Investing in a Bond Bubble?

i consider the prices of most assets to be fair relative to each other, but given the powerful role of interest rates in determining those prices, and the fact that interest rates are the lowest we've ever seen. Isn't it reasonable that many asset prices are the highest we've ever seen? For example, with the p e ratio of the s and p 500 in the low twenties, the earnings yield the inverse of the p e ratio, is between four % and five %. To me, that seems fair relative to the yield of roughly one point two five % on the tenyure treasury note. If the p e ratio were at the post world wor to average of 16, that would...