Tuesday, January 29, 2019

Liturgical Languages

This is an (incomplete) list of languages that continued to be used for religious purposes long after they ceased to be used in everyday life:

* Sumerian was used for religious purposes long after Akkadian became the everyday language of Mesopotamia, 

* Hattic persisted in religious use long after Hittite was the language of Anatolia, 

* Coptic continue in religious use by Coptic Christians mostly in Egypt and Ethiopia long after it ceased to be used in everyday speech.

* Hebrew persisted in religious use long after it was a dead language in everyday use (and before it was revived as a living language).

* Latin continued in religious use long after it ceased to be used in everyday speech. 

* Old Church Slavonic continued in religious use long after it ceased to be used in everyday speech.

* Sanskrit continued in religious use in South Asia long after it ceased to be used in everyday speech.

While not exactly analogous (because it was and continues to be in many places a superstrate rather than a substrate language of colonizers and missionaries), classical Arabic is still used for Islamic religious purposes, but it is not really spoken on an everyday basis anymore in its classical form.


What languages am I missing?

How much can tribal languages of Native Americans and Siberian peoples, for example, be seen in this context and framework?

Monday, January 28, 2019

The State of SUSY

This is a republication of a post at the Physics Forums with some minor edits.
Is supersymmetry still possible or has it been proven wrong?
Short Answer

Supersymmetry is still possible because it has many adjustable features that can be tweaked to remove it from the exclusion ranges of existing parameter space (keep in mind that SUSY is a class of theories and not just a single theory). But, the kinds of SUSY theories that are still possible are increasingly unlike the ones that theorists had hoped for when they came up with SUSY and the versions that remain possible do increasingly little to solve the unsolved problems in physics that it was invented to solve. 

So, confidence that SUSY is an accurate description of the universe and the popularity of SUSY related research is declining, although this decline is lagging behind the experimental and theoretical disappointments that have emerged because so many individual physicists and so many major physics experiments have invested so much in exploring this possibility.

Long Answer

There is no positive observational evidence for supersymmetry. And, because many supersymmetry theorists had expected to see signs of it at the Large Hadron Collider, or in other kinds of observations, this has considerably dampened enthusiasm for this class of theories, although it remains an area of vigorous and high volume investigation.

A substantial share of the papers published by the collaborations at the Large Hadron Collider consider how the data collected (which is basically always consistent with the Standard Model in areas pertinent to supersymmetry theories) limit the parameter space of various varieties of simplified or generic supersymmetry theories. For the most part, various supersymmetric particles (sparticles) are excluded in mass ranges up to several hundred GeV to 1 TeV.

There are also indirect probes of higher masses such as the potential muon g-2 discrepancy, the beta function of Standard Model constants, the mass of the Higgs boson, and the similarity of the observed Higgs boson to the predicted properties of a Standard Model Higgs boson of that mass. Those indirect measurements disfavor SUSY, although not definitively, up to about 10 TeV mass scales for the lightest supersymmetric particles.

The mass of the Higgs boson is particularly important because at the observed mass, the Standard Model equations do not pathologically break down and produce non-physical results (like probabilities that do not add up to 100%) at any energy scale up to the GUT scale (the hypothetical scale at which gauge unification can take place in SUSY theories). At many other possible Higgs boson masses, the Standard Model equations would have broken down, making some sort of beyond the Standard Model physics necessary to explain reality at high energies.

The Higgs boson mass also implies that the universe is at least "meta-stable" (i.e. stable on time lengths comparable to the age of the universe), while many other possible Higgs boson masses would have been unstable, which would mean that the universe shouldn't exist, which would imply the need for beyond the Standard Model physics such as SUSY to prevent this from happening. So, again, the Higgs boson mass actually observed makes this kind of new physics unnecessary.

