The Science of Life Lecture Series

This is a natural continuation of Chapter 1 Section 2 .  When we make models, we need to make sure that, when we run the numbers, the dimensions of the solution naturally make sense.  The word "dimension" in physics means something more general than the definition we are used to here in every day life.  We typically think of dimensions as length, width, and height; we do live in a three dimensional world, after all.  The word dimension in science means the units that we are working with.  This could be Distance (like length of a box), or is could be time (duration of a trip), or it could be mass (I weigh 15 stone).  The dimensions of density are kilograms per cubic meter (kg/m 3 ). When these dimensions are used in mathematical equations, they are treated as if they are variables we've seen in Algebra ; they can be canceled and squared like any other value in mathematics.  For example, if we have a room that is 20ft.×30ft.×15ft, then we multiply the numbers togethe

This material comes from Chapter 1 Section 2 of the Newtonian Physics Lecture Series. If we cannot interact with matter directly, or if we want to make a prediction of a system before we build the system to test it, we draw up a model of the system related to the phenomenon in question.  Chemistry is a good example of this.  We cannot observe the molecules directly with our eyes, so we model the reaction with the known laws of physics and chemistry. Using these models, we predict the behaviors and results of the chemical reaction based upon the interactions between the components of the system or between the system and its surroundings.  The words "system" and "surroundings" will come up in this lecture series and have specific definitions, so I may as well define them now.  The "system" is everything under direct study in the moment we are studying it.  The surroundings are everything outside of the system, but still have an affect on th

Before we get into actual Physics, commentary must first be made about the foundations of all science, including physics.  The fundamental basis for all physics is the concept of units.  After all, when I say "The speed is 6", that is meaningless.  Am I talking about m/s, km/hr., miles/hr, knots?  Which units am I using? There is a system of measurement which has been around for centuries, but has been globally standardized for use in science since 1960 .  This system is called the Système international from the French, who was the first to widely adopt the concept shortly after their Revolutionary War against Britain.  The shorthand for this system is SI, and the fundamental units it uses for classical mechanics is the meter, the second, and the kilogram.  There are other fundamental units in Classical Physics, but those deal with either electricity or waves, and since those are covered in their own separate semesters, I'll cover those fundamental units for those sem