If allowing your smartphone to run out of power during the day doesn’t make you feel silly enough, consider this: Every hour it’s idle in your pocket or bag, the sun is bathing the earth in enough energy to run the world economy for a year.
The obvious fix here is to turn every square inch of your body into a power plant—solar could be the ultimate accessory, more important than purses, satchels, or, well, sunglasses. But first, there’s the science part.