Dark Energy

Dr. Fred Raab

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Three types of measurements…

Relic Light from Big Bang Imaged by WMAP satellite

showing structure of infant universe

13,000,000,000 years ago Sloan Digital Sky

Survey of one million galaxies showing walls and voids of

universe over billions of light years

Supernova distance/brightness measurements extending out to billions of light years

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The big surprise: thinking before and after 1998

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Cosmic Convergence: 3 lines of evidence tell the same tale

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Parting thoughts

• Three independent lines of evidence agree that:» Expansion of universe is accelerating

» About 25% of the density of “stuff” in the universe is made of matter

» Most of the matter is “dark matter”, unlike any other form of matter discovered to date

» About 75% of the density of “stuff” in the universe is “dark energy”, unlike any other form of energy discovered to date

» “Dark energy” powers the accelerating expansion of the universe.

Is the universe blowing up?

Stay tuned…