None of these kinds of observational evidence can completely rule out supersymmetry, because at a sufficiently high energy scale, supersymmetric phenomena "decouple" from low energy phenomena and do not have effects on low energy phenomena that are large enough to discern. But, if SUSY phenomena can only be discerned at such high energy scales then it probably can't be seen not just at the LHC, but also at the next generation collider, which is not something that generates great research enthusiasm for a theory. If SUSY doesn't give rise to any phenomena different from the Standard Model at energy scales below 10,000 TeV, for example, it is much less salient to the nature of the universe and to physicists who have no way to study those energy scales in the foreseeable future. A scenario in which there are new beyond the Standard Model physics at extremely high energies, but there is nothing new between what we have already observed and those extremely high energies, is called a new physics "desert", or the "nightmare scenario" for today's high energy physicists.

Another difficulty is that as the parameter space of possible SUSY theories is constrained by experiment after experiment, the kinds of SUSY theories that can be consistent with the data grow more and more baroque and hence more disfavored by Occam's Razor. The most minimal realization of SUSY, the MSSM, for example, is either ruled out or very nearly ruled out, by existing evidence, although less minimal realizations of SUSY are still possible.

More generally, there are basically no anomalous results in high energy physics relative to Standard Model expectations that are explained well by SUSY. If there was really such a dramatic departure from the Standard Model with so many new particles and interactions lurking just around the corner in terms of energy scale, you would expect to see, at a minimum, lots of anomalies over a wide range of experiments that were individually subtle but collectively all seemed to point in the same direction. But, we aren't seeing that.

Certainly, there are unsolved questions and anomalies in high energy physics. For example, we still have no meaningful ability to predict in advance the spectrum of scalar and axial vector mesons that are observed at colliders. But, most of these unsolved questions and anomalies involve situation in quantum chromodynamics where measurement imprecision and calculations that are very hard to do precisely because the math is very difficult are present but SUSY and the Standard Model would make essentially the same predictions, or in some other area (like the "strong CP problem") where SUSY does not provide a ready, long anticipated explanation.

SUSY was originally formulated to make phenomena at the "electroweak scale" of low hundreds of GeVs to be more "natural" in a technical sense. Even if SUSY was discovered at 10 TeV it would not serve the purposes for which it was originally devised very well.

Another motivation to formulate SUSY was that it provided candidate particles beyond the Standard Model for dark matter, called SUSY WIMPs, with an expected range of masses and some fairly well defined properties. But, while dark matter particles are not ruled out experimentally (and indeed are supported by lots of evidence and lots of researchers), the particular varieties of WIMPs that would be expected to be dark matter candidates in SUSY theories (whose interactions with other particles and properties except mass are largely predicted by the theory), are almost completely ruled out by LHC experiments, direct dark matter detection experiments, and the dynamics of dark matter that can be inferred from astronomy observations. The "hot" candidates for dark matter like sterile neutrinos, axion-like dark matter, "warm dark matter", self-interacting dark matter, and primordial black holes, are all inconsistent with the SUSY WIMP dark matter candidates that had seemed so appealing before evidence was collected.

SUSY was also popular because it was seen as the primary or exclusive low energy realization of string theory, at a time when there was a widely shared naive hope that a single possible string theory variant would uniquely define the reality that we observe if we just developed the theory a little further. But, as the problem of connecting high level abstractions in string theory to low energy phenomenology proved much more murky than anticipated, and in the last year or two, it became apparently that most or all realizations of string theory have properties that are inconsistent with the observed universe in a categorical and generic way, yet another motivation for SUSY has been undermined, although not entirely eliminated.

Even one of the great "beautiful" features of SUSY (gauge unification at the GUT scale) in the minimal supersymmetric model (MSSM) that seemed to hold true at the time it was originally formulated, is no longer consistent with existing more precise measurements of physical constants and the beta functions of SUSY constants predicted in the MSSM.

SUSY is more mathematically tractable than the Standard Model in many respects and as a result, its predictions about systems that are difficult to analyze analytically or numerically can help give us useful intuition about high energy physics systems, because SUSY and the Standard Model are necessarily very similar to each other at low to intermediate energy scales. But, enthusiasm for SUSY and its low energy theory of everything counterpart, SUGRA (supergravity), has waned considerably because of these recent developments.

