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What did WMAP measurements reveal about the early universe?
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The Wilkinson Microwave Anisotropy Probe (WMAP) provided transformative insights into the early universe by mapping irregularities in the cosmic microwave background (CMB).1
Key findings from WMAP include:
- Density Variations: The probe detected temperature fluctuations of 0.0002 K, which represent sound waves echoing through the dense universe approximately 380,000 years after the big bang. These variations indicate where matter eventually coalesced to form modern stars and galaxies.1
- Age and Composition: WMAP determined the age of the universe to be 13.8 billion years. It also measured the early universe's composition as 63 percent dark matter, 12 percent atoms, 15 percent photons, and 10 percent neutrinos.1
- Cosmic Evolution: The mission confirmed that the first stars formed half a billion years after the big bang and discovered a cosmic background of neutrinos.1