Archive for December, 2008

More recommended webcomics

26 December 2008

It’s been a while since I told you to go read Girl Genius, which is still my favorite webcomic, and xkcd, which runs a close second.  They are still the only webcomics from which I actually own merchandise.  However, I have some more to recommend that you check out.

First, the delightful and charming tale of a young yeti on his own in the forest: The Abominable Charles Christopher.  Charles Christopher is the yeti, a naïve but large character with an open heart and a silent demeanor.  He travels and makes friends, exploring his world.  In addition to following Charles Christopher’s adventures, the comic (by Karl Kerschl) also portrays vignettes featuring the other furred and feathered denizens of the woods.  Soap operas play out among the birds and rabbits, and while I would never watch a soap opera on TV, Kerschl’s art is engaging and his animals expressive and I am drawn in.  Give Charles Christopher a try if you liked Watership Down, or if you enjoy Miyazaki films such as My Neighbor Totoro.

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Lucy Lyall’s Kaspall also features animals, but the denizens of Kaspall (a city) are human-like and have furry faces and tufted ears and clawed hands.  They wear clothes and are in the roles of police, landladies, bartenders, professors, fishermen, students.  We observe a regular society that also includes actual humans, and which has several mysteries.  Why do humans show up in Kaspall and why can’t they get home again?  What is causing mysterious deaths?  And whose dreams are becoming reality?  This fantasy uses mystery to draw in the reader and I keep checking in every Monday to see if there are new clues or revelations.

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Cartoonist Kate Beaton is in a completely different vein.  Not only does she draw human characters, they are mostly historical figures such as Napoleon, Benjamin Franklin, Jane Austen, Nikola Tesla, and many of the Prime Ministers of Canada.  She doesn’t draw a story, and so it doesn’t have a title, other than “Kate Beaton’s comics.”  You can see her work on her comic site or on her Livejournal.  Beaton is a master of expression, and her characters sneer, pout, crave, grumble, and munch in simple line drawings.  She also draws insightful little conversations between herself and her younger self which go exactly as one might expect: poorly.

I hope you give each of these comics a glance at least once.  If you don’t like them, maybe you know someone who would enjoy reading them.

UPDATE: Kate Beaton seems to be calling her webcomic “Hark! A vagrant” now, after her Livejournal.

December catch-up and a lesson

26 December 2008

Wow, I sure haven’t posted much this month.  It’ll be the worst month in the short history of this blog if I don’t work hard to catch up.

What do you know…I’ve been busy!  We had another Physics Olympics meet in December, but I did not host it at my school.  I just had to get a team of kids ready to compete!  Also, my online graduate course ended, and I had to take a final exam.  I’ve started a team of 7 kids on a competition called Real World Design Challenge, which is sponsored by the Department of Energy, and I spent a bunch of time on e-mailing and setting up accounts and installing software, etc.  Plus there was all that shopping and wrapping to do, and I even managed to go out twice!

Unfortunately, I have also wasted an inordinate amount of time on Facebook, updating my status and checking up on former students who spent much of December using their Facebook status to count down the days until they were on break (generally about a week before I was going to be on break, of course).  Several of them came to visit at school during the last three days before my break began, and I got to explain to some of my former AP physics students what I learned this semester about Newton’s 3rd Law of motion.  Namely, that it isn’t true.

(This is where you gasp.  Or gape.  Now shut your mouth and keep reading.)

I’m not kidding.  That whole thing about “for every action, there is an equal and opposite reaction…”  you know what I mean, right?  What it is supposed to mean is that when one object exerts a force on another object by interacting with it, the object exerting a force also experiences a force, and it’s the same amount of force but in the opposite direction.  So if I run into the wall, the wall runs into me.  If I push down on the floor, the floor pushes up on me.  These forces are electrical in nature: the electrons in me are repelled by the electrons in the wall, to such an extent that my atoms never even get close to the wall’s atoms (on the atomic scale) and I just bounce right off the wall.  If I am injured and the wall isn’t, that’s simply because I am squishier than the wall.  That’s an example of Newton’s 3rd Law working as expected.