However, SUSY is still an attractive target because it is a coherent alternative to the Standard Model that makes predictions that can be calculated for any given set of parameters, and has lots of moving parts that prevent it from being ruled out definitively. Many of the alternative beyond the Standard Model theories in particle physics such as "Technicolor" (a composite Higgs boson theory) and composite Standard Model fermion theories, are in an even greater shambles in the wake of the discovery of the Higgs boson and nothing else at the Large Hadron Collider. And, less objectively, lots of theorists and phenomenologists also have a lot of sunk investment in supersymmetric theories which they have devoted many years and sometimes whole careers to master and develop and can't easily develop some new research agenda at this stage of their career.

Post Script

As my explanation above suggests, I am not among those who think that supersymmetry is an accurate description of reality.

The Anti-Universe

This paper discusses what I think, in broad outlines, particularly the portion in bold, although not necessarily the specifics, is the most likely explanation of the baryon asymmetry of the universe, although it may never be possible to prove (I blogged a 2017 paper on the same theme previously). See previous discussion of the concept here and here and here and here and here and here. I don't think, however, that it is necessary to inject right handed neutrinos or dark matter into this mix. 

Sabine Hossenfelder mentions and discusses this paper in a recent post.

The Big Bang, CPT, and neutrino dark matter

We investigate the idea that the universe before the Big Bang is the CPT reflection of the universe after the bang, so that the state of the universe does {\it not} spontaneously violate CPT. The universe before the bang and the universe after the bang may be viewed as a universe/anti-universe pair, created from nothing. The early universe is radiation dominated and inflationary energy is not required. We show how CPT selects a preferred vacuum state for quantum fields on such a cosmological spacetime. This, in turn, leads to a new view of the cosmological matter/anti-matter asymmetry, and a novel and economical explanation of the dark matter abundance. If we assume that the matter fields in the universe are described by the standard model of particle physics (including right-handed neutrinos), it is natural for one of the heavy neutrinos to be stable, and we show that in order to match the observed dark matter density, its mass must be 4.8×108 GeV. We also obtain further predictions, including: (i) that the three light neutrinos are majorana; (ii) that the lightest of these is exactly massless; and (iii) that there are no primordial, long-wavelength gravitational waves.
Comments:43 pages
Cite as:arXiv:1803.08930 [hep-ph]
(or arXiv:1803.08930v1 [hep-ph] for this version)

About Alphabets

For what it is worth, I think that Indus script is probably not an alphabet or even a relatively comprehensive logogram system (where an image represents a concept linked to the symbol visually rather than to the sound made when it is spoken) like the hieroglyphic system or Chinese characters. It is more like a collection of logos and street sign symbols. I think that the same can be said of the Vinca script of the Balkans.

An abjad is a writing system in which vowels are not marked or only marked in an incomplete and secondary manner. An abugida is like an abjad, but each consonant has an secondary attached vowel notation. In a featural alphabet, like Hangul, the shape of the characters has a systematic relationship to the nature of the sounds that each letter represents.

Some of the evolutionary links are also somewhat debatable and many of the alphabets have multiple registers of letters based upon context (e.g. different fonts and capital v. lowercase and printed v. cursive letters in English).

It is also worth observing that the same evolutionary chain of alphabets encompass multiple language families. They originate with the Afro-Asiatic languages but spread to Indo-European languages, South Caucasian languages, Dravidian languages, Altaic languages (arguably both Mongolian and Korean), Tibeto-Burman languages, Mon-Khmer languages, and Tai-Kadai languages. There are also alphabets derived from these alphabets which are used in language families not shown on the charts (some of which were devised or influenced by missionaries, colonialists, or visiting scholars in recent times).

Alphabets and script styles are areal features that do not indicate that the underlying languages have a "genetic" relationship to each other.

Friday, January 25, 2019

ATLAS Run-2 Data Tugs Down Global Higgs Boson Mass Estimate

We have Run-2 top quark mass measurements from CMS and Run-2 Higgs boson measurements from ATLAS in two channels and in one CMS channel (which tugs the global average up by about 0.09 GeV), but combined measurements including Run-2 results for neither mass measurement. 

