It doesn't interact with baryonic matter and it's completely invisible to light and other forms of electromagnetic radiation, making dark matter impossible to detect with current instruments. But scientists are confident it exists because of the gravitational effects it appears to have on galaxies and galaxy clusters.
Thereof, is dark matter the ether?
According to theory, dark matter is the invisible mass that accounts for this behavior, and the undetectable substance makes up five times more of the universe than the matter we can see. Starkman's controversial counterproposal is that the presence of ether in the universe better explains the galaxies' behavior.
When did we discover dark matter?
The first to suggest the existence of dark matter, using stellar velocities, was Dutch astronomer Jacobus Kapteyn in 1922. Fellow Dutchman and radio astronomy pioneer Jan Oort also hypothesized the existence of dark matter in 1932.
How is dark energy affecting the universe?
The curve changes noticeably about 7.5 billion years ago, when objects in the universe began flying apart as a faster rate. Astronomers theorize that the faster expansion rate is due to a mysterious, dark force that is pulling galaxies apart. One explanation for dark energy is that it is a property of space.