Dark Energy is ahypothetical form of energy that exerts a negative, repulsive pressure, behaving like the opposite of gravity. It has been hypothesised to account for the observational properties of distant type Ia supernovae, which show the universe going through an accelerated period of expansion.
People also ask
What is the nature of dark energy?
The remaining portion of the universe consists of ordinary matter and dark matter. Dark energy, in contrast to both forms of matter, is relatively uniform in time and space and is gravitationally repulsive, not attractive, within the volume it occupies. The nature of dark energy is still not well understood.
How much of the universe is dark matter and energy?
By fitting a theoretical model of the composition of the universe to the combined set of cosmological observations, scientists have come up with the composition that we described above, ~68% dark energy, ~27% dark matter, ~5% normal matter. What is dark matter? We are much more certain what dark matter is not than we are what it is.
How does dark energy affect the expansion of the universe?
Since dark energy works against gravity, more dark energy accelerates the universe鈥檚 expansion and retards the formation of large-scale structure. One technique for measuring the expansion rate is to observe the apparent brightness of objects of known luminosity like Type Ia supernovas.
How can we measure dark energy’s power?
Some researchers have measured dark energy’s power using the cosmic microwave background, a dim echo of the Big Bang, and produced one estimate. But other astronomers, who measure dark energy’s strength using the light of distant cosmic objects, have produced a different value, and nobody has yet been able to explain the discrepancy.