From pencils to programming and graphene: Graphite’s role in the transmission of knowledge

Adam Blaxhall (UK) Once a mystery substance thought to be a type of lead, graphite is now one of the most vital components in the ever-expanding world of complex electronics. But this ‘mineral of extremes’ is more than just the familiar grey material we find in pencils. Rather, it is a specific form of the element, carbon (another is diamond) and, from writing products to electrical circuitry, graphite plays an increasingly important role in how we process, communicate and transfer information – and there’s still much to learn from its untapped potential. Graphite: the only mineral for the job A popular misconception is that lead pencils are made from lead (Fig. 1). Fig. 1. Putting lead in your pencil? Graphite was originally considered to be a form of lead and went by the name ‘plumbago’. In fact, they never have been. Graphite – mistaken for a form of lead – has been the main ingredient in the pencil since the largest, purest deposit of the mineral ever discovered was unearthed in Borrowdale in Cumbria, UK in the 1500s (Fig. 2). Fig. 2. Graphite. Graphite is ideal for pencils because its giant structure of carbon atoms – formed of honeycomb-like layers stacked on top of each other – is such that the bonds between atoms are stronger than the bonds between layers. It’s this physical property that gives graphite its soft and slippy texture, and allows the layers to slide off one another. So, when a pencil moves across a surface, … Read More

To access this post, you must purchase Annual subscription, 12 Month Subscription or Monthly subscription.

Pale white dot

Steven Wade Veatch (USA) and Vishwam Sankaran (India) “There’s nothing new under the sun” goes a famous saying and these words are very apt when trying to understand Earth’s climate trends. Thanks to numerous discoveries made about Earth’s ancient past, we now know that our climate has never been static. According to geological and palaeontological records, climate change has affected the Earth throughout geologic time. In this context, this is the second of a series of articles about climate change over geological time. The first is A warming medieval climate supports a revolution in agriculture by Steven Wade Veatch and Cheryl Bibeau. To understand climate change today, researchers study past climates and events that affect climates, such as volcanic activity, solar radiation, sunspot activity, astronomical changes and other factors that influence climate. Once we understand the dominoes that have fallen during the past climate change events, we can understand and predict – to some degree – the kind of patterns that may follow current trends. To do this, scientists piece together clues from past climates provided by rock formations. Scientists likewise examine fossil records that yield climate signals from the past. These fossils range from prehistoric pollen to dinosaurs. Putting both geological and fossil records together reconstructs ancient climates and environments. More recent climate change is studied through climate records held in polar ice caps and ice sheets, ice cores, glaciers, isotopes of elements (like oxygen, carbon and sulphurfur), soil sediments and tree rings. When we think of the term … Read More

To access this post, you must purchase Annual subscription, 12 Month Subscription or Monthly subscription.