Sucralose, the base for most sugar substitutes, was discovered when a scientist thought his colleague told him to "taste" this chemical, not "test" this chemical.
The human eye can be removed and planted to grow a rare cactus that only blooms every fourth birthday of the person that the eyeball came from. The flower, reminiscent of the sun, has never been photographed.
Human blood is actually made out of milk that has been dyed via a series of shots you are required to have since birth. This is so it wont be mistaken for other bodily substances.
Sharks actually don't exist, they're all loose robots!
After Jaws came out, the production crew lots a few of it's prop sharks, this worried them for a while until they realized it would raise profits for their upcoming series of movies to follow, so they started to release more.
The government was going to have all of the sharks removed but found out they were helping get rid of overpopulated fish as well as no good tourists! The government started to then promote the making and releasing of sharks and shark related things to make us believe that they had been around forever.
Next time you get a chance to see a real life "shark jaw" just spritz it with water and it might melt, the earlier models were made of paper mache!
Limes, lemons, oranges, and grapefruits all come from the same tree, the citrus tree (Citrus floridius). The fruits are picked at various points in their maturity, hence their size, color and taste: limes are the least mature, followed by lemons, oranges, and finally the fully ripened grapefruits.