Household bugs and rodents are not the only vermin that plague us, our homes, and pest control. Some also exist in the digital world, the most prominent of which is noise.
In communications system, noise is the energy or disturbance that causes random fluctuations in electrical and electromagnetic signals. In other words, it disrupts an otherwise smooth electronic communications flow, causing your internet connectivity as well as your mobile phone signal to go awry.
Electronic noise comes in various forms, natural and man-made as well as internal and external. Below are just some of them:
These are the disturbances that usually come from the electronic circuit itself. Here are some examples:
Also known as Johnson-Nyquist noise after the two engineers who discovered it, this noise comes from random thermal motion of electrons (the source of electricity) inside the conductor. In short, the hotter the electronic circuit gets, the more likely the electric signal will be disturbed. This type of noise cannot be completely removed, although it can be reduced to some extent by using cooling devices which can be installed on the circuits.
While thermal noise depend on the electrons’ temperature, shot noise or Poisson noise involves its flow. It occurs whenever there are statistical fluctuations in the electric current of a circuit, making it also unavoidable. Its characteristics are somewhat similar to rain falling on rooftops; the raindrops fall quietly and with relatively constant flow speed. Shot noise can also be caused by photons in optical devices, since it’s associated with the particle nature of light.
This type of noise occurs when the time taken by the electrons to travel from the emitter to the collector of the circuit’s transistor becomes similar to the time needed to complete the signal being amplified.
These, on the other hand, come from outside the electronic circuit and the communication systems.
This usually comes from lightning discharges during thunderstorms as well as other electrical disturbances that occur in nature.
This type of noise is man-made, and it can come from the ignition electric motors and switching gears of your cars, planes and ships as well as from your wires and fluorescent lamps.
While both atmospheric and industrial noises are produced in Earth, extraterrestrial noises come from outside our planet. Types of extraterrestrial noise include:
The Sun in our solar system is involved in electronic communications more than you think! Even in normal conditions, it can disrupt smooth electronics communications with the constant radiation it produces due to its high temperature. And sometimes disturbances like corona discharges and sunspots can increase solar noise.
And the bad news is, the Sun isn’t the only star capable of generating extraterrestrial noise; other stars are just as mean to our communications systems! Despite being too far off to cause significant havoc to out circuits, their sheer numbers can produce cosmic noise, with an intensity range somewhere between 8MHz and 1.43 GHz.
Sadly, no electronic circuit and communications systems are 100% noise free. These digital “pests” are here to stay, annoying us every now and then by disturbing our internet connections and our mobile phone signals. Yet still, somehow, it’s much less annoying than and hazardous to our health than your local vermin, but we don’t need to worry about those: we have pest control to take care of it.