After this point, most astronomers agree that the universe will continue to expand, cooling and losing energy in the process. (businessinsider.com)
Dark matter particles can penetrate all other forms of matter, which means that they may even be able to traverse right through our planet without losing any energy whatsoever. (sciencedaily.com)
An ideal gas is assumed to not lose energy that is added to the system. (scholarsandrogues.com)