from the urls-we-dig-up dept
Measuring natural phenomena isn't always easy. There are a lot of interesting things that can be measured without a lot of fancy equipment, but some things can't be measured without just the right conditions and materials. Here are a few links on measuring some cool (or actually kinda hot...) things.
- Did you know that the speed of gravity is about equal to the speed of light with an error of less than 1%? It's a speed that's measured from the decay rate of binary pulsar systems. [url]
- The Earth is radiating a lot of heat (forty-four trillion watts!), but the source of that heat isn't entirely obvious. About half of the heat seems to be accounted for (radioactive decay of elements, etc), but there's around 20 trillion watts that's still a bit of a mystery. [url]
- Vikings probably didn't use magnetic compasses to help them navigate since magnet-based compasses weren't popular in Europe until the 1300s. Vikings might have used "sunstones" -- crystals of calcite -- and birefringence to determine the sun's position even in foggy conditions. [url]
- To discover more interesting science-related stuff, check out what's currently floating around the StumbleUpon universe. [url]