Researchers show for the first time that gravity can exist without mass

Dark matter is a theoretical type of matter that scientists believe exists due to gravitational effects that cannot be explained by current theories of gravity unless there is more invisible matter in the universe. This idea has been around for almost a century and was first proposed by Dutch astronomer Jan Oort in 1932 to explain the “missing mass” required for the formation and cohesion of galaxies.

Dr. Richard Lieu of the University of Alabama in Huntsville has proposed a new theory that explains gravity without requiring dark matter. He argues that gravity can exist without mass, which could challenge current understanding of dark matter.

Dr. Lieu’s research focuses on finding alternative solutions to the equations of general relativity. He suspects that the extra gravity required to hold galaxies and galaxy clusters together may come from shell-like structures known as topological defects, which likely formed during a significant change in the state of matter in the early universe.

In summary, it can be said that Dr. Lieu’s theory does not suggest the need for dark matter to explain the extra gravity, but rather that this gravity could come from these cosmic structures that arose during the formation of the universe.

Lieu says: “It is currently unclear what exact form of phase transition in the universe could lead to topological defects of this type. Topological effects are very compact regions of space with a very high density of matter, usually in the form of linear structures known as cosmic strings. But 2D structures such as spherical shells are also possible.”

“The shells in my work consist of a thin inner layer of positive mass and a thin outer layer of negative mass; The total mass of both layers – which is all that can be measured in terms of mass – is exactly zero, but when a star lies on this shell, it experiences a large gravitational force that pulls it toward the center of the shell.”

The gravitational force influences the fabric of space-time and allows objects to interact regardless of their mass. For example, it is known that massless photons (light particles) are affected by the gravity of astronomical objects.

Dr. Lieu explains this Light can bend around concentric shells in a galaxy or galaxy cluster, causing it to bend slightly inward as it passes through each shell. The cumulative effect of penetrating many shells results in a measurable deflection that can mimic the gravitational effects typically attributed to dark matter. This is similar to the way we measure the strength of gravity using the orbits of stars.

Dr. Lieu argues that these shells may be massless, meaning we may not need to look further for dark matter to explain the observed gravitational effects.

Future research will likely examine how galaxies or clusters form from these shells and how these structures evolve over time.

Lieu concludes: “This article does not attempt to address the problem of structure formation. A point of debate is whether the shells were originally planes or even straight strings, but angular momentum winds them up. The question also arises as to how the proposed grenades can be confirmed or refuted through targeted observations.”

“Of course, the availability of a second solution, even if very powerful, is not enough on its own to discredit the dark matter hypothesis – at best it could be an interesting mathematical exercise.” But it is the first evidence that gravity exists without Mass can exist.”

Magazine reference:

1. Richard Lieu. The binding of cosmological structures through massless topological defects. Monthly Notices of the Royal Astronomical Society. DOI: 10.1093/mnras/stae1258