Monday, January 29, 2024

An Organic Neutrino Telescope

The idea of just hooking up instruments to trees in a forest is the most novel approach to developing a high energy neutrino telescope I've seen.
The primary challenge in detecting ultrahigh energy (UHE) neutrinos with energies exceeding 10^16 eV is to instrument a large enough volume to detect the extremely low flux, which falls as ∼E^−2. 
We explore in this article the feasibility of using the forest as a detector. Trees have been shown to be efficient broadband antennas, and may, without damage to the tree, be instrumented with a minimum of apparatus. A large scale array of such trees may be the key to achieving the requisite target volumes for UHE neutrino astronomy.
Steven Prohira, "The forest as a neutrino detector" arXiv:2401.14454 (January 25, 2024).

Tuesday, January 23, 2024

Which Came First? Canals Or Cities

Irrigation canals arose so long before cities did that these canals and the agriculture that they are a testament to, couldn't have been the reason that cities came to be. So, maybe religion and not agriculture is the key factor.

The latest data from Ancient Mesopotamian city of Girsu shows that agriculture built around system of irrigation canals existed for a 1000 years before the first city was built.

From the Old European Culture blog

The excerpt below is from the body text of the linked article (an educated layman's level publication, not a scientific journal):

Rey and his team used new technologies to understand the development of the city, flying drones over the vast, 250-hectare site. The images they gathered show the extent to which the irrigation system was embedded throughout the city and its surrounds.

Heavy rainfall, a product of climate change, also washed away the top layer of the soil, making the outlines even more apparent. 
Working with archaeologists from five universities in Iraq, led by Jaafar Jotheri of Al Qadisiyah, the British Museum team dug out shells and other material from the bottom level of the canals to be carbon-dated. The results were startling: the canals seem to have been dug in the fifth millennium BC. .

“The big surprise is that the largest irrigation canals date to the prehistory of Mesopotamia. That means they are much, much older than the birth of the city, by about 1,000 years," says Rey. "Traditionally, what you read is that development in Mesopotamia begins at the end of the fourth millennium, around 3300 BC. That’s when there was an important transition from pre-urban to urban and the invention of writing.

"But the canals that we have dated recently sets the date back to the fifth millennium, which means that irrigation is not the key, the spark that triggered the urban construction and the invention of writing. And that's a really important discovery.”

Before, archeologists believed that once the ancient Sumerians learnt to irrigate their crops, they were able to move from subsistence farming to the social and religious hierarchy that the elaborate temples of Girsu attest to.

But the Girsu Project’s discoveries, which Rey has written up for a paper that has passed peer review but which is still to be published, show that the Sumerians were living with well-watered plains for a full millennium before they began to build the temple complexes.

What changed? What moved the needle towards a more complex society?

Rey speculates that the shift was unrelated to the environment but rather owed to the pattern of thinking of those living in Girsu: an ideological transformation. Temples and administrative buildings allowed the powers ascribed to the gods to reside in one site, which was embedded into a larger social and political structure.

“It was a domestication of the power of the gods,” Rey says, in an adaptation of the phrase usually used for Sumerian development of the domestication of water.

Wednesday, January 17, 2024

New Historical Linguistics Paper Get IE Languages Badly Wrong

A new paper in Nature Communications on historical linguistics fails disastrously by claiming that the Indo-European languages had a Neolithic dispersal time from Anatolia. This utterly undermines the credibility of the methodology as a whole, and makes it not worth even bothering to read carefully in any other respect. Mountains of work in myriad papers considering ancient DNA, linguistics, and archaeology, done by far more competent researchers, contradict this paper. This paper never should have cleared peer review.

The idiots who wrote this fatally flawed paper are Sizhe Yang, Xiaoru Sun, Li Jin, and Menghan Zhang.

Friday, January 12, 2024

Why Did The Amazonian Upano Civilization Collapse?

The Upano civilization in the foothills of the Andes Mountains in Eastern Ecuador had a city the size of Roman era London at about the same time as Roman era London, the discovery of which was just published yesterday, in the journal Science.

