Astronomy In Colonial Era Chile

Despite the fact that Roman Catholicism has no doctrinal mandate that churches be built in a manner that has significance related to astronomy (and didn't in the 16th century), although there were traditions in support of that idea, many colonial era Roman Catholic churches in northern Chile were built in a manner that reflected these considerations. New world church construction in the 16th century reflected somewhat different considerations.

From the introduction and conclusion:

The spatial orientation of ancient Christian churches is one of the most characteristic features of their architecture (Dietz 2005). In Europe and in many remote sites where the missionaries arrived, there is a clear tendency to orient the altars of the temples in the solar range; namely, the axis of the temple, from the front door towards the altar, is aligned to those points on the horizon where the Sun rises on different days of the year. Among these days, there is a marked preference for those corresponding to astronomical equinoxes, when the axes point towards geographical east, the direction which down through the ages has symbolized the eschaton: the second coming of Christ in kingly glory (McCluskey 2015). However, even within the solar range, alignments in the opposite direction –with the altar to the west– are not uncommon, although they are exceptional because they do not follow the canonical pattern (see Gangui et al. 2016a, and references therein).

Soon after the Spanish settlement in the Viceroyalty of Peru, Francisco de Toledo decided to reorganize the territory and its population. He focused on the trade routes of the southern Andean area, the main objective of which was to organize the transport of silver from Potosi to the Pacific and also that of quicksilver from Huancavelica to the high Andean mines. On the way to the city of Arica, official maritime port for the merchandise since 1574, there appeared small villages and tambos with stable populations. Modest chapels and churches in this region emerged in strategic locations along the route which trajinantes marched to transport the precious metals from Potosi to Arica beaches, particularly around the Lluta and Azapa valleys. . . . 

Our results show that, unlike what is commonly found in studies involving European historical churches, in the temples we studied here we found no single orientation pattern valid throughout the whole region. However, we found that almost half of the churches surveyed were oriented within the solar range, with a dominant share in those presenting their altar towards the west. We have also identified some notable cases where the orientation of the temples seems to follow the location of distinctive elements of the landscape –as volcanoes or other aboriginal culturally relevant apus– rather than the rising or setting Sun during meaningful dates for the particular dedication of the churches, a fact that brings to mind more the Aymara worship (BouysseCassagne 1987) than the 16th century Instructions on Ecclesiastical Building written by the Italian Cardinal Carlo Borromeo (1985). 

Archaeoastronomy in northern Chile: Andean churches of the Arica and Parinacota region

Alejandro Gangui, Angel Guillen, Magdalena Pereira

(Submitted on 8 May 2019)

We present the results obtained from the analysis of the precise spatial orientations of almost forty old colonial Christian churches located in the Arica and Parinacota region. This is an extended and difficult to travel area that received little attention from parish priests, and where one might expect some dialogue to have taken place between the Western tradition and the local Aymara culture in regard to the design and construction of temples. We also briefly comment on our plans to explore neighboring areas to the region here studied, which include many additional historical constructions that share similar cultural traditions.

Comments:	Paper presented at The Road to the Stars, a joint Meeting of ISAAC, INSAP and SEAC, held in Santiago de Compostela, Spain, 18-23 September 2017. arXiv admin note: substantial text overlap with arXiv:1604.00260
Subjects:	History and Philosophy of Physics (physics.hist-ph)
Cite as:	arXiv:1905.04139 [physics.hist-ph]
	(or arXiv:1905.04139v1 [physics.hist-ph] for this version)

Leading String Theorists Still In Denial

The extent to which high profile string theorists are unwilling to admit their failures is stunning (via Woit).

Quantum Physics Still Weird

The linked article is one of the more scientifically accurate description of a general aspect of quantum physics (the seeming segregation of particles and some of their properties) that strongly defies a classic understanding of reality.

These are not big dollar experiments. But, they are clever and get as some very different kinds of fundamentals than expensive high energy physics experiments do.

Lambda CDM Still Doesn't Fit The Galaxy Scale Data

Here is yet another paper showing that it is very hard to explain galaxy level dynamics with a simple Lamda CDM model (a.k.a. the Standard Model of Cosmology).

Using large scale structure data and a halo model to constrain Generalised Dark Matter

Daniel B Thomas, Michael Kopp, Katarina Markovič

(Submitted on 7 May 2019)

Constraints on the properties of the cosmological dark matter have previously been obtained in a model-independent fashion using the Generalised Dark Matter (GDM) framework. Here we extend that work in several directions: We consider the inclusion of WiggleZ matter power spectrum data, and show that this improves the constraints on the two perturbative GDM parameters, c2s and c2vis, by a factor of 3, for a conservative choice of wavenumber range. A less conservative choice can yield an improvement of up to an order of magnitude compared to previous constraints. 

In order to examine the robustness of this result we develop a GDM halo model to explore how non-linear structure formation could proceed in this framework, since currently GDM has only been defined perturbatively and only linear theory has been used when generating constraints. We then examine how the halo model affects the constraints obtained from the matter power spectrum data. 

