Donnie’s Blog

The summer break is finally here, and I for one am very excited about this summer. This year I have a SURF student helping me out with the implementation of my “educational database system” in Java. The working name is currently NanoDB, although I am certainly open to other suggestions.

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A few days ago my WordPress installation was hacked. This is not a big surprise, since I haven’t been keeping up with the releases as they came out, and there have been a lot of security bugfixes along the way.

The hack was also very subtle, or it didn’t really accomplish a whole lot. I am not entirely sure what to make of it. But the exploit basically involved using the WordPress upload functionality to drop a PHP script into my /tmp directory, and also to ensure that it would always be run when a WordPress page was rendered.

Fortunately, when this happened, it broke certain parts of my website, so it became obvious pretty quickly. Also, fortunately, I keep a week’s worth of backups around, so if I catch a problem right away then I can roll back my installation to the day before the problem.

So that’s what I did this time; I rolled back my website software to before the hack, then I applied the latest and greatest upgrades, and finally I went through some of the “site-hardening” guides for making it much harder to hack these pieces of software.

We shall see if it actually solves the problems! And I for one will be much more diligent about applying upgrades when they come out…

Finally I have an Uninterruptible Power Supply on my server! “Uninterruptible” is decidedly over the top, but at least I’ll get clean shutdowns now if the power carks it on me.

I went ahead and got one of the APC battery-backup systems, a Back-UPS ES 750VA model. (This model is discontinued now; APC has a new, more streamlined version with the same general features.) The UPS has a port that allows you to connect it to a USB port, so that the power supply can tell the computer that things are about to get ugly. I still need to set up the power-monitoring software on my Linux box, but after that, I should be all set.

At long last, I am finally getting back to building my 13.1″ telescope!

The last time I did anything with that beast, I think I had just finished the 320-grit grinding. The surface looked great; reflections from the wet mirror were really beginning to look sharp. But, there was one little problem: the mirror’s focal length was awfully long. I was looking at a telescope that would probably be 6-7 feet tall, and for a 13.1″ mirror that is a little silly. I didn’t want to have to stand on a stool just to look through my little telescope. For an 18″ aperture, that might be completely reasonable, but for a 13″ it’s just silly. Going back over my mirror-grinding e-mails, I think my technique was causing the problem. Regardless, at the time I was pretty frustrated with the thing so I wrapped it up and put it in a box for a future time.

Nearly five years passed… and in the meantime I decided that what I really needed to do was to just go back to the beginning and deepen the curve of my mirror, then go through the intermediate stages again with a little more care. It took a while for me to warm up to the idea though. Mirror-grinding is hard and painful work. I think I needed to forget how bad it was before I went back to try again!

So, I finally got around to ordering more mirror-grinding grit from Newport Glass Works, a pretty cool company that I definitely want to use again once I get this telescope done and begin working on the next one. I ordered a grit-kit that contains all of the different grit-sizes, along with cerium oxide and pitch. The grit-kit showed up today (my last day of lectures, quite convenient), so I should be able to get back into the mirror-grinding pretty quickly. This should be a lot of fun!