The Run-2 data from ATLAS pulls the world average down from the 125.09 GeV average from ATLAS and CMS combined based on Run-1 data alone, mostly because the Run-2 diphoton decay channel measurement at ATLAS was significantly lower than the previous measurement.

In all other respects the LHC measurements of the Higgs boson are consistent with the Standard Model expectation to increasing precision, which constrains beyond the Standard Model theories that modify the properties of the Higgs boson.

From here (this is actually old news).

An error weighted average of the new Run-2 CMS data and the new Run-2 ATLAS data, with the Run-1 combined weighted average, yields a new average of 125.08 GeV with a somewhat smaller margin of error than the previous 0.24 GeV. 

A Higgs boson mass of 124.65 GeV, which is notable because it would be the mass at which half of the Higgs vev squared is equal to the sum of the square of the masses of the fundamental Standard Model bosons, is still a value barely consistent with the Run-2 data to date within two sigma.

Tuesday, January 22, 2019


The following analysis of the Italian word "ciao" is from here:
I often close letters with "ciao", which means both "hello; hi" and "bye; goodbye". When I do this, I am essentially saying "I am your slave". 
Borrowed from Italian ciao (“hello, goodbye”), from Venetian ciao (“hello, goodbye, your (humble) servant”), from Venetian s-ciao / s-ciavo (“servant, slave”), from Medieval Latin sclavus (“Slav, slave”), related also to Italianschiavo, English Slav, slave and Old Venetian S-ciavón ("Slav"), from LatinSclavonia (“Slavonia”). Not related to Vietnamese chào (“hello, goodbye”).
The Italian salutation ciao, which is now popular in many parts of the world outside Italy, originated in the dialects of northern Italy. In the dialect of Venice, ciau literally means "servant, slave," and is also used as a casual greeting, "I am your servant." Dialectal ciau corresponds to standard Italian schiavo, "slave," and both words come from Medieval Latin sclāvus. Declaring yourself someone's slave might seem like an extravagant gesture today, but expressions such as Your obedient servant or Your servant, madam were once commonplace in English. Similarly, the Classical Latin word servus meaning "slave" is still used as an informal greeting in southern Germany and in Austria, the Czech Republic, Slovakia, Hungary, Poland, Romania, Ukraine, and other parts of central Europe that were formerly part of the Austro-Hungarian Empire. At the opposite end of the world, in Southeast and East Asia, one even finds words that originally meant "slave"or "your slave" but have developed into pronouns of the first person through their use in showing respect and humility. In Japanese, for example, the word boku is used to mean "I, me," especially by boys and young men, and it comes from a Middle Chinese word meaning "slave" or "servant" and now pronounced pú in Mandarin.
American Heritage Dictionary, 5th ed.

Monday, January 21, 2019

Passings Of Little Known Great Minds

Woit has had three obituaries at his Not Even Wrong blog since Christmas Eve. All three are brilliant people, although none are household names.

Another Dark Matter-Less Galaxy (NGC1052-DF4) Is It Proof Of MOND?

This paper replicates the result seen in a sister galaxy. MOND explains this with the "External Field Effect" something absent from conventional General Relativity.

A second galaxy missing dark matter in the NGC1052 group

The ultra-diffuse galaxy NGC1052-DF2 has a very low velocity dispersion, indicating that it has little or no dark matter. Here we report the discovery of a second galaxy in this class, residing in the same group. NGC1052-DF4 closely resembles NGC1052-DF2 in terms of its size, surface brightness, and morphology; has a similar distance of D=19.9±2.8 Mpc; and has a similar population of luminous globular clusters extending out to 7 kpc from the center of the galaxy. Accurate radial velocities of seven clusters were obtained with the Low Resolution Imaging Spectrograph on the Keck I telescope. Their median velocity is v=1445 km/s, close to the central velocity of 22 galaxies in the NGC1052 group. The rms spread of the observed velocities is very small at σobs=5.8 km/s. Taking observational uncertainties into account we determine an intrinsic velocity dispersion of σintr=4.2+4.42.2 km/s, consistent with the expected value from the stars alone (σstars7 km/s) and lower than expected from a standard NFW halo (σhalo30 km/s). We conclude that NGC1052-DF2 is not an isolated case but that a class of such objects exists. The origin of these large, faint galaxies with an excess of luminous globular clusters and an apparent lack of dark matter is, at present, not understood.
A tweet from van Dokkum states:
and I found a twin of NGC1052-DF2, with the same weird population of globular clusters and super low velocity dispersion. Meet NGC1052-DF4! What the paper can't convey is how incredibly surprised we were!
He also tweeted this image of the system (which naively makes it look further from NGC 1052 but closer to NGC 1035), but it is hard to discern distances between objects since depth is not known with that precision.

