New Definitions Of Metric Units Take Effect On May 20, 2019

New definition of the international system of units will take effect on May 20, 2019.

The international system of units, the SI, is the system of units in which:

* the unperturbed ground state hyperfine splitting frequency of the caesium 133 atom Δ𝑣(133Cs)hfs is exactly 9 192 631 770  hertz,

* the speed of light in vacuum 𝑐 is exactly 299 792 458   meter per second,

* the Planck constant ℎ is exactly 6.626 069 57×10−34   joule second,

* the elementary charge 𝑒 is exactly 1.602 176 565×10−19 coulomb,

* the Boltzmann constant 𝑘 is exactly 1.380 648 8×10−23   joule per kelvin,

* the Avogadro constant 𝑁A is exactly 6.022 141 29×1023   reciprocal mole,

* the luminous efficacy 𝐾cd of monochromatic radiation of frequency 540×1012      hertz is exactly 683 lumen per watt,

where the hertz, joule, coulomb, lumen, and watt, with unit symbols Hz, J, C, lm, and W, respectively, are related to the units second, meter, kilogram, ampere, kelvin, mole, and candela, with unit symbols s, m, kg, A, K,K$\text{K}$, mol, and cd, respectively, according to the relations Hz=s–1(for periodic phenomena), J=kg m2 s–2, C=A s, lm=cd sr, and W=kg m2 s–3. The steradian, symbol sr, is the SI unit of solid angle and is a special name and symbol for the number 1, s  so that
sr=m2 m−2=1.

Deriving Basic Units

The means by which these constants should be operationalized is also spelled out in the fine print. Specifically:

The choice of physical constants was made on the basis of minimal uncertainty associated with measuring the constant and the degree of independence of the constant in respect of other constants that were being used. Although the BIPM has developed a standard mise en pratique (practical technique) for each type of measurement, the mise en pratique used to make the measurement is not part of the measurement's definition – it is merely an assurance that the measurement can be done without exceeding the specified maximum uncertainty.

Caesium 133 is used to define the second. The Planck constant is used to define the joule given the second. Boltzmann constant is used to define the degree Kelvin given the joule. The speed of light is used to define the meter given the second. The kilogram, meter and second are used to define the watt. The second and the watt and the properties of a laser of a certain color are used to define the lumen and candela. The elementary charge is used to define the coulomb which is used with the second to define the ampere. The steradian is mathematically defined.

Casesium 133, Planck's constant and the speed of light could also be used to determine the kilogram and the kilogram's mass can also be determined directly from the definition of the mole (I would think that the former is as a practical matter easier to get precise about than the latter). So, the mole is just an alternative (potentially not quite exactly the same at the part per billion level) way to define the kilogram and could have been omitted, even though as a practical matter it is probably easier to operationalize that the method using casesium 133, Planck's constant and the speed of light. A presume that the fine print favors one method over the other, or at least resolves the conflict, if there is a discrepancy between two ways of defining the kilogram.

The History Of The Metric System

In some ways, the reform represents a return to the metric system's historic roots in physical constants after the Enlightenment motivated post-French Revolution thought that spawned it.

The original definition of the meter adopted in March of 1791 was one ten millionth of the distance between the North Pole and the Equator through Paris. From 1889 until 1960, the meter was defined in terms of reference objects. 

From 1889 until May 20, 2019, the kilogram has been defined in terms of reference objects. But, the gram was calibrated originally to be equal to the mass of one cubic centimeter of water. 

The size of the degree in Celsius and Kelvin temperatures is designed to be 1% of the difference in temperature between the freezing point of water and the boiling point of water. 

The calorie was originally the amount of heat required to raise the temperature of 1 kg of water from 0 to 1 °C at 1 atmosphere of pressure.

The original definition of the second was based on Earth's average rotation during 1750–1892, which takes, on average, about 31,556,736 seconds (60 seconds a minute, 60 minutes an hour, 24 hours a day, 365 days a year except in leap years divisible by four and not divisible by 100 when there are 366 days a year).

An erg is the amount of work done by a force of one dyne exerted for a distance of one centimeter. In the CGS base units, it is equal to one gram centimeter-squared per second-squared (g⋅cm2/s2). It is thus equal to 10^−7 joules or 100 nanojoules (nJ) in SI units.

The joule is an energy unit that flows naturally from thinking in terms of kilograms, meters and seconds (it is one kg*meter squared per second squared a.k.a. one Newton meter a.k.a. one Pascal times cubic meters). It can also be defined as:

* The work required to move an electric charge of one coulomb through an electrical potential difference of one volt, or one coulomb-volt (C⋅V). This relationship can be used to define the volt.

