This is a nice surprise: MIT researchers made the unexpected discovery that when two or more water droplets merge and jump away from a superhydrophobic [1] surface, the droplets carry an electric charge. How does it work? First, you need the right kind of superhydrophobic surface. Next, add humid air. As droplets condense and form on the superhydrophobic surface, they … [Read more...]
What’s the difference between AC and DC?
An off-the-grid novice asked us this question today: What's the difference between AC and DC? There are a few quick answers: AC (Alternating Current) looks like a wave, and DC (Direct Current) looks like a straight line. Batteries or dry cells use DC, while AC comes from your electrical wall outlet. However, if you’re using a portable computer, you’re actually using both AC … [Read more...]