Kelvin-Helmholtz instability creates beautiful wave-like cloud patterns in the sky, or billow clouds. Different layers of the atmosphere can have different densities with air moving at different ...

What’s most appealing about the new wave of wallpaper designers is the youthful, dynamic patterns on offer – for example, Ottoline’s much-loved ‘Madame Ziggle’, a quirky, cheerful zigzagged stripe ...