Dark Energy May Be Devouring All the Dark Matter in the Universe
We've never been able to confirm a direct observation of dark matter, but someday it may be a moot point, as a new study shows that dark energy is gradually consuming all the dark matter in the universe.
Dark matter is a type of matter that only minimally interacts with matter that is detectable to humans. It does not emit or absorb light, so cannot be seen, but gravitational effects on regular matter have led scientists to conclude that there is five times more dark matter than regular matter in the Universe. Dark energy is a force that is opposed to gravity, and makes up almost 70% of the Universe. Dark matter provides a scaffolding for cosmic structures, such as galaxies and galaxy clusters, to form, while dark energy is thought to precipitate the expansion of the Universe. Understanding the interaction between the two could have enormous implications for our conception of the future of the Universe.
According to David Wands, director of the Institute of Cosmology and Gravitation at the University of Portsmouth and leader of the study, "On a cosmic scale, this is about our Universe and its fate."
The current predominant model of dark matter and energy in the scientific community, called the Lambda Cold Dark Matter model, asserts that there is a static amount of dark energy in the Universe, known as the "cosmological constant." But physicists have been observing for some time now that certain data, notably the data collected by the Planck satellite, is inconsistent with the cosmological constant model, leading Wands and his colleagues to consider the possibility that the amount of dark energy in the Universe is actually variable. Using this data and data from other recent experiments, the research team built a model of the Universe that they believe accounts for many discrepancies, particularly the fact that cosmic structures do not seem to be growing at the predicted rate. According to this new model, the amount of dark energy is increasing as it consumes dark matter. The increase in dark energy would explain the accelerating rate of the expansion of the universe, while the decrease in dark matter explains the slower growth of cosmic structures.
Wands said in a statement, "Dark matter provides a framework for structures to grow in the Universe. The galaxies we see are built on that scaffolding and what we are seeing here, in these findings, suggests that dark matter is evaporating, slowing that growth of structure."
The results were published in Physical Review Letters, a peer-reviewed journal, but they still need to be confirmed by comparisons to more data in order to be accepted by the scientific community. However, Professor Dragan Huterer of the University of Michigan, urges physicists to take this study seriously: "The paper does look very interesting. Any time there is a new development in the dark energy sector we need to take notice since so little is understood about it. I would not say, however, that I am surprised at the results, that they come out different than in the simplest model with no interactions. We've known for some months now that there is some problem in all data fitting perfectly to the standard simplest model."
If the findings are, in fact, true, then what does this mean for the future of our universe? Since dark matter provides the framework necessary for galaxies and other structures to form, the Universe will decrease in complexity until it is virtually an empty space. According to Wands, "If the dark energy is growing and dark matter is evaporating we will end up with a big, empty, boring Universe with almost nothing in it."