How come the white and black snow we see sometimes on TV is a result of the Big Bang? (the cosmic radiation)

I meant the random dot pixel pattern of static in TVs, when there is no signal.

  • $\begingroup$ What do you mean by the term TV snow? $\endgroup$ – physics2000 Mar 19 '18 at 14:39
  • $\begingroup$ @physics2000 Skip to 2:09 of this video youtu.be/1HBkZPyfpdE $\endgroup$ – ClassicEndingMusic Mar 19 '18 at 16:45
  • $\begingroup$ What we used to call "the ant races" when I was a kid. $\endgroup$ – Solomon Slow Mar 19 '18 at 17:00
  • $\begingroup$ Nah! Snow was around since I was a kid, but The Big Bang Theory has only been around since 2007. $\endgroup$ – Hot Licks Mar 19 '18 at 18:43
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    $\begingroup$ @hotlicks, physics laugh: R dR dR dR (sometimes includes dtheta) $\endgroup$ – niels nielsen Mar 19 '18 at 21:31

This is because a significant amount of the relic radiation of the big bang lies in the radio frequency range used to transmit TV picture information, on old-style analog television sets. That radiation is picked up by the TV's antenna and presented to its circuitry as if it were part of the picture signal. Since the big bang signal is random, the image of it that your TV produces consists of random dark and light spots that jump around in random positions on the screen, which radio engineers refer to as "snow" because when superimposed on a regular TV transmission, it appears as if it is snowing in the image.

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    $\begingroup$ But the CMB is not the major component of noise in an analog TV, correct? Back in my days as a TV repairman (both tube and solid state), I saw 'snow' on the screen even with the antenna input terminals shorted across. Most of this noise was, I believe, thermal noise generated by the very high gain RF amplifier. $\endgroup$ – Alfred Centauri Mar 20 '18 at 0:38
  • $\begingroup$ estimates vary, but approx. 10% to 20% of TV snow is CMB. $\endgroup$ – niels nielsen Mar 20 '18 at 2:05

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