The External Field Effect In MOND

Stacy McGaugh explains at his blog, Triton Station, how important it is to consider the external field effect (in which external gravitational fields prevent MOND effects from arising) when using astronomy data to determine if MOND is a good description of reality. Because, when the external field effect is strong enough, MOND reduces to Newtonian gravity.

Quick Human Evolution Hits

* John Hawks makes a pretty convincing case, from several studies using different methodologies but reaching similar conclusions, that about 1.1 to 1.5 million years ago, hominins split into two populations, the smaller of which (about 20% of the total) was the progenitor population of modern humans, Neanderthals, and Denisovans, and the larger of which (about 80% of the total) contributed about 20% to modern human genetic ancestry right around the time, about 300,000 years ago, that modern humans are first found in the archaeological record. The rub: fitting that into a narrative drawn from non-genetic evidence is challenging, because we don't know what ghost population the population that we broke off from and then partially hybridized with represents. He cites to many academic journal articles for his blog post whose citations are in a bibliography at the end of the linked article.

* Footprints from a group of about eight Paranthropus boisei about 1.4 million years ago seem to imply a larger scale of social organization for this early hominin than was previously assumed. The linked story cites to: Kevin G. Hatala, et al., "Insights into hominin body size, locomotion, and behavior from Early Pleistocene trackways in northern Kenya." 123(31) Proceedings of the National Academy of Sciences (2026). DOI: 10.1073/pnas.2530996123

* Descriptions of the last chimpanzee-hominin ancestor may be wrong because we have underestimated the things that primates can do with their feet. The linked story cites to: Luke D. Fannin, Carmen Pape, W. Scott McGraw. "A kinematic convergence in ape and monkey vertical climbing informs debates on early hominin arborealism." 123(35) Proceedings of the National Academy of Sciences (2026) DOI: 10.1073/pnas.260818312

Simple Math Made Hard

It is worth noting that none of the complexities below involve anything more sophisticated that pre-calculus study and logs and trig functions, and perhaps the early part of a first course in calculus, both of which are often taught at the high school level.