so i've been meaning to write about solar eclipses for a while. this afternoon (10 jun 2002) there was a partial eclipse of the sun, which means that the moon passed in front of the sun, covering up part of it. of course, you can't look directly at it, any more than you can look directly at the sun normally, but if you have special mylar eclipse-viewing sunglasses (or other appropriate filter), you can look directly at it.

i have such a pair of glasses, and i showed the eclipse today to a bunch of my coworkers. they were all pretty impressed by it. one even said something like "that's the coolest thing i've ever seen!", which of course i'm sure she didn't mean, she was just speaking in hyperbole...

but the thing is that with a total eclipse, that statement would not be nearly so hyperbolic. partial eclipses are often described in terms of the percentage coverage of the sun. today's was 65% where i was -- meaning that about two-thirds of the visual area of the sun was blocked by the moon. but that figure is highly misleading, as it seems to imply that the experience is about two-thirds of the experience of a total eclipse. this could not be further from the truth. i would say that any partial eclipse -- even a 95% partial -- is less than 2% of the experience of a total eclipse.

in a total eclipse, you get maybe an hour and a half or so of gradually increasing partial eclipse, as the moon moves across the sun, followed by around two minutes or so of totality, during which the moon completely covers the sun, followed by another hour and a half of decreasing partial.

and to be fair, partial eclipses are pretty cool. but total eclipses are a completely different thing. there's simply no comparison. it's worth going outside to see the crescent sun of a partial eclipse, but it's worth travelling half-way around the world to see those two minutes of totality. seriously.

my parents brought my sister and i to see a total eclipse somewhere in oregon on 26 feb 1979. i was about three and a half years old at the time, so i don't really remember it. but my parents were so amazed by it that they found out when the next several total eclipses would be, and decided then -- in 1979 -- to go to hawaii in 1991 and to europe in 1999. these are the only things in their whole lives that they've ever planned 12 and 20 years in advance and actually done.

for the one on 11 jul 1991, we went to hawaii. it was only total on the big island of hawaii. (i guess it was 98% or 99% on the other islands.) my immediate family and several other relatives and family friends went there for a week. we did some snorkeling and tourist-y stuff, but the real highlight of the trip was the eclipse. i think totality was to be at about 10:30am or so, so every morning leading up to the eclipse, my dad went driving around to find a spot where he estimated that we would have optimal chance of not having clouds. on the day of, we went to the spot he'd selected, set up a telescope, viewed the partial eclipse... after a little while of that, it got cloudy, and we started to worry, but then about 15 minutes before totality, the clouds opened up. i think the clouds even covered the sun again shortly after totality -- the timing was really pretty amazing. apparently there were quite a lot of people on the island who were not so lucky. so i guess my dad's empirical research paid off (or else we were just plain lucky)... it would have been very disappointing (especially for those of us who, unlike me, remembered the 1979 one) to go all that way only to be "zipped out" (that's what the real eclipse-chasers call it when clouds prevent an eclipse-viewing).

then for the one on 11 aug 1999, my family (again, along with some extended family and friends) went to hungary. my aunt chose hungary because among all the places in europe that the shadow was to sweep across, hungary seemed to have among the better clear-sky records for august. and we were not disappointed -- the sky was completely clear that day.

in addition to several small pairs of binoculars (the kind you might carry around to go bird-watching or something), we had a telescope and a pair of very large binoculars (like, really large, not the kind you'd use for bird-watching). there were about twenty of us there. and totality was to be only two minutes and twenty seconds. which meant each person would get about 6 seconds of viewing through each of the tripod-mounted instruments. so the day before the eclipse, we rehearsed that process. we lined up, i think in decreasing order by height, in order to minimize adjustments to the tripods. each person had to look quickly through the telescope, then step over to the binoculars. i think on our second run-through of that, we did it in under two minutes.

anyway, so then on the day of, we had the viewing instruments all set up to view the sun's corona, we had a large sheet of white butcher paper on the ground to see the shadow bands, we knew when and where to look for the diamond ring effect, bailey's beads, and solar prominences... we were about as prepared as we could be. but even as one of the people who had seen totality before, i really was not prepared for it.

totality really is quite possibly the most amazing thing i have ever seen. it's completely indescribable. perhaps you've seen photographs -- a black disc with the white corona shooting out from it. some of those pictures are pretty spectacular. but no photograph can do it justice.

being inside the umbral shadow of the moon is a completely visceral experience. lisa spontaneously burst into tears. i totally forgot about our rehearsed plan for viewing through the instruments -- if lisa hadn't tugged my sleeve, i would have just stood there staring, with my jaw hanging open. before she tugged my sleeve, i think she had even said something to me that i completely failed to hear. seeing the corona magnified in each of the instruments was cool, but for me, looking through any instrument feels a little too removed from it -- staring up at the whole sky at once with the naked eye is really what the experience is really all about.

all of a sudden, the sun goes black. the sun isn't meant to be black. the sun rises each morning. the sun shines brightly yellow all day, as it moves across the sky. and then the sun sets, maybe turning a bit orange-ish. but the sun does not turn black. it just doesn't. this is just fundamentally wrong.

in spite of all my attempts to describe it, it really is simply indescribable. i think perhaps the best way to convey how amazing it is, better than any photograph you may have seen, better than my rambling on about it, is for you to listen to people's reactions during totality.

so here's a recording from 11 aug 1999: eclipse.mp3. this clip is about 3 minutes long, and totality begins about 30 seconds in. you don't hear me much in there, i think i was mostly just too dumbstruck to even say "wow".

all i can say is, if you ever have an opportunity to see a total eclipse, do not hesitate. you must go.