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.
In December 1980, 19-year-old Jean Hilliard nearly froze to death after her car slid off the road in rural Minnesota. Stranded in subzero temperatures, she walked two miles to a friend's house, collapsing just feet from the door. Discovered six hours later, Hilliard was completely rigid, her skin ice-cold and her eyes fixed and unblinking. Doctors initially feared she was dead, but after hours of gradual rewarming at the hospital, she miraculously revived with minimal lasting damage, baffling medical professionals and becoming a testament to the resilience of the human body.
HN commenters generally express amazement at Jean Hilliard's survival after being frozen solid. Several question the specifics of how she froze and thawed, wondering about the exact temperature, duration of exposure, and the thawing process. Some speculate about the role of alcohol in her survival, referencing its antifreeze properties, while others caution against assuming it played a positive role. A few users share anecdotes of other surprising cold-weather survival stories, including one about a frozen cat revived with warm water. Some commenters also discuss the article's writing style, with one pointing out the effective use of short sentences to build tension. Several express gratitude for the "good news" story amid otherwise bleak headlines.
"The Human Alphabet," published in 1848, presents a whimsical yet structured exploration of letterforms created by contorting the human body. Engraved by artist Edward Lumley, the illustrations depict men, women, and children individually and in groups, painstakingly arranged to mimic each letter of the alphabet. The poses range from simple to complex, demonstrating both the flexibility of the human form and the ingenuity required to achieve these typographic representations. Ultimately, the work serves as a playful intersection of art, anatomy, and typography, offering a unique visual interpretation of the alphabet.
Hacker News users discussed the historical context and artistic merit of human alphabets. Some noted similar formations depicted in older works, like a 15th-century manuscript. Several appreciated the diversity represented by including non-Western alphabets, pointing out examples from Ethiopia and India. There was debate about the practicality and accuracy of the formations, with some questioning how legible or standardized they truly were, particularly for languages with larger character sets. Others found the concept aesthetically pleasing and fascinating, appreciating the ingenuity and creativity of representing language through the human body. A few comments focused on the photographer's skill in capturing these intricate poses. The overall sentiment leaned toward appreciation for the historical curiosity and visual appeal of the human alphabets.
Summary of Comments ( 59 )
https://news.ycombinator.com/item?id=43102425
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.
The Hacker News post titled "Gravitational Effects of Small Primordial Black Hole Passing Through Human Body" (https://news.ycombinator.com/item?id=43102425) has a modest number of comments, sparking a discussion around the plausibility and effects of such an event.
Several commenters focus on the extremely low probability of this event actually occurring. One commenter points out the vastness of space and the tiny size of a human, making a collision incredibly unlikely. Another echoes this sentiment, emphasizing the rarity of primordial black holes themselves, combined with the low chances of intersection with a human.
The discussion then delves into the potential consequences if such an improbable event were to occur. One commenter, referencing the paper's calculations, highlights that a small primordial black hole (PBH) passing through the body would likely cause negligible damage, contrary to what might be assumed. They explain that the gravitational force exerted would be incredibly localized and brief, leading to a minor displacement of tissues rather than any catastrophic damage. This comment sparks a small thread discussing the inverse square law and how the rapid transit of the PBH minimizes its overall effect.
Another commenter questions the assumption of a straight trajectory through the body. They propose that the PBH might interact with the Earth's gravitational field, potentially leading to a more complex path, like an orbit. This raises further questions about the duration and overall effect of the PBH's interaction with a human in such a scenario, which goes unanswered in the thread.
One commenter injects a touch of humor by wondering if such a transit would be detectable as a sudden, unexplained weight loss.
Finally, a commenter circles back to the probability aspect, highlighting the greater risks posed by everyday occurrences compared to the astronomically low chances of a PBH encounter. They mention that worrying about such an event is akin to worrying about being struck by lightning while simultaneously winning the lottery – a colorful analogy emphasizing the extreme improbability.
In essence, the comments section explores the implications of the paper's findings with a mix of scientific curiosity and healthy skepticism, acknowledging the extremely low probability of the event while exploring the theoretical consequences. The discussion remains grounded in the paper's focus on small PBHs and their relatively minor impact on the human body, should such an improbable encounter occur.