ILT at PS 161

Walking into the computer lab at PS 161 I thought I was observing a group of evil geniuses rubbing their hands together as they formulated their plans for world domination.

Evil geniuses?

Fortunately, the world can breathe easy, as these students were rubbing their palms together to begin their exploration of friction.

Exploring friction on the computer.

Friction is the rubbing together of two objects. Using computer simulations developed at the University of Colorado , Boulder ( students were able to see how friction worked at the molecular level.  This helped them understand why their hands got so warm when they rubbed them together.

Fun fact – do you know that if you create friction between certain objects they might melt, or even set on fire?

After their introduction to friction students moved on to explore a side effect of friction that doesn’t involve flames -static electricity. (

Douglas explaining how the simulation works.

The simulation provided each student with 2 balloons and 1 sweater on their screen.  Students rubbed two balloons together, rubbed the balloons on the sweater, rubbed the balloons on the sweater then together, and on and on in as many combinations as you can imagine.  For anyone who has done this experiment with a balloon and their own sweater you know the balloon will stick to the sweater after you rub them together, but what makes this happen?

The simulation highlighted protons (the positively charged part of an atom) and electrons (the negatively charged part of an atom) allowing students to see how protons and electrons transferred back and forth between the objects – or attracted (brought together) or repelled (pushed away) the objects depending on how the balloons and sweater were used.

So why does that balloon stick to your sweater?  When a balloon is rubbed against a sweater electrons jump from the sweater to the balloon giving the sweater a positive charge and the balloon, left with only electrons, a negative charge.  Because positive and negative charges are attracted to each other the electron-heavy balloon is drawn to the proton-heavy sweater.

As a science educator I loved to see all of the science exploration happening, but I might have enjoyed seeing the interactions between the HDWC/PS 161 and the Teachers College graduate students even more.  Who knows how many budding scientists will be getting college advice from these technology experts they get to engage with every week?!

Talking about friction.