Philosophy
fromBig Think
2 days agoThe flimsy case for evolving dark energy
Theoretical physicists risk falling into motivated reasoning by overly believing speculative ideas without sufficient supporting evidence.
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.
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.
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.
This system is truly extraordinary. We're seeing the radio equivalent of a laser halfway across the universe. Fundamentally, masers and lasers are focused beams of light in the same frequency. In the realm of astrophysics, these can arise from clouds of dust being excited into a higher energy state from the light emitted by other sources, like stars and black holes.
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
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.
The fastest human in the world, according to the Ancient Greek legend, was the heroine Atalanta. Although she was a famous huntress who joined Jason and the Argonauts in the search for the golden fleece, she was most renowned for the one avenue in which she surpassed all other humans: her speed. While many boasted of how swift or fleet-footed they were, Atalanta outdid them all. No one possessed the capabilities to defeat her in a fair footrace.
A dead star 730 light years away appears to be forming a powerful structure around itself - and despite their best efforts, astronomers aren't sure how. The cosmic corpse, designated RXJ0528+2838, is an incredibly dense stellar remnant known as a white dwarf, with a Sun-like star orbiting around it. This binary arrangement isn't uncommon throughout the universe, but what is strange is the structure surrounding the former body: a highly energetic and luminescent cloud known as a nebula,
The universe is exploding. Or parts of it are. The night sky may seem calm, even serene, but that masks events of a catastrophic and nearly unimaginable scale. Across the galaxy and even the cosmos itself, immense outbursts of energy occur that could easily vaporize our planet. Happily, space is vast, and the terrible distance between these events and us diminishes what we see to a faint glowusually.
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.