Exploding manholes are one of those weird and interesting side effects of living in a large city. Imagine walking down the street when all of a sudden a manhole covers flies 50 feet in the air!
Solar energy is abundant and infinitely renewable. Therefore, it's not surprising to see the proliferation of devices that rely on the sun -- especially solar aircraft.
If it takes $1 million a year to save the California condor, how much would it take to save every endangered species? Is it possible, and how can we save species we don't even know exist?