Science
Solids Explained: The State of Our World
An introduction to solids, the state of matter defined by structural rigidity, and why new discoveries in materials science make them a hot topic.
What is it?
A solid is one of the fundamental states of matter, characterized by structural rigidity and a definite shape and volume. In a solid, particles like atoms or molecules are packed tightly together in fixed positions. While these particles are not stationary—they vibrate in place—they lack the energy to move past one another, which distinguishes them from liquids and gases. Solids can be broadly classified into two types based on the arrangement of their particles. Crystalline solids, such as metals and salt, have a highly ordered, repeating geometric structure. In contrast, amorphous solids, like glass and plastic, have a disordered and irregular arrangement of particles.
Why is it trending?
The study of solids, known as solid-state physics, is a cornerstone of modern technology and materials science. This field is constantly trending due to groundbreaking discoveries of new materials with unique properties. Researchers are developing materials that defy traditional expectations, such as those that shrink when heated or can behave as both a liquid and a solid. Recent advances include identifying a new state of matter within glassy solids. These innovations are crucial for advancing technology, leading to the development of more efficient semiconductors for electronics, next-generation batteries, and novel materials for aerospace and construction.
How does it affect people?
Solids are fundamental to nearly every aspect of human life. The ground we walk on, the buildings we live in, and the tools we use are all composed of solid materials. The specific properties of solids—such as hardness, elasticity, and conductivity—are harnessed for countless applications, from the copper wires that transmit electricity to the plastics used as insulators. The choice of solid materials in our environment can also directly impact our health and well-being. For example, building materials can affect indoor air quality, while the sensory qualities of materials like wood or stone can influence our psychological state.