This archaeological civilization collapsed in approximately 300-600 CE, and the area was only repopulated by the Huapula culture, ca. 800 CE, two centuries or more later.

Why did it collapse?

Several possibilities suggest themselves.

1. The Roman empire was brought down, in significant part, by a major climate event that was global in scope. It could be that the same climate event caused the Upano civilization to collapse halfway around the world. As explained at the link:
Work by dendro-chronologists and ice-core experts points to an enormous spasm of volcanic activity in the 530s and 540s CE, unlike anything else in the past few thousand years. This violent sequence of eruptions triggered what is now called the ‘Late Antique Little Ice Age,’ when much colder temperatures endured for at least 150 years.
But we don't know much about the climate impact of this event in Ecuador or its vicinity. We do know, however, that an extreme climate event did cause a massive population collapse in South America, including the Amazon region, around 6200 BCE. We also know that the Medieval Climate Anomaly, a warm period of the Northern Hemisphere from ca. 1000 CE -1200 CE was matched by similar effects in South America:
The vast majority of all South American land sites suggest a warm MCA. Andean vegetation zones moved upslope, glaciers retreated, biological productivity in high altitude lakes increased, the duration of cold season ice cover on Andean lakes shortened, and trees produced thicker annual rings.
Similar comparisons have been made to South America for Europe's Little Ice Age from 1500 CE to 1850 CE. In that time period, "the climate of southwestern Brazil was wetter than it is now, for example, while that of the country's Northeast region was drier."

The correlations seem to be driven, in part, by ocean temperatures.

2. After a thousand years, soil exhaustion similar to the soil exhaustion that was an important cause of the late Neolithic population crash in Europe could have made the civilization unviable. As the abstract of the 2019 paper linked in this paragraph explains that event:
The focus of this paper is the Neolithic of northwest Europe, where a rapid growth in population between ~5950 and ~5550 cal yr BP is followed by a decline that lasted until ~4950 cal yr BP. The timing of the increase in population density correlates with the local appearance of farming and is attributed to the advantageous effects of agriculture. However, the subsequent population decline has yet to be satisfactorily explained. One possible explanation is the reduction in yields in Neolithic cereal-based agriculture due to worsening climatic conditions. The suggestion of a correlation between Neolithic climate deterioration, agricultural productivity, and a decrease in population requires testing for northwestern Europe. Data for our analyses were collected during the Cultural Evolution of Neolithic Europe project. We assess the correlation between agricultural productivity and population densities in the Neolithic of northwest Europe by examining the changing frequencies of crop and weed taxa before, during and after the population “boom and bust.” We show that the period of population decline is coincidental with a decrease in cereal production linked to a shift towards less fertile soils.
3. They could have been defeated militarily by a neighboring civilization such as the Muisca confederation which was well established in the Northern Andes by the 8th century CE, the Tairona civilization thrived in the Sierra Nevada de Santa Marta mountain range in northern Colombia from the 1st century CE until the Spanish arrival in the 16th century, the Moche civilization that thrived on the north coast of Peru from about 100 to 800 CE, the Wari Empire was located in the western portion of Peru and existed from the 6th century to the 11th century, or the Tiwanaku empire was based in western Bolivia and extended into present-day Peru and Chile from 300 to 1000. See generally here.

4. They could have fallen to a wave of Old World diseases brought to South American through pre-Columbian first contact with Polynesian seafarers, albeit, a wave of diseases less severe (or overcome and recovered from with more time to do so) than in the Columbian European first contact case.

5. They could have not actually collapsed, but relocated. Precedents for this kind of mass migration include the Na-Dene people of Canada who migrated to the American Southwest (around 1000 CE), and the Ancestral Puebloans (around 800-900 CE). For example, the geographically nearby Cañari civilization, whose capital is reputed to be the source of the mythical city of El Dorado, that existed contemporaneous with the 13th to 16th century Inca civilization, could have been derived from the descendants of the Upano people.