However, let’s look at when this doesn’t work: in certain cases of the magnetic force between moving charged particles.  First, you need to understand a few things.  Magnetic fields are created by moving charged particles (like electrons moving inside atoms) and only interact with moving charged particles.  Any moving charged particle makes a magnetic field.  The earth’s magnetic field is created by moving charged particles in the earth’s core.  The magnetic field of a refrigerator magnet is caused by electrons in large clumps of atoms that are all moving in similar ways, so that their tiny magnetic fields all add up to make one strong enough to defy gravity and hold bits of paper to your refrigerator.

So if a moving charged particle gets into a magnetic field, it experiences a magnetic force that happens to be perpendicular to both the direction the particle is moving in and the direction the magnetic field is pointing.  Direction the field is pointing?  Yep, if you have a bar magnet filled with electrons moving in atoms such that they are adding up all their fields, the field has a direction.  It points away from the magnet at the “North” pole and it points toward the magnet at the “South” pole and alongside the magnet it points in the opposite direction from the way it points at the ends.  It is this directionality of the field that allows a compass needle to point toward the North pole of the earth, enabling you to do your orienteering or navigating or whatever.

So, the moving charged particle moves into the field, and it experiences a force to the side (compared to the way it was moving) because of that perpendicular business.  The field was created by another moving charged particle.  Does that particle experience an equal and opposite force?

NO.

In this example, the positive particle is moving to the left and the negative charged particle is moving down.  At a certain instant in time, the two particles are exactly above one another as shown.  The negative charged particle is in the field produced by the moving positive particle, and experiences a force to the right.  The positive charged particle is directly behind the negative charged particle, and in this location there is no magnetic field from the moving negative particle.  No magnetic field, no magnetic force on the positive particle, and goodbye Newton’s 3rd Law!

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So I hope you enjoyed this little physics lesson, and maybe I will treat you to another one sometime!

It’s the best!

14 December 2008

Warning: girl stuff in this post.

Ever since I started shaving my legs and armpits as a teenager, I have been inept at it. Which is to say I tend to nick myself with the razor and it hurts.  So I have avoided shaving.  For years I didn’t shave at all, which gave some people the impression that I was vegetarian (I have no idea how that follows, but there you go) or possibly lesbian.  Why not “European” or “contra dancer” I don’t know.

For some more years, I shaved only in the summer, when my skin is less covered by clothing, and again right before any fancy winter event I might attend wearing sheer hose or a sleeveless dress.  Then even more recently, I bought one of those rotating-tweezer devices that yanks out your hair by the roots.  These work best when your hair is 1/8 to 1/4 of an inch long, so I  shave a week or two before I actually want to start using it and then just use that.  It works great, but the first couple of times each summer still hurt, as you might expect from yanking your hairs out by the roots.  And I do not enjoy pain!

In a couple of weeks, it will be New Year’s Eve, and time for the annual Hogmanay Ball.  I have a new outfit this year, and it is sleeveless, so I figured I’d better shave this weekend so I could use the rotating tweezer thingy and look all smooth and conventional for the ball.  I pulled a box out of the cupboard that contained a free razor that had arrived by mail several years ago addressed to my husband and set aside for “just in case.”  My husband uses an expensive electric shaver, so I figured I would use the freebie.

I showered, and tried the new razor on my armpit.  I had to double-check to make sure it had done something.  No scraping!  No burn!  It felt like gliding a piece of plastic under my arm.  And the shave was very very smooth!  I did my legs: same sensation.  No cuts!  No pain!  This thing is amazing!

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I can highly recommend the Gillette Fusion razor to all of you who shy away from shaving due to nicks and cuts from your usual razor.  The five blades really do change the amount of pressure per blade (I can say that with confidence as a physics teacher) and it makes for very smooth skin afterward.  Here is a closeup of the blades:

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In addition, the blade cartridge comes off the handle, so you just have to buy more blade cartridges when they go dull.

So, if you are looking for the best razor, ladies, go for this one.  I can’t speak for how it works on faces, so if there are any guys who manage to read this far through all the girl talk, you are on your own as far as testing it out.

As big as grapefruit

13 December 2008

citrus

This week the annual shipment of Florida citrus from my parents arrived.  A heavy box filled with navel oranges and pink grapefruit, which are now taking up most of a shelf in the refrigerator.  As you can see, the oranges are nearly as large as the grapefruit!

I’m looking forward to sectioning some fruit for a yummy ambrosia I can take in my lunch this week.  Thank you mom and dad!  Thank you very much!