Oh my, this is stunning: a DIYed bathroom floor lights up with tiny fiber optics stars!

The secret is to thread the fibers into the grout lines. Apparently, for safety, the light source needs to be outside the bathroom (or, I imagine, whatever the local code calls for) and, of course, you need to start with a bare floor or to demo the existing surface, so it’s not a quick project by any measure. The results are amazing, though.
See the full star floor tutorial by Balrd at Instructables.
Found via Buzzfeed.
In Here is an occasional feature highlighting geeky spaces created by our fellow geeks all over the world.