It is interesting to consider the dramatic discontinuity in belief as a function of logic combined with faith. Believe in nothing without proof and life is simple. However, this requires that much of human experience is ignored, which as a human I find illogical, narrow, and limited. Science may have a very long way to go and unknowns will always remain. So what of claimed experiences can be believed? As is evident from the many religions of the world and their roles in guiding cultures and even political systems, it is clearly human nature to accept certain things on faith. On the other hand, even the most devout follower of any faith suffers from doubts. In a strangely paradoxical way, as much as we want to believe, we also want proof. This is a cruel dichotomy of human nature. What can be real in this universe and beyond? Does an omniscient, omnipotent, eternal, or nearly eternal being exist? If, based on four thousand years and more of history, one chooses to believe this as the case, then the limits for “real” are undefined. Would any limits apply? Most of humankind believes that a God could and does intervene in human affairs. For example, the average Christian or Muslim accepts that they might encounter an angel, or some other divine being. Most would not expect this as a normal part of human experience but they do believe that it’s possible. A person from any one of many mainstream religions accepts that the delivery person at the door is probably employed by UPS, but he could be an angel. Granted, it’s extremely unlikely that an angel would knock on the door but it could happen. Now, if you ask, could the UPS person really be an alien? Of course not! But there is a very slight chance that he could be an angel. It’s possible because logic allows for this given the beliefs that we accept. In fact, it’s even possible that the almighty himself could knock on the door. By many traditional beliefs it could happen. So why would an otherwise rational person accept such extreme possibilities? How do we get from UPS personnel to angels, or the almighty, or even type IV beings (Michio Kaku et al), for that matter? [Also, I can't help but notice, which is more logical, that an angel is knocking, or that ET is knocking?] How does one make the jump from consideration, to belief, and then to all of the ramifications of that belief? A little consideration reveals that beliefs are dramatically discontinuous. In a moment of acceptance, maybe a moment defined by a feeling, one word, or maybe by one sentence that pushes one over the edge into belief, we go from UPS personnel, to the possibility of angels, in a heartbeat. It is not evident right away but eventually all of the ramifications for any belief come spilling out. In a similar fashion, one look in a telescope unseated humankind as the center of the universe. One equation or two resulted in two generations [and more] of scientific debate about live-dead cats and parallel universes. A few more equations gave us time dilation, worm-holes, black-holes, and even serious discussion of closed time-like curves – time travel. Of course the great irony of modern physics is that it hopes to simplify things, but it appears that existence isn’t a simple thing. So in less than a page of text and equations we were propelled from the clockwork universe of Newton, and into the ultra-strange worlds of Quantum Theory, General Relativity, and now M Theory with its full range of potentials for added dimensions, parallel universes, and even the possibility for supreme beings that can leap from universe to universe. Are you certain about who’s knocking at the door? At least four thousand years of human experience and one hundred years of physics say that you can’t be sure.