Hubble constant and dark energy
Kirshner, Robert P. Department of Astronomy, Harvard University, Cambridge, Massachusetts.
- Measurement of the Hubble constant, H
- Importance of precisely measuring H
- Using infrared light to measure dark energy
- Dark energy and the cosmological constant
- Links to Primary Literature
- Additional Readings
One great surprise in science was the discovery published in 1998 that the expansion of the universe has been speeding up over the past 5 billion years. This cosmic acceleration is attributed to the effects of a “dark energy” that provides a springy quality to empty space itself, producing faster expansion as time goes by. Astronomers are closing in on a precise measurement of the present rate of cosmic expansion (the Hubble constant), determining how the expansion has changed over the 13.7 billion years since the big bang, and using the results to learn more about the nature of dark energy.
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