This image unveiled March 21, 2013, shows the cosmic microwave background (CMB) as observed by the European Space Agency's Planck space observatory. Among the discoveries: The universe is older than ...

The cosmic microwave background can help scientists piece together the history of the universe. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

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Temperature fluctuations on the microwave sky may be expressed as a sum of spherical harmonics, just as music and other sounds may be expressed as a sum of ordinary harmonics. A musical note is the ...

Sound of space: interstellar mission reveals previously undetected background noise New data sent back from Nasa’s Voyager 1 probe shows that interstellar space hums with a sound like gentle rain ...