the breakdown

Shopping Cart Science

Sometimes it hurts to be reminded of fundamental principles of physics

Here we have a beautifully illustrated example of Newton's First Law of motion involving shopping carts. Did some force push those carts out the back end of the trailer? Not at all.

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When Is Carbon an Electrical Conductor?

Just ask this poor pencil

And the $64,000 question is ... does graphite conduct electricity? It certainly does! The video demonstration displays this quite convincingly. Graphite is an interesting material, an allotrope of carbon (as is diamond). It displays properties of both metals, and nonmetals. However, like a metal, graphite is a very good conductor of electricity due to the mobility of the electrons in its outer valence shells.

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Playing Games With Science: N3wton

Newton's Third Law plays the starring role in this simple but provocative game

Newton's Third Law is often quoted as "For every action there is an equal and opposite reaction." As N3wton's title suggests, the Third Law is at the heart of this little physics-oriented computer game. Click to play. (Warning: there's music.)

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Popping Power

Can cell phones pop popcorn? Just watch

Let's set the record straight. This first video is a clever hoax. It is not possible to pop popcorn using cell phones. See how it's done in the second video.

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Feeling Gravitee's Pull

Who's up for a round of interplanetary golf?

When playing golf in outer space, it's important to keep in mind Newton's Universal Law of Gravitation:

F = Gm1m2 / r2

This equation describes the force of gravity between any two masses separated by a distance r between their centers. G is a constant of nature that we call the universal gravitational constant.

See it in action in this week's online game, Gravitee.

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Playing Games With Science: Magic Pen

Physics you can draw

[Via Diggy Games]

Welcome to Magic Pen. This fascinating little game displays a delightful plethora of physics principles in action. The object of Magic Pen -- as in some similar games, like Crayon Physics Deluxe -- is to roll a ball into a goal. The catch is that you can't touch the ball directly: you can only interact with it by drawing shapes with the mouse. These shapes then interact with the ball, obeying basic principles of physics. For example, draw a rock. The rock then falls due to gravity, collides with the ball, and pushes it towards the goal, which is marked by a flag.

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Trampoline Basketball

The science of jumping higher

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That Amazing Devil Gravity

Do heavier things fall faster than lighter ones? In practice? In theory?

Here we have a clip from the excellent movie adaptation of Tom Stoppard's play Rosencrantz and Guildenstern are Dead. In addition to engaging and nuanced performances by Gary Oldman, Tim Roth, Richard Dreyfus, and Iain Glen, the script is full of thought-provoking metaphysical introspection, and some delightful physics introspection as well. It's well worth renting.

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Apparently Weightless

Why are these astronauts floating around? It's not because of zero gravity

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Everyday Electromagnetism

How can a magnet move a copper penny?

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Ancient Bungee Jumping

Bungee jumpers use rubber cords to absorb the force of their fall; in Vanuatu, they use vines

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When is a daredevil jump not a jump? When it's a flight

When is a daredevil stunt jump actually a "jump" and when does it become a form of ill-advised rocket flight? While we enjoy the dramatic and circus-esque musical soundtrack in the video, let's also appreciate some interesting physics issues relevant to Kenny Powers' unsuccessful jump. I'm not sure how carefully they thought this one through, but I suspect at least they must have recognized that their "souped-up" Lincoln Continental had to be under rocket power not only during the approach and up the ramp but during the jump (flight) as well.

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Splendid Oscillation

Learn how to destroy expensive glassware with the power of sound

A few weeks back we looked at the phenomenon of resonance with oscillating metronomes. As a follow-up to that meditative and Zen-like video, we've included a crystal-clear demonstration of that favorite old opera singer's trick: shattering a wine glass with resonance.

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The Breakdown: Can YOU Bend a Bullet?

Physicist Adam Weiner analyzes the magic behind Wanted's mind-bending ballistics

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Oscillate Wildly

Metronomes generally keep their own beat -- that's why we love them -- but when several get together, a compromise is hammered out

This charming little video demonstrates the principle of resonant frequency using oscillating metronomes. The mechanical wind-up metronomes used worldwide during the dreaded Saturday piano lesson employ an inverted pendulum to keep even time intervals. The resonant frequency of the pendulum is adjusted by moving the mass up and down. Sliding the mass higher up the rod decreases the resonant frequency of the pendulum by increasing its rotational inertia.

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