For close on a century, scientists have speculated that the universe contains more matter than can be straightforwardly watched, known as dark matter. They have also observed the presence of a dark energy that is more effective than gravitational fascination.
Both theories have been the subject of debate that accounts for the movement of stars in galaxies and for the accelerating expansion of the universe respectively. But according to scientists at the University of Geneva (UNIGE), both of the concepts may be no longer valid.
Their new study based on the scale invariance of the empty space, potentially solving two of astronomy’s greatest mysteries.
In 1933, the Swiss cosmologist Fritz Zwicky made a revelation that left the world astounded. He suggested there is actually substantially more matter in the universe than we can actually see. This matter is nothing but the dark matter. Later on, the concept more likely to gain more importance.
In 1970, a US astronomer Vera Rubin explained the movements and speed of the stars. Next scientists started to find out different resources for identifying dark matter – in space, on the ground and even at CERN – but without success.
However, in spite of the enormous resources that have been implemented, no theory or observation has been able to define this dark energy that is allegedly stronger than Newton’s gravitational attraction.
In other words, dark matter and dark energy are still two mysterious concepts.
André Maeder, honorary professor in the Department of Astronomy in UNIGE’s Faculty of Science said, “The way we represent the universe and its history is described by Einstein’s equations of general relativity, Newton’s universal gravitation, and quantum mechanics. The model-consensus at present is that of a big bang followed by an expansion.”
“In this model, there is a starting hypothesis that hasn’t been taken into account, in my opinion. By that I mean the scale invariance of the empty space; in other words, the empty space and its properties do not change following a dilatation or contraction.”
He further explained, “The unfilled space assumes a primordial part in Einstein’s conditions as it works in an amount called the cosmological constant. The resulting universe model depends on it.”
Now, based on this model, scientists are further examining the model of the universe, pointing out that the scale invariance of the empty space is also present in the fundamental theory of electromagnetism.
While testing their model, scientists found that the model predicts the accelerated expansion of the universe without having to factor in any particle or dark energy. It suggests dark energy may not actually exist since the acceleration of the expansion is contained in the equations of the physics.
During another session, scientists focused on Newton’s law of general relativity. The law is also slightly modified when the model incorporates this hypothesis.
Applying this law on clusters of galaxies leads to masses of clusters in line with that of visible matter. Means, no dark matter is needed to explain the high speeds of the galaxies in the clusters.
The law also predicted that the high speeds reached by the stars in the outer regions of the galaxies (as Rubin had observed), without having to turn to dark matter to describe them.
According to scientists, this discovery could pave the way for a new conception of astronomy, one that will raise questions and generate controversy.
André Maeder said, “The announcement of this model, which at last solves two of astronomy’s greatest mysteries, remains true to the spirit of science: nothing can ever be taken for granted, not in terms of experience, observation or the reasoning of human beings.”