The less-conservative wavenumber range shows a significant difference between linear and non-linear modelling, with the latter favouring GDM parameters inconsistent with ΛCDM, underlining the importance of careful non-linear modelling when using this data. 

We also use this halo model to establish the robustness of previously obtained constraints, particularly those that involve weak gravitational lensing of the cosmic microwave background. 

Additionally, we show how the inclusion of neutrino mass as a free parameter affects previous constraints on the GDM parameters.

Dark matter is not the only way that one can explain the cosmic background radiation signatures (which is what Lambda CDM does best). But, it is a paradigm that simply cannot be reasonably fit to very hard data from observations of galaxy dynamics. Sooner or later, the evidence is going to force the astronomy and physics community to recognize that gravity modification and not dark matter particle theories are what explains dark matter phenomena and probably also dark energy phenomena (which are described as a gravity modification, i.e. the cosmological constant, in the Lambda CDM cosmology model).

The introduction to this paper is also informative:

The ΛCDM cosmological model does a good job of reproducing the current cosmological observations. In this model, the standard model of particle physics is supplemented by a cosmological constant Λ and a dark matter particle. This dark matter particle is assumed to interact purely due to the influence of gravity and to have a negligible (initial) velocity dispersion, thus the name Cold Dark Matter (CDM). In perturbative calculations this is typically modelled as a pressure-less perfect fluid. As a result, many cosmological constraints on the dark matter density are, more correctly, constraints on the density of this pressure-less perfect fluid. More generally, CDM is evolved by solving the collision-less Boltzmann equation. This is done on large scales using cosmological perturbation theory (implemented in Boltzmann codes such as class and camb) and on smaller scales using N-body simulations and other non-linear methods.  

Since we are entering the era of so-called “precision cosmology,” in which many cosmological parameters have been measured with 1% accuracy or better, it is timely to consider whether such an idealised and simple dark matter model is sufficient when analysing the data. There are many physical dark matter models that do not yield precisely CDM, for example Warm Dark Matter (WDM) [1–3] or ultra light axions (one example of Fuzzy Dark Matter (FDM)) [4, 5]. In addition, recent work on the Effective Field Theory of Large Scale Structure (EFTofLSS) [6] shows that even an ideal CDM candidate develops a more complicated energy momentum tensor, even on linear scales, once the non-linearities that inevitably form on small scales back-react on the large scales. This causes an effective pressure and viscosity on large scales. 

From a non-cosmological perspective, despite a large number of direct and indirect detection experiments for dark matter, no convincing detections have been made, and many theoretically favoured regions of parameter space have been ruled out [7–12]. Thus, there are strong reasons to go beyond the simplest ways of modelling dark matter. 

In [13], the Generalised Dark Matter (GDM) model (first proposed in [14]) was examined in some detail, notably how it relates to particular physical models. GDM adds to the CDM energy momentum tensor a background pressure, pressure perturbation and anisotropic stress. Closure relations are then postulated to match qualitative properties of known models, like massive neutrinos, and in order to de-correlate background and perturbative properties. GDM encompasses WDM, FDM and the EFTofLSS effects as well as other physical models, so it is sufficiently versatile for examining dark matter properties in a model independent fashion. In [15], all GDM parameters were constrained using Cosmic Microwave Background (CMB) data, supported by additional data on the cosmological expansion history (see section 4.3 in this paper and references therein for comparison to earlier works constraining partial or similar parameters to those we consider here, such as [16–18]). The results showed no evidence for any non-CDM properties of dark matter. This was expanded on in [19], where an improved freedom was given to one of the GDM parameters; this was used to demonstrate for the first time that there is no cosmological epoch where the data would favour a nonzero equation of state, and furthermore that there is no cosmological epoch where the data is consistent with zero dark matter density, thus showing the strength of the GDM approach to testing the CDM paradigm. An independent group subsequently [20] verified some of the results in [15], as well as using some late time matter clustering data; we will comment further on this later in the paper. Further work constraining the GDM parameters is now ongoing by other groups, see e.g. [21]. It was noted in [15] that matter power spectrum data could not only improve the constraints on the GDM parameters, but also has the potential to break a degeneracy between two of them (see section II). 

The robust use of such data requires a non-linear extension of the GDM model, which is not present in the literature. It was also noted in [15] that the inclusion of a non-linear extension to perturbation theory for ΛCDM makes a difference to the CMB lensing potential. This effect is of a similar magnitude, but opposite sign, to that of GDM with parameters saturating the constraints found in [15]. In this paper we develop a halo model for GDM which allows us first to test the robustness of the results in [15], and second to use matter power spectrum data from the WiggleZ survey [22] to improve the constraints on the GDM parameters. 

