August Science Readings
Well I'm only 5 days into the month as I start, this time.
| ToDo List Black Body radiation/a> |
| Latter-day Gamma-ray Coordinate Network |
| New evidence of plant food processing in Italy before 40ka |
| End of document |
2023-08 August Science Readings.
And I've got to the end of the month with very little done. Other stuff in life. Several things got into the pipeline, but I haven't got time for.To Do List - Black Body radiation & Mean Free Path
linkOnce again a question of the form "If this [whatever] gets so-much hotter, how will it's colour (black body spectrum) change?"
OK, it's obviously a question for whatever equation produces the "hump" (log-log) or "spike" (linear-linear) graph in all the physics (astrophysics) text books. So I know qualitatively what will happen. But I want to calculate how much it'll change. Which calls for a spreadsheet.
- Specification
- Put in a base temperature, get a colour (peak frequency). Put in a second temperature, get a second colour.
- Tabulate temperatures and colours. One datum is that 2.83 K gives a signal in the microwaves - CMB. 21cm Hydrogen? Orange is arounf 1600k
- subsidiary : wavelengths for colours - it's got to be tabiulated somewhere. If only well-known emission/ absorbtion lines like sodium-D = yellow. Obviously this is going to be rather arbitrary.
- I shouoldn't neeed to plot the BB radiation curves, but I'd like to. Two temperatures, can OO(Calc) do "fill between"? Can Google Calc? Obviously ties into item 2.
Just listening to the radio, about getting stars started, and the concept of Mean Free Path reared it's ugly head again. Need to look at that too.
Latter-day Gamma-ray Coordinate Network
linkFor a number of years (since ... when I was on CI$, so pre-2000) prompt reporting from space-based Gamma Ray detectors has used a mailing list to distribute alerts of spike in GR detections, and by inference, the occurrence of a gamma-ray burst somewhere on the sky. That system has been deprecated as larger numbers of "high energy events" are being monitored, from gravity-wave detectors (3 systems), neutrino detectors (3 operating, several in construction) gamma- and x-ray space telescopes amd other systems. That's annoying, because the simplicity of checking my email has been replaced with needing to register on a NASA website, download and install Python, compile and install several programmes (I'm not sure how many), and then get really informative responses :
topic=gcn.classic.text.AMON_ICECUBE_COINC, offset=None b'Subscribed topic not available: gcn.classic.text.AMON_ICECUBE_COINC: Broker: Unknown topic or partition' topic=gcn.classic.text.FERMI_GBM_TRANS, offset=None b'Subscribed topic not available: gcn.classic.text.FERMI_GBM_TRANS: Broker: Unknown topic or partition'
Which is as useful as something not very useful.
As so often, the documentation seem to know that all users will know everything about what and how a "streaming protocol" is, and how to use one. Which ... well they call it "Kafka", and the name is well-chosen. I know how K. felt.
OK, now I'm getting some "content" - I left the terminal with the python code running while doing other stuff :
topic=gcn.classic.text.FERMI_GBM_ALERT, offset=917
b'TITLE: GCN/FERMI NOTICE\n
NOTICE_DATE: Mon 07 Aug 23 14:38:00 UT\n
NOTICE_TYPE: Fermi-GBM Alert\n
RECORD_NUM: 1\n
TRIGGER_NUM: 713111879\n
GRB_DATE: 20163 TJD; 219 DOY; 23/08/07\n
GRB_TIME: 52674.82 SOD {14:37:54.82} UT\n
TRIGGER_SIGNIF: 6.7 [sigma]\n
TRIGGER_DUR: 0.064 [sec]\n
E_RANGE: 2-2 [chan] 23-47 [keV]\n
ALGORITHM: 26\n
DETECTORS: 0,0,1, 0,0,1, 0,0,0, 0,0,0, 0,0,\n
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230807610/quicklook/glg_lc_medres34_bn230807610.gif\n
COMMENTS: Fermi-GBM Trigger Alert. \n
COMMENTS: This trigger occurred at longitude,latitude = 236.15,-12.07 [deg]. \n
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger. \n' Which isn't much help, but I'd also received an email with the same content. The email is more USABLE.
New evidence of plant food processing in Italy before 40ka
https://www.sciencedirect.com/science/article/abs/pii/S0277379123002093?dgcid=coauthor Quaternary Science Reviews Volume 312, 15 July 2023, 108161(Prepared a while ago, offline. Stalled.)
If anyone actually thought about the implications behind the hype about the "Palæolithic Diet", none of this would come as a surprise. But since thinking about things is antithetic to the interests of the "influencers" behind the "Palæolithic Diet", then it's unlikely to get much traction from them.
Abstract : Evidence of plant food processing is a significant indicator of the human ability to exploit environmental resources. The recovery of starch grains associated with use-wear on Palaeolithic grinding tools offers proof of a specific technology for making flour among Pleistocene hunter-gatherers.
Let’s get this clear – this is HUNTER GATHERERs