Alpha waves (8-12 Hz) happen when we are relaxed with eyes closed, as in meditation. Theta waves (4-7 Hz) are common in the lighter stages of sleep or the transition from waking to sleeping.
The first three stages of sleep are characterised by three types of brainwaves: alpha waves, theta waves and delta waves. The former are typically recorded when we’re in the process of falling ...
Using an air vortex cannon to focus the sound waves from the bass reflex port, it ‘wiggles’ the flame out in a matter of seconds, as illustrated with a thermal camera. Compared to the much ...
A sound wave is a vibration that travels through a solid, liquid or gas such as the air or water. A loud sound has a large amplitude, a high pitched sound has a high frequency. Musicians and ...