Self-interacting neutrino models also don't work:

Constraining the Self-Interacting Neutrino Interpretation of the Hubble Tension

Nikita Blinov, Kevin J. Kelly, Gordan Krnjaic, Samuel D. McDermott

(Submitted on 7 May 2019)

Large, non-standard neutrino self-interactions have been shown to resolve the ∼4σ tension in Hubble constant measurements and a milder tension in the amplitude of matter fluctuations. 

We demonstrate that interactions of the necessary size imply the existence of a force-carrier with a large neutrino coupling (>10−4) and mass in the keV -- 100 MeV range. This mediator is subject to stringent cosmological and laboratory bounds, and we find that nearly all realizations of such a particle are excluded by existing data unless it carries spin 0 and couples almost exclusively to τ-flavored neutrinos. Furthermore, we find that the light neutrinos must be Majorana, and that a UV-complete model requires a non-minimal mechanism to simultaneously generate neutrino masses and appreciable self-interactions.

Comments:	10 pages, 2 figures, 3 appendices
Subjects:	Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
Report number:	FERMILAB-PUB-19-175-A-T
Cite as:	arXiv:1905.02727 [astro-ph.CO]
	(or arXiv:1905.02727v1 [astro-ph.CO] for this version)

A Much Earlier Polish Genocide

In the late Neolithic/Copper Age/early Bronze Age period, in what is now southern Poland, the incoming Indo-European Corded War culture people, who were metal age farmers with horses, were executing women and children from the invaded existing (probably non-Indo-European) Globular Amphora culture of semi-nomadic cow and pig herders, and then burying them in mass graves.

Around 2,800 BCE, in what is now southern Poland, a family group of fifteen individuals associated with the Globular Amphora culture (GAC) were massacred. They were probably captured and executed, because each victim was killed with a blow to the head from the same type of weapon, possibly a stone axe, and lacked defensive wounds. The dead were mostly women and children. They were buried in a mass grave, but with great care and very likely by someone who knew them well.

This Late Neolithic mass grave is the focus of a new ancient DNA and archeological research paper at PNAS by Schroeder et al. (see here). The authors tentatively attribute the massacre to the Corded Ware culture (CWC) people, who were expanding rapidly at the time across much of Europe from their homeland on the Pontic-Caspian steppe.

From Eurogenes. 

UPDATE May 9, 2019:

Razib Khan has some detailed genetic analysis and interesting speculations about the likely context of the killings (he thinks that the slaughter may have occurred while the adult warrior men were away from the village and then lovingly and carefully buried the kin that they discovered when they returned, which is a historically attested tactic in pre-modern war).

END UPDATE

The genocide that came to Poland later, during World War II, should be familiar to everyone, even though, in fact, many people never learned anything about it.

Bell Beaker blogger, meanwhile, recounts a group grave from Spain from the Bell Beaker era (basically, Copper Age/early Bronze Age) containing multiple girls who were beheaded, although this account has less context for why this might have been done.

In both cases, the massacres were from the prehistoric era. But, in my view, legendary historical Biblical accounts of the ancient Hebrews committing similar atrocities, for example, in Chapter 31 of the Hebrew Bible book of Numbers, provide the best attested insights from a period as close in time as we have available, about the kinds of political and social contexts that this could have involved.

New Studies Invert The Direction Of The Spread Of The Sino-Tibetan Languages

Razib Khan provides a new capsule history of greater Chinese linguistics and genetic ancestry informed by two new linguistic studies. I agree pretty much 100% with his analysis, which is set forth lucidly and succinctly.

The traditional view, which had been the paradigm in Sino-Tibetan linguistics pretty much since linguists have first looked at the issue scientifically, had been that this language family originated in Tibet and the vicinity where there is great linguistic diversity within the language family, and then spread to the central Yellow River Valley from which modern Chinese civilization including the Han ethnicity and Chinese language family expanded. How people from the Tibetan highlands managed to assert so much cultural dominance at this juncture isn't explained, but founder effects can explain all sorts of seemingly improbable data.

But, two new independent studies, taking a closer look at the data, which makes sense in a multi-disciplinary context, have now reached the opposite conclusion. 

Instead, the evidence now suggests that the Sino-Tibetan language family emerged in the central Yellow River Valley along with the rest of modern Chinese civilization about 7,000 years ago (ca. 5000 BCE, in a time period not that different temporally from the time frame of the emergence of the Indo-European languages). With only brief exceptions that did not replace the pre-existing language of the people or cause widespread demic replacement (e.g. a brief period of Mongol rule under the empire of Ghengis Khan), all of the subsequently archaeological cultures of China that have been successors, in turn, to the original northern Chinese millet farming Yangshao culture from which the Sino-Tibetan language emerged, in linguistic, cultural and demographic continuity with the Yangshao people. The Yangshao people, in turn, were probably local hunter-gatherers who independently invented agriculture in their own autochthonous East Asian Neolithic revolution.