Thursday, January 11, 2024

A Huge Lost City In The Amazon

The archaeological culture associated with this lost city, the same size as Roman era London, is so obscure that it didn't even have its own Wikipedia page and wasn't mentioned in the Pre-Columbian History of Ecuador page on Wikipedia.

LIDAR has discovered a city that was once home to 100,000 people in eastern Ecuador, in a time period roughly contemporaneous with the Roman Empire, that was ultimately reclaimed by the Amazon jungle. As Boing Boing explains:
Other reports describe it as a "valley of lost cities" spread throughout the region. The implications appear to be quite spectacular: a sprawling urban civilization larger than nearby Mayan cultures.
The linked report isn't quite as generous in estimating the number of people who lived there, but provides further details:
The settlements were occupied by the Upano people between about 500 BC and AD 300 to 600 – a period roughly contemporaneous with the Roman empire in Europe, the researchers found.

Residential and ceremonial buildings erected on more than 6,000 earthen mounds were surrounded by agricultural fields with drainage canals. The largest roads were 33 feet (10 meters) wide and stretched for 6-12 miles (10-20km).

While it is difficult to estimate populations, the site was home to at least 10,000 inhabitants – and perhaps as many as 15,000 or 30,000 at its peak, said archaeologist Antoine Dorison, a study co-author at the same French institute. That is comparable to the estimated population of Roman-era London, then Britain’s largest city.

The article and its abstract are as follows: 

A dense system of pre-Hispanic urban centers has been found in the Upano Valley of Amazonian Ecuador, in the eastern foothills of the Andes. Fieldwork and light detection and ranging (LIDAR) analysis have revealed an anthropized landscape with clusters of monumental platforms, plazas, and streets following a specific pattern intertwined with extensive agricultural drainages and terraces as well as wide straight roads running over great distances. Archaeological excavations date the occupation from around 500 BCE to between 300 and 600 CE. The most notable landscape feature is the complex road system extending over tens of kilometers, connecting the different urban centers, thus creating a regional-scale network. Such extensive early development in the Upper Amazon is comparable to similar Maya urban systems recently highlighted in Mexico and Guatemala.

According to the Supplemental Materials:
Based on radiocarbon dating mentioned above and on the stylistic and stratigraphic classification of the remains discovered during our excavations, a cultural chronology of 2700 years could be established for the region. This sequence was recently revised and will be presented in a subsequent paper. It presents the succession of four or five cultural assemblages: 
1. Sangay culture: from around 700 to 500 BCE. This first occupation left few remains. 
2. Kilamope Culture: from 500 BCE. These were the first mound builders. Pottery of Kilamope culture is characterized by curvilinear incised decorations, the use of reddish slip and various fine prints and incisions.  
3. Upano Culture: probably from 500 BCE to 300/600 CE. They built earthen mounds and they were contemporaneous or successors of the Kilamope groups. Pottery of the Upano culture is mainly characterized by rectilinear incisions and painted decorations. 
4. Huapula Culture: from 800 to 1200 CE. After the disappearance of the Upano, Huapula groups reused the mounds abandoned by their predecessors. Huapula ceramic is characterized by decorations based on the corrugated modality using wavy patterns, and marks the appearance of modern Jivaroan-speaking populations in the region. 
5. Shuar Culture: They follow the Huapula of whom they are the direct heirs. The cultural evolution of this region is comparable with that known in other Amazonian areas: after sparse occupation, appearance of dense societies during the first phases (Kilamope and Upano cultures) while around 800 CE, the archaeological record indicates a fragmentation of the system with the emergence of smaller and dispersed groups. 
Since the European contact and until the end of the 19th century at least, the Upano basin has been occupied by Shuar groups of the Chicham-Aents culture (recent self-naming to replace the previous inadequate term “Jivaro”). Then came the Spaniards and, later, settlers coming from the Andean high plateaus.

The Supplemental Materials also mention and briefly describe four other ancient Amazonian urban centers that have been located in Cotoca, Llanos de Mojos, Bolivia; Hertenrits, Western coastal plain, Suriname; Kuhikugu, Upper Xingu, Brazil; and El Gaván, Llanos de Barinas, Venezuela.

