Engineering Sphere

Back when I was a (delusional) engineering student, I had to take my fair share of physics classes.  Some might say slightly more than my fair share.  One of my professors had an odd and somewhat alarming propensity to set us problems that involved livestock.  Cows on ice skates.  Sheep in catapults.  Horses on pogo sticks.  The imagery was actually quite disturbing and rather makes me wonder about his misspent youth.  Each of these problems would end with the line, ‘for ease of calculation, assume the animal is a sphere.’

Now the distinction between a mathematical sphere and an engineering sphere is a fine one to make.  They aren’t the same thing, and knowing which one you’re dealing with can have all sorts of real-world ramifications.  But the habit of assuming livestock are all spheres tends to lead to fits of giggles whenever I drive past a field full of critters.  The Boy was in this class too, and ‘engineering sphere’ is still part of our household lexicon.

All of which is my rather rambling and indirect way of bringing me to the topic of your thumbs.  Bear with me, there is a connection.  Take a second and lay your hands flat on a table or desk or wall.  See how your thumbs stick straight out from the side of your hand, it’s in a plane with your other fingers?  Ok, now pick your hands up and hold them relaxed in front of you.  See how your thumbs are no longer sticking straight out of the side of your hands but are instead a bit closer in toward your palms?  Yeah.  That’s where your thumbs spend most of their days.

This thumb placement thing becomes important when you’re thinking about knitted hand coverings.  It comes up for me in fingerless mitts, but it would be important in gloves or mittens too.  You know how some pairs of mitts seem to constantly be twisting around your arm?  How the back part isn’t ever centered right when you’re wearing them?  And if it is then the underside of your arm is all twisty?  Yeah.  A lot of that goes away if you remember to put your thumb stitches a tiny bit in towards your palm, instead of straight out to the side.  Take a look at these.

That guy in the front, he’s got his thumb sticking straight out to the side.  Exactly like your thumb doesn’t usually do.  And see how the fabric looks a bit bunched up and shoved over and uneven (hard to convey in a picture, but I had to fight to get it as smooth as it is, and even then it’s wanting to twist).  Now look at the dude in the back, he’s got his thumb set a bit forward of his fingers.  That’s where your thumb usually hangs out.  See how the fabric on the back of the hand looks smoother and straighter?  These mitts have their thumbs tucked under, just the littlest bit.  That means they look awkaward when they’re on a glove form with his thumb sticking straight out, but look very good on a glove form with his thumb in a more natural position (or, say, on a human hand, which is likely more important).

Pretending your thumbs stick straight out the side of your hands may make the calculations easier, but it’s about as accurate as pretending that cow is a sphere.  Move your thumb stitches in towards your palm, just a tiny bit (really, it can be as little as a stitch or two), and you’ll find your mitts don’t twist around and fit much better.