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People often use the term 'static' or 'static noise' to describe the sound of an untuned radio - which is more accuractely called white/pink/brown noise depending on the frequencies present.

I'm curious as to why it's called 'static'. What's unchanging?

From wikipedia all I could see was:

Alternatively, the use of an FM radio tuned to unused frequencies ("static") is a simpler and more cost-effective source of white noise

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    All I have is conjectures; this is a fascinating question! My guesses are: the noise doesn't change, so it's "static"; static electricity discharges cause radio noise, so the continuous noise was called "static". Last guess: this is a "standing", unchanging noise, so it's "static". There seem to be no good online etymologies that address this. – Joe McMahon Jun 24 '15 at 1:19
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    @Tonepoet - It believe (without having looked at this) it would be called white noise because all audible frequencies are represented- much like how white light is made of all visible frequencies. pink noise must cover frequencies at the lower end, and brown noise... I'm not sure. – dwjohnston Jun 24 '15 at 2:02
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    The term "static", in this sense, refers to the phenomenon you experience when you shuffle your feet on the carpet in the wintertime, then reach out and touch a metal object. Static electricity is constantly being discharged in the atmosphere, due to thunderstorms and other atmospheric phenomena. – Hot Licks Jun 24 '15 at 2:03
  • Turns out brown noise isn't named for the color, interesting fact en.wikipedia.org/wiki/Brownian_noise – dwjohnston Jun 24 '15 at 2:05
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    I'm getting déjà vu! This question was asked previously, in almost exactly reverse! – Patrick M Jun 24 '15 at 14:05
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The Wikipedia article is, um, not as technically correct as it could be.

FM interstation hiss should not be called static. FM interstation hiss is not really accurate white noise (equal power at all frequencies) either, although it comes close.

True "static" wrt radio reception usually does not happen on FM, at all. (It can, if the source of the interference is extremely strong, or if the FM receiver's "AM rejection ratio" is poor, but this is uncommon.) It happens on AM.

It is indeed caused by discharges of static electricity - hence the name - mostly in the upper atmosphere. This noise was called "static" long before Edwin Howard Armstrong developed FM radio, in a successful quest to vanquish the noise.

The term is apt: If you tune an AM radio to an unused frequency, and then shuffle across the floor and touch a doorknob - or separate two dissimilar fabrics, fresh from the dryer, from each other - or pet a cat - ideally all in cold dry weather - you will produce static discharges (some big enough to see and feel as sparks), and you will hear pops and clicks in the radio speaker that are exactly like the rest of the "static" you hear on AM, except in intensity.

( Heck, Heinrich Hertz first created the first (known) human-generated radio waves in exactly this manner, by making sparks. I say "known" because people have obviously been making static discharges for forever, but we didn't know they produced electromagnetic waves - radio waves - until then. "Spark-gap" transmitters were all we had until rotary alternators came along. (Tesla's patents that are supposedly for "inventing radio" concern the rotary alternator, which was later improved on by Alexanderson.) )

So - why is FM interstation hiss called "static"? In technically correct usage, it isn't. In common use, though, when FM came along, people didn't distinguish between the hiss heard on an untuned FM receiver and the "static" pops and clicks from AM. They just knew that the latter had been called "static", and so in popular usage this was generalized to "noise from a radio receiver (and, later, TV receivers) when tuned to a weak or no station".

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    There are plenty of misconceptions affecting English, while they may be factually incorrect, if we share them, they can aid communication. I can describe a crackling sound on an FM transmission as static and, many people will understand, even though this sound is not caused by static electricity. The origin of a word needn't directly affect is applicability, depending on context. What is right for a physics lesson differs from a poem. – Jodrell Jun 24 '15 at 7:56
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    Just to be overly (and ridiculously) pedantic, Hughes demonstrated a spark gap transmitter and receiver he'd accidentally invented the previous year to the Royal Society years before Hertz. Unfortunately, it was also in 1880, the year before Heaviside's simplification of and the general acceptance of the implications of Maxwell's work, so it was dismissed as simple induction at the time. (And let's face it, Tesla claimed he invented everything in later life, including the Geissler tubes that were created about the time of his first birthday.) – bye Jun 24 '15 at 10:07
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    Another somewhat pedantic remark: even in the original meaning, "static" was not due to static electricity, but to discharges of electricity, which by definition are not static. The electric charge may have been built up in a static manner, but once there is a discharge, it gives a (very brief) electric current. – Marc van Leeuwen Jun 24 '15 at 11:27
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    Your response to the question at issue begins, “FM interstation hiss should not be called static. FM interstation hiss is not really accurate white noise (equal power at all frequencies) either ...", doesn’t actually address the OP's question which is, WHY is the white/pink/brown noise of an FM radio tuned to an unused frequency called 'static' or 'static noise'? We are dealing here with questions of language and its usage, and while I appreciated the quality information conveyed in your response it remains focused on technical matters of electricity. – user98990 Jun 24 '15 at 15:26
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    @LittleEva: I see what you mean. I have added another paragraph to address that explicitly (also in line David Richerby's comment). Thanks! – Jamie Hanrahan Jun 24 '15 at 20:39
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Static noise in a receiver is produced by static electrical charges, i.e., stationary charge, the kind not running in a circuit.

