1878 I'm Feeling Bitchy

Wednesday, June 25, 2008

I'm really feeling nasty lately, like all my famous calm and cool has fled, and everything is bugging me. It's been building and building over several months. I want to snap at everyone and everything. I have no patience left. "Damn it, do it right or get out of my way!"

I think it might be because there's someone important to me with whom I have been very patient. (My first word choice there was "forgiving", but actually, there's been nothing to forgive. He/she has done nothing wrong, technically.) Anyway, every bit of my patience and understanding and tongue-biting has gone that direction, and there's none left for anywhere else. I know this person is doing the best he/she can, so I've tried very hard to understand, but, well, it's just one thing after another. Our relationship is such that I can't (yet?) bring myself to say "I've had it. I quit." It's like the little girl with the little curl - when it's good it's very very good, but when it's bad it's horrid.

I've tried to diffuse it by writing that person castigating letters, and then not sending them. That works to get me to sleep on nights when my mind keeps going in circles, when I'm angry getting it out does help, but it does nothing for the bigger problem.

I need to handle this differently. I need to learn a new approach. Maybe all it will take is redefining terms, or expectations. Until then, I'll be pretty pissy.

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So, I've a few things right now that are annoying me beyond their worth.

1.) A friend had a party a while ago, and I just found out about it. He said he was sorry I wasn't able to attend. I said I hadn't been aware of it. It turns out that he had called another person to get my phone number (remember my "psycho ex-girlfriend"? Her. I had just made it clear to her, again, that I can't be pals with her because she's toxic to me), and she told him not to worry, she'd call me and invite me. She didn't, and I suspect she had no intention of doing so.

This thoroughly pisses me off.

But saying anything will only escalate hostilities.

2.) We know how little respect I have for the vaulted Mensa IQ. I value intelligence, and I've found it everywhere, inside and outside of Mensa. Some of the deepest stupidity is to be found within Mensa, mainly because some people are so convinced they're brilliant that they must therefore be right, and won't listen to anything that doesn't fit with their own conclusions.

We have a Yahoo Group for the local Mensa, for discussions, news, activities, and so on. I have decided I am never ever EVER going to post anything there ever ever again, no matter how tempting. No matter how carefully you explain something, there will always be at least one person (and always one particular person) who obviously didn't read the whole message and goes off half-cocked, and no matter how much you try to explain it better, she obviously doesn't let anything get past her initial misunderstanding. I've given up and let her have her way more often than I can stand, but no more. I quit.

This situation thoroughly pisses me off.

But saying anything is futile.

3.) There's another more national Mensa Group I follow. The best of the best, don't you know. Brilliant minds all, of course, just ask them. Someone posted a puzzle she had read but couldn't solve, requesting an answer: "You have a piece of rope that just fits around the Earth. If you put 1-metre high sticks right around the equator and lay the rope on top, how much longer does the rope need to be to make ends meet?"

I was amazed and disgusted by the stupidity exhibited in the responses. (As I said, I'm feeling especially bitchy.)

• "The answer depends on what number you use for the circumference of the earth, and that's in dispute."
• "Wouldn't you need to know the thickness of the sticks?"
• "okay, i am not good at spatial relations, so i'm not getting this. if the stick is 1 meter high, how does that add 2 meters to the diameter? I understand it's 2, because there's one on each side, but I don't understand what height of the stick has to do with the diameter." [Silk says - OMG! Read her last sentence again! She understands NOTHING!]
• "First- how do you know the stick is vertical, it never says so in the question. Second- why doesn't the thickness matter? If it's thicker, that would make it stick out farther, right? thus using more rope?" [Silk says - It doesn't matter. Reread the question. Did you miss the word "high"? What does "high" mean to you? The rope is raised 1 meter no matter how you set or lay the sticks.]
  
• "If C=piRsquared R is increased by 1 meter pi (3.14)x1 squared = 9.859 meters"

Oh! My! God! How did these people get into Mensa? Some obviously didn't really read the question. Some read too much into it. Still others didn't carefully read the explanation when the correct answer was given, and continued to argue. The last guy up there had the general idea, but 1) he used the formula for the area of a circle instead of for the circumference, both of which he'd learned in grade school, and 2) even if we were after the area (somehow), you don't square Pi! Ever! All of which is especially egregious since the correct answer and explanation had already been given, but by damn he knew HE was right, so he had to "correct" everyone! Without, of course, crediting, understanding, or checking the previous answer.