The Hubble Constant Tensions And Related Tensions


This screenshot is from this recent blog post at Triton Station.

In the year 2007, there were as sweet spot where a lot of cosmology measurements seemed to line up consistently. But, seventeen years later, as a result of new and improved data, this is no longer true, because the cosmic microwave background data from Planck show that the Hubble constant was too small in the early universe and that the cluster baryon fraction was too high. 

The Hubble constant measurements (straight horizontal bar) and the Planck cosmic microwave background constraints (which includes an early after the Big Bang Hubble constant measurement) are flatly inconsistent, which is the "Hubble tension." 

Another Take On The Wide Binary Debate

While I'll need to look more carefully to see if the external field effect/stronger gravity regime effects (which normally makes MOND irrelevant at the solar system level) have been considered appropriately, this is a new paper looking at a different set of wide binary data in a different way that the GAIA data driving the main wide binary-MOND debate.
Modified Newtonian Dynamics (MOND), postulating a breakdown of Newtonian mechanics at low accelerations, has considerable success at explaining galaxy kinematics. However, the quadrupole of the gravitational field of the Solar System (SS) provides a strong constraint on the way in which Newtonian gravity can be modified. In this paper we assess the extent to which modified gravity formulations of MOND are capable of accounting simultaneously for the Radial Acceleration Relation (RAR) -- encapsulating late-type galaxy dynamics -- the Cassini measurement of the SS quadrupole and the kinematics of wide binaries in the Solar neighbourhood. We achieve this by extending the method of Desmond (2023) to infer the location and sharpness of the MOND transition from the SPARC RAR under broad assumptions for the behaviour of the interpolating function and external field effect. We constrain the same quantities from the SS quadrupole, finding that it requires a significantly sharper transition between the deep-MOND and Newtonian regimes than is allowed by the RAR (an 8.7σ tension under fiducial model assumptions). This may be relieved by allowing additional freedom in galaxies' mass-to-light ratios -- which also provides a better RAR fit -- and more significantly by removing galaxies with bulges. We show that the SS quadrupole constraint implies, to high precision, no deviation from Newtonian gravity in wide binaries in the Solar neighbourhood, and speculate on possible resolutions of this incompatibility between SS and galaxy data within the MOND paradigm.
Harry Desmond, Aurélien Hees, Benoit Famaey, "On the incompatibility of the Radial Acceleration Relation and Solar System quadrupole in modified gravity MOND" arXiv:2401.04796 (January 9, 2024).

Forty Physics Conjectures

These are some conjectures about physics that are floating around in my head:

1. Sphalerons, the only Standard Model process in which baryon number and lepton number are not separately conserved, although baryon number minus lepton number is conserved, do not exist, because baryon number and lepton number conservation have the effect of making the energy density necessary for a sphaleron interaction physically impossible.

2. The baryon number of the universe minus the lepton number of the universe is zero, which in turn, implies that the number of neutrinos in the universe is extremely close to the number of anti-neutrinos in the universe.

3. Neutrinos are not Majorana particles and do not have Majorana mass.

4. There are no right handed neutrinos and there are no left handed anti-neutrinos.

5. Neutrinos do not acquire mass via a see-saw mechanism.

6. The Big Bang is at the center of the universe's time dimension. We are on one side of it in time. There is a mirror universe before the Big Bang in time, where due to entropy, time appears to flow in the opposite direction and the universe is anti-matter dominated rather than matter dominated.

7. Cosmological inflation does not exist.

8. Matter-energy conservation is absolute. Thus, the total mass-energy of the universe is constant and finite, although what this means in a global sense as opposed to a local sense is subtle and tricky due to the variations in the rate at which time passes and spatial contraction due to special and general relativity.

9. CPT (combined charge-parity-time) conservation is absolute.

10. The particle set of the Standard Model of Physics includes all fundamental particles except a massless spin-2 graviton that couples in proportion to mass-energy with a coupling constant that is a function of Newton's constant G. Quantum gravity does exist.

