Now, a new investigation shows that dark matter – the elusive and invisible material that makes up most of the material in the universe – may behave like normal matter when reacting to the pull of gravity. For decades, scientists have debated whether dark matter might obey the same physical laws that govern stars, planets, and all other visible matter in the universe.

Taking a cue from our vast universe, where galaxies appear to be swirling inside giant cosmic structures in which dark matter appears to sink into gravitational wells in the same way that normal matter sinks, a group led by the University of Geneva tested whether this is true even on smaller scales and found that it mostly does, closing that long-standing mystery. Dark matter probably obeys gravity, but the mystery force has yet to be ruled out.

According to a report based on the findings published in Nature Communications, researchers studied the motion of galaxies to determine whether dark matter is affected only by gravity or perhaps some unknown force is involved. Camille Bonvin at the University of Geneva said measurement theory and galaxy velocities, when related to gravitational depth, could be used to find out whether such a ‘fifth force’ exists for dark matter.

The research did not find any solid evidence that such force would have much effect on it. Dark matter obeys known physics such as Euler’s equation, but any additional force must be extremely weak – about 7 percent under the strength of gravity.

Future LSST and DESI data may identify microscopic forces as weak. Researchers suggest that the strength of gravity is 2 percent. Scientists say upcoming observations may eventually uncover the true nature of dark matter and any hidden cosmic forces influencing the universe.