We have been assuming for decades that the expansion of the universe is accelerated by dark energy. A study says it was all a statistical mirage

Astronomers have spent decades trying to unravel the mysteries of subject and the dark energy. However, now a team of scientists from the University of Oxford has launched the most controversial of solutions: There is nothing to look for, because dark energy does not exist. And they have been so hot. Logically, the reactions have not been long in coming. Some researchers believe that it is an interesting solution that is worth continuing to investigate. Others, however, consider that they do not have enough evidence to demolish an entire cosmological model. After all, there are many more signs of the existence of dark energy than those they have been in charge of denying. Supernovas too weak. Dark matter and energy emerged as a solution to the problem of the expansion of the Universe. This is a phenomenon by which galaxies are increasingly distant from each other. But not because they are moving from their place, but because the space between them is widening. Something like that happens with a balloon on which we paint a series of dots. The more the balloon is inflated, the further apart the dots become. Today we don’t just know that the Universe is expanding. We also understand that it is an accelerated expansion, since the speed at which it expands is faster if we measure nearby galaxies than if we focus on points in the Universe closer to the Big Bang. All of this is measured like any speed. Distance between time. The distances are calculated using the Ia supernovae as a reference, since they have a very characteristic brightness that acts as a lighthouse and serves to map the Universe. The authors of the just-published study also used supernovae to make their own calculations, but they focused on one of the most current catalogs available. about them. There, they saw that younger supernovae have a dimmer glow, which could have led scientists to overestimate their distance, giving rise to the misconception that the universe is expanding rapidly. Dark energy as a solution. In fact, according to the Theory of General Relativitywhat is expected it would be that the expansion of the Universe slowed downsince galaxies experience the gravitational pull of their own neighbors and this should act as a brake. It would be something like what happens with the speed of a ball that is thrown upward. Little by little the Earth’s gravity slows it down until it reaches a point where it stops and falls. However, that doesn’t happen. There must be something reversing this effect and that is where dark energy comes into play, since would exert negative pressure which prevents collapse due to this gravitational pull and, in the process, increasingly accelerates the expansion. Now, where does that dark energy come from? Nobody knows, just as nobody has found solid evidence for the existence of dark matter. Supernovas help measure distances in space It’s not the first time. In fact, this team of scientists from the University of Oxford has already gone against the dark energy hypothesis in the past. Initially, they pointed out that the calculations on the accelerated expansion of the Universe would have statistical errors and that, if these were resolved, there would be nothing to solve with the existence of dark energy. However, they did not provide much evidence about these alleged errors. Now, they have shed a little more light with their new study, which is why the controversy has been much more intense. For and against. In statements to New Scientist Bielefeld University astronomer Dominik Schwarz points out that he finds this research very interesting, since it could explain the origin of all the discrepancies that made it necessary to launch the dark energy hypothesis. On the other hand, Joshua Frieman, from the SLAC National Accelerator Laboratory in the United States, tells in the same medium that we have evidence about the acceleration of the expansion of the Universe from multiple sources, including other supernova data sets, measurements of large-scale structure and cosmic microwave background radiation. Therefore, supernova analysis alone does not serve to disprove anything. Logically, more tests will be necessaryboth for and against dark energy. For now, it seems that the defenders of its existence win, while those who believe otherwise continue to be considered controversial. Images | DES Collaboration/NOIRLab/NSF/AURA/M. Zamani | NASA/CXC/Rutgers/G.Cassam-Chenaï, J.Hughes et al.; Radio: NRAO/AUI/NSF/GBT/VLA/Dyer, Maddalena & Cornwell; Optical: Middlebury College/F.Winkler, NOAO/AURA/NSF/CTIO Schmidt & DSS In Xataka | 110 years later, Einstein is still winning bets: the Euclid telescope has discovered a ring in space-time

Serial murderers had their boom in the 80s. Today they are a statistical rarity

If there is a genre of entertainment that has emerged strongly in recent years, that is certainly True Crime. There are series, podcasts and even documentaries made with AI On real crimes. Many of them deal with the stories of dreaded serial killers; Ted Bundy, Jeffrey Dahmer, John Wayne Gacy… They all have their series. However, although serial killers have become a cultural phenomenon, the figures show that their activity was concentrated in a very specific period of time and in a special country. Why are there no serial murderers? An American phenomenon Number of serial murderers per country. Source: Radford University He FBI defined the serial killer as the one who has killed more than two people on two different occasions. According to him Annual series murderers report and victims of the University of Radford of 2020, 67.7% of registered cases came from the United States. There are countries that have registered more than a hundred cases such as Japan, India, South Africa, Canada or England with almost 200 cases. However, we talk that the United States has 3,690 documented cases, while the rest of the countries in the combined list reaches 1,168 cases, the difference is abysmal. Because There are more serial murderers in the United States? A reason is that there is More records and statistics that in other countries, so the real percentage could be biased. The media impact and glorification From some of these murderers it would also have been a determining factor for others to act as imitators. In addition, the ease of geographical mobility within the country facilitated that these profiles could act without being detected. Three decades of “fashion” Cases of serial murderers in the United States. Source: Radford University, Graphic of Vox.com The graph represents the moment in which the murderers began to kill and we see how most of the most notorious cases They are concentrated in a period of three decades. Here the crimes of Ted Bundy, Jeffrey Dahmer, David Alan Gore or Tommy Lynn Sells occurred, to name a few examples. The wave began to rise in the late 50s, when the criminal records were improving, rose radically in the 70s and reached its peak in the 80s. According to IFL Sciencein the 80s there were 254 active serial killers, with its maximum peak in 1987 where there were more than 400 victims. In the 90s the figure dropped to 227 active murderers. The trend was falling pronounced and in the 2010 only 66 cases were recorded. Why there are no serial murderers Researchers blame the decline of serial murderers to several factors, especially related to Advances in criminal investigation. Police records are more exhaustive and communication between the different security forces is better. This allows to find similarities in cases and facilitate the identification of possible serial profiles. Research methods are more sophisticated. The DNA test It began to be used in cases of murders In the mid -80sbut the first techniques were more rudimentary, the analysis took a long time and there was not a wide database to compare. Technological advances are another determining factor. The presence of Security cameras In shops and public places he has helped resolve countless crimes worldwide. For example This study He concluded that the British transport police could increase its crime resolution rate from 23 to 48% thanks to the security cameras material. The Internet searches They have also been decisive in many cases, such as Brian Walshethat when his wife disappeared he looked on Google “how much time passes until a body begins to smell” and “10 ways to get rid of a corpse.” This, together with images of the suspect buying cleaning material and an ax in Home Depot, led to their arrest for murder. But perhaps everyone’s greatest advance has been mobile telephony. In addition to the images of the cameras, the triangulation of the signal of mobile phones It allows to locate both the suspects and the victims, being able to reconstruct their movements. Mobiles are key tools in many investigations and we have seen it in notable cases such as Asunta Basterrahe Urban Guard Crime or that of Diana Quer. The decline of serial killers coincides with a Generalized fall of violence since the 90sbut without a doubt all advances in research and technology have made it easier for today to catch the culprits. In potential serial murderers, in many cases They do not commit a second crime. Cover image | Netflix In Xataka | A person has made Media Spain hook the most horrendous crimes: Clara Tiscar and ‘Criminopathy’

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