#physics-fundamentals

#physics-fundamentals

During the pandemic, many researchers expressed reluctance to share their ideas for fear of professional repercussions, such as losing credibility or funding. This culture of silence is particularly detrimental in critical situations like a pandemic, where new ideas could save lives.

For more than two millennia, mathematicians have produced a growing heap of pi equations in their ongoing search for methods to calculate pi faster and faster. The pile of equations has now grown into the thousands, and algorithms now can generate an infinitude. Each discovery has arrived alone, as a fragment, with no obvious connection to the others. But now, for the first time, centuries of pi formulas have been shown to be part of a unified, formerly hidden structure.

A core question we want to understand is where did matter come from. And then, if you know about antimatter, it's natural to ask, why is that not here? The process is not understood and we are hunting for clues as to why it happened, says Dr Christian Smorra, a physicist on the Baryon Antibaryon Symmetry Experiment (Base) at Cern.

Light is one aspect of the Universe that, for most people, holds a deep and noticeable value in everyday life, helping them to navigate, learn from, and connect with the world around them. Yet it's not particularly difficult to imagine life without it. After all, many nonhuman animals live in lightless environments. However, as Gideon Koekoek, an associate professor of physics in the research group Gravitational Waves and Fundamental Physics

We now recognize that even ideas like "when" and "where" are subject to the laws of Einstein's relativity, and that in relativity, space and time are not absolute quantities, but rather are relative to each and every unique observer.

According to Einstein's General Relativity, for every black hole that exists within the Universe, there are only three properties that go into it that matter in any way: the black hole's total mass, the black hole's net electric charge, and the black hole's intrinsic angular momentum, and that's it. It doesn't matter what type of matter went into the black hole in order to form it; all that matters is its mass, charge, and angular momentum.

Star-formation will eventually end, and then the last shining stars will burn out. Galaxies will dissociate due to gravitational interactions, ejecting all masses and leaving only supermassive black holes behind. And then those black holes will decay via Hawking radiation, leaving only cold, stable, isolated bodies, from which no further energy can be extracted, all accelerating away from us within our dark energy-dominated Universe.

Analogue quantum simulations are a useful tool for investigating these systems, particularly in regimes in which the applicability of numerical techniques is limited. For different simulator platforms, figures of merit include the electron bandwidth and interaction strength, temperature and the number of simulated lattice sites. Their use is further underscored by the ability to realize distinct lattice geometries, on-site degrees of freedom and by the physical observables that are accessible to experimental measurement.

In terms of making things happen, energy is an indispensable consideration. Systems spontaneously tend towards the lowest-energy state. When a system reaches equilibrium, no further energy can be extracted. That maximum entropy, lowest energy state is the inevitable end-state of the Universe. But until that moment arrives, reactions of all kinds will occur, continuing to liberate energy. In our bodies, chemical bonds break and reform: releasing energy.

A supercooled microscopic ferromagnet proves the existence of gyroscopic magnetic behaviour that has been long sought by physicists.

Y.W. designed the experimental protocols, performed experiments, analysed the data and wrote the manuscript. Y.H., X.K., D.C., J.X.X. and W.Z. performed experiments and edited the manuscript. Y.C. and S.P. edited the manuscript. M.J., X.P. and J.D. proposed the experimental concept, designed experimental protocols and proofread and edited the manuscript. All authors contributed with discussions and checking the manuscript. Corresponding authors Correspondence to Min Jiang or Xinhua Peng.