Somewhere in the time frame of 3000-4500 years ago (ca. 1000 BCE to 2500 BCE, around the time of the Bronze Age to early Iron Age in Europe, West Asia and the Mediterranean basin), Chinese pioneers settled in Tibet. The Tibetans have had since then to diversify linguistically, in a place geographically isolated from the homogenizing influences of Chinese empires, where the geography and limited population density in this harsh environment also keep these communities from dominating and assimilating each other. It isn't unusual for highlands to harbor relict cultural and linguistic diversity that expanding civilizations wipe out elsewhere (see, e.g., the Nuba Mountains of Sudan and the Caucasus Mountains).

But,  in the Chinese lowlands, almost from the start around 7,000 years ago, Chinese civilization has been unified by either one or a small number of interacting kingdoms and empires, more or less through to the present. This political and economic unity, fostered, in part, by a lack of natural geographic barriers, has prevented the core Chinese languages from diversifying very much.

This model isn't the most intuitively obvious from a shallow look at the data at the forest level, but it is consistent with archaeological evidence and genetic evidence as well as the linguistic data, and provides much better motives to explain the spread of the Chinese languages and civilization in Tibet, East Asia, Southeast Asia and the easternmost part of South Asia.

The papers are: “Dated language phylogenies shed light on the ancestry of Sino-Tibetan” and "Phylogenetic evidence for Sino-Tibetan origin in northern China in the Late Neolithic".

Also notable are papers noted here by commentator "Matt": One regarding the arrival of Austrasiatic in Vietnam about 4500 years ago, and two more re Austronesian expansion, which is also almost simultaneous with all this at 5000-4000 YBP. Linguistic phylogeny, and McColl et al 2018 confirms Austronesian ancestry at north coast of Borneo by 4000 YBP at least.

Previous relevant posts at this blog include:

* Northern Chinese Ancient DNA

* The Early History of Agriculture In Eastern Asia

* The Earliest Domesticated Rice In China

* Ancestry Analysis In Han Chinese Populations With Functional Immunity Genes

* The Homelands Of Modern Asian Languages And Y-DNA Clades

* Ancient Han Chinese DNA

* Oldest Pottery Now From China Rather Than Japan

* How, When And Where Did Agriculture Arise In China?

* Genetic Evidence Links Yayoi To Northeast China

* Chinese Legendary History Coroborated

* An Ancient Plague In A Collapsing Northern Chinese Civilization
* The Demographic History Of Southeast Asia
* The Modern Genetics Of Island Southeast Asia
* 89% Of The Vietnamese Share 14 Surnames

Pre-Columbian Bolivians Used Psychoactive Drugs

Psychoactive drugs weren't particular to the Old World. They were used by shamans in the highlands of the Andes Mountains around 1000 CE.

In a Bolivian rock shelter likely used 1,000 years ago for religious rituals, archaeologists found a collection of drug paraphernalia that still contains traces of psychoactive plants. A pouch made from three fox snouts likely contained a stash of leaves and seeds. From New Scientist: 

(The items) include a 28-centimetre-long leather bag, a pair of wooden snuffing tablets, a snuffing tube, a pair of llama-bone spatulas, a textile headband, fragments of dried plant stems and a pouch made from three fox snouts stitched together. The snuffing tube and tablets feature ornate carvings of human-like figures. 

Melanie Miller at the University of Otago, New Zealand, and her colleagues used mass spectrometry to analyse samples from the pouch and plant stems. They detected five psychoactive compounds: cocaine, benzoylecgonine (BZE), bufotenine, harmine and dimethyltryptamine (DMT).

From here.

A picture of the pouch described above.

The source is: "Chemical evidence for the use of multiple psychotropic plants in a 1,000-year-old ritual bundle from South America" (PNAS).

DMT (the active ingredient in Ayahuasca) is a psychedelic drug in the same effect category as LSD and "magic mushrooms." It is often used in connection with harmine.

In large doses, harmine can cause agitation, excessively low or high heart rates, blurred vision, hallucinations, dangerously low blood pressure, and a tingling, pricking, chilling, burning, or numb sensation on the skin with no apparent physical cause. In low doses it is a cancer drug, an anti-depressant of the MAOI variety, and promotes bone growth.

Bufotenine is chemically a close relative of DMT found in toad secretions (it can be lethal in high doses) and in certain South American seeds.

Cocaine is widely used illegally as a general nervous system stimulant and is considered highly addictive when used in that manner at the doses common in those uses. Benzoylecgonine (BZE) is a metabolite of cocaine.

Given the mix of compounds that were found together, and their effects, the hypothesis that this was the drug stash of a shaman is very plausible. This fits attested examples of how these compounds have been used by indigenous South American people.

FLAG 19, LC & P, And The Extended Koide Formula

Abstract

As the quark masses and Higgs boson mass have been measured more precisely over the last few years at the LHC as summarize by the Particle Data Group through its 2018 data, and in lattice determinations using the quark mass measurements in the FLAG 19 report, it is worth re-examining two phenomenological relationships between them: the LC & P hypothesis and the extended Koide's formula for quarks.