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    Further searching finds the Free Dictionary in agreement: "Interference or noise, such as crackling in a receiver, produced when static or atmospheric electricity disturbs signal reception." – Joe McMahon Jun 24 '15 at 1:25
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    Except that "static" in FM radios isn't caused by static electricity. – David Richerby Jun 24 '15 at 9:01
  • @DavidRicherby Most people who listen to radio are not engineers. To them, all interference seems the same, and the technical cause is hardly relevant. They use the term static to refer to the sound, regardless of the reason. If you asked them what the difference is between AM and FM, most would be hard pressed to answer (except something like "AM is mostly talk radio, FM is music and public radio"). – Barmar Jun 29 '15 at 20:04
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    @Barmar I agree but I think you're missing the point. The question is, why is the noise called static? The answer is not, "Because it's caused by static electricity"; the answer is "Because one kind of it is caused by static electricity and the other kind isn't but it sounds similar enough that we use the same word." I'm not suggesting that people should use a different word for the noise of an untuned FM radio; I'm saying that we should give the correct explanation of why that word is used. The technical cause is 100% relevant to why we use the word "static", which is what was asked. – David Richerby Jun 29 '15 at 20:13
  • @DavidRicherby That's a much better way to say it. Your curt "except that" suggests that the answer given is wrong because it doesn't describe all kinds of static. – Barmar Jun 29 '15 at 20:15
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Why is white noise called 'static'?

OP refers to the sense of static employed in physics, where it represents electrical interference. My intuition is that we refer to noise, or white noise as static because it interferes - disrupts, distorts and obscures - the data or information we are trying to focus on, which is a cause of aggravation.

How static came to be used in this sense I don’t know. I could only find this brief entry on its etymology, but the figurative sense therein seems dispositive.

static (n.) "random radio noise," 1912, from static (adj.). Figurative sense of "aggravation, criticism" is attested from 1926.

etymonline

interference noun: 1. the action of interfering or the process of being interfered with. 2. Physics the combination of two or more electromagnetic waveforms to form a resultant wave in which the displacement is either reinforced or canceled.

• the fading or disturbance of received radio signals caused by unwanted signals from other sources, such as unshielded electrical equipment, or broadcasts from other stations or channels.

synonyms: disruption, disturbance, distortion, static

Google

white noise noun: 1. (General Physics) a. sound or electrical noise that has a relatively wide continuous range of frequencies of uniform intensity. b. noise containing all frequencies rising in level by six decibels every octave.

The Free Dictionary

noise noun: 2. technical irregular fluctuations that accompany a transmitted electrical signal but are not part of it and tend to obscure it.

random fluctuations that obscure or do not contain meaningful data or other information. "over half the magnitude of the differences came from noise in the data"

Google

In general, 'noise' can refer to anything that interferes with what we want: it might be a single voice of someone sitting next to us in a movie.

Any kind of filtered noise signal can be called 'colored noise', which is just to say that it is not a pure white noise. In audio, the most common color encountered is 'pink noise': Realized as sound, white noise sounds like the hiss of an untuned FM radio, or the background noise on a cassette tape player. Because of the particular characteristics of the human ear, the sound of white noise is dominated by the very highest frequencies.

About Colored Noise

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It commonly is referred to as "static" because, as explained in earlier posts, the term has been used regularly in the context of "the sound heard from a radio tuned to an unoccupied channel", it is considerably more concise than that preceding phrase and it is generally understood to have that meaning. In truth, even in the original context of AM radio reception of noise from electro-static discharges, the term "static" is erroneous because in order for a discharge to occur, the (previously) static charge must move and is therefore no longer static. So in the original context, the term "static" was an abbreviation for "electro-static discharge".

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I am pretty sure I have the answer because I remember when I first noticed people mistakenly calling white noise static.

When a CRT TV with a built in analog tuner would have it's antenna disconnected or on a channel with no tower transmitting on that frequency you would hear the white noise and see the black and white scrabbled picture. The TV is unusable in this state so, when people would turn on a TV and encounter this they would often turn the TV off. Turning a CRT TV off make the tube act as a Van de Graaff generator sending positively charge ions to the front of the screen: static. If you touched it with your hand you would then pull these ions into your body which would have more negative ions since you are standing on the ground. As a kids my siblings and I would also sometimes place our heads against the TV to get these ions in our hair to make it stand on it's end. When you touch the TV tube with these ions a faint crackle sound or "static sound" is heard. The static sound was not too different from the white noise you had just heard from the lack of an antenna signal when the TV was on. Thus, the association between white noise, a term not in the vocabulary of the general public (while static was), and the noise of static electricity transfer to a body, was made. Obviously the static sound was a short burst while the white noise is constant, but the association still stuck.

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  • That's a good answer that would be made even better if you could provide a source for the analysis. Do you know of one? – JBH Sep 14 '17 at 19:18
  • It's my personal observation. Others are free to corroborate as to whether or not that was their own experience. – nsputnik Sep 14 '17 at 21:10

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