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21 February 2005 — Garden Science

How useful is your college degree?

I often joke with my friends who have Hard Science backgrounds, ridiculing them for not studying something more useful: a social science perhaps, like psychology. This is all ironic, of course, since there are few degrees more useless than psychology and few more useful than a Hard Science.

Sometimes my lack of Hard Science education thwarts me in unexpected ways. I have a fundamental lack of understanding about electricity, for example, meaning that when I'm rewiring the house, I'm undertaking a leap of faith. I have a poor grasp of rudimentary physics concepts. Biology is basically a grand mystery to me. I may be able to tell you all about Maslow's Hierarchy of Needs, or to discuss the fascinating merits of Gestalt theory, but I cannot tell you where the pancreas is located.

I did take astronomy in college, for what it's worth; yet, having astronomy as one's lone physical science isn't particularly useful.

Usually.

Our newly tilled garden (can you believe I tilled the garden plot in mid-February?!?) is currently completely shaded by the arborvitae hedge to the south of our lot. I've planted peas along the fence, next to the hedge, but I have little hope that they'll germinate without the warming rays of the sun. When will they get the sun? We know that the garden plot received full sun during the summer, but we haven't really paid attention to it since.

This sounds like a job for Astronomy Man!

I tried to work this out in my head as Kris and I were driving home the other night: "So if Portland is just north of the 45th parallel, that means the sun is about 45-degrees high in the sky at the Vernal Equinox, right?"

"I don't know," said Kris, my wife, upon whom I generally rely to answer all of my Hard Science questions. She's not so good at astronomy, though.

"I think that's so," I said. "And we know that the sun ranges 46-degrees from solstice to solstice, right? The tropics are at 23 degrees north and south latitudes. That means the sun must move approximately eight degrees a month. Give or take." — I figure the sun's apparent trajectory must "flatten" near the solstices and "accelerate" between them — "So, in theory, the noon-day sun must sit at 22 degrees above the horizon at the Winter Solstice, and it must be at 68 degrees above the horizon at the Summer Solstice. Our garden plot is ten feet wide and is only now just in complete shade. When will it be in full sun?"

I knew how to frame the problem, you see, but then I ran into trouble. I could not determine the proper geometry formula to work out in my head. Even now, I'm not sure I have enough information. I know the approximate angle of the sun at one-month intervals, and I know the length of the shadow cast by the arborvitae on Feb. 21st, so can I determine the position of the shadows one month from now? Two months from now?

I don't know.

But I'm going to have fun trying!

(This problem would be a whole lot easier with visual aids. This web site may help.)

Comments
On 21 February 2005 (09:54 AM), J.D. said:

I know that after my entry on learning Latin, some of you were asking yourself, "Could this weblog possibly get any geekier?"

This entry is my way of saying, "Of course! It can always get geekier..."

:)


On 21 February 2005 (10:23 AM), Amanda said:

To answer the question posed, a Humanities degree is not useful at all.

I need a sign that says, "Will think for food."


On 21 February 2005 (10:34 AM), Anthony said:

I resent the comment that this is a geeky subject (even geekier than Learning Latin, which is by implication even geekier than spending hours comparing and contrasting the merits of various imaginary superheroes).

This is a Real Subject, investigating something that affects you directly, the understanding of which will enable you to actually make better decisions about the Things that Matter.

If most people are not at all interested in such things, it is their privelege and their loss.

I am well aware that my tastes do not represent those of the average reader of this blog, but I would be pleased to see more entries like this one.

I don't think I know how to figure that problem either(anyway, I don't feel like trying right now), but I want to hear what you figure out.


On 21 February 2005 (10:41 AM), Anthony said:
a Humanities degree is not useful at all.
This reminds me of a quote from Wendell Berry.
"The so-called humanities probably do not exist. But whether they exist or not or are useful or not, they can sometimes be made to support a career."

Apparently the key word is "sometimes."


