There are a variety of cosmology and science related predictions about things that have not been discovered yet. There are for example predictions about when we will discover extraterrestrial life as well as other predictions about observed events. See e.g. http://predictionbook.com/predictions/3186 http://predictionbook.com/predictions/2803 .
I like to make predictions about things like quantum mechanics and decision theory and cosmology and fun stuff like that. Can PredictionBook be used for this? If so, what should the guidelines be? Figured I'd make this a Discussion post so as to encourage the habit of betting on logical uncertainty.