A previous posts on point can be found here and here. The authors explain in the introduction the implication of these results for the dark matter paradigm:
With this confirmation, the central unanswered question is whether NGC1052-DF2 is an isolated case or representative of a population of similar galaxies. This is important for judging the likelihood of interpretations that require unusual orbits or viewing angles (see, e.g., Ogiya 2018) and, most importantly, for judging the relevance of NGC1052-DF2 for our ideas about galaxy formation and the relation between dark matter and normal matter. With the important exception of tidal dwarfs (Bournaud et al. 2007; Gentile et al. 2007; Lelli et al. 2015), it is thought that a gravitationally-dominant dark matter halo is the sine qua non for the formation of a galaxy. If galaxies such as NGC1052-DF2 are fairly common we may have to revise our concept of what a galaxy is, and come up with alternative pathways for creating galaxy-mass stellar systems. Here we report the discovery of a galaxy that shares essentially all of NGC1052-DF2’s unusual properties, to a remarkable degree. It is in the same group, has a similar size, luminosity, and color, the same morphology, the same population of luminous globular clusters, and the same extremely low velocity dispersion.
In contrast, MOND understands why this is happening and predicted this result before "The Breakfast Club" was in theaters in the early 1980s.

Galactic Rotation Curves Still Well Behaved

There have actually been a lot of interesting papers about gravity and dark matter in the past little while, but given ill health I'll also simply note this one without much comment or formatting. It affirms and refines the data supporting some kind of modified gravity hypothesis.

The baryonic Tully-Fisher relation for different velocity definitions and implications for galaxy angular momentum

Federico Lelli (1), Stacy S. McGaugh (2), James M. Schombert (3), Harry Desmond (4), Harley Katz (4) ((1) European Southern Observatory, (2) Case Western Reserve University, (3) University of Oregon, (4) University of Oxford)
We study the baryonic Tully-Fisher relation (BTFR) at z=0 using 153 galaxies from the SPARC sample. We consider different definitions of the characteristic velocity from HI and H-alpha rotation curves, as well as HI line-widths from single-dish observations. We reach the following results: (1) The tightest BTFR is given by the mean velocity along the flat part of the rotation curve. The orthogonal intrinsic scatter is extremely small (6%) and the best-fit slope is 3.85+/-0.09, but systematic uncertainties may drive the slope from 3.5 to 4.0. Other velocity definitions lead to BTFRs with systematically higher scatters and shallower slopes. (2) We provide statistical relations to infer the flat rotation velocity from HI line-widths or less extended rotation curves (like H-alpha and CO data). These can be useful to study the BTFR from large HI surveys or the BTFR at high redshifts. (3) The BTFR is more fundamental than the relation between angular momentum and galaxy mass (the Fall relation). The Fall relation has about 7 times more scatter than the BTFR, which is merely driven by the scatter in the mass-size relation of galaxies. The BTFR is already the "fundamental plane" of galaxy discs: no value is added with a radial variable as a third parameter.
It turns out that there are actually quite a few ways that you can tweak gravity to produce this result. This kind of detail helps to discriminate between them. The chart below is a screenshot from the paper capturing its central conclusion:

Friday, January 18, 2019

Quote of The Day

Scientists found that while Pluto was originally a planet, it no longer identifies as one. So we need to respect its position as a Trans-Neptunian Object… along with all the other trans-planets.
From here (Chris Rusche, July 21, 2014).

Still need a little more humor to meet the 3% quota.

