If Aristotle had grown up in space his physics intuition might have been better. He believed heavy objects fell faster than light ones, but it turns out that when you take drag into account an object's weight doesn't matter. David Scott, Apollo 15 astronaut, tests this prediction made by Galileo Galilei several hundred years after we are told Galileo attempted a similar experiment atop the leaning tower of Pisa. Galileo's tale may be apocryphal, but Scott's is verifiable.

LINKS GOOD ON 2006-12-14

Having just seen a hammer and feather fall at the same rate, it should be no surprise that planes and people too can fall at the same rate. In this clip a plane undergoes a controlled parabolic fall along with its contents. Since the person and the plane are both falling at the same rate the person appears weightless. This is free-fall and why astronauts appear weightless. They are NOT so far from earth that gravity doesn't pull on them. Orbiting is just falling without hitting the ground.

LINKS GOOD ON 2006-12-14

There are many student-produced recitations of Newton's Laws out there. Here's one I'd like to share. It's not flashy. Nor does it present anything particularly insightful from a physics standpoint. However, the science IS there, and you can't help but see the effort and skill that went into making this. My compliments to ZachMG. Well done.

LINKS GOOD ON 2006-12-14

When lying on a bed of nails one spreads his/her weight over many nails distributing the force, lessening the pressure, and avoiding self skewering. Breaking a cinder block atop the "volunteer" drives this home. The block takes the bulk of the force from the hammer's blow, however. After all, it is quite massive/fragile and doesn't accelerate much before breaking. Consequently, it barely even pushes on our trusting "volunteer."

LINKS GOOD ON 2006-12-14

There's only so much momentum in the world. Our pilot starts with none, momentum being the product of mass and velocity. Then suddenly, it seems, there is momentum where once there was none. The CO2 sprays backwards with a sizable momentum, and nature compensates, propelling the wagon forward and assuring the two add up to zero. Thanks conservation of momentum.

LINKS GOOD ON 2006-12-14