Slide 1
The cosmic microwave background is not light from the first instant
The cosmic microwave background is ancient light from a particular early stage of the universe. It is not an image of the very first instant.
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The cosmic microwave background comes from an early stage of the universe, roughly 380,000 years after its beginning in the standard cosmological account. It is extraordinarily old light, but it does not show the first instant.
Slide 2
Neutral atoms let early light travel more freely
Early light repeatedly scattered from charged particles in hot plasma. As neutral atoms formed, light could travel much more freely.
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Earlier, light repeatedly interacted with the hot plasma filling the universe. As conditions changed and neutral atoms formed, photons could travel much more freely. That transition explains why the background radiation provides a view of this particular epoch.
Slide 3
The radiation preserves an early temperature pattern
Small temperature variations in the cosmic microwave background preserve information about the early universe.
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The CMB reaches us as microwave radiation. Its small temperature variations preserve information about differences in the early universe. Interpreting that information requires measurement and physical models, rather than treating each colored region as a directly photographed object.
Slide 4
Planck’s map colours represent measured differences
Colors in a Planck cosmic microwave background map encode tiny temperature differences, not the visible appearance of the young universe.
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A Planck CMB map uses colors to show tiny temperature differences. Those colors are not the visible appearance of the young universe. The scale and processing context belong with the map because they explain what the apparent pattern actually encodes.
Slide 5
The view is of an early stage, not an outer edge
The cosmic microwave background is evidence from an early transparent universe, not a picture of an outer edge.
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The CMB is evidence from an early transparent universe, not a picture of the universe's edge or proof of every cosmological claim. Its value becomes clearer when the date, measurement and limits remain attached to the image.