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Posts Tagged ‘education’

Math Can Be Cool. No, Seriously!

January 25, 2011 1 comment

I did physics in University, and I had to take math courses. I hated the math courses.

And I like to make jokes at my friends who did Applied Math or Pure Math as their degrees, because I just found it so boring.

But dammit if this isn’t the coolest thing I’ve seen all day:

Notice it starts with the Fibonacci Sequence, makes a Fibonacci spiral, and from there it just keeps going.

Awesome.

Girls Who Bike to School Get Better Grades

December 21, 2010 2 comments

Via Wikimedia Commons

The Holidays are upon us, which means everyone at work is on vacation and I have a lot more stuff to do and shopping to do after work. Unfortunately, my dear blog has suffered.

But I am back, and I got a good one for you.

A recent study published in the Archives of Pediatric and Adolescent Medicine looked at 1700 high school students and how they get to school. Some walk, some take the bus, some bike, etc.

When they looked at the female grades they found that girls who actively commute to school, i.e. bike or walk, did about 4% better than girls who took the bus or drove.

Active commuting to school was associated with better cognitive performance (all P < .05) in girls but not in boys, independent of potential confounders including participation in extracurricular physical activity. In addition, adolescent girls who spent more than 15 minutes actively commuting to school had better scores in 3 of the 4 cognitive performance variables (all P < .05) than those who spent less time actively commuting to school (≤15 minutes) as well as better scores in all of the cognitive performance variables (all P < .001) than girls inactively commuting.

Interestingly, they did not see this difference in the male participants of the study. Why this happens, is a bit of a mystery.

It could be that the girls are more alert when they get to school if they walk/bike, resulting in better performance. But if that were the case, you would expect to see this difference in boys who actively commute to school as well.

It could be that girls to actively commute feel better about themselves, and therefore do better in class. This would fit in with a previous study I wrote about in which girls who write about their values before class tend to get better grades.

More and more these kinds of studies are showing that innate intelligence is not as big a factor for success in school as was thought a few decades ago.

A positive state of mind is important as well, especially for girls.

The Physics of Coffee Rings

November 24, 2010 Leave a comment

In keeping with the abstract on the physics of jump rope, the 63rd meeting of the American Physical Society has yielded yet another fascinating study.

63rd Annual Meeting of the APS Division of Fluid Dynamics

Volume 55, Number 16 

Abstract: RU.00007 : Coffee ring deposition in bands

Authors:

  Shreyas Mandre
    (Brown University)

  Ning Wu
    (Colorado School of Mines)

  Joanna Aizenberg
    (Harvard University)

  Lakshminarayanan Mahadevan
    (Harvard University)

Microscopic particles suspended in a liquid are transported and deposited at a contact line, as the contact line recedes due to evaporation. A particle layer of uniform thickness is deposited if the particle concentration is above a threshold; below this threshold the deposit forms periodic bands oriented parallel to the contact line. We present a model for the formation of these bands based on evaporation leading to the breakup of the thin liquid film near the contact line. The threshold results from a competition between evaporation speed and deposition speed. Using this model, we predict the thickness and length of the bands, making the control of patterned deposition possible.

[My comments: The authors used glass particles in a liquid to mathematically model how rings form. They can make these predictions using parameters such as evaporation rate and surface tension of the liquid. Aside from just being interesting, this study may have some practical implications for working at small scales.

Controlling the ring deposition process would be useful for creating such things as new microphysics tools operating at a scale where pliers or other traditional tools for moving particles cannot operate,” notes Mandre. (From Physorg.com)]

The Physics of Solar Power

July 6, 2010 2 comments

In my previous post, I discussed how President Obama is helping to fund the development of Solar Energy. I thought I would then take the opportunity to explain a bit of the physics behind solar power.

Don’t worry, you won’t find any equations here :)

First, lets start with the sun. That big bright thing up in the sky.

The sun generates light, and light can be thought of as a bunch of tiny packets of energy. These packets are called “photons”. The different amounts of energy in a photon will correspond to the colour of the light that is emitted. For example, photons of the colour blue have more energy than photons of the colour red.

Energy increases from left to right (Source: Opensource Handbook of Nanoscience and Nanotechnology)

 

So how do we harness the energy in these photons? We can use Photovoltaic cells. Put simply, they convert solar energy into electricity. Let’s see how…

A photovoltaic cell is made of special materials called semiconductors, which are made of things like silicon (Yes, that stuff used to make fake boobs. Isn’t science awesome?).

Now, all atoms are made up of a nucleus (which is made of protons and neutrons) and electrons which circle around the nucleus.

Electrons can actually absorb the energy from a photon, but this happens only if the photon has a very specific amount of energy (a specific colour). When an electron does absorb a photon, it causes the electron to “jump”, and sometimes even break free of the entire atom! Electricity is a constant flow of electrons, which we refer to as an electric current.

Silicon structures like to hold onto their electrons. They don’t normally let them move around which makes silicon what we call an insulator. But in a Photovoltaic cell we add impurities, little bits of stuff that doesn’t belong there. The impurities will actually encourage the silicon to release its electrons and let them move around.

Now the magic happens. So a photon (those little packets of energy from the sun) hits the Photovoltaic cell. If the photon has just the right energy, it will knock loose one of the electrons in the silicon atoms. And, because of the impurities, that electron will move around.

If you get enough electrons moving around, you get an electric current which we can then use to power all of our awesome toys!

Thats it in a nutshell. If you want to read about this stuff in a bit more detail, check out the links spread all through this post, or some of the cool sites below.

Hooray for Physics!

Further Reading:

http://science.howstuffworks.com/solar-cell.htm

http://www.physlink.com/Education/AskExperts/ae451.cfm

http://science.nasa.gov/science-news/science-at-nasa/2002/solarcells/