Shallow Thoughts : tags : eclipse
Akkana's Musings on Open Source Computing and Technology, Science, and Nature.
Fri, 24 Oct 2014
We had perfect weather for the partial solar eclipse yesterday.
I invited some friends over for an eclipse party -- we set up
a couple of scopes with solar filters, put out food and drink
and had an enjoyable afternoon.
And what views! The sunspot group right on the center of the sun's disk
was the most large and complex I'd ever seen, and there were some much
smaller, more subtle spots in the path of the eclipse. Meanwhile, the
moon's limb gave us a nice show of mountains and crater rims silhouetted
against the sun.
I didn't do much photography, but I did hold the point-and-shoot up to
the eyepiece for a few shots about twenty minutes before maximum eclipse,
and was quite pleased with the result.
An excellent afternoon. And I made too much blueberry bread and
far too many oatmeal cookies ... so I'll have sweet eclipse memories
for quite some time.
[ 09:15 Oct 24, 2014
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Tue, 22 May 2012
I've just seen the annular eclipse, and what a lovely sight it was!
This was only my second significant solar eclipse, the first being a
partial when I was a teenager. So I was pretty excited about an
annular so nearby -- the centerline was only about a 4-hour drive from home.
We'd made arrangements to join the Shasta astronomy club's eclipse party
at Whiskeytown Lake, up in the Trinity Alps. Sounded like a lovely spot,
and we'd be able to trade views with the members of the local astronomy
club as well as showing off the eclipse to the public. As astronomers
bringing telescopes, we'd get reserved parking and didn't even have to
pay the park fee. Sounded good!
Not knowing whether we might hit traffic, we left home first thing in
the morning, hours earlier than we figured was really necessary.
A good thing, as it turned out.
Not because we hit any traffic -- but because when we got to the site,
it was a zoo. There were cars idling everywhere, milling up and
down every road looking for parking spots.
We waited in the queue at the formal site, and finally got to the
front of the line, where we told the ranger we were bringing
telescopes for the event. He said well, um, we could drive in and
unload, but there was no parking so we'd just have to drive out
after unloading, hope to find a parking spot on the road somewhere,
and walk back.
What a fiasco!
After taking a long look at the constant stream of cars inching along in
both directions and the chaotic crowd at the site, we decided the
better part of valor was to leave this vale of tears and high-tail it
back to our motel in Red Bluff, only little farther south of the
centerline and still well within the path of annularity. Fortunately
we'd left plenty of extra time, so we made it back with time to spare.
The Annular Eclipse itself
One striking thing about watching the eclipse through a telescope was
how fast the moon moves. The sun was well decorated with several excellent
large sunspot groups, so we were able to watch the moon swallow them
bit by bit.
Some of the darker sunspot umbras even showed something like a
black drop effect
as they disappeared behind the moon. We couldn't see the same
effect on the smaller sunspot groups, or on the penumbras.
There was also a pronounced black drop effect at the onset and end
The seeing was surprisingly good, as solar observing goes. Not only
could we see good detail on the sunspot groups and solar faculae,
but we could easily see irregularities in the shape of the moon's
surface -- in particular one small sharp mountain peak on the leading edge,
and what looked like a raised crater wall farther south on that
leading edge. We never did get a satisfactory identification on
After writing and speaking about eclipse viewing, I felt honor bound
to try viewing with pinholes of several sizes. I found that during early
stages of the eclipse, the pinholes had to be both small (under about
5 mm) and fairly round to show much. Later in the eclipse,
nearly anything worked to show the crescent or the annular ring,
including interlaced fingers or the shadow of a pine tree on the wall.
I wish I'd remembered to take an actual hole punch, which would have
been just about perfect.
I also tried projection through binoculars, and convinced myself that
it would probably work as a means of viewing next month's Venus
transit -- but only with the binoculars on a tripod. Hand-holding
them is fiddly and difficult. (Of course, never look through
binoculars at the sun without a solar filter.) Look for an upcoming
article with more details on binocular projection.
The cast of characters
For us, the motel parking lot worked out great. We were staying at the
Crystal Motel in Red Bluff, an unassuming little motel that proved to be
clean and quiet, with friendly, helpful staff and the fastest motel
wi-fi connection I've ever seen. Maybe not the most scenic of
locations, but that was balanced by the convenience of having the car
and room so close by.