* The work required to produce one watt of power for one second, or one watt-second (W⋅s) (compare kilowatt-hour – 3.6 megajoules). This relationship can be used to define the watt.

Current in ampere's was defined by setting the magnetic force constant ${\displaystyle k_{\mathrm {m} }}$ to unity and electric potential is defined in such a way as to ensure the unit of power calculated by the relation is an erg/second. This was slightly refined to produce the current soon to be replaced definition of the ampere which was that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 m apart in vacuum, would produce between these conductors a force equal to 2×10^−7 newton per meter of length (i.e. two dynes).

The previous definition of the mole was the amount of substance of a system that contains as many elementary entities as there are atoms in 0.012 kilogram of carbon-12 (i.e. in 1 gram of a carbon-12 standard based atomic mass unit). The mole was thus derive of the gram which was derivative of the mass of one cubic centimeter of water which was derivative of the meter.

The new physical constant based definitions still bear homage to these motivating concepts for metric system basic units, as the numbers selected aren't natural at all in their own reference frames.

Other Impacts

All measurements in the U.S. customary system of measurements are defined exactly in terms of S.I. units, so they will also change subtly on May 20, 2019.

The inch in the U.S. customary system is defined to be exactly 0.0254 meters, so all U.S. customary measurements of length, area and volume will change on May 20, 2019. The U.S., the United Kingdom and other Commonwealth countries agreed on this definition effective July 1, 1959. (The speed of light in miles per second will now be: 186,282.397 to the nearest part per billion, leaving a rounding error of about 1 part per 20 billion.)

Likewise, the U.S. customary system pound is defined to be exactly 435.59237 grams by agreement between the U.S., the United Kingdom, and other English-speaking countries in 1959, so all units of weight in the U.S. customary system (or strictly speaking analogs of U.S. customary system measurements of weight converted to measurements of mass).

The degree Fahrenheit, which is defined as exactly 5/9ths of a degree Kelvin in magnitude, so it will change on May 20, 2019. 

A degree Celsius and a degree Kelvin are defined to be equal in magnitude. There is an exact conversion between degrees Celsius and degrees Fahrenheit (since 32 degrees Fahrenheit is exactly 0 degrees Celsius and 212 degrees Fahrenheit is exactly 100 degrees Celsius). But, Celsius is not an S.I. unit. 

By international agreement, since 1954 the unit degree Celsius and the Celsius scale are defined by absolute zero and the triple point of Vienna Standard Mean Ocean Water (VSMOW), a specially purified water. This definition also precisely relates the Celsius scale to the Kelvin scale, which defines the SI base unit of thermodynamic temperature with symbol K. Absolute zero, the lowest temperature possible, is defined as being exactly 0 K and −273.15 °C. The temperature of the triple point of water is defined as exactly 273.16 K (0.01 °C).

The calorie is also a metric, but non-S.I. unit based upon the properties of water. It is the amount of energy needed to heat on cubic centimeter of liquid water (which has a mass of one gram) by one degree Celsius. It is about 4.1868 J. A dieter's calorie is 1000 calories or one kilocalorie, or about 4186.8 J.

How to change from U.S. customary units to metric units.

I have long recommended that the U.S. make the change over to metric units partially, first converting (1) from Fahrenheit to Celsius and Rankine to Kelvin, (2) from horse power to watts, (3) from BTUs and tons of refrigeration and foot-pounds to joules and calories, and (4) from slugs to Newtons, while deferring conversion of more familiar units later. Since few people use Rankine, tons of refrigeration, foot-pounds and slugs, those conversions would be painless. More people use horse power and BTUs, but both are used on a very isolated basis and would require reforms primarily by a few big corporations in a small number of industries. For most people, the first wave would primarily mean converting from Fahrenheit to Celsius.

Conversion from more familiar U.S. customary units of length, area, volume and weight to metric and S.I. units would take place later, to minimize the amount of conversion shock taking place at one time. This is because so many legacy measurements (e.g. land surveys and recipes) are in convenient multiples of U.S. customary units.

This would probably best be broken up into different waves based upon the industry or type of thing measured, continuing current trends which use metric units for some purposes and U.S. customary units for others.

Commentary

One of the subtle issues of the redefinitions is that it obscures, without truly eliminating, issues related to the precision with which we can measure the physical constants that are given exact defined values (most of which were in the parts per billion plus or minus an order of magnitude). The new definitions are generally designed to match existing values to nine significant digits of precision.

I'm disappointed that they didn't decide to define the speed of light in a vacuum to be exactly 300 000 000 meters per second, even though I understand why they did (for back compatibility). The difference would be a reduction of 0.7 millimeters per meter.

Likewise, if we were starting over from scratch, defining the coulomb as as 1 x 10^19 elementary electric charges would have made sense. But, we are victims of our past.

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.