On 21 February 2005 (11:05 AM), Courtney said:

J.D., just cut down the arborvitae and voila! there's the sun! You don't even have to go to the trouble of figuring out the astronomy stuff. Then again, the arborvitae stumps are a pain in the ass to dig up. Just ask Andrew!


On 21 February 2005 (11:08 AM), Doug said:

In a previous entry, you mentioned listening to Garrison Keillor's Writer's Almanac. Did you ever hear Garrison read the poem about the kid in 5th grade who mis-pronounced "Des Moines"? Do you know the title/author of the poem?


On 21 February 2005 (12:43 PM), J.D. said:

So, Nick and I spent some time this morning puzzling all this out. We used handy trig tables to determine the approximate shadow lengths at one-month intervals, but there's a problem with our calculations.

"Isn't your lot on a slope?" he asked.

And it is. All of our assumptions assumed a right-traingle when there's no right-triangle to be had. (Which is not all bad. The error is in my favor, meaning we'll get more sun than I calculated, not less.)

We came up with a technique whereby I can measure the approximate slope of the lot (at least near the garden) in order to arrive at a more precise measurement.

"You're just doing all this to be goofy, aren't you?" he asked after a particularly brain-wracking calculation.

"Not at all," I said. "This has very real implications on our garden and when we can plant things. Also, I talked with the neighbors and they said we can prune the hedge" — the hedge is on their lot, Courtney, so we can't just cut it down — "and by working this stuff out we can figure out how much we'd have to trim it in order to get sun where we want it when we want it."

Garden science, that's what this is. In fact, I'm going to change the entry title to reflect this! :)


On 21 February 2005 (05:44 PM), Paul J. said:

Arborvitae=evil
Arborvitae=yucky

KILL THE ARBORVITAE!


On 21 February 2005 (07:02 PM), Kris said:

Boy, some very hostile gardeners out there! I agree that arborvitae is none too pretty, nor does it bloom, bear fragrant leaves, provide food for native species or turn fabulous with fall foliage. But, it does have its place. In this particular case, the neighbor's arborvitae hedge is a welcome barrier between our yards. Since it's theirs, and we want it there, but not overgrown, we have volunteered to give it its annual shearing. A good deal all around.
Now, don't get me started on forsythia-- I can't stand the stuff!


On 21 February 2005 (09:46 PM), Lane said:

Quince was the bain of my existence... I paid someone to rip out a giant 'growth' in my yard. Beautiful, but painful ... literally. The little red flowers did not last long enough for the price of all the suckers and the rapier-like thorns.

And I like my Forsythia.


On 21 February 2005 (10:18 PM), Dana said:

Richard Feynman said:

The theoretical broadening which comes from having many humanities subjects on the campus is offset by the general dopiness of the people who study these things...

(relurk) =)


On 22 February 2005 (10:53 AM), J.D. said:

A quick update on my garden-based astronomy. I calculated the approximate shadow lengths for the next several months, and it seems that the area next to the fence will never get sun, which makes sense, but doesn't mesh with what I remember from last summer.

Also, most of the garden will be in full sun by the end of April, despite the fact that none of it is in full sun now. A sizeable chunk will actually be in full sun just a month from now. Trimming the neighbor's arborvitae will help, of course, but not as much as you might think.

Also, Nick suggested that we measure the slope of the yard, so yesterday afternoon Kris and I took a board and a level and went to work. We figure that in the 83 inches of the board's length, the ground dropped about 4-1/2 inches. Not much of a slope (so little that I didn't actually perform additional calculations), but enough to buy us a few extra inches of sun, probably.

I'm sorry, Anthony, that I'm not feeding you precise numbers here. I left them all at home. Suffice it to say that I worked out the precise angle of the sun on the 21st day of each month, and plotted that against the height of the hedge. I used the cotangent to find the approximate length of the shadows.

I think it would be fun for me to mark my predicted spots for the extent of the hedge's shadow, and then to compare these predictions with reality during the next few months. At any event, we ought to note the sun's location for future reference and garden planning...


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