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.
Some say the world will end in fire; some say ice. Others prefer to trot out obscure scientific theories. Strange as it might seem, the pole shift hypothesis, in which the Earth’s crust and mantle (or outermost layers) move as one piece, did not spring from the fevered imaginations of the sandwich-board set, but from scientific circles, and it’s rooted solidly in physics.
Of course, that doesn’t mean Hollywood got it right …
Space is as hostile as environments come. Astronauts encounter temperatures that swing from 248 F (120 C) to -148 F (-100 C), and that’s just near Earth. The temperature of deep space plummets to -454 F (-270 C). Even the relative comfort of a space station—with its carefully regulated temperature, pressure and mix of gases—offers no escape from the ravages of prolonged exposure to microgravity.
If ever a setting called for robotic assistance, space is that place; but working in place of and, particularly, alongside humans requires a combination of strength, gentleness and dexterity unequaled by robots found anywhere else. Let’s take a look at …
We tend to think of nanotechnology as the stuff of the future, but it’s already here, in hundreds of consumer products and industrial applications. As progress in this minuscule world has accelerated, concern for the environment and for public health has led to a call for green nanotechnology—approaches that accentuate the positive and eliminate the negative. In this article, we’ll take a tour of how these many approaches are playing out.