The new study confirms that gravity works as predicted by Isaac Newton and Albert Einstein. Dark matter does indeed exist, scientists assert.
Gravity for most people is the force that pulls everything, including us, towards the surface of the Earth. But for physicists, gravity is a phenomenon that shapes the form and evolution of the largest structures in the universe. Astrophysicists conducted a large-scale study of gravity in vast cosmic structures and found that it behaves exactly as the long-established laws of physics predict. This research confirms that dark matter, which holds galaxies together, indeed exists, writes Focus.
Scientists from Pennsylvania State University used data from the Atacama Cosmology Telescope to study the movement of galaxy clusters at enormous distances. For decades, scientists have observed unusually rapid movement of galaxies in galaxy clusters, suggesting that gravity may act differently than predicted by Isaac Newton and Albert Einstein.
According to the scientists, it was surprising not only the movement of galaxies but also the rapid movement of stars within them. These objects are moving too fast for the amount of mass they contain. Therefore, two opposing theories arose: either there is an invisible dark matter in the universe that creates additional gravity, or the existing theory of gravity by Einstein needs to be modified.
Now physicists have conducted a study of gravity in galaxy clusters separated by hundreds of millions of light-years, making it the largest study of gravity to date.
The results show that gravity weakens with distance according to the inverse square law, first described by Newton and later incorporated into Einstein's general theory of relativity, which is the best description of gravity. The inverse square law states that gravity weakens in proportion to the square of the distance between objects with mass.
The findings refute alternative theories of gravity that suggest that at very large scales, gravity behaves differently than Einstein predicted. This research confirms that the invisible component of the universe, dark matter, does exist and shapes cosmic motion.
Physicists say that galaxies in the universe move differently than they should according to gravity alone. Their movement is influenced by dark matter through additional gravity.
To reach such conclusions, astrophysicists analyzed subtle distortions of the cosmic microwave background radiation. This light emerged about 380,000 years after the Big Bang and has been spreading through the universe ever since. When this light passes through massive galaxy clusters, it is distorted by their movement, leaving traces that scientists can detect.
The results matched precisely with the theories of Newton and Einstein, showing no evidence that gravity weakens differently than expected at vast cosmic scales.
By extending gravity tests to distances far exceeding the scale of individual galaxies, the study provides one of the most comprehensive confirmations of the standard cosmological model to date.
Essentially, Newton and Einstein correctly described gravity at different scales, and there is no need to change the general theory of relativity, physicists say, while the additional gravitational pull is created by dark matter, though it remains unclear what it is made of.
