# Chapter 2 - Physics in Industrial Instrumentation

## Chapter 2 - Physics in Industrial Instrumentation

Everything there is to know about physics – excerpted from “Everything you need to know about school” in the September 16, 2008 edition of the Seattle periodical The Stranger:

If stuff is still, it doesn’t like to move; if stuff is moving, it doesn’t like to stop. The more stuff you are trying to move, the more you need to push it to speed it up. When you push on stuff, it pushes back on you. Stuff likes other stuff, from a distance at least. Stuff likes becoming more chaotic, but cannot be created or destroyed; stuff can be rearranged. (All that is Isaac Newton.) Energy, like stuff, cannot be created or destroyed, only changed from one kind to another. Energy can be stored in movement, bonds between stuff, and many other places. Changes in how energy is stored allow us to do things – like bake, drive, get up tall buildings, and kill each other. (That’s Sadi Carnot.) Also, stuff is energy. Stuff is a lot of energy. (That’s Albert Einstein.) Compress plutonium with explosives and the atoms fission, releasing the energy stored in stuff. When the energy is released in downtown Nagasaki, you kill about 40,000 people right away and another 40,000 over time. (Thanks, Enrico Fermi!)

There is a lot of truth to this quote, despite its sarcastic tone. Physics really is the study of matter and energy, and of the laws governing the interactions of both. The movement of matter largely follows the laws described by Isaac Newton (so much so that this category of physics is often referred to as Newtonian physics). The flow and transformation of energy is a category called thermodynamics. Albert Einstein went on to equate matter with energy through his famous equation $$E = mc^2$$ which helped usher in the age of nuclear physics.

Physics is important to the study of industrial instrumentation because its laws describe and explain so many applications of measurement and control. As a teacher, one of the things I like to tell students is that their chosen field is really nothing more than applied physics. Granted, there aren’t too many applications of macroscopic projectile motion in industrial measurement and control, but on a microscopic level this is what all moving fluids are: an extremely large collection of independent molecules obeying Newtonian laws of motion. Physics is the study of stuff, while instrumentation is the discipline of measuring and controlling stuff. The better you understand stuff, the better you will be able to measure and control that stuff. Enjoy!

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