Alexander Villas: Wow!This is a lot to chew on - it is almost like mixing physics and philosophy. The key to "modern" physics is to point out that the rules change when you do things like move a mass at speeds that approach the speed of light and so on. You can't mix the earth physics and astro physics and get a reasonable result, so be careful. For example, Einstein never said that mass can be converted to energy, he said that the relationship between the two exist. If we could make the conversion, we could power the whole earth with just waste products ala the "Mr Fusion" from Back to the Future movie!Anyway, to answer your question - if you believe the basic rules of thermo dynamics then you know that entropy is only going one way which tells us that as some point chaos will return, but I predict this to be long after humanity is extinct. You are better off worrying about saving enough for retirement!Today is the meeting of two infinities - the past and the future. Bot! h are endless. The universe will last "forever" but with no people, what difference does it make?Perpetual motion is only possible in a zero energy state - think about satellites.Keep on thinking!...Show more
Christopher Calcano: The whole argument ignores the Second Law of Thermodynamics. True, energy-matter cannot be destroyed. However, available energy CAN be destroyed. Available energy is the energy we care about, that can be destroyed: The gas you burn is gone forever, the coal and uranium we burn to produce electricity is also irreversibly depleting, sun is using up its fuel and once it is gone it is gone, etc. Since your argument is not taking into account the very important Second Law, it is fundamentally flawed and inaccurate from a physical standpoint.Perpetual motion by itself is a phrase in the English language that implies that something "moves forever". This is possible in outer space (The spacecraft Voyager is very likely to be in motion pretty much for! ever; Satellites ARE NOT in perpetual motion). Perpetual motio! n is perfectly possible, what is NOT possible is to extract work from an object in perpetual motion. So, perpetual motion is possible, alright, but who cares? you cannot make anything useful out of it....Show more
Maynard Phoubandith: 1) The ultimate fate of our particular bubble of space-time is unknown. However, the idea that it is a "steady state" universe has been well-demolished. Our universe continues to expand, and there is no clear evidence that it will not do so essentially forever. Matter is being destroyed all of the time in stars, where four hydrogen nuclei are fused into a helium nucleus, which has only 3.97 times the mass of a single proton. The rest forms the energy the star radiates. So even in a closed system like a star, the balance of matter and energy is constantly changing.2) This is a possibility. Since we cannot even "see" all of our own universe, however, there is no practical way to know. 3) There is a difference between infinite and ! eternal. It is likely that our space-time universe is not infinite, and that it contains some (very large) total sum of mass and energy. Consider a single photon, which is essentially just a ripple in space-time. If it travels unobstructed by interactions with matter at the speed of light, it will remain unchanged and continue perpetually in motion. A perpetual motion machine as it is commonly understood however, is one that produces more energy than it consumes indefinitely, or somehow extracts energy from the heat of its surroundings and converts it to work. Both types are forbidden either by conservation laws or the 2nd law of thermodynamics. So, while being perpetually in motion may be possible, it cannot be used for any practical purpose without violating physical laws....Show more
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