Redshift is when an object moves away from an observer, for the past 90 years it has been measured. Unexpected dimness was detected from one of the most distant galaxies! In the 1990s, dark energy was proposed to explain this phenomena but Astronomers are unable to observe dark energy directly but use it to explain a force that is thought to be responsible for the accelerating pace of the expansion of the universe.
Physorg made an announcement that dark energy though unable to be observe directly has been measured with more precision than ever before by astronomers using the SLAC National Accelerator Laboratory.
“By combining their observations of galaxy clusters with other cosmological data, the scientists made the most precise dark energy measurements to date. The new measurements are consistent with the simplest model, in which dark energy is a “cosmological constant”—an energy field that is uniform throughout space and time. The idea of a cosmological constant was introduced by Albert Einstein in 1917, but soon fell out of favor. In recent years, the idea has become popular again as a way of explaining the accelerating expansion of the universe.”
“The observations also weigh against so-called “modified gravity” models, in which gravity is either stronger or weaker than predicted by Einstein’s Theory of General Relativity. The new results show that the growth of cosmic structure is consistent with the predictions of General Relativity, supporting the view that dark energy drives cosmic acceleration.”
What is being measured is X-ray emissions from galaxy clusters which is then combined with a theoretical model of dark energy. Light can be measured, but darkness? No, it cannot be measured. On another theoretical entity, Nature published an interesting debate on whether or not dark energy is a mystery which some scientists believe that 5 percent is observed and understood while 95 percent is not observed and understood. Other scientists believe it’s no mystery at all…
“We must demand more of cosmology than just piling on components or constants to a model to reproduce observations. Otherwise, we would still happily be adding epicycles to the Ptolemaic model of planetary motion. Cosmological models, along with their constants and components, must be grounded in laws of nature that we understand. The magnitude of the cosmological constant cannot currently be explained by any physics we know. Until it is, it is a mystery.”
I must applaud the comment above even though I disagree with his conclusion about the universe! The approach of studying a “Theoretical Entity” like dark matter and dark energy is not good science. There is a saying, “for every complicated physical phenomenon there is a simple, wrong explanation.” –astronomer Tommy Gold. Giving labels like “cosmological constant” to things in the universe they don’t understand themselves with no natural laws doesn’t make the science any better! It suggests a contest to see who can invent a concept that goes beyond experience then gets popularized so it could be deemed as factual. In reality, if creation scientists would be doing stuff like this, they would be laughed at.