March 28, 2013 science fact
Neutrinos are small, just mind-mindbogglingly small. As in, the electron is 10,000 times more massive than its corresponding neutrino (maybe, we can’t calculate the masses of neutrinos yet. However, we do know the upper limit is 2 ev/c^2). In addition, neutrinos are neutral. These two facts mean they are incredibly difficult to detect since they only interact with matter via the weak force. So even though something on the order of 100 trillion neutrinos are passing through you every second, the probability of interacting with a neutrino in your lifetime is 1 in 4.