11. Dark matter effects are a non-perturbative effect of the self-interaction of gravitons, which are largely a function of the total mass-energy of the system and the extent to which the system is not spherically symmetric. Dark matter effects confine gravitons to within a gravitationally bound, non-spherically symmetric system to an extent greater than they would be if the system was spherically symmetric. The appearance that the amount of dark matter in the universe is constant is a function of early galaxy and structure formation. This implies that the tendency of satellite galaxies to be in the same plane of space is not a coincidence. This explains why the amount of apparent dark matter in a galaxy is related to the extent that it is non-spherical. This explains why there is relatively more apparent dark matter in galaxy clusters than in galaxies. Because gravity is so weak, these non-perturbative effects not considered in general relativity as conventionally applied, are negligible in systems smaller than galaxies. 

12. Dark energy phenomena are due to systems with apparent dark matter not exerting a gravitational pull on mass-energy outside the system to the same extent that these systems would if they were spherically symmetric. The notion that dark energy is a substance created as space-time expands is an illusion. The Hubble constant and cosmological constant are merely approximations of this effect which are not fundamentally constant and are a product of dark matter phenomena over time.

13. Self-interaction of gravity effects lead to earlier galaxy formation than would occur in their absence.

14. MOND is a phenomenological approximation of self-interaction of gravity effects. Gravitational self-interactions give rise to the external field effect predicted by MOND. The strong equivalence principle of general relativity is not a true hypothesis. 

15. There are no dark matter particles and there is no such thing as dark energy.

16. The sum of the square of the fundamental particle masses is equal to the square of the Higgs vacuum expectation value, which is a largely function of the weak force coupling constant. This sets the overall mass scale of the massive fundamental particles (i.e. the fundamental particles other than gluons, photons, and gravitons).

17. All neutrinos have a non-zero mass, even though the smallest neutrino mass eigenvalue is very small (on the order of 1 meV or less).

18. The three Standard Model neutrinos have a "normal" mass hierarchy.

19. The relative masses of the charged leptons, and the relative masses of the quarks, respectively, are dynamically balanced through W boson interactions, by a formula that is an extended Koide's rule formula. This inherently links the quark masses to the CKM matrix and the lepton masses to the PMNS matrix.

20. Koide's rule for charged leptons and charged lepton universality work because the neutrino masses are so tiny relative to the charged lepton masses, and so much more similar to each other than the charged lepton and quark masses, that the deviations from Koide's rule and charged lepton universality that they cause are negligible and undetectable with current technological means.

21. The masses of the neutrinos arise partially from their self-interactions via the weak force and partially from their W boson interactions with the charged leptons and the other neutrinos.

22. The point-particle paradox of the Standard Model is resolved because fundamental particles are fundamentally narrow waves, call them field excitations, and are not actually points.

23. There are no "extra dimensions" of space-time beyond the three dimensions of space and one dimension of time.

24. It is most accurate to describe the fact that quantum entanglement cannot be simultaneously respect causality, locality, and reality, as a causality violation. Thus, when one entangled particle's state is determined, that information goes backward in time to the point of entanglement and then forward in time to the other entangled particle.

25. The CKM matrix and the PMNS matrix completely describe the transition probabilities of the W boson, and the CP violating parameter in each of these matrixes is the sole source of CP violation in the universe. Forces with massless carrier bosons, i.e. electromagnetism carried by the massless photon, the strong force carried by massless gluons, and gravity carried by massless gravitons, can't violate CP because they travel at the speed of light and don't experience time, while Higgs bosons can't violate CP because it has no electromagnetic charge and has even parity, leaving only the weak force carries by the W and Z bosons as a potential source of CP violation. See also this Physics.SE post which observes that: "parity violating weak interactions forced the model to have massive vector and axial vector exchange bosons."

26. It is possible that CP violation actually has a separate fundamental source than the other CKM and PMNS matrix elements that just manifest inseparably from each other in what we can observe, and it is possible that the three non-CP violating parameters of each matrix can actually be described with fewer than three parameters in a deeper theory.

