Scientists’ opinion: Gravity can exist without mass

A recently published paper proves that even objects and structures that have no mass can generate gravitational force. This means that the rotation features of galaxies can be explained without dark matter. However, this raises many new questions.

Gravity can exist without mass. Source: phys.org

Gravity without mass

It is generally believed that gravity cannot exist without mass. After all, it is a fundamental feature of the latter. However, Richard Lieu at the University of Alabama in Huntsville has recently published a paper proving that this force can occur even when there is actually no mass.

If it really turns out to be as he tells us, it will greatly change our whole view of the universe. Because it will turn out that the elusive particles of dark matter will no longer have to be searched for. Because they’ll be unnecessary.

To date, the existence of this exotic type of substance has not been proven by any direct observation. However, the available motion and rotation of galaxies cannot be explained by considering only the gravitational forces produced by ordinary matter.

What a new theory says

In his paper, Lieu attempted to find a new solution to the gravitational equations from the general theory of relativity. He worked with their simplified version, known as the Poisson equation, and applied it to galaxies and their clusters. And it was they who gave him a possible alternative answer.

The researcher argues that the source of additional gravitational force, which is necessary to give galaxies the appearance they have, may be topological defects that arose at the dawn of the universe. Usually these include linear structures like strings, which have a thickness less than the nucleus of an atom, but a length of tens and hundreds of light years.

However, Lieu’s research has shown that there may be concentric topological space defects that arose during the phase transition. They are a kind of bubble, they have positive mass on the inside and negative mass on the outside, so overall they have none. However, they create a gravitational field.

These concentric anomalies of space are so large that stars can literally lie on top of them. And they give galaxies and their clusters the look we’re used to. The researcher admits that his theory, although it eliminates the need to search for dark matter, creates even more questions.

On his own, he can’t explain the phase transition that was supposed to create the spatial anomalies. And he doesn’t say how to prove their existence. Gravity remains one of the most mysterious forces in the universe.

According to phys.org