The LC & P Hypothesis

The global LC & P relationship between the fundamental particle masses and the Higgs vev proposed in 2013 that the sum of the Yukawas of the fundamental particles of the Standard Model is exactly 1 still holds to within 1.3 sigma of the currently measured masses of the top quark and Higgs boson.

This hypothesis, if true, strongly constrains the parameter space of beyond the Standard Model massive particles that derive their mass from the Higgs mechanism to a mass range that has been thoroughly tested in a manner that rules out non-Standard Model particles of most kinds.

But, it is increasingly clear that the contributions of the fundamental fermions and the fundamental bosons are not equal, although this equality is still not entirely ruled out. The sum of the Yukawas of the fundamental fermions using the best available data is 0.4940 and the sum of the Yukawas of the fundamental bosons using the best available data is 0.5022. It takes a top quark value about 2.6 sigma from the measured value and a Higgs boson value about 3.3 sigma from the measured value to bring both of them to 0.5 exactly. 

The approximate symmetry between fermions and bosons in this relationship echos supersymmetry and may help explain why supersymmetric models can serve as approximations of Standard Model phenomena. This also suggests a new unsolved question in physics (that really isn't truly a problem any more than the hierarchy problem or naturalness problem are), which is:

"Why are fundamental boson masses slightly heavier relative to fundamental fermion masses than we might naively expect?"

The Extended Koide Formula

Rivero's extended Koide's formula from 2011 for quarks can be adjusted in a manner that I suggested in 2013 based upon the ansatz that the relative values of the charged fermion masses arises dynamically from the W boson interactions between these fermions and the fermions that they can be transformed into via W boson interactions. 

How does the adjusted extended Koide's formula for quarks compare to the experimental measurements?

Quark Type - Adjusted Extended Koide Mass - FLAG 19 Mass- PDG Mass (all in MeV)

top 172,743 v. 173,000 +/- 400 (-0.64 sigma) v. 173,000 +/- 400 (-0.64 sigma)

bottom 4192.98 v. 4,198 +/- 12 (-0.49 sigma) v. 4,180 +40-/-30 (+ 0.32 sigma)

charm 1293.21 v. 1,282 +/- 17 (+0.66 sigma) v. 1,275 +25/-35  (+ 0.73 sigma)

strange 92.274758 v. 93.12 +/- 0.69 (-1.22 sigma) v. 95+9/-3 (- 0.91 sigma)

down 5.32 v. 4.88 +/- 0.2 (+2.2 sigma) v. 4.7 + 0.5/-0.4 (+1.24 sigma)

up  0.0356 v. 2.5 +/- 0.17 (-14.5 sigma) v. 2.2 +0.5/-0.4 (- 5.4 sigma)

These values are consistent at or near the two sigma level, depending upon the measurements used for comparison purposes, with all of the quark masses except the up quark mass which is grossly at odds with the experimentally measured value.

So, while Rivero's extended Koide's formula is a good first order approximation for quarks based solely on the electron and muon masses, and my adjustments are a good second order approximation for quarks that incorporates CKM matrix data, at least one more layer of adjustment is needed to actually capture physical reality.

This also suggests a new unsolved question in physics (that really isn't truly a problem any more than the hierarchy problem or naturalness problem are), which is:

"Why does the up quark have more than a negligible mass?"

Note that even though these are merely phenomenological relationships based on some hunches about a possible underlying physical mechanism (and Koide and others have also proposed different underlying physical mechanisms), even if they are not accurate for the reasons proposed, they do give us a deeper understanding of the manner in which they quantities are related that is more than merely random.

Reductions in the uncertainty in the measurements of the top quark mass and Higgs boson mass that are likely to occur in the foreseeable future will greatly increase the extent to which these hypotheses are tested empirically in a convincing manner.

A detailed analysis of these issues appears below the fold.

The Copper Age Prince With The Crystal Dagger

A 2018 account of a Copper Age man buried with a crystal dagger and twenty young women in what is now Spain has to have been one of the most intriguing in the past year.

Denisovans Were In Tibet First

The partial jaw bone shown above (which on my laptop screen is close to its actual size) from 160,000 years ago in Tibet was identified initially as Denisovan because the shape of the teeth in it had features unique to the Denisovan teeth from a Siberian cave from which Denisovan DNA was detected. The identification was confirmed by comparing non-DNA proteins in the Tibetan sample which degrade less readily than DNA does. 

The jaw bone brings us much closer to figuring out what Denisovan's looked like since we only had teeth and DNA until now, although our sense of what they looked like is still very fuzzy. There are a number of instances of East Asian hominin remains with a mix of archaic and modern features that might be Denisovans or might be something else, but those haven't yielded DNA or other evidence necessary to confirm or rule out the possibility that the samples are from the same species.

We already knew that it was likely that Denisovans had lived in Tibet because the high altitude adaptation genes in humans there today were introgressed from Denisovan DNA and then grew ubiquitous because those genes had selective advantage. This also implies that there was a Denisovan presence in Tibet as recently as 40,000-50,000 years ago when modern humans first arrived there. 

