Models of reality

In this chapter it is specified what aspect of reality we will be interested in and how we will go about its exploration.



Introduction

Counting on your fingers is not going to cut it if you want to fly to the Moon

Bjarne Stroustrup

It is a good starting point though

Anonymous “sage”




The only sources for what we know about the world are our own direct experience and the knowledge passed by other people. The latter can be seen as an up-to-date map of reality, provided the map is honest. Refining it and adding new areas is a slow process because it relies on direct experience which happens to be full of pitfalls. I believe the hazards can be divided into two broad categories:

Another problem is that in certain domains e.g. a lifestyle, a “map” good for one person is useless for everybody else. We are not going to talk about that here though. Instead, we will focus on the physical world, which behaves the same for everyone.

The map of physical reality was painstakingly put together over the last few millennia. Why did it take so long? Well, overcoming the obstacles on the list above is very difficult.

In the next few sections, we will take a very brief tour of how our perception of reality has evolved over the centuries.



Moody spirits

The simplest, naïve explanation of how the world works is based on the assumption that nature is human-like. If it rains, the sky is crying and if it’s sunny, the sky is happy etc. A moody spirit governing every aspect of reality is a very natural view.

To this day if some object doesn’t behave the way we expect, the instinctive reaction is getting angry at it, just like it was a naughty person. This tendency is an illustration of the first problem on the obstacles list from the previous section.



Regularities

At large, a theory of moody spirits doesn’t stand up to scrutiny because reality is full of regularities: day always follows night, seasons follow each other in a predictable manner etc.

To spot these regularities, we simply need to observe nature close enough or choose to be inquisitive and perform experiments. Of course, the problems mentioned in the introduction will always get in the way, so the road will be bumpy.



Models

After finding a regularity, we can build a model of the aspect of reality related to the regularity in question. One of the oldest models is a calendar. Our ancestors figured out how many days there are in a year and by counting them from some starting point they could predict the seasons, something that greatly increased the efficiency of agriculture.

The procedure of building a model can be divided into a handful of steps:

  • spotting some regularities e.g. when a ship approaches the port, first, we only see the mast sticking out above the horizon
  • producing a model e.g. the realization that Earth may not be flat
  • checking if the new model reproduces the correct predictions of the old ones if we had any e.g. Earth is so big that the local area around any point on its surface looks flat
  • exploring predictions of the new model and testing them against the reality e.g. the Moon observed from the southern hemisphere should look upside down in comparison with its appearance from the northern hemisphere etc.

After taking a closer look at the procedure presented above, it is apparent that reasoning is quite instrumental in building models and exploring their predictions. In the next chapter we will explore this subject thoroughly.