Entropy is not wrong

I saw this rather objectionable video on Youtube.

URL:
http://www.youtube.com/watch?v=PIa9hjsIQJ4

Actually, entropy is not wrong. The second law of thermodynamics says that the entropy of a closed (or isolated) system like the Universe must not decrease. Indeed, the entropy of the universe is increasing.

Entropy is disorder. At the moment, in the universe we have localised areas of high energy (e.g. stars), surrounded by vast areas of low energy (deep space). Entropy would undo this energy differential by seeing to it that the energy was equally dispersed, and no transfers took place (since all space had the same low energy).

This low energy is not in a usable form, but still counts towards heating the universe by the tiniest of amounts. Heat is the low-quality form of energy that is most easily transferred to equalise energy, so we can see how this process drives the lives of stars, when they slowly cool over billions of years and eventually end up either exploded, or at a much closer temperature to outside space. This is the "thermodynamic" arrow of time.

This notion of the "arrow of time", a concept developed by Arthur Eddington, is one of the chief drivers of causality and the reason we can experience "time".

The notion of entropy can be further imagined by considering the number of possible arrangements for quanta of energy to occupy in a given configuration. The greater the number of arrangements, the greater the entropy. As the boundaries of the universe push ever outwards, the number of available locations in which energy can exist is constantly increasing.

As energy dissipates out to occupy some of this space, it reduces the energy available in the ordered areas of the universe away from the extreme edges. Thus we can see the start of the process that will eventually lead to the much-vaunted "heat death" of the universe, where all local energy sources are exchanged for a dead deep space at fractions of a degree above absolute zero. This is the "cosmological" arrow of time.

There are other arrows of time as well, which can be looked at in more detail here.

It is always a subject which really fascinates me.