Atomic Structure

This blog had a humor deficit that I'm working to backfill.

From here.

Fun fact: 43 out of 1571 posts at this blog are tagged humor (about 3%).

Monday, January 14, 2019

More Evidence That Hobbits Aren't Dwarf Erectus

A 2018 paper from Sweden adds more evidence to the conclusion of two prior papers which conclude that:
H. floresiensis seems to be deeply rooted in the phylogeny of Homo and not closely related to Indonesian H. erectus.
From John Hawks.

Problems With The Hypothesis The Bell Beaker People Derive From The Hungarian Yamnaya

Davidski at Eurogenes points out some problems in the ancient DNA evidence with the hypothesis that the Northern and Central European Bell Beaker people are derived from the Hungarian Yamnaya people. There are lots of archeological and geographic reasons why this hypothesis is plausible and the autosomal genetic evidence isn't inconsistent with this hypothesis, but the ancient Y-DNA data doesn't really support this conclusion so far.

We care because the Bell Beaker people were the last major wave of migration into Northern and Western Europe (in the late Copper Age and Bronze Age) before the gene pools in those regions came to be very similar to those of modern Europe. The Bell Beaker people are also notable because many people believe (although I am somewhat skeptical of the claim for reasons beyond the scope of this short post) that the Bell Beaker people were the original Indo-Europeans in this part of Europe. At any rate, the Bell Beaker people without a doubt were very important in causing the people of Western Europe and Northern Europe to become the people that they are today.

We know, in very general terms that the Bell Beaker people have significant European steppe ancestry, and we know about when they started to appear on the scene, but we lack the kind of more specific understanding of where in particular they came from and what route they took that we have in the case of many other notable mass migration in world history (especially in the late prehistoric period).

Good Problems And Non-Problems

I agree 100% with Sabine Hossenfelder's list of what are and are not "good problems" in fundamental physics in a recent post at Backreaction.

In short: inconsistencies between accepted theories or between accepted theories and observation are problems, while dissatisfaction with the form of the laws of Nature that have been experimentally discerned are not.

I would add that it isn't inherently wrong to look for more elegant ways to describe existing descriptions of the laws of Nature that are not inconsistent with observation or other physical laws, but that this doesn't make them "problems" that need to be solved by physicists. (In the same way, even tough there is more than one way to prove the Pythagorean Theorem, the validity of the Pythagorean Theorem ceased to be a "problem" once it was first proven, even though not every means of proving it had been articulated at that point.) 

I also agree that her placement of the phenomena associated with "dark matter" at the top of her list of "good problems" is appropriate. The existence of these phenomena are established by overwhelming evidence and they can only be explained with "new physics" or (at least) a major reinterpretation of existing physics as it is applied today. Further, figuring out the cause of "dark matter phenomena" is likely to have applications that are predictive, in addition to explaining existing knowledge.

Tuesday, January 8, 2019

Earlier Out of Africa Evidence

A jaw bone and teeth found at least 177,000 years ago in what is now Israel appears to be that of a modern human, pushing back the earliest known evidence of modern humans out of Africa by at least 57,000 years. This is much older than the estimated date of the most recent common ancestor (TMRCA) of all extent Eurasians based upon some genetic evidence although other genetic evidence suggests an even earlier date.
Earliest modern humans out of Africa

Recent paleoanthropological studies have suggested that modern humans migrated from Africa as early as the beginning of the Late Pleistocene, 120,000 years ago. Hershkovitz et al.now suggest that early modern humans were already present outside of Africa more than 55,000 years earlier. During excavations of sediments at Mount Carmel, Israel, they found a fossil of a mouth part, a left hemimaxilla, with almost complete dentition.

The sediments contain a series of well-defined hearths and a rich stone-based industry, as well as abundant animal remains. Analysis of the human remains, and dating of the site and the fossil itself, indicate a likely age of at least 177,000 years for the fossil—making it the oldest member of the Homo sapiens clade found outside Africa.


Israel Hershkovitz, et al., "The earliest modern humans outside Africa" 359 (6374) Science 456-459 (January 26, 2018) DOI: 10.1126/science.aap8369