To Your Health: Tips to protect yourself from UV rays
There are some steps you can take ... you get the equivalent of 1 minute of UVB rays for each 30 minutes you spend in the sun. So one hour in the sun wearing SPF 30 sunscreen is the same as spending two minutes totally unprotected. People often do not ...
How NASA Photographs the Sun
NASA isn't afraid to stare into the sun. In fact, it's imperative that it does. A severe enough ... allow only this extreme ultraviolet light to get through. And then they have a CCD [an image sensor] where the pictures are taken. We have a lot of fancier ...
How Long Does It Really Take To Drive Around Manhattan?
That's within two minutes of how long Google Maps would tell you that the 26.5 mile route would take. But what I learned about the run isn't just how long it takes to drive around Manhattan at night with reasonably light ... how many times we get cut ...
How do you photograph the Moon?
Give it a couple of minutes ... With the moon you want to do the exact opposite, showing as much surface detail - craters and mountains - as possible. But unless you happen to be a god, you can't just move the sun around to get the best light.
How Much Sun Does It Take to Make Vitamin D?
People are puzzling over the new Vitamin D guidelines ... the sun's zenith and the fact that the Earth is tilted. As a result, much less UV light reaches northern latitudes in the winter. People who live south of Los Angeles (34 degrees north) get enough ...