But rest assured - no one's faith in their superiority will be in the least bit shaken. Just ask them.

That thoroughly pisses me off.

But saying anything is shouting down a well.

(And before a lurker leaves a comment accusing me of the same attitude, the original name of this blog was "I Don't Understand". There are a lot of things I will admit I don't understand, but at least I'm willing to listen, question, examine, and try to learn.)

I have more faith in the people reading this post. The problem is very simple. There's no trick. It doesn't require anything more than remembering how to find the circumference of a circle.

Go think about it a bit. You might have to quickly review the definitions of and the relationship between the diameter of a circle and its circumference, and draw a few pictures.
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. Answer and math lesson follow the pause.
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. Hint: Circumference (distance around) = Pi times the diameter (distance across the middle), where we'll use 3.14159 for Pi. Think about what the sticks are doing.
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. Another hint: The diameter or circumference of the earth isn't given in the problem, so it probably doesn't matter. So give the earth a circumference of, oh, say, zero, and then consider whether that changes anything.
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Answer:

Forget the rope. Think of how the sticks increased the diameter, and therefore the circumference.

The diameter has been increased by 2 meters, i.e. by one stick-worth on either end of the diameter.

Since the circumference is Pi times the diameter, and we have increased the diameter by 2 meters, then the increase in the circumference is Pi times 2, or 3.14159 times 2, or 6.28318 more meters ...

... no matter where you swing the diameter (around the equator, pole to pole, or at an odd angle, just so it goes through the center), no matter what the true diameter or circumference of the earth is. In fact, you could use the moon or a marble or an atom instead of the earth, and the increase would still be 6.28318 meters.

Math lesson:

Like the guy in the list above, I sometimes confuse the formula for circumference with the formula for area of a circle, and forget when to use the diameter and when to use the radius. It's easy to forget. Unlike a square, you can't figure a circle out out just by looking, and sometimes we get confused.

Here's how I remember, by comparing the circle to a square.

Draw a square.

Now draw a circle inside the square, with the sides of the circle touching the sides of the square.

Draw a line across the center of the circle. This is the diameter of the circle. We'll call it "D" for short. The radius (or "R") is half that - the distance from the center to the edge.

Note that "D" is also the length of each side of the square.


Distance around - circumference:

Finding the distance around a square (perimeter) is easy. Just imagine walking around it. It's D+D+D+D, or 4 times D.

Notice that the distance around (circumference of) the circle is obviously less than the perimeter of the square - we cut the corners when we walk around it. So it will be like 4 times D, but somewhat less than 4 times D. How much less? That's that famous magic Pi you hear of in school. Pi is (rounded off) 3.14. So Circumference = 3.14 times D.

(This isn't an explanation why, it's just a way to remember the formula....)

Two radii make one diameter. So we can also say Circumference = 3.14 times 2R.


Now for the area.

Finding the area of a square is easy. It's D times D. (If the square is 6 feet by 6 feet, then it's 6 times 6 or 36 square feet. We do this all the time with flooring and paint estimates.)

Notice that the area of the circle is somewhat less than the area of the square, again because we're leaving out the corners.

We know the area of the square is D times D, or D squared. We know the area of the circle will be less, and we suspect that 3.14, Pi, is going to be involved again, but how? Well, it would be nice if we could just multiply D times D, and then multiple that by 3.14, but, uh, it should be obvious that's going to be waaaaaay too big. Maybe we could divide D times D by 3.14? Nope, that will come out too small. It's apparent just by looking that the area of the circle is lots more than one third of the area of the square.

We've gotta get that "4" in there somehow, so the 3.14 can be less.

Mentally redraw the circle in the square, and this time we'll concentrate on the radius.



Now it's easy to see that the area of the square is 4 R squares, or equal to 2R times 2R, or 4 times R-squared. Whoop! It's also apparent that the area of the circle is slightly less than that, or (our magic number, Pi) 3.14 times R-squared!

The area of a circle is 3.14 times R-squared.

(Again, not an explanation, but a way to remember it. And sorry about the made-up notation, but I'm not excited about messing with fonts to get the superscript for "squared". You know what I mean, right?)

Ok. No more excuses for forgetting the formulae for the circumference and area of a circle. Just think of it in relation to a square.
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