I thought this would be an interesting question to ask on a physics forum since measurement is the fundamental aspect of all science. We spend on third of our lives asleep and a portion of that time dreaming, yet you can not measure a dream but, in my opinion, it's an integral part of our human experience. Many people throughout history have had spiritual experiences yet you can not measure a spiritual experience. What value should we place on such things. They are real phenomenon experienced by multitudes of people. What i mean by this question is how should we define reality, and what place in that definition is there for things which can not be measured.