Day 90

** Note: This is posted on Day 94, but is the original post intended for Day 90. I was reminded that I was falling behind again. I really need to do better at this.

Of the four states of matter, gas is probably the most interesting to me. While not all compounds can exist in the definitive forms (solid or liquid), all matter can, at some point, exist as a gas. Plasma, which is the 4th state of matter, is actually the most abundant state of matter in the universe, but is an abstract extension of the gaseous state.

A solid is that which has a definite shape and occupies a definite volume. A liquid is that which has a definite volume, but an indefinite shape. A gas has neither a definite shape nor a definite volume. For those curious few who made it this far, plasma is pretty much a nucleus floating in a sea of free electrons, which allows free movement of negative and positive charges which gives plasma certain properties apart from gases. In the universe plasma is by far the most abundant form of matter, but in our world it is the least talked about.

There are 2 processes where a compound or element can change to a gaseous state - evaporation and sublimation. Sublimation is the process where a chemical goes straight from a solid to a gas. Fog machines produce fog by melting dry ice (frozen carbon dioxide). Carbon dioxide cannot exist as a liquid... it goes straight from being ice to a gas - hence we get fog machines. Evaporation is that process by which a chemical goes from a liquid to a gas. I think we're all pretty much familiar with the term.

To see evaporation in action one can take a pot of water, turn on the stove, and watch the water boil until there is eventually nothing left in the pot. The water is still present, but its state has changed. Since gas has no fixed shape or volume, that same mass of water vapor now may occupy the entire room.

Of course, once the water evaporates, the presence of the water is for the most part intangible. When it comes to gases, it is most often the case that we can only smell them, which is a good thing when a grocery bagger does something silly like putting the ammonia and bleach in the same bag (for those who don't know, when you mix ammonia and bleach the reaction yields pure chlorine gas which is a very bad thing for breathing). Then again, in some cases if you can smell a gas, it is much too late to do anything about it (mustard gas and hydrazine are classic examples). Extreme examples aside, sometimes it is taken for granted that we even have air to breathe because of the intangible nature of gaseous matter.

Evaporation itself is mostly what inspires this post. When heat energy is applied, the kinetic energy level of matter increases. All matter has energy stored in it's bonds called potential energy. This potential energy, sometimes called resting energy, maintains the arrangements of molecules in a compound. As one can imagine, solids have the most potential energy whereas gases have very little potential energy. On the flip side, gases have a lot of kinetic energy, also known as energy in motion, whereas solids have almost no kinetic energy.

This is where it gets counterintuitive - condensation (gas to liquid) and freezing (liquid to solid) are heating processes whereas melting (solid to liquid) and evaporation are cooling processes. In order for condensation and freezing to occur, the kinetic energy must be converted to potential energy. This is accomplished as the molecules absorb the kinetic energy. Liquid water to ice absorbs energy, even though is has to be cold in order for freezing to occur. Conversely, melting and evaporation release energy. It takes energy to break the arrangements of the molecules, but that breaking converts that potential energy to kinetic energy. In this way, the molecules are considered cooled. It is screwy, but when you move into areas such as thermodynamics and meteorology, it begins to make sense.

So what does this have to do with anything in real life? I believe we have all had that time when a dream we've held onto has vanished. There as many reasons for this as there are people on this planet. My own recent experience has seen the ingredients necessary for evaporation come together. The only question that remains is if the water will be taken off the fire before it comes to a boil and the dream is all but gone.

I will wait and see what happens at this point, which is really all I can do anyway.

There is no picture today as, to be really honest, I just didn't have it in me. Goodnight to all of you, my faithful and not-so-faithful readers.