The Second Law of Thermodynamics has several variations. One version says that
             some heat is always wasted when converting heat into mechanical energy. In other words
             all heat can not be completely converted into mechanical energy. Another states that heat
             normally flows from high to low temperatures. So why do hot cups cool off, well the
             answer lies in the fact that the universe is expanding. Say the universe started off infinitely
             small and infinitely dense, then expanded at an exponential rate as fluctuations in density
             increased, eventually forming galaxies. This explanation of the universe would explain the
             existence of the thermodynamic arrow of time. Because the universe is expanding,
             disorder is increasing. It can't be stopped. No one and nothing is powerful enough to
             break the laws of thermodynamics. Albert Einstein once said, "Thermodynamics is the
             only physical theory of general nature of which I am convinced that it will never be
             overthrown." If you want to know what's going on in the physical world, you simply
             To understand the forward flow of time, suppose that God decided that the
             universe should finish in a state of high order but that it didn't matter what state it started
             in. This would mean that disorder would increase with time. One could observe a broken
             bottle gathering itself together on the floor and jumping back up onto the table. Such
             beings would have a psychological arrow of time that is backward. This means that I
             could take a warm Pepsi, set it on the counter and the colder particles in the room would
             become closer together and surround the bottle thus cooling the Pepsi. This makes the
             second law of thermodynamics questionable. Disorder increases with time because we
             measure time in the direction in which disorder increases.
             Why don't we see broken things gathering themselves
             ...