Which is evidence for the existence of dark energy?(1 point) Responses Galaxies that are rotating at a constant rate. Galaxies that are rotating at a constant rate. Black holes that are expanding at a constant rate. Black holes that are expanding at a constant rate. Pulsars that seem to be moving closer at an accelerating rate. Pulsars that seem to be moving closer at an accelerating rate. Supernovae that are moving away at an accelerating rate.
Supernovae that are moving away at an accelerating rate.
The evidence for the existence of dark energy is the observation that supernovae are moving away at an accelerating rate.
The evidence for the existence of dark energy comes from multiple observations and measurements in cosmology. One of the strongest pieces of evidence is the observation of supernovae that are moving away at an accelerating rate. This discovery was made in the late 1990s by two independent research teams.
To obtain this evidence, astronomers studied the brightness and redshift of supernovae, which are exploding stars. They expected that the expansion of the universe would cause the distant supernovae to appear dimmer and have a higher redshift (indicating they are moving away). However, what they found was that these supernovae were even dimmer and had a higher redshift than what was predicted based on the known theories of the universe's expansion.
This discrepancy led scientists to propose the existence of an unknown force, called dark energy, which is responsible for the acceleration of the universe's expansion. Dark energy is believed to make up a large portion of the total energy content of the universe, but its exact nature remains a mystery.
It's important to note that the other options you mentioned, such as galaxies rotating at a constant rate, expanding black holes, and pulsars seemingly moving closer at an accelerating rate, are not evidence for dark energy. These phenomena may have different explanations within the framework of known physics.