My glasses

I'm nearsighted, or myopic, so I have to wear either glasses or contacts. This means that my eyes can only focus on nearer objects and not farther ones. The lenses in my eyes are not able to focus the image on the retina, at the back of my eyes, because the eye is too long. The lenses in my glasses are diverging lenses, which spread out the light so that my eyes can focus the light on the back of the eye.

When you look at the glasses closely, you can also see the way the image through the glasses is not in focus in the camera and the image does not quite line up with the rest of the page of writing. This is because of the refraction caused by the glass, and the lens is also acting to make the image seem a little smaller.

Rainbows!

Yesterday, I found this prismy thing by the back door. It's supposed to be hung in a window, and make rainbows.
With help from my parents to hold the flashlight, I got lots of pretty pictures of rainbows. :P The prism is acting as a lens, and refracting the light through dispersion. Since the n value of the glass is different from that of the air, the light will refract and chromatically disperse. Different wavelengths refract differently, so we see a rainbow of colors from the white light of the flashlight.
Pretty colors!

Ice skating

Ok, since I forgot/weren't allowed to take pictures on the ice, I'll have to make do with the one from the Ice Palace website... :P

Like a typical physics student, the first thing that came to mind when I was attempting to skate was that ice is an almost completely frictionless surface. This means that you can glide for a long time on ice because almost all of the energy remains kinetic energy and isn't converted to heat or potential energy (don't ask me where the potential energy would go...). A force must be applied by the skater to get moving at all, and so you need to provide a force forward by pushing with your feet. When the skate is pointing in the direction of it's velocity, the friction coefficient and friction force is very low, while when the skate is pointing perpendicular to the velocity the friction force is very high. When skating, you can take advantage of this friction by pushing yourself forward with your skate sideways so you can have more traction to push yourself forward. Another important part of skating is balance, so your center of mass must be directly above your skate blade or you will fall over. Also, if you stop suddenly (say, someone skates right in front of you, and you don't want to hit them) by digging in your toe pick to increase the friction, although there is a negative acceleration on the skates, the rest of your body is still moving at a constant velocity, and you will often tip forward just enough so your center of mass is no longer above your skates, and you lose your balance.

Wow, that was a long blog... :)