1.2.1: Careful Observations- Documentation, Measurements, and Patterns

Learning Objectives

• Explain the importance of documentation, measurement and pattern recognition in science.
• Correctly document measurements.
• Express patterns qualitatively, graphically, and mathematically.

It takes better observations to have a better understanding of the natural world. There are several ways that we can do this, many of which pre-date what we now refer to as science.

Documentation

It’s one thing to say that observations do not matter, but it’s quite another thing to say that maybe you made an observation but do not remember everything about it correctly. Careful documentation can aid in this process. Maybe you have an interest in starting a regular routine that you think will improve the quality of your life. Documenting the start of this routine and the quality of your life that you experience afterwards might be a way of learning whether the routine is helpful (and of course there are many apps for things like fitness, budgeting, time management, and cooking that have been created to help with this tracking process). The same process can be applied to any observation about the natural world. What time of year did you plant something, and did it grow the way you hoped it would? This information can be helpful to you the next year to make plans for planting again.

If enough people are able to document their observations of the world, this information can be compiled and shared for others to use. Note the difference between compiling observations and compiling ideas (as the scholastics did). If your goal is to understand the world that we live in, the written documentation of what someone else has observed can be quite helpful. Perhaps it was observed in a time or place that you don’t have access to. Perhaps the records of someone else’s plant growing process will help you to get the results that you want when you plant your own. This sort of documentation is one of the key aspects of science. Documentation is helpful in recognizing patterns in the natural world. As we shall soon see, this recognition of patterns is an important part of science.

Around 1400 CE, during the Ming dynasty, the Yongle Encyclopedia was created. This was one of the largest encyclopedias ever created, and included many subject areas beyond just science. The ability to share information in this way is one of the keys to scientific progress. Scientific knowledge is not built by the works of a single man (as one might assume based on the way Scientific Laws have often been named), but by the collective work of a community of diverse scholars.

Figure \(\PageIndex{1}\): A page from the Yongle Encyclopedia from the Chester Beatty Library. Public Domain

Measurements

Another way to learn more about the world is to make better observations. If you observe something as large, or tall, or tiny those are subjective observations which do not allow for finding patterns in nature. If you can quantify the observation it allows for an increased ability to recognize patterns. Maybe large things that are 8 feet tall follow different patterns than large things that are 10 feet tall. You will not know this if you are not able to measure (and then document) that difference.

People learned how to make repeatable measurements before documented history. This was helpful for economic reasons. If you wanted to sell and/or meal plan the food you had harvested, it was helpful to know how many ephas of grain you had and how many shekels of coin you could receive in return for them. The epha was a measure of volume and the shekel was a measure of mass. In fact, the process of measuring a harvest each year could be considered a scientific observation.

Measurements have become a very key part of science. As we make or report a measurement, it is important that we include both a number and a unit. Think of it like the difference between 100 dollars and 100 cents. If you do not know the unit, you do not actually know anything about the results of the measurement.

One of the things that has allowed science to progress so much is the ability to make better measurements. Sometimes new devices allow us to make better observations that unlock some understanding of the natural world that we did not have before.

Key Concept: Every measurement must include both a number and a unit.

Patterns

As more observations are documented, and the quality of those observations is improved by the use of measurements, patterns might begin to emerge. These patterns are often the key to understanding the next step in the process of science. As we begin to notice patterns, we can then use our understanding of those patterns to make predictions about what might happen next.

Some of the earliest scientists lived before recorded history and they used this sort of pattern recognition of the natural world for survival. Keeping track of the patterns of both weather and astronomy helped ancient nomadic people decide when it was time to move towards geographies that had better resources for them. By around 700 BCE, Babylonian astronomers had developed an observation based predictive model for the movement of the planets. This may have been the very first scientific revolution.

Figure \(\PageIndex{2}\): A Babylonian tablet from 164 BCE recording an observation of what has since been called Halley's comet (British Museum, public domain)

We have many skills to aid with pattern recognition in science that we will introduce throughout this text. There are often trends where two aspects of an object change together. For example, as a child gets older they get taller. One way to measure this trend would be to mark their height on a wall on each of their birthdays. You would likely find that children grow at variable rates (hence the term growth spurt). In this case, a purely qualitative description is sufficient, a sentence such as “children grow as they get older.”

But for some patterns, the trend is more pronounced. For example, if you were to measure the mass and volume of a single aluminum pellet and then repeat this process for 5, 10, and 20 aluminum pellets you would definitely see a trend: as the mass goes up, so does the volume. But you might notice this trend is not quite as variable as that for growing children. At this point we could make a line graph of the data to see what kind of variability exists. The graph would show a straight line connecting the data points. We call this sort of relationship a direct relationship. We can express it as

\[m=kV \nonumber \]

where m is the mass, V is the volume, and k is some constant that relates these two quantities together. (It turns out the constant k is a property called density, and this is a relationship we will explore in more detail later in this text.)

This practice of changing some aspect of nature and measuring another aspect of it is a key part of scientific experiments that we will explore in more detail in the next subsection. It is also a very powerful tool. If you wanted a certain mass of aluminum pellets but were only able to measure the volume of those pellets, you could use the direct relationship developed here in order to determine what volume of pellets to use. These sorts of relationships in the field of science are what has allowed us to create the high tech society in which we now live.

Section Summary

• Documentation is a useful aspect of the process of science, and access to information previously documented by others can be just as useful.
• More accurate observations can occur via measurements, and new measuring devices continually expand the scope of science.
• Every measurement contains both a number and a unit.
• Pattern recognition is very important in science, and leads to important descriptions of the relationship between measurements.
• In a direct relationship, two aspects of nature increase together which can be shown graphically or in an equation.