Genetically, Denisovans share a genetic clade with Neanderthals and appear to have diverged from modern humans at about the same time, but the Denisovans have a much less successful population history than the Neanderthals did, in the Siberian individuals, at least, because there is are genome based indications of a continually small effective population size among Denisovans.

There is also lots of introgressed Denisovan DNA in Papuans, Australian Aboriginal people, Filipino Negritos, people from Oceania with Papuan ancestry. All of this started to be visible in people who live just past the Wallace line. There is a much smaller percentage of Denisovan DNA in mainland Southeast and East Asians. Recent data suggests that Denisovan DNA in mainland Asians and that Denisovan DNA in Papuans are from highly diverged Denisovan clades and hence that there were at least two distinct instances of Denisovan introgression in Southeast/East Asia, before even considering a third one in Tibet.

The paper is:

Fahu Chen, et al., "A late Middle Pleistocene Denisovan mandible from the Tibetan Plateau." Nature, 2019 DOI: 10.1038/s41586-019-1139-x

A blog report with lots of images and a Bigfoot angle is here.

Most Of The Standard Model Is Irrelevant Most Of The Time

This is cut and pasted from an answer that I provided at Physics Stack Exchange to a question regarding the impact that second and third generation quarks have in our daily lives:

Every nucleon has what are called sea quarks in it, in addition to the valence quarks that define the nucleon as a proton or neutron. Some of those sea quarks, especially the strange quarks, have some secondary relevance in practical terms regarding how the residual strong nuclear force between protons and neutrons in an atomic nucleus is calculated from first principles and how stable a free neutron is if you calculate that from first principles. Strange quarks are also found in the Λ0 baryon (which has quark structure 𝑢𝑑𝑠), which is present at a low frequency in cosmic rays, but has a mean lifetime of only about two tenths of a nanosecond and is only indirectly detected in the form of its decay products.

Strange quarks are also relevant at a philosophical level that could impact your daily life, because mesons including strange quarks called kaons, are the lightest and most long lived particles in which CP violation is observed; thus, strange quarks are what made it possible for us to learn that the laws of physics at a quantum level are not independent of an arrow of time.

You could do a lot of sophisticated engineering for a lifetime without ever knowing that second or third generation quarks existed, even nuclear engineering. Indeed, the basic designs of most nuclear power plants and nuclear weapons in use in the United States today were designed before scientists knew that they existed. The fact that protons and neutrons are made out of quarks was a conclusion reached in the late 1960s and not widely accepted until the early 1970s, although strange quark phenomena were observed in high energy physics experiments as early as the 1950s. Third generation fermions were discovered even later. The tau lepton was discovered in 1974, the tau neutrino in 1975, the b quark in 1977, and the top quark in 1995 (although its existence was predicted and almost certain in the 1970s).

Otherwise, these quarks are so ephemeral and require such concentrated energy to produce, that they have no real impact on daily life and are basically never encountered outside of high energy physics experiments, although some of them may be present in and influence to properties of distant neutron stars. Second and third generation quarks also definitely played an important part in the process of the formation of our universe shortly after the Big Bang.

The only second or third generation fermion in the Standard Model with significant practical engineering applications and an impact on daily life and on technologies that are used in the real world are muons (the second generation electron). Muons are observed in nature in cosmic rays (a somewhat misleading term since it doesn't include only photons) and in imaging technologies similar to X-rays but with muons instead of high energy photons. Muons are also used in devices designed to detect concealed nuclear isotypes. Muons were discovered in 1937, although muon neutrinos were first distinguished from electron neutrinos only in 1962, and the fact that neutrinos have mass and that different kinds of neutrinos have different masses was only established experimentally in 1998.

65 BSM Theories And Core Theory Principles That I Doubt

While I am willing to entertain arguments and evidence to the contrary, I very strongly doubt that any of the following (which are common components of beyond the Standard Model theories except the last which is part of "core theory") are true (some of which are redundant):