27. The probability of a two generation transition in either the CKM matrix or the PMNS matrix is equal to the product of the probabilities of each of the possible one generation transitions in those matrixes.

28. The beta functions of the Standard Model are slightly wrong, in a manner only discernible at very high energies, because they fail to include the slight impact of gravity on the running of the Standard Model constants.

29. There is no muon g-2 anomaly. The present anomaly is solely due to a miscalculation of muon g-2 because the experimental data that was used to substitute for first principles calculations of it are flawed.

30. The reason that there can't be more than three generations of fundamental fermions is that no fundamental particle can have a mean lifetime of less than the W boson as a t' or b' quark would, and fermions must come in complete generations.

31. The internal structure of the scalar mesons and axial vector mesons are basically isolated problems that will be solved one by one. There is not a single overarching cause that explains all of them. But all of them can be fully explained with existing QED and QCD, and the fundamental particles of the Standard Model. The full hadron spectrum is possible to calculate in principle from the Standard Model although this is challenging in practice and may require the development of new mathematical techniques.

32. It is not impossible that the universe flowing from our Big Bang (both before it and after it) is not all that there is, but any other universes have effects that are difficult or impossible to observe, not just as a matter of astronomy observation technology limits, but because any observable effects of other universes on our universe that have reached us at the speed of light, are so far slight.

33. The universe is not perfectly homogeneous and isotropic even at the largest observable scale, due to amplifications over time of effectively stochastic variation in the early instants after the Big Bang.

34. Big Bang nucleosynthesis is fundamentally sound, and most of the differences between theory and observation (e.g. in Lithium abundance) are due to errors in how we model post-Big Bang nucleosynthesis and our failure to find elements that are indeed out there.

35. The "Bang" of the Big Bang is due to matter-antimatter annihilation as matter tries to move forward in time from before t=0 and antimatter tries to move backward in time from after t=0.

36. The space volume of the Big Bang at t=0 is not necessary zero.

37. There was a maximum temperature and energy scale at t=0 in the Big Bang, which provides a de facto ultraviolet limit to the running of the fundamental constants of the Standard Model.

38. Newton's constant runs with energy scale in the same way that the Standard Model constants do, but the running of Newton's constant has been slight since shortly after the Big Bang.

39. There is probably a maximum mass-energy density equal to the mass per event horizon volume of the smallest possible stellar black hole, which is slightly higher than the maximum mass-energy density of the most dense possible neutron star.

40. It is possible to devise a "within the Standard Model" theory that explains why the Standard Model has the particle content, particle properties, and experimentally measured physical constants that it does in a more reductionist manner than the Standard Model plus quantum gravity, but it is not string theory, it is not supersymmetric, and it is probably not a conventional grand unified theory that fits the Standard Model into a single overarching Lie group.


41.    The Many Worlds Hypothesis is not correct.

Wednesday, January 10, 2024

LambdaCDM Still Broken

The dark galaxy "Nube", the largest low surface brightness galaxy of its kind, shouldn't happen in the LambdaCDM model:

With a stellar mass of ∼4 × 108M and a half-mass radius of Re = 6.9 kpc (corresponding to an effective surface density of ⟨Σ⟩e ∼ 0.9 M pc−2), Nube is the most massive and extended object of its kind discovered so far. The galaxy is ten times fainter and has an effective radius three times larger than typical ultradiffuse galaxies with similar stellar masses. Galaxies with comparable effective surface brightness within the Local Group have very low mass (tens of 105M) and compact structures (effective radius Re < 1 kpc). Current cosmological simulations within the cold dark matter scenario, including baryonic feedback, do not reproduce the structural properties of Nube.

In educated layman's terms:

Nube is an almost invisible dwarf galaxy discovered by an international research team led by the Instituto de Astrofísica de Canarias (IAC) in collaboration with the University of La Laguna (ULL) and other institutions.

