So you want to dive deep?

During last week's class, and at the request of several who wrote ahead to make sure that we were going to "dive deep," we dove deep into science. Here's an example of how deep the discussions often go:

In a modern chemistry textbook (link), students read the following:

"Matter comes in many forms. The fundamental building blocks of matter are atoms and molecules. These particles make up elements and compounds. An atom is the smallest unit of an element that maintains the chemical identity of that element. An element is a pure substance that cannot be broken down into simpler, stable substances and is made of one type of atom."

Sound good, so far? No, actually. There's so much missing.

For most people, this seems simple. The statements are matter-of-fact about how material objects exist.  We read them and assume that this has been seen and proven and when we look at a piece of wood or a drop of water, we tell ourselves that beyond the reach of our eyes, there is actually no “wood” or “water” but simply atoms arranged in different ways to cause different substances to appear to us, like an Impressionist painting composed of dots of paint.

If we move back, however, to the early 1900s, students were taught the following in The Elements of Chemistry: Inorganic and Organic. Norton, S.A. 1884 (link):

"We know nothing of the manner in which the ultimate particles of matter are arranged together: we believe that they are arranged in accordance with certain theories which we shall now proceed to develop.

All masses of matter may be subdivided into very small particles; but it is probable that there is a limit to this subdivision, and that all bodies are made up of particles so infinitesimally small that they are inappreciable to our senses. By the terms of this theory,

A molecule is the smallest particle of matter capable of existing in the free state:

An atom is the smallest particle of matter that is capable of entering into or existing in a state of chemical combination."

Notice how carefully the old teachers distinguished facts from theories.  The textbooks tells students plainly that scientists believe in theories and that teaching about atoms and molecules is a matter of faith not facts.

In this same textbook, Norton warns of errors that people are prone to when they speak of the science and its facts.  We read:

"The facts of chemistry are established by experiment, and are capable of being reproduced. They find a practical application in the arts, which is altogether independent of any explanation that may be made of them. When, however, we attempt to reason upon these facts, to classify them, to interpret them, we at once begin to form theories. A theory which renders a reasonable explanation of a great number of facts is useful (1) because it enables us to group them into a system, and (2) because it often leads to new experiments and to the discovery of other facts.

We are liable to three errors: (1) we may assume that to be a fact which has no existence; or (2) we may sometimes mistake a phenomenon, so as to imagine that to be a cause which is only an effect of some unknown cause; or, finally, (3) we may become so accustomed to the language of theory as to mistake its definitions for facts."

Can you  not see how different the mind of the student formed by this older textbook is than the modern textbook which commits the third error learned of?  Teaching of atoms and molecules, in modern textbooks, is no longer couched in terms of  theory and belief.  It is presented as immutable fact.  What is fact is that there is no more proof that atoms actually exist today than there was in 1900. The language of theory has simply been abandoned by modern scientists.

Swap out the word "chemistry" for "video analysis" or your specific forensic science discipline, Norton's caution still makes for great advice - from 1884.

This simple discussion, generic to science, has profound implications in the forensic sciences. I speak often of what we "know" vs. what we can "prove," of the null hypothesis, and of conducting valid experiments. Remember the NAS Report's conclusion in 2009 - forensic science sucks at science. Well, how does forensic science remedy the situation - by engaging in actual science. That all starts with understanding how science is conducted.

As relates to measurements, comparisons, vehicle determinations, and etc., we start with the basics. To get to a vehicle determination, we must first have a nominal resolution sufficient to address the task. Same with photogrammetry - we need sufficient nominal resolution of the item or object of interest so that the measure will (at least) exceed the error. We also must understand that a measurement can't be used to identify something. The measure only contributes to the classification of the item or the object.

So, if you want to dive deep - really deep - our classes are open to all who have an enquiring mind. Even our introductory courses move beyond simple button pushing to explore the depth of the discipline.