1. The PMNS matrix has more than four parameters or does not imply percentages that add to 100%.
2. Sterile neutrinos that oscillate with active neutrinos exist.
3. There are right handed neutrinos and left handed anti-neutrinos.*
4. Neutrinos have Majorana mass.*
5. A seesaw mechanism gives rise to neutrino mass.*
6. Neutrinoless double beta decay is possible in a manner that does not conserve lepton number.
7. Proton decay occurs.
8. There are tree level flavor changing neutral currents.
9. Lepton number is not conserved or baryon number is not conserved outside sphaleron interactions.
10. The baryon number of the universe at t=0 plus an infinitesimal amount was 0.
11. The lepton number of the universe at t=0 plus an infinitesimal amount was 0.
12. The baryon number of the universe minus the lepton number of the universe at t=0 plus an infinitesimal amount was 0.
13. Dark matter particles (other than gravitons) exist.
14. Axions exist.
15. Supersymmetric particles exist.
16. There is a fourth generation of Standard Model fermions.
17. There are pseudo-scalar, charged or different mass scalar Higgs bosons.**
18. There are fundamental fermions other than those identified in the Standard Model below the GUT scale.**
19. There are fundamental bosons not identified in the Standard Model below the GUT scale, other than gravitons and possibly one or two bosons related to neutrino mass and/or neutrino oscillation.**
20. CPT symmetry is violated under any circumstances.
21. There are any interactions involving massless carrier bosons that show CP violation.
22. There are any massless particles that interact via the weak force.
23. There are any massive particles that do not interact via the weak force.
24. There are any neutrinos with zero mass.
25. There are massless fundamental fermions.
26. Thera are leptoquarks.
27. There are tachyons.
28. Negative mass exists.
29. There are more than four dimensions of space-time, either large or tiny.***
30. Mass-energy conversation is violated locally at t=0 plus an infinitesimal amount.
31. The topology of space-time is sufficiently warped or non-local to give rise to traversable worm-holes.****
31. Fundamental physical constants vary in space-time for any reason other than energy-scale.
32. Gravitons that have non-zero rest mass exist.
33. The actual physical value of muon g-2 differs from the correctly calculated value under the Standard Model.
34. The neutron lifetime discrepancy is anything other than measurement error or a theoretical error.
35. The muonic hydrogen radius discrepancy is anything other than measurement error or a theoretical error.
37. The CKM matrix has more than four parameters or does not imply percentages that add to 100%.
38. It is possible for anything resembling life as we know it to enter a black hole without dying.
39. The observed Higgs boson has properties different from those that the Standard Model Higgs boson is predicted to have at its experimentally observed mass.**
40. Gravity behaves exactly as predicted in classical General Relativity (as applied today) in all circumstances without modification even in the extremely weak field limit.

I doubt that any of the following (which are common components of beyond the Standard Model theories) are true (some of which are redundant), but far less intensely:

1. It is impossible to derive any of the experimentally determined physical constants of the Standard Model from a deeper theory.
2. The sum of the square of the fundamental particle masses does not when evaluated at some proper energy scale such as pole masses or the Higgs vev, equal the square of the Higgs vev.
3. The probability of a transition from a first generation fermion to a third generation fermion in the CKM matrix is ever not equal to product of the probability of a transition from a first generation fermion to a possible second generation fermion and to the probability of a transition from that possible second generation fermion to a third generation fermion.
4. There are violations of lepton universality significantly greater than the square root of the ratio of the neutrino masses to the charged lepton masses.
5. Koide's rule for charged leptons is inaccurate by significantly greater than the square root of the ratio of the neutrino masses to the charged lepton masses.
6. The reason that Koide's rule works for charged leptons cannot be generalized in some manner to explain the quark and neutrino masses.
7. The differences in mass between the charged leptons and the neutrinos is unrelated to the relative strengths of the electromagnetic coupling constant and the weak force coupling constant.
8. The neutrinos have an inverse mass hierarchy.
9. The lightest neutrino mass is as large as the difference between the lightest and second lightest neutrino mass.
10. The net electric charge of the universe is non-zero.
11. Sphaleron interactions actually occur physically.
12. There is a multiverse other than an anti-universe at times before the Big Bang.
13. Cosmological inflation occurred.
14. The temperature of the Big Bang was not finite.
15. The temperature of the Big Bang can be exceeded in the universe at latter times.
16. There are (or were) primordial black holes for more than an instant.
17. There are substances in the universe with greater density than the most dense possible neutron star or the smallest possible stellar black hole.
18. Dark energy is a non-Standard Model substance of some kind (other than a gravity modification).
19. Massless gravitons do not exist.
20. Gravitational energy cannot be localized.
21. There are ever violations of mass-energy conservation involving gravity.
22. General relativity correctly models the self-interactions of gravitons.
23. The strong equivalence principle is not violated by an external field effect.
24. Lorenz violation is possible in detectable amounts for long distances (e.g. kilometers or more) in a time period comparable to the age of the universe.
25. Free glueballs (i.e confined composite structures made purely of gluons) exist.

At some point, I may want to make an additional list of the beyond the Standard Model physics theories which I do believe are possible given these constraints. But, not today.

I believe that these principles would be a better and more fruitful guiding force for hypothesis generation in theoretical physics than many of those  those commonly in use today such as (1) "naturalness", (2) the "hierarchy problem", (3) the "strong CP problem", (4) the hypothesis that at at t=0 plus an infinitesimal amount the aggregate baryon number of the universe was zero and the aggregate lepton number of the universe was zero, (5) the anthropic principle, and (6) multiverse reasoning.

Footnotes and Clarifications

* To be clear, I don't claim to have the answer to the source of neutrino mass, I simply think that all of the above statements are not true and that some other mechanism than those set forth is the actual source of neutrino mass.