The name was suggested by the 5-year-old daughter of one of the researchers in the group and is due to the diffuse appearance of the object. Its surface brightness is so faint that it had passed unnoticed in the various previous surveys of this part of the sky due to the object's diffuse appearance as if it were some kind of ghost. This is because its stars are so spread out in such a large volume that "Nube" (Spanish for "Cloud") was almost undetectable.

This newly discovered galaxy has a set of specific properties which distinguish it from previously known objects. The research team estimate that Nube is a dwarf galaxy 10 times fainter than others of its type, but also 10 times more extended than other objects with a comparable number of stars. . . . this galaxy is one-third of the size of the Milky Way[.]

The authors, in the introduction, working from the dark matter particle paradigm, recounts some of the LambdaCDM model's problems:

Many cosmological observations at large scales suggest that dark matter can be well described as a cold and collisionless fluid (see e.g. White & Rees 1978; Blumenthal et al. 1984; Davis et al. 1985; Smoot et al. 1992). 
Nonetheless, the predictions of this model at galactic scales have faced an increasing number of challenges, such as the “cusp-core” problem, the “missing satellite” problem, and the “too-big-to-fail” problem (see e.g. Boylan-Kolchin et al. 2011; Weinberg et al. 2015; Del Popolo & Le Delliou 2017). 
Many of these problems can be mitigated by the effect of baryon feedback on the dark matter distribution (see e.g. Davis et al. 1992; Governato et al. 2010; Di Cintio et al. 2014). However, if the number of stars or their spatial density were low enough, it would be difficult to argue that stellar feedback could be responsible for affecting the dark matter distribution, because there would not be enough energy to change the location of the dark matter (see e.g. Peñarrubia et al. 2012; Oñorbe et al. 2015). 
In parallel, while the direct detection of dark matter particles remains out of reach, other alternatives to the cold dark matter model have gained traction, and are being applied to solve the small-scale challenges. These include the warm dark matter scenario (see e.g. Sommer-Larsen & Dolgov 2001; Bode et al. 2001), self-interacting dark matter (Spergel & Steinhardt 2000), and fuzzy dark matter (composed of ultralight axions with masses in the 10^ −23 – 10^−21 eV range; see e.g. Sin 1994; Hu et al. 2000; Matos & Arturo Ureña-López 2001). 
For these reasons, the search for objects with extremely low stellar surface densities (where the effect of baryonic feedback is not expected to be relevant) promises to probe the microphysical nature of dark matter, that is, the properties of the dark matter particle.

I don't think that the dark matter particle paradigm is correct. Dark matter and dark energy phenomena are probably gravitational law phenomena that arise from our misunderstanding of how gravity works in galaxy scale and galaxy cluster scale systems. But, ruling out various dark matter particle scenarios does advance the cause of demonstrating that the LambdaCDM Standard Model of Cosmology is wrong, and narrows the task of showing that the cause of these phenomena is gravitational rather than particle based.

It is frustrating that any professional astronomers still take the LambdaCDM model seriously, but paradigm changes like this take hold when the proponents of the old model die, not when new evidence rules them out, scientific method be damned. 

Monday, January 8, 2024

Old World And New World Foods

Selected foods absent or nearly absent from the pre-Columbian New World:

Animal Based
* Beef
* Lamb
* Goat
* Pork
* Chicken
* Limited dairy

Plant Based
* Almond
* Anise
* Apricot
* Asparagus
* Bananas
* Barley
* Basil
Brassica oleracea (a plant species that includes cabbage, broccoli, cauliflower, kale, Brussels sprouts, collard greens, Savoy cabbage, kohlrabi, and gai lan).
* Cantaloupe
* Carrot
* Celery
* Chickpea
* Cinnamon
* Coriander
* Coffee
* Cucumber
* Cumin
* Eggplant
* Fennel
* Flax
* Garlic
* Ginger
* Grape wine and wine grapes
* Hazelnut
* Kiwifruit
* Leek
* Lentil
* Lettuce
* Mace
* Mango
* Melons
* Millet
* Mint
* Nutmeg
* Okra
* Olive
* Onion
* Opium poppy
* Oranges
* Oregano
* Parsnip
* Peas
* Peaches
* Pears
* Pistachios
* Pomegranate
* Radish
* Rosemary
* Rye
* Hops
* Sage
* Sesame
* Soybean
* Spinach
* Sugar cane
* Tumeric
* Turnip 
* Wheat

