I’m definitely adjusting to and enjoying life in the suburbs, but I will always miss Boston’s public transportation system. Living in the suburbs without a driver’s license means two things:
1) I don’t go as many places as I used to.
2) I have to walk a lot farther to get to the places I do go to, whether it’s to get to a bus stop or to get to the location itself.
One of this week’s journeys took me across a pedestrian overpass high above a major freeway. Though I recognized the safety hazards of doing so, part of me definitely wanted to grab the nearest objects I could lift and go all-out Galileo. Yes, I know objects fall at the same rate (when air resistance is absent or negligible), but I want to see it for myself. Particularly from atop a pedestrian overpass high above a major freeway.
I frequently think about falling objects, partially because I used to be a physics teacher and partially because I am a clumsy person who drops things a lot. It’s hard to get students to really believe that objects fall at the same rate. Their direct observations tell them otherwise; after all, they know that, if their teacher drops a piece of paper and a textbook at the same time, the textbook will hit the ground first.
But that’s just because of air resistance. A piece of notebook paper and a textbook have roughly the same amount of air pushing up on them as they fall, but this force has a greater effect on the less massive paper. If we could just eliminate the air pushing up on the paper, we’d see that the two objects fall at the same rate. So how can we stop air from pushing up on the underside of the paper?
When I tackled this topic as a teacher, this was the point when I would put the piece of paper on top of the textbook and ask my students to predict what would happen when I dropped the two items together. Most said that the piece of paper would fly off the textbook and slowly flutter back down to the ground.
That isn’t what the paper does, but you don’t have to take my word for it.
In the name of science, get a piece of paper and a book and give it a go.