Digest of sci-fi news for the week, about which we did not write anything
Space is expanding at an ever-increasing rate. This cosmic acceleration is caused by dark energy and is a central aspect of the evolution of our universe. The rate of cosmic expansion can be expressed in terms of the cosmological constant, commonly known as the Hubble constant, or the Hubble parameter.
There are many ways to measure the Hubble parameter, but in general they fall into two categories. One general method uses the CMB, while the other considers distant supernovae. There is a third approach, using astrophysical masers emitted by the accretion disks of black holes, but so far it has not been very well developed. Unfortunately, the two described very good, very accurate measurements of the cosmic expansion give different results. The accuracy of these results is high enough that we now know that one or both of them must be wrong.
And recently, a group of researchers introduced fourth approach. It includes a supernova and some gravitational lensing. If there is a galaxy between us and a distant quasar, then the light from the quasar is distorted, passing near the galaxy so that we see several images of the distant object. Since the different lensing paths around the galaxy have different lengths, we see each quasar image slightly shifted in time. The difference can be tens or hundreds of years, which is negligible for quasars. But in the case of a relatively active process, like a supernova explosion, gravitational lensing could allow us to observe the same supernova multiple times.
Group of theoretical physicists predicted the possibility of the appearance of an unusual feature of space-time, which for an outside observer will look like a black hole, but upon closer examination will turn out to be a defect in the very fabric of the Universe.
Einstein’s general theory of relativity predicts the existence of black holes formed when giant stars collapse. But the same theory predicts that at their centers there are singularities, that is, points with infinite density. Since we believe that infinite density cannot exist in the universe, we take this as a sign that Einstein’s theory is incomplete. But after nearly a century of searching for extensions, we still haven’t found a better theory of gravity.
But we have candidates, including string theory. In string theory, all particles in the universe are actually microscopic vibrating loops of a string. In order to provide the full range of particles and forces that we observe in the universe, these strings cannot simply vibrate in our three spatial dimensions. Instead, there must be additional spatial dimensions that collapse on their own into manifolds so small that they elude everyday detection or scientific experimentation.
These are known as ultrafast jets, powerful cosmic winds emitted by supermassive black holes at the centers of active galactic nuclei, or quasars. These winds move at close to the speed of light and in turn influence the behavior of supermassive black holes during their active phase.
These gaseous outbursts are believed to fuel the process of star formation in galaxies, but they are not yet well understood. Astronomers are interested in learning more about them in order to improve our understanding of what drives galactic evolution.
This goal is served by the SUper massive Black hole Winds in the x-rAYS (SUBWAYS) project, an international study dedicated to the study of quasars using the ESA XMM-Newton space telescope.
The first results of this project shared a group of scientists led by the University of Bologna and the National Institute of Astrophysics (INAF) in Italy. In a paper describing their findings, the team presented X-ray spectroscopic data characterizing the properties of ultrafast outflows in 22 luminous galaxies.
What does the inside of a carbon atom look like? New research, conducted by the Forschungszentr Jülich, Michigan State University and the University of Bonn, provides the first definitive answer to this question. During the study, scientists simulated all known energy states of the nucleus.
Among them is the mysterious state of Hoyle. If it did not exist, then carbon and oxygen would be present in the Universe only in trace amounts. Ultimately, we also owe our existence to him. The results of the study are published in the journal Nature Communications.
People trying to shed pounds often reduce their calorie intake by drinking diet drinks, artificially sweetened treats, and other foods that contain sugar substitutes. However, according to a new World Health Organization assessment, these artificial sweeteners are ineffective for weight control and, worse, increase long-term risk of type 2 diabetes, cardiovascular disease, and even death.
IN published recent WHO guidance recommends against the use of artificial sweeteners for weight control or overall health. The recommendation applies to healthy children and adults, but is not intended for people with pre-diabetes who may still benefit from the use of artificial sweeteners.
“Replacing free sugars with non-sugar sweeteners does not help manage weight in the long run. People need to consider other ways to reduce their intake of free sugars, such as eating foods with naturally occurring sugars, such as fruits, or unsweetened foods and drinks,” Francesco Branca, WHO Director of Nutrition and Food Safety, said in a statement. “People need to comprehensively reduce the amount of sugar in the diet, starting at an early age to improve their health,” he added.
Scientists are not only trying to find a cure for Parkinson’s disease, but also looking for the best ways to detect the disease early and contain its development.
Now new tool, which can be quickly launched on a typical laptop, uses artificial intelligence to detect key signs of illness years before symptoms such as tremors and slow movements appear. It is called CRANK-MS: Classification and Ranking Analysis using a neural network generating knowledge from mass spectrometry.
Using machine learning, the tool looks for specific chemical compounds (metabolites) in the blood, identifying patterns that could potentially predict or protect against disease.