Selected foods absent from the pre-Columbian Old World:

Animal Based
* Turkey

Plant Based
* Acai
* Agave
* Allspice
* Arrow root
* Avacado
* Brazil nut
Capsicum peppers
* Cashew
* Cassava
* Cactus a.k.a. prickly pear
* Chia
* Cocoa
* Corn (i.e. Maize)
* Cranberry
* Maple sugar
* Papaya
* Peanuts
* Pecan
* Pineapple (a.k.a. ananas)
* Potatoes
* Pumpkins
* Quinine
* Quinoa
* Squash (Acorn, Butternut)
* Strawberries
* Sweet potatoes
* Tobacco
* Tomatos
* Vanilla (there was an Old World species in the Levant sometimes used to flavor wine, but it was never domesticated or widely used)
* Zucchini

Wednesday, January 3, 2024

A Young Man From The Steppe Died In Roman Britain

The Roman Empire connected some people from very distant places for the time. A new ancient DNA find corroborates ancient Roman historical records from the second century CE.

• Ancestry outlier identified in rural Roman Britain dating to 126–228 cal. CE
• Genetically related to contemporary Sarmatian- and Caucasus-associated groups
• Stable isotope analysis reveals life history of mobility
• Deployment of Sarmatian cavalry to Britain in 175 CE is a plausible explanation

In the second century CE the Roman Empire had increasing contact with Sarmatians, nomadic Iranian speakers occupying an area stretching from the Pontic-Caspian steppe to the Carpathian mountains, both in the Caucasus and in the Danubian borders of the empire. In 175 CE, following their defeat in the Marcomannic Wars, emperor Marcus Aurelius drafted Sarmatian cavalry into Roman legions and deployed 5,500 Sarmatian soldiers to Britain, as recorded by contemporary historian Cassius Dio. Little is known about where the Sarmatian cavalry were stationed, and no individuals connected with this historically attested event have been identified to date, leaving its impact on Britain largely unknown. 
Here we document Caucasus- and Sarmatian-related ancestry in the whole genome of a Roman-period individual (126–228 calibrated [cal.] CE)—an outlier without traceable ancestry related to local populations in Britain—recovered from a farmstead site in present-day Cambridgeshire, UK. Stable isotopes support a life history of mobility during childhood. 
Although several scenarios are possible, the historical deployment of Sarmatians to Britain provides a parsimonious explanation for this individual’s extraordinary life history. Regardless of the factors behind his migrations, these results highlight how long-range mobility facilitated by the Roman Empire impacted provincial locations outside of urban centers.
Marina Silva et al., 'An individual with Sarmatian-related ancestry in Roman Britain" Current Biology (December 19, 2023).

Hat tip to Bernard Sécher's blog post "An individual of Sarmatian ancestry in Roman Britain" of today. Professor Sécher sums up the paper as follows (translated by Google from the original French with my slight editorial translation corrections):
Human remains have been discovered in an isolated grave near the village of Offord Cluny located in Cambridgeshire in the south-east of England. An osteological analysis showed that this individual is a young adult aged between 18 and 25 years old. The sex of the individual could not be determined from osteological analysis. A radiocarbon measurement on a tooth gave a date between 126 and 228 AD. 
They also analyzed the genome of this individual. The results showed that this individual was a man. The authors then carried out a Principal Component Analysis to be able to compare this genome with that of other ancient individuals. Interestingly it differs from all other genomes from Roman Britain. On the other hand, it is located close to the ancient genomes of Anatolia and the Caucasus. In particular, the genome has genetic affinities with individuals from the end of the Bronze Age of Armenia and the Alans belonging to the Sarmatian confederation, located north of the Caucasus[.]