Bench Degree·LASERSchapter

Before You Start

One page. The parts list for the whole volume is Appendix A, at the back of the book; Chapter 1 will tell you what it needs. This page is the part you should not find out later.

This volume has a hard limit on it, and the limit is the reason it is cheap.

Everything on this list is Class 2 or below: visible light, under one milliwatt. That is the ordinary keychain pointer. Every experiment in all seventeen chapters runs at that level, and Chapter 1 shows how much real physics is available there, including measuring the wavelength of light to three significant figures with a compact disc.

Nothing in this book asks you to buy a laser more powerful than that, and the reason is not caution for its own sake.

Every other volume in this series is written on the assumption that a hazard announces itself. A hot pump barrel hurts and you pull your hand back. A shock startles you before it harms you. Your retina has no pain receptors. A beam capable of destroying your central vision does so silently, with no warning and no repair, and the first indication is that part of your sight has gone.

Chapter 2 is that argument in full, and it is Chapter 2 rather than Chapter 16 on purpose. Read it before you buy anything, and read it before you decide this book is being fussy.

Everything above Class 2 is explained in these pages and never attempted. You will finish this volume able to read the specification of a six-kilowatt cutting head and say exactly what it would do to you. You will not be asked to own one.

Bench Degree

Get the degree without the diploma.

Learn the material, not how to pass the exam.