I found a site about this book on metaphysics or something, and the author tried to give some examples of where physics falls short or contradicts itself... this guy was clearly no scientist, but I couldn't think of a good explanation for a few things he pointed out, so maybe we can =) "As we all know, perpetual motion machines are impossible, and claims of such devices are a clear sign of bad science. Yet our science states that an object dropped into a tunnel cut through the Earth would be accelerated to the center by gravity, then decelerated as it approached the other end, only to be accelerated down again, over and over – endlessly. This describes an actively operating mechanism that never ends and never drains a power source – an impossible perpetual motion scenario, according to today’s physics." "How can freezing water expand, even bursting metal pipes, with no energy input to explain it? A balloon left in the sun will expand and burst, in the process doing work against the surrounding atmosphere and its elastic skin, which is balanced by the energy input from the sun, so it is no mystery. However, freezing water has no energy input -- in fact, just the opposite. Energy continually drains from the water as it cools toward freezing. So, how does the water suddenly expand with such force from within that it easily bursts metal pipes?"