For those of you who think that this topic is related to “Matters,” an album by the punk band Pulley, or “Matter,” a science fiction book by Iain Banks, I am sorry to disappoint you. However, before you stop reading, let me assure you that matter in the scientific sense is also an interesting topic, and I am going to attempt to define this subject for you (not that I am a chemist, but I do know what matters).
Let me start by saying that the next time someone asks you, “What is the ‘matter’?” your reply should be “everything” as matter indeed is everything around us (at least everything that is physical). If you want to be a bit more scientific, matter can be defined as everything that has mass and volume and takes up space, and it does matter very much as it is what brings physical existence into being. Anything in the universe that is not matter is energy, and energy actually matters also as it acts on matter. Are you confused yet?
The word matter comes from the Latin word materia which means wood (do not infer from this that all matter is wood; however, it is certainly true that all wood is matter). To take it one step further, the word materia can be traced back to the word mater meaning mother, and indeed matter is the mother of everything physical (not to be confused with The Mothers of Invention, a band popular in the 60’s and 70’s). Anyway, let’s continue as we have several matters to attend to in our effort to define this subject.
The four states of matter are solids, liquids, gasses and plasma. I am quite sure that when I was in school, I was told that there were three states of matter (but it was kind of a one-horse town). It is true that the plasma state is not common so that perhaps explains it. I was also taught that matter is everything that can be perceived with the senses, but that was before we found out about dark matter which we cannot perceive with the senses at all. However, dark matter still matters as it likely makes up about 90 percent of the mass in the universe. This is not to be confused with Darth Vader (and the dark force), although dark matter is likely made up of about 70 percent dark energy (which could be called a dark force).
All matter is made of atoms (and therefore all matter is alike). However, different types of matter are made of different types of atoms (and therefore all matter is also different). We describe matter by looking at its physical properties. However, the physical properties of matter can change. If you drop a glass on the floor, the description of its physical properties no longer holds water (and neither does the glass). If you leave ice in a warm room, the physical properties of the ice will change (and will be all over the floor). These are all physical changes.
Matter can also undergo chemical changes which change the matter into something altogether (in other words, it becomes a horse of a different color). You cannot reverse chemical changes (if you don’t believe me, try changing spoiled milk into something you want to drink).
The description of matter has changed over time as scientists have advanced their understanding of the universe. For example, in the eighteenth century Sir Isaac Newton saw matter as the building blocks of the universe; however, it was not until the nineteenth and twentieth centuries that an understanding of the substances that composed these building blocks began to emerge. The definition of matter was enlarged to include the fact that it is made up of atoms and molecules. It was also found that matter has both chemical and electrical properties.
There are four different properties of matter: weight, volume, mass and density. Mass is the amount of matter in an object, and it does not change (of course if you take some of the matter out of the object, that is another matter). The volume is the amount of space a particular object occupies. Density (not to be confused with many people’s intellectual capacity) is the measure of how much mass is contained in a given unit volume. Weight has to do with attraction (and you thought attraction only governed human actions silly you) between objects due to gravity. For example, you are attracted to your computer through gravity (perhaps that explains why you spend more time with your computer than your spouse).
In summary, matter can be described as the substance of which physical objects are composed. It is what is generally observable (although light is not considered matter). Some physicists define matter as everything that is composed of elementary particles called fermions (this is elementary my dear Watson). However, this would include some things that are never seen except in physics experiments (could this be an effort by physicists to take over everything that matters).
If you have come to the conclusion from all this that there is no easy definition for matter, then you would be correct (but didn’t your parents tell you that nothing worth having comes easy).
Of course there is also antimatter, but I will leave that for another time.