** This is subject to the caveat that there could be more fundamental fermions or bosons that can only combined to, or interact to give rise to dynamically, the Standard Model particles. For example, I do not rule out the possibility that the Higgs boson is a composite particle made up of a W+ boson, a W- boson, a Z boson and a photon, or that all Standard Model fundamental particles are vibration modes of a fundamental string.

*** Dimensionality might, however, be an emergent property of space-time and not fundamental.

**** I do not rule out the possibility that there are microscopic non-local connections at approximately the Planck length scale that could connection to profoundly distant points in space-time that are not traversable.

Another Modified Gravity Paper

This paper has interesting things to say, but thinking about gravity modification in terms of a particular radial distance, rather than in terms of a particular gravitational field strength seems to miss one of the core insights about any gravitational modification that must follow from MOND's phenomenological successes. I've listed the references below the fold as it is a quite nice list of papers on gravitational approaches to dark matter phenomena.

Galactic dynamics and long-range quantum gravity

Matteo Tuveri, Mariano Cadoni

(Submitted on 26 Apr 2019)

We explore in a systematic way the possibility that long-range quantum gravity effects could play a role at galactic scales and could be responsible for the phenomenology commonly attributed to dark matter. We argue that the presence of baryonic matter breaks the scale symmetry of the de Sitter (dS) spacetime generating an IR scale r0, corresponding to the scale at which the typical dark matter effects we observe in galaxies arise. It also generates a huge number of bosonic excitations with wavelength larger than the size of the cosmological horizon and in thermal equilibrium with dS spacetime. We show that for r≳r0 these excitations produce a new component for the radial acceleration of stars in galaxies which leads to the result found by McGaugh {\sl et al.} by fitting a large amount of observational data and with the MOND theory. We also propose a generalized thermal equivalence principle and use it to give another independent derivation of our result. Finally, we show that our result can be also derived as the weak field limit of Einstein's general relativity sourced by an anisotropic fluid.

Comments:	20 pages, no figures
Subjects:	General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Other Condensed Matter (cond-mat.other); Superconductivity (cond-mat.supr-con); High Energy Physics - Theory (hep-th)
Cite as:	arXiv:1904.11835 [gr-qc]
	(or arXiv:1904.11835v1 [gr-qc] for this version)

More Archaic Admixture In Africa

A new paper (open access) continues the ongoing effort to ferret out the nature of the archaic "ghost populations" that admixed with modern humans in Africa, sometimes relatively recently as evolutionary history goes. The archaic introgression percentages inferred statistically are on the same order of magnitude as Neanderthal and Denisovan introgression into the Eurasian populations where this introgression is found.

Razib discusses this paper and another one that I blogged a few days ago at Gene Expression. He notes that the genetic case for archaic admixture in Africa is solid but that the details should be viewed with some skepticism in light of the methods used to discern it. It would be interesting to see if the details of the new paper's model could be replicated from another different set of 21 individuals from the same 15 reference populations using the same methods.

The paper is as follows (with a quick and dirty cut and paste with emphasis added in the abstract):

Whole-genome sequence analysis of a Pan African set of samples reveals archaic gene flow from an extinct basal population of modern humans into sub-Saharan populations

• Belen Lorente-Galdos†,
• Oscar Lao†,
• Gerard Serra-Vidal†,
• Gabriel Santpere,
• Lukas F. K. Kuderna,
• Lara R. Arauna,
• Karima Fadhlaoui-Zid,
• Ville N. Pimenoff,
• Himla Soodyall,
• Pierre Zalloua,
• Tomas Marques-Bonet and
• David ComasEmail authorView ORCID ID profile

†Contributed equally

Genome Biology201920:77

https://doi.org/10.1186/s13059-019-1684-5

©  The Author(s). 2019

• Received: 17 August 2018
• Accepted: 28 March 2019
• Published: 26 April 2019

Abstract

Background

Population demography and gene flow among African groups, as well as the putative archaic introgression of ancient hominins, have been poorly explored at the genome level.

Results

Here, we examine 15 African populations covering all major continental linguistic groups, ecosystems, and lifestyles within Africa through analysis of whole-genome sequence data of 21 individuals sequenced at deep coverage. We observe a remarkable correlation among genetic diversity and geographic distance, with the hunter-gatherer groups being more genetically differentiated and having larger effective population sizes throughout most modern-human history. Admixture signals are found between neighbor populations from both hunter-gatherer and agriculturalists groups, whereas North African individuals are closely related to Eurasian populations. Regarding archaic gene flow, we test six complex demographic models that consider recent admixture as well as archaic introgression. We identify the fingerprint of an archaic introgression event in the sub-Saharan populations included in the models (~ 4.0% in Khoisan, ~ 4.3% in Mbuti Pygmies, and ~ 5.8% in Mandenka) from an early divergent and currently extinct ghost modern human lineage.

Conclusion

The present study represents an in-depth genomic analysis of a Pan African set of individuals, which emphasizes their complex relationships and demographic history at population level.