More Thoughts On Red River

The first twelve episode cours of the anime Red River a.k.a. Anatolia story, based upon the long hit manga series of the same name finished yesterday, and has prompted me to research the actual history of the period depicted in this historical fiction piece (another twelve episodes are contracted for the fourth quarter of this year).

One of the points highlighted by the series that often gets overlooked in academic research is that: (1) the Hittites, the Mittani kingdom, a Mesopotamian regime, and the Egyptian 18th dynasty, were all contemporaneous, and (2) that these kingdoms meaningfully interacted with each other, exchanging correspondence, diplomats, and brides with each other, and engaging in military conflicts with the intermediate Hittite empire.

At least two royal Egyptian brides were from the Mittani Kingdom in roughly the 14th century BCE when Red River is set.

This is especially notable because, while the everyday commoners in the Mittani Kingdom were Hurrian language speakers (a language associated with the highlands of the Zargos Mountains and to a lesser extent the eastern Anatolian highlands where the possibly related Hattic language was spoken), the Mittani elites in the 1300s BCE spoke a Sanskrit derived Indo-Aryan language (that gave rise, most famously, to the Hindi language of northern India) and worshiped Indo-Aryan gods in their pantheon that became part of the Hindu religion rather than the Avestan language and religion that was starting to emerge in what is now Iran at around this time. (A cultural affiliation that neither the anime or the manga make much of.)

The Indo-Aryan linguistic and religious link to western Iran and connection the Anatolia and Egypt, disappears, however, when the Mittani kingdom falls, for historical reasons that like its brief appearance in the Mittani kingdom have since been lost and are currently unknown.

The Mittani kingdom featured in Red River as a major military adversary of the Hitties, therefore, provides a concrete human, person to person bridge between the culture of South Asian Indo-Europeans and late Bronze Age ancient Egypt: two cultural worlds usually thought of as unrelated and independent of each other despite being contemporaneous.

Actual history is unclear over whether the famous ancient Egyptian Queen Nefertiti was one of those Mittani brides or not, as the manga and anime assert, because it is a legitimate historical possibility and makes for a good story. But the historicity of the Mittani kingdom providing two royal brides to Egypt in the historical era in which Red River is set is not seriously questioned, nor is the Red River story point that at least one of those marriages was driven to a significant extent by a Mittani expectation of receiving large amounts of gold from Egypt in exchange (although, historically, the Egypt failed to deliver the gold).

Is There Really No Cusp-Core Problem?

I'm highly skeptical of a study that purports to contradict decades of previous observational data whose results had a broad consensus in the field of galaxy dynamics (and which was the main motivator for dark matter particle models such as self-interacting dark matter, warm dark matter, and axion-like particle/fuzzy/ultralight dark matter), with a small "curated" sample. 

I also question comparing  this small curated sample mostly to cold dark matter simulations which themselves are often devised to fit the data rather than having a rigorous physics basis. 

This comes across as cherry picking rather than as the robust observational constraint that the paper claims to be seeking to develop, particularly where there doesn't seem to be a lot of attention given to the uncertainties in their observational data points. 

There seem to be a lot of observation points outside the CDM range in Figure 4 below, and Figure 5 represents only comparisons with simulations, which again, aren't very rigorous reproductions of pure physics and have a strong phenomenological matching component.

Also, while this paper purports to quantify how much energy from stellar feedback is necessary to produce the observed results (which is a worthwhile and important thing to do), its analysis of whether that amount is actually plausible and has a strong physics justification is lacking.

But I'm blogging this paper anyway. That's because I don't want to ignore papers just because they might disagree with my preconceived notions. It is better to engaged and struggle with scholarship that you doubt, and to change your mind if it is sufficiently convincing. 

The images below are the ones described in the arXiv comment from the authors as containing the "main results."

Two of the most prominent small-scale challenges to the cold dark matter (CDM) paradigm are the cusp-core and diversity-of-rotation-curves problems. The former concerns the shallow inner DM density profiles inferred for many galaxies compared with the cusps predicted by collisionless CDM, while the latter concerns the wider range of inner DM densities and rotation curve shapes inferred observationally than hydrodynamical simulations traditionally reproduce. Robust observational constraints on DM core sizes and halo densities are therefore essential for testing both the nature of DM and the impact of galaxy formation processes. 

We analyse the inner DM distribution of a curated sample of 48 gas-rich galaxies and 8 Milky Way gas-poor satellites, spanning 6 orders of magnitude in M∗. We find substantial scatter in DM core sizes and degrees of coreness, with both cuspy and cored haloes occurring over a broad M∗ range. The cores are energetically consistent with stellar feedback, requiring modest supernova energy coupling efficiencies of order 0.1−1%. Comparisons with the NIHAO, FIRE-2, and EDGE simulations reveal broad agreement in the inner DM densities and logarithmic slopes of observed and simulated galaxies. 

The main residual differences concern the steep slopes of some massive simulated galaxies and differences in SHMRs. Using a rotation-curve diversity diagnostic from previous work, we find that extreme discrepancies with simulations are absent from our curated sample and largely attributable to uncertain kinematics or baryonic mass distributions. Within the scope of our analysis, we find no evidence of a systematic inner-density tension between our galaxy sample and current ΛCDM hydrodynamical simulations. Together with the modest energetic requirements for core formation, this substantially alleviates the cusp-core and diversity-of-rotation-curves problems.

Pavel E. Mancera Piña, Justin I. Read, Jorge Sarrato-Alós, Claudia Muni, "Dark matter haloes from dwarf to massive galaxies: no systematic inner-density tension with ΛCDM hydrodynamical simulations" arXiv:2609.25220 (September 21, 2026) (Accepted for publication in A&A).

T-Rex Was Warm Blooded

A new study of a T-Rex tooth has determined that these dinosaurs were warm blooded, unlike almost all reptiles today (except leatherback sea turtles and Argentine black and white tegus), but like modern birds, which are the sole surviving branch of dinosaurs.

Despite an extensive history of study, quantitative constraints on the thermophysiology of Tyrannosaurus rex remain limited. Here, we derive a thermodynamically based determination of T. rex body temperatures from clumped isotopes in tooth enamel. Measurements of three T. rex teeth from the Late Cretaceous Hell Creek Formation yield a temperature of 36.3 ± 2.5°C (1 SE), comparable to modern endotherms. Teeth of coeval Hell Creek Formation crocodilians yielded temperatures significantly lower than did those of T. rex. Comparison with proxy-derived paleotemperatures and model simulations indicates that T. rex maintained a higher body temperature than its environment. Projected habitat suitability for T. rex based on these results shows that most of the North American paleocontinent, including colder and higher latitudes, were potentially accessible to the species.

Randon J. Flores, "The body temperature of Tyrannosaurus rex" 12(38) Science Advances (September 16, 2026) DOI: 10.1126/sciadv.aeb7653.