line,
but nowhere bothers to tell me what the radial velocity of a star is or why I should care about it. The same treatment is given to all the other subjects touched on in the chapter, like emission line stars, Hertzsprung-Russel diagrams, and Fraunhofer lines.
I could give many more examples from this chapter or almost any other. Compared to this book, Linux HOWTOs are a model of clarity.
Friday, April 26, 2002
I have now completely redone the blog template and CSS, and although it frightened me at first after I republished by claiming to be unable to access the site, things now seem to be working OK, more or less. The layout problems I was experiencing were largely due to incompatible expectations by the template and my own entries, which I have managed to synchronize better now. I doubt if I will ever get the results to validate with all the stuff that gets added automatically, but at least it lays out as intended.
I'm sure I could do better if I took the trouble to read the instructions, and maybe I will even do that at some point.
Hmm…once again I am experiencing the problem that when the text box for entering the content starts to scroll, I can no longer see the Post and Publish buttons. Could this be another Mozilla bug?
Thursday, April 25, 2002
OK, what's going on here? In my naïveté I understood that “blogging tools” were supposed to make web publishing easier. I have just spent far longer in a cycle of editing, publishing, re-editing and re-publishing the previous entry than it would have taken me to write the whole bloody thing out in HTML source in emacs and ftp it to a web site — and it still looks horrible.
My first attempt in MozBlog went to the trouble of translating my HTML tags into plain text by converting “<” to “<” etc, and though moving to Blogger solved that problem, nothing I could do would straighten out the funky line wrapping. Yuk. Yuk. Yuk. And where do the buttons at Blogger disappear to after you write a few lines? Heaven knows how I will ever publish this rant.
It was interesting to discover that Mozilla has had a severe Bidi bug in print headers just about for ever. Print headers didn't exist when we designed Bidi; we never noticed the bug when they sneaked in a few months before we started checking code in to the tree; and nobody has ever noticed it since. It just goes to show that people don't print much, or don't look very hard at the results.
Tuesday, April 16, 2002
The latest edition of the usually excellent LangaList recommends me to go to ContentAudit for a good laugh, but as I enter the site my (admittely paranoid) alarm triggers are going off one after the other. Why does the site want my email address? Why does it redirect me to a page saying
“Attention Netscape Users
Content Audit is currently designed for Internet Explorer only.”
However funny the results, if the site wants to scan my hard drive from within the browser while online, and is only willing to do this through IE, I think I'll give it a miss and get my laughs somewhere else.
Sunday, April 14, 2002
Everyone else seems to be doing it, so why not me? The title, if you were wondering, is "על הא ודא", which is Aramaic for "On This And That".
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