Category Archives: Physics

Where to park your RV in space: Lagrangian points

Lagrangian points
Image courtesy NASA.

So, you’re looking for a scenic spot in the solar system to set up Lagrange Acres, your space trailer park, but you can’t abide the planet-side property taxes. Space is nice enough, but who can afford the fuel necessary to stay in a stable orbit? If only there were some place to park where you wouldn’t be whipped around by gravitational fields like a tether ball, you’d be in business. The question is, where?

Well, friend, I’m here to help. See, in space, as on Earth, the real estate mantra remains the same: location, location, location.

What are Lagrangian Points?

Ground control to Major Tom (Thumb)

Tonga
Tonga. Map courtesy CIA.

Who doesn’t love a story about the little guy who makes it big, or the underdog that overcomes? Take these five mighty mites. What they lack in geographical size they make up for in strong economies and supersized space aspirations. As the new space race heats up, and as the airless reaches cease to be the sole province of superpowers, who knows how far their ambitions will carry them?

5 Tiny Countries with Big Space Dreams

A noiseless, patient rover

Curiosity rover descends on sky crane
Image courtesy NASA/JPL-Caltech

On Aug. 6, 2012, a new rover will touch down on Mars — bigger, badder and bristling with more gear than a spelunker convention. Although rocking the same suspension system and basic design, Curiosity, aka the “monster truck of science,” is so much heftier than its predecessors that NASA and JPL had to invent an entirely new way to land it: one part HALO jump, one part rocket-hovering sky crane. Its mission: investigate if the right conditions exist, or ever have, to support microbial life.

How the Mars Curiosity Rover Works

Superconductors? When frogs fly

levitating frogOne of the unwritten rules of physics says you can’t get something for nothing; at best, you can swing a fair exchange rate between energy in and energy out. The problem is heat:  Like an energy embezzler, it skims off the top of chemical reactions, physical systems and electrical circuits (which is why we can’t have perpetual motion machines).

Superconductors don’t break the laws of thermodynamics, but they do manage to find some fairly large loopholes. Send current through a superconducting wire, and it loses no energy to resistance. Bend the wire into a loop, and it will hold charge indefinitely. Levitate it above a magnet, and the sun will devour the Earth before it will fall.

Plus, it can levitate a frog.

What is Superconductivity?
Quiz: How Super are Superconductors?

Because if it were green, we wouldn’t know where to stop mowing

Why is the sky blue? Everyone supposedly knows, but just about everybody gets it partially wrong. Don’t feel bad, though; the answer has so many parts, it took philosophers and scientists from Aristotle to Maxwell to answer it.

Besides, it’s a bit of a trick question …

Why is the sky blue?