top 10 incredible sound part 2

Whistlers

Whistlers are low frequency radio waves that are detected on radio receivers. Lightning strikes create radio waves, which then travel along the earths magnetic field lines through the magnetosphere and ionosphere, meaning they can be detected far away from any actual thunderstorms. In the plasma of the upper atmosphere, higher frequencies of radio waves travel faster, so a receiver will pick up higher frequencies first, followed by lower frequencies in a descending tone. The radio waves occur at frequencies low enough such that they can be converted directly into sound through a speaker, where you can hear the characteristic “whistling” sound. They can be heard almost anywhere in the world. They have also been detected on Jupiter, showing lightning occurs there.



Space Dust

. How the sound was created is not as complicated as on other entries on this list – dust from the rings was hitting the radio antenna. Still, considering that the sound was made by a tiny probe, traveling at over 35,000 mph, through a ring of dust 144,000km wide and over 1.2 billion km away, it still seems slightly creepy.



Sonic Booms

Sonic booms are created as an aircraft breaks the sound barrier, at around 761 mph. As an aircraft travels along, it creates a series of pressure waves in front and behind the aircraft, which themselves travel at the speed of sound. When the aircraft reaches the speed of sound, these pressure waves cannot travel away from each other and collapse into a huge shock wave. This in fact results in two sonic booms – one at the front of the aircraft, and one at the back shortly afterwards. The two sonic booms can be heard quite clearly on the video above. The ThrustSSC, the first car to break the sound barrier, produced a similar double-sonic boom.



Ice

On a frozen lake, where the ice is quite thick, disturbances in the ice, such as the ice naturally freezing or moving, create sounds that reverberate to create a very unique sound. The sound can also be created by throwing stones onto a frozen lake. In the video above, if you turn your speakers up, you can hear this sound being produced (it is quite quiet). From further away, a lake that is freezing will sound like it is “singing”, as in this video.



Superb Lyrebird

The Superb Lyrebird is a songbird found in south-east Australia which impresses females not by creating its own impressive birdsong, as with other birds, but by accurately mimicking the songs of other birds. It has an incredible vocal range, and can mimic the calls of over 20 other birds, which are so accurate even the birds it is impersonating cannot tell the difference. What has made this bird famous, however, is how well it can imitate other sounds it hears, such as car alarms, chainsaws, car engines starting, drills, electric motors, and sometimes human voices. The only other bird to do this is the much rarer Albert’s Lyrebird, also found in south-east Australia. Above is a famous clip of a Superb Lyrebird from the David Attenborough documentary “The Life of Birds”.