I have seen a vector explanation of time dilation that our net velocity in space-time is the speed of light. Most of that velocity for slow spatial speeds is in the time dimension. As you go faster in a spatial dimension, your speed in the time dimension reduces, because the net vector magnitude...

Some air conditioners work with evaporative processes. So I'm not sure why people wouldn't just use a sprinkler that turns on for a minute every hour or half hour or whatever in order to wet the roof. The water will not only absorb the heat from the sun, but when it evaporates won't it also take ...