The Scientist’s Essay for 1. Investigating Materials
Why are Material Properties Important?
Whether designing a bridge, a bookcase, a heart valve, a tennis racquet or a microchip, the engineer begins with a thorough understanding of the physical and chemical properties of the available materials.
Since science strives to describe and understand the world around us, the properties of the substances that comprise that world are of almost self-evident interest. As soon as we begin to focus on those properties, the list of intriguing questions is virtually endless:
- Why do some materials float in water while others sink?
- Why are some materials transparent while others are opaque?
- Why do some materials feel cold to the touch while others don’t?
- Why do some materials conduct electricity and others don’t?
- Why do some liquids mix and stay mixed, while others separate?
- Why are a few materials attracted to magnets, while most aren’t?
- Why do some materials bend, while others break?
- How can a combination of two materials have properties unlike either of its constituents?
- What happens to a material’s properties when its temperature changes?
Answering these and similar questions has been a central and challenging area of scientific inquiry for centuries, and has led to the discovery of such surprising and unexpected phenomena as superconductivity. The current excitement about nanoscience centers on how the properties of materials change when the objects they comprise reach the scale of tens or hundreds of atoms.
From a practical standpoint, material properties are the starting point for engineering and technology. Imagine our world, for example, without plastics or semiconductors — materials that have been understood and exploited only for the past several decades. Whether designing a bridge, a bookcase, a heart valve, a tennis racquet or a microchip, the engineer begins with a thorough understanding of the physical and chemical properties of the available materials.
For any of these purposes, the first steps are careful preparation of materials of well-defined composition and quantitative measurement of the relevant properties, and large numbers of scientists and engineers spend the bulk of their time on those tasks.
—Roger Tobin
