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Canada olympic medal totals11/19/2023 ![]() When your TV or radio isn’t tuned into a channel that is brodcasting clearly, it picks up whatever radio transmissions are available and displays those transmissions as the black and white static that is oh-so annoying when you are trying to acrobatically align your TV antenna and stand in just the right place to clearly show your favorite program. Your television antenna is constantly being bombarded by these signals, but when it’s tuned to a specific station the overwhelming intensity of the signal at that frequency makes a crisp picture on your screen, and drowns out everything else. The CMB peaks in the microwave, at around 160 Ghz, but the frequency of CMB photons can be lower than 100 Mhz (.1 Ghz). These analog signals are broadcast between 7-1002 Mhz, and TV tuners are designed to receive in this range. Why does your TV or radio allow you to tune into the Big Bang, however poorly? Analog television signals are basically radio waves that your television picks up, decodes, and turns into an image on your television using what’s called a cathode ray tube (CRT) in older televisions, and in newer TVs, plasma displays. In other words, your TV and radio are telescopes, good for receiving transmissions here on Earth, but really, really bad telescopes for viewing the Universe (a 1:100 signal-to-noise ratio is pretty poor). The same is true for FM radios – when the radio is tuned to a frequency that is between stations, part of the hiss that you hear, called “white noise”, is leftover radiation from the Big Bang some 13.7 billion years ago. ![]() Part of that interference – about 1% or less – comes from background radiation leftover from the Big Bang, called the Cosmic Microwave Background (CMB). Some of the “snow” is from other transmissions here on Earth, and some is from other radio emissions from space. That’s right – when you are between channels on an analog television, the snow that you see on the screen is made up of interference from background signals that the antenna on your TV is picking up. You may be surprised, though, that the change in signal may no longer allow you to see leftover radiation from the Big Bang in the static on your television screen. To those anticipating the higher-quality picture and more reliable signal that this switch will afford, the delay is surely a downer, though some stations may begin broadcasting digital signals before this date. The switch from analog to digital television broadcasting signals in the United States, which was originally scheduled for February 17th, has been postponed until June 12th, 2009.
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