Do you know that “half full or half empty glass” story?
It applies to a recent experiment conducted in an attempt to detect dark energy, one of the mysteries about the universe that most puzzles scientists. The tests came to nothing, but instead of simply being shelved, research can serve to limit researchers’ options and make later studies more assertive in their quest for enigmatic strength.
Where’s the energy, guys?
As you may know, the universe is constantly expanding – although theoretically it should be involuting and drawing everything into its center because of the action of gravity. However, this is not what has been observed and, to explain this curious contradiction, astrophysicists have suggested the existence of a force that opposes the gravitational force, the so-called “dark energy”.
Scientists theorize that this force is a property inherent in the cosmos itself, and as it expands and more space is created, more dark energy would emerge in the universe. So much so that, according to forecasts and estimates, more than 70% of the universe would be composed of this force. However, to this day no one has been able to detect the presence of dark energy in order to prove its existence.
Did not work…
The experiment we are talking about now (and it came to nothing …) is just one of many, where researchers at Imperial College London and the University of Nottingham, both institutions in England, tested a model based on “5th force” theory, that is, the idea that dark energy would be an extra force that interacts with matter, beyond the 4 known ones – which would be electromagnetic, gravitational, and strong and weak nuclear.
Since, according to this theory, the 5th force should be hidden or blocked by matter. In the cosmos, it would travel through a vacuum and be obstructed by large bodies such as stars and planets. For example – so British researchers recreated an environment similar in the lab to try to detect dark energy.
The team placed a small metal sphere in a vacuum chamber and released atoms to fall freely into the space. Scientists also used an atomic interferometer to see if any forces would interact with the particles. The expected, if there was a 5th force, is that the atoms would deviate slightly as they passed the metal sphere, but the team saw nothing – and the particles fell as they should when exposed only to the 4 known forces.
Boring, right? But do you know what we commented about the story of the “half full or half empty” glass? Although the experiment did not solve the dark energy mystery, the researchers said; The experiment had its positive side, since at least they know that this theory put to the test can now be crossed out of the list of alternatives and scientists may focus their attention on exploring other possibilities.
Radial Acceleration Ratio
Enrico Garaldi and his colleagues used one of the fastest supercomputers in the world to simulate the distribution of matter from; So-called dwarf galaxies, or satellites, small galaxies that surround the Milky Way or Andromeda, for example.
They focused on a relationship known as the “radial acceleration ratio” (RAR). In disk galaxies, stars move in circular orbits around the galactic center. The acceleration that constantly forces them to change direction to rotate is caused by the attraction of matter in the galaxy. RAR describes the relationship between this acceleration and the acceleration caused by visible matter only. Providing a hint about the structure of galaxies and their distribution of matter.
“We now simulate, for the first time, the RAR of dwarf galaxies with the assumption that dark matter exists. It turns out that they behave as small versions of the larger galaxies,” says team member Professor Cristiano Porciani. Astronomers have been observing for years that these satellite galaxies challenge the most widely accepted theories.