And we were able to show the eclipse to locals
and motel guests who wouldn't have been able to see it otherwise.
Many of these people, living right in the eclipse path, didn't even
know there was an eclipse happening, so poor had the media coverage been.
(That was true in the bay area too -- most people I talked to last week
didn't know there was an eclipse coming up, let alone how or where to
We showed the eclipse to quite a cast of characters --
- The mother with medical problems, obviously feeling quite poorly
but still bringing her husband and son out for repeated views.
- the woman who said she didn't want to be in the sun because she'd
been drinking too much by the pool.
- The family where Dad kept looking through paper glasses the kids
insisted was a "3-D viewer". Alarmed, we took a look, and found it
was a perfectly reasonable eclipse viewer marked SAFE FOR SOLAR VIEWING.
- The teen girl who kept looking directly at the sun despite everyone
telling her not to ... I hope she didn't damage her vision.
- The kid who wanted to borrow my binocular to look at some birds
circling in the distance. I wanted to let him, but with all the
attention on the sun I was too nervous, so instead I changed the
subject and showed him how to identify turkey vultures (wings in a V,
tipping from side to side) even without binoculars).
- The man who sat in a parking space near us reading a catalog,
telling us repeatedly he was just reading his catalog. When Dave
insisted he come and take a look, he looked in the eyepiece for about
ten seconds, then looked Dave in the eye and informed him solemnly
that he was just reading his catalog.
- The family who'd been instructed by their grandmother, in the hospital
awaiting an operation, to watch the eclipse and bring back pictures for her.
I hope they got some decent ones!
In between visitors, we had plenty of time to fiddle with equipment,
take photos, and take breaks sitting in the shade to cool down.
(Annularity was pleasantly cool, but the rest of the eclipse stayed
hot on an over 90 degree central valley day.)
There's a lot to be said for sidewalk astronomy! Overall, I'm glad
we ended up where we did rather than in that Whiskeytown chaos.
Here's my collection of
from the "Ring of Fire" Annular Eclipse, May 2012, from Red Bluff, CA.
[ 11:42 May 22, 2012
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Wed, 16 May 2012
This Sunday, May 20th, the western half of the US will be treated
to an annular solar eclipse.
Annular means that the moon is a bit farther away than usual, so it
won't completely cover the sun even if you travel to the eclipse
centerline. Why? Well, the moon's orbit around the earth
isn't perfectly circular, so sometimes it's farther away, sometimes
nearer. Remember all the hype two weeks ago about the "supermoon",
where it was unusually close at full moon? The other side of that
is that during this eclipse, at new moon, the moon is unusually far
away, and therefore a little smaller, not quite big enough to cover
Since the sun will never be totally covered, make sure
you have a safe solar filter for this one -- don't look with your
naked eyes! You want a solar filter anyway, if you have any kind of
telescope or even binoculars, because of next month's once-in-a-lifetime
Venus transit (I'll write about that separately).
But if you don't have a solar filter and absolutely can't get one
in time, read on -- I'll have some suggestions later even for people
without any sort of optical aid.
But first, the path of the eclipse.
Here in the bay area, we're just a bit south of the southern limit of the
annular path, which passes just south of the town of Redway, through
Covelo, just south of Willows, then just misses Yuba City and
Auburn. If you want to be closer to the centerline, go camping at
Lassen National Park or Lake Shasta, or head to Reno or Tahoe
If you're inclined to travel, NASA has a great
2012 eclipse map you can use to check out possible locations.
Even back in the bay area, we still get a darn good dinner show. The partial
eclipse starts at 5:17 pm PDT, with maximum eclipse at 6:33. The sun
will be 18 degrees above the horizon at that point, and 89%
eclipsed. Compare that with 97% for a site right on the centerline --
remember, since this is an annular eclipse, no place sees 100%
coverage. The partial eclipse ends at 7:40 -- still well before
sunset, which isn't until 8:11.
Photographers, if you want a shot of an annular eclipse as the sun
sets, you'll need to head east, to Albuquerque, NM or Lubbock, TX.
A little before sunset, the centerline also crosses
near a lot of great vacation spots like Bryce, Zion and Canyon de Chelly.
I mentioned that even without a solar filter, there are ways of
watching the eclipse. The simplest is with a pinhole. You don't need
to use an actual pin -- the size and shape of the hole isn't critical,
as you can see in this
of the sun through the leaves of a tree during a 2005 eclipse in Malta.
If you don't have a leafy tree handy, you can even lace your fingers
together and look at the shadow of your hands. This eclipse will be
very low in the sky, continuing through sunset, so you may need to
project its shadow onto a wall rather than the ground.
If you have some
time to prepare, take a piece of cardboard and punch a few holes
through it. Try different sizes -- an actual pinhole, a BBQ skewer,
a 3-hole punch, maybe even bigger holes up to the size of a penny.
You might also try using aluminum foil -- you can get very clean
circular holes that way, which might give a crisper image.
Here's a good page on
What works best? I don't remember! It's been a very long time since
the last eclipse here! Do the experiment! I know I will be.
If you do have a telescope or binoculars but couldn't get a solar
filter in time, don't despair. Instead of looking through the
eyepiece, you can project the sun's image onto a white screen or even
the ground or a wall. Use a cheap, low-power eyepiece -- any eyepiece
you use for solar projection will get very hot, and you don't want to
risk ruining a fancy one.
Point the telescope at the sun -- it's easy to tell when it's
lined up by watching the shadow of the telescope -- and rotate the
eyepiece so that it's aimed at your screen, which can be as simple
as a sheet of paper. Be careful where that eyepiece is aimed -- make
sure no one can walk through the path or put their hand in the way,
and if you have a finderscope, make sure it's covered.
This solar projection method works with binoculars too, but you'll want
to mount them on a tripod so you don't have to hold them the whole time.
Of course, another great way to watch the eclipse is with your local
astronomy club. I expect every club in the bay area -- and there are a
lot of them -- will have telescopes out to share the eclipse with the
public. So check with your local club --
San Jose Astronomical Association,
Peninsula Astronomical Society,
San Francisco Sidewalk
San Francisco Amateur Astronomers,
or any of the others on the AANC's list of
Astronomy Clubs in Northern California
Chronicle's list of astronomy clubs.
This eclipse should be pretty cool -- and a great chance to test
out your solar equipment before next month's Venus transit.
When I went to put the event on my wall calendar last month, I discovered
the calendar already had an entry for May 20: it's the start of Bear
Awareness Week. So if you head up to Lassen or Shasta to watch the
eclipse, be sure to be aware of the bears! (Also, maybe I should get a
calendar that's a little more in tune with the sky.)
[ 21:12 May 16, 2012
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Tue, 25 Jan 2011
Eclipse has been driving me batty with all the extra spaces it adds
everywhere -- blank lines all have indents on them, and lots of
code lines have extra spaces randomly tacked on to the end.
I sure wouldn't want to share files like that with coworkers
or post them as open source.
I found lots of suggestions on the web for eliminating extra whitespace,
and several places to configure this within Eclipse,
but most of them don't do anything.
Here's the one that actually worked:
Enable Perform the selected actions on save.
Enable Additional actions.
In the Code Organizing tab., enable
Remove trailing whitespace for All lines.
Review all the other options there, since it will all happen automatically
whenever you save -- make sure there isn't anything there you
Dismiss the Configure window.
Review the other options under Save Actions, since these will
also happen automatically now.
Don't forget to click Apply in the Save Actions
Whew! There are other places to set this, in various Code style
and Cleanup options, but all all the others require taking some
like Source->Clean up...
By the way, while you're changing whitespace preferences,
you may also want the
Insert spaces for tabs preference under
An easy way to check whether you've succeeded in exorcising the
spaces -- eclipse doesn't show them all, even when you tell it to --
:set hlsearch in vim, then search for a space.
(Here are some other ways to show
spaces in vim.) In emacs, you can
true, but that
doesn't show spaces on blank lines; for that you might want
or similar packages.
[ 15:42 Jan 25, 2011
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Tue, 07 Dec 2010
I've been doing some Android development, using the standard Eclipse
development tools. A few days ago, I pasted some code that included
a comment about different Android versions, and got a surprise:
What do you think -- should I change all the "Android" references
[ 11:09 Dec 07, 2010
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