New research is mapping the chaotic interior of charged black holes, revealing a surprisingly complex structure. Using sophisticated computational techniques, physicists are exploring the turbulent dynamics within, driven by the black hole's electric charge. This inner turmoil generates an infinite number of nested, distorted "horizons," each with its own singularity, creating a fractal-like structure. These findings challenge existing assumptions about black hole interiors and provide new theoretical tools to probe the fundamental nature of spacetime within these extreme environments.
The paper explores the theoretical biological effects of a primordial black hole (PBH) with a tiny mass (around 10^15 grams) passing through a human body. While such an event is improbable, the authors calculate the gravitational forces exerted by the PBH as it traverses different tissues. They find that these forces, though exceeding Earth's gravity by many orders of magnitude for a brief period, are unlikely to cause significant macroscopic damage due to the extremely short interaction time. However, the study suggests potential disruptions at the cellular level, specifically stretching of DNA molecules, which might lead to mutations or other biological consequences. The overall conclusion is that while mechanically disruptive effects are likely minimal, biological impacts from the induced strains warrant further investigation.
Several Hacker News commenters expressed skepticism about the practicality of detecting the effects described in the paper, especially given the rarity of primordial black holes and the subtle nature of the gravitational influence. Some questioned the assumptions made in the calculations, like the density and velocity of the black holes. Others pointed out that other everyday gravitational forces, like those from nearby objects or even the moon, would likely dwarf the effect of a tiny black hole passing through the body. A few commenters engaged in humorous speculation about potential (and unlikely) biological impacts, while others debated the overall significance of the research. Several users also discussed the plausibility of primordial black holes as dark matter candidates.
One year after the groundbreaking image of M87's black hole shadow, the Event Horizon Telescope (EHT) collaboration released further analysis revealing the dynamics of the surrounding accretion flow. By studying polarized light emissions, the team discerned the structure of the magnetic fields near the event horizon, critical for understanding how black holes launch powerful jets. The observations show a turbulent, swirling accretion flow, dominated by tangled magnetic field lines, which are thought to be crucial in powering the jet and extracting energy from the black hole's rotation. This reinforces the understanding of M87 as an active black hole, actively accreting material and launching energetic jets into intergalactic space. The polarized view provides a crucial piece to the puzzle of black hole physics, helping confirm theoretical models and opening new avenues for future research.
HN commenters discuss the implications of the new M87 image, focusing on the dynamic nature of the accretion disk and the challenges of imaging such a distant and complex object. Some express awe at the scientific achievement, while others delve into the technical details of Very Long Baseline Interferometry (VLBI) and the image reconstruction process. A few question the interpretation of the data, highlighting the inherent difficulties in observing black holes and the potential for misinterpretation. The dynamic nature of the image over time sparks discussion about the complexities of the accretion flow and the possibilities for future research, including creating "movies" of black hole activity. There's also interest in comparing these results with Sagittarius A, the black hole at the center of our galaxy, and how these advancements could lead to a better understanding of general relativity. Several users point out the open-access nature of the data and the importance of public funding for scientific discovery.
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https://news.ycombinator.com/item?id=43173773
Several commenters on Hacker News expressed excitement about the advancements in understanding black hole interiors, with some highlighting the counterintuitive nature of maximal entropy being linked to chaos. One commenter questioned the visual representation's accuracy, pointing out the difficulty of depicting a 4D spacetime. There was discussion about the computational challenges involved in such simulations and the limitations of current models. A few users also delved into the theoretical physics behind the research, touching upon topics like string theory and the holographic principle. Some comments offered additional resources, including links to relevant papers and talks. Overall, the comments reflected a mix of awe, curiosity, and healthy skepticism about the complexities of black hole physics.
The Hacker News post titled "New Maps of the Chaotic Space-Time Inside Black Holes" generated several comments discussing various aspects of the linked Quanta Magazine article. Many commenters expressed fascination with the complexity of black holes and the challenges of understanding their inner workings.
Several comments focused on the nature of chaos within black holes. One commenter questioned the meaning of chaos in this context, asking how it differs from randomness. Another explained that the chaos arises from the extreme sensitivity of the spacetime within a black hole to initial conditions, meaning even the smallest perturbation can drastically alter the future trajectory of an object inside. This sensitivity makes predicting long-term behavior inside the black hole effectively impossible, although the underlying equations are still deterministic. The concept of Lyapunov exponents was mentioned as a way to quantify this chaotic behavior.
Some discussion centered on the limitations of current models and the difficulties of visualizing higher-dimensional spaces. One user pointed out the limitations of the 2D representations used to illustrate these complex systems and how they can oversimplify the true nature of the phenomena. Another commenter speculated about the potential role of quantum gravity in resolving some of the mysteries surrounding black holes, acknowledging that current physics models struggle at the singularity.
The computational aspects of the research were also mentioned. One commenter praised the researchers for their innovative use of numerical methods to solve the complex equations governing the interior of black holes.
Several users expressed a sense of awe and wonder at the immensity and strangeness of black holes, with one describing them as "cosmic garbage disposals." Another pointed out the seemingly paradoxical nature of black holes, where the laws of physics as we know them break down.
Overall, the comments reflect a mixture of scientific curiosity, a desire to understand complex concepts, and an appreciation for the mysteries that still surround black holes. They highlight the challenges faced by physicists attempting to model these extreme environments, while also showcasing the exciting advancements being made in our understanding of them.