Latest news with #JukkaTulkki
Yahoo
20-05-2025
- Science
- Yahoo
Scientists May Have Found a Way to Simplify Gravity. It Could Change Physics as We Know It.
Here's what you'll learn in this story. A new paper uses a simplified model to prove that gravity can be unified between quantum and standard physics. The simpler model still meets the established requirements for a robust unified gravity theory. Even if this theory does not prove revolutionary, it shows that new ways of thinking are possible. Two scientists in Finland are claiming to have advanced the cause of a unified theory of gravity, including 'a complete, renormalizable theory of quantum gravity.' Physicists have long tried to mesh gravity with the standard model of physics by, in a sense, comparing like with like—how can we describe gravity using measurable things in a way that aligns with how the standard model describes electromagnetic, weak, and strong forces? The key—according to the duo's new research, which appears now in the peer reviewed journal Reports on Progress in Physics—lies in a particular type of theory called a gauge. A gauge is a way to measure something that is comparable to other things, like India's narrow gauge railways. In physics, gauge theory helps scientists take all the measurable things they know and align them in order to find commonalities or definitions. Using an old English expression, we can define a duck as something that walks like a duck and quacks like a duck. Once something is a proverbial duck, many other properties—like its color, size, or area of origin—can't change its duck-ness. The duck-ness gauge only requires waddling and quacking. In this paper, physicists Mikko Partanen and Jukka Tulkki turn the universe at large into a bunch of overlapping, finite relationships of symmetry that act as microcosms of the entire standard model. They describe a system with eight dimensions, then break it into pieces that each use four of those dimensions. Finally, they write, '[f]our symmetries of the components of the space-time dimension field are used to derive a gauge theory, called unified gravity.' Basically, their goal was to find the mathematically smallest model that could still hold up to all the rules required of a theory of unified gravity (one that unites the standard model and quantum physics). This work finds a middle ground between a simplified 'toy model' and the complexity of a full model of spacetime. One of the keys is that, within a gauge relationship, many terms can simply be canceled out, the same way you may have learned to do in algebra and calculus. Partanen and Tulkki claim that by substituting new (but equivalent) values for parts of their formulae, they've created a gauge model that no longer relies on a contentious variable. 'In contrast to previous gauge theories of gravity, all infinities that are encountered in the calculations of loop diagrams can be absorbed by the redefinition of the small number of parameters of the theory in the same way as in the gauge theories of the Standard Model,' they conclude. In other words, gravity may not need to be as complicated as we've made it—at least, mathematically speaking. A key term in this research is normalization, or renormalization. This is a form of matching reality (and observable qualities within it) to the pure mathematics of a model. Any theory of unified gravity must hold up to how we measure the effects of gravity in our portion of spacetime—or anywhere else in the universe, for that matter. The scientists chose a compact model over a noncompact one, meaning that their model doesn't have any missing pieces that they aren't sure how to categorize. There's no quacking fish or waddling giraffe gumming up the works of what a duck must be. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Yahoo
07-05-2025
- Science
- Yahoo
Breakthrough Gravity Explanation Is a Step Closer to 'Theory of Everything'
Yahoo is using AI to generate takeaways from this article. This means the info may not always match what's in the article. Reporting mistakes helps us improve the experience. Yahoo is using AI to generate takeaways from this article. This means the info may not always match what's in the article. Reporting mistakes helps us improve the experience. Yahoo is using AI to generate takeaways from this article. This means the info may not always match what's in the article. Reporting mistakes helps us improve the experience. Generate Key Takeaways A new way of explaining gravity could bring us a step closer to resolving the heretofore irresolvable differences it has with quantum mechanics. Physicists Mikko Partanen and Jukka Tulkki at Aalto University in Finland have devised a new way of thinking about gravity that they say is compatible with the Standard Model of particle physics, the theory describing the other three fundamental forces in the Universe – strong, weak, and electromagnetic. It's not quite a theory of quantum gravity… but it could help us get there. "If this turns out to lead to a complete quantum field theory of gravity, then eventually it will give answers to the very difficult problems of understanding singularities in black holes and the Big Bang," Partanen says. "A theory that coherently describes all fundamental forces of nature is often called the Theory of Everything. Some fundamental questions of physics still remain unanswered. For example, the present theories do not yet explain why there is more matter than antimatter in the observable Universe." Gravity really is the thorn in the side of a nice, neat explanation of the behavior of the Universe. It's the fourth, and weakest, fundamental force, but doesn't play well with the other three. Quantum theory describes how the physical Universe behaves on really small scales – atomic and subatomic – but it doesn't work with the large-scale Universe, where gravity takes over. Classical physics and general relativity describe gravity really well, but not the quantum realm. So far, the two theories have proven irresolvable; yet, the Universe exists quite merrily with both in it, so scientists believe there has to be a way to make them play nicely. Because the problem has proven so intractable, however, it's likely that it won't be solved all at once, but in incremental, but important, steps. The incremental step Partanen and Tukki have taken is to have described gravity in the context of a gauge – a concept of quantum field theory in which the behavior of particles is described in a specific field. An electromagnetic field is one example of a gauge. So is a gravitational field. "The most familiar gauge field is the electromagnetic field. When electrically charged particles interact with each other, they interact through the electromagnetic field, which is the pertinent gauge field," Tulkki explains. "So when we have particles which have energy, the interactions they have just because they have energy would happen through the gravitational field." A diagram demonstrating the flat space-time of the quantum field and the curved field expected for quantum gravity. (Mikko Partanen and Jukka Tulkki/Aalto University) The Standard Model is a gauge theory that describes the strong, weak, and electromagnetic forces, and it has specific symmetries. To bring gravity theory closer to the Standard Model, Partanen and Tulkki sought to apply those symmetries to a gauge theory of gravity. Their published results seem promising. "Our theory brings the gauge theory of gravity closer to the gauge theories of the Standard Model as compared with the conventional gauge theories of gravity," they write in their paper. It is important to note that the work is very, very far from a theory of quantum gravity. It does, however, represent an important avenue for enquiry that may significantly advance the quest for a solution to this pressing problem in physics. To that end, the Partanen and Tulkki invite other scientists to participate in advancing the work. The paper goes to a certain point, and the theory works well within that limit, but it's going to require a lot more physics and stress-testing. "Full understanding of the implications of unified gravity on the field theories," the researchers write, "will be obtained only after extensive further work." The paper has been published in Reports on Progress in Physics. Related News
