Doppler Effect As an object moves through air, it must push some of the air out of the way. But the object also creates sound waves as it moves through the air. As a moving source of sound the object causes a ‘doppler’ effect. When that object reaches the speed of sound, air cannot readily move out of the way and a shockwaves is formed. When the object is moving faster than sound, the resulting sounds travel behind the object creating a sonic boom.
Moving in air When an object such as an airplane moves through the air, it increases the frequency of the sound waves ahead of it, due to its velocity. This is the Doppler effect, where the pitch of the sound is heard as higher when the object is moving toward you and the pitch is lower, as the object moves away.
Longer Wavelength Lower Frequency
Shorter Wavelength Higher Frequency
Speed of Sound When the moving object or airplane reaches the speed of sound, it catches up to the sound waves it is creating, and they bunch up at the front end of the object, forming a shock wave. This is a reason that it is difficult for an airplane to break the sound barrier.
Shockwaves Created
Supersonic Speeds When an aircraft travels at supersonic speeds or is moving faster than sound, it leaves the sound waves it makes behind it. These waves fan out and cause a sonic boom.
Sonic Boom
Carl holderness hello@carlholderness.co.uk
“Doppler” Type The doppler typeface is designed to be purely decorative. A travelling object is illustrated through a thicker line and forms the basic structure of the individual letterforms where the object moving. As this object moves through space the sound waves generated create a body of waves which forms the body of each letterform. Rings illustrate a varying amount of speed according to each letterform. Ascenders, descenders and greater character width increase line length and result in longer chains resulting in faster speeds that are supersonic. Shorter, more contained letterforms result in slower speeds which do not break the sound barrier and create a ‘doppler’ effect.
Carl holderness hello@carlholderness.co.uk
Doppler Type
As an object moves through air not only must push some of the air out of the way, but it also creates sound waves. This moving source of sound causes what is known as the Doppler effect. When the object reaches the speed of sound, air cannot readily move out of the way and a shock wave is formed. When the object is moving faster than sound, the resulting sounds travel behind the object, creating a sonic boom. This typeface explores the shapes created using sound waves and the wake of sound which objects leave behind them. For more information and other experimental typeface designs got to: carlholderness.co.uk