Here's what that little sphere on the top of your dashboard is for

If you've ever noticed a strange sphere on your car's dash and wondered what it's for, you're not alone. Here's what that odd ...
IEEE Spectrum on MSN

See the sky like never before with a DIY eyepiece

So I decided to build a low-cost DIY amplifying eyepiece, to make it easier for visitors to observe deep-sky objects but ...