We Get A Completely New Skeleton Every Ten Years
We don't want to alarm you, but the bones you're using right now aren't the ones you were born with. They aren't even the bones you had ten years ago. Yes, some of us switch skeletons more often than we switch mattresses (jury's out on which one's grosser).
Through a process very appropriately known as "remodeling," your skeleton completely regenerates itself over time. Every decade or so, you essentially get a full-body re-boning job, and you don't even have to move out during the renovation. Like a good general contractor, our body tries to balance the processes of bone removal and replacement so our skeletal structure stays strong and un-collapsed. As we age, the whole removal/replacement balance gets shoddier, which leads to problems like bone weakening and osteoporosis. But on the upside, you can now tell your friends you have Doctor Who powers (technically)!
AlgaeCal IncYour dog is looking at this and going "Dear lord, infinite food."
Replacing bones isn't the only thing done to our skeletons without our input. Apparently, human bodies are fans of the "less is more" philosophy. We're born with over 300 bones, many of which are made of cartilage, but by the time we reach adulthood, we're left with 206. That's because as we grow, our bodies replace the cartilage with bone and fuse some bones together, giving us our final piece count. Or that's the cover story created by the gnomes who steal your bones at night and sell them on eBay.
Your Body Emits (A Teensy Bit Of) Light
"You're glowing!" is a descriptor we usually reserve for pregnant women and/or nuclear power plant workers, but it's true of the rest of us too. A group of Japanese scientists with a bit too much free time have determined that human beings glow in the dark. Using cameras so sensitive they could detect even a single photon, the researchers photographed volunteers in a completely dark room over the course of several days. The result was not a lawsuit from the volunteers, but the first-ever images of the "ultra-weak" photons emitted by the human body (obviously, too weak for the naked eye to detect).
Kobayashi, Et. Al./PLoS OneIn the fourth photo, they asked him to remember that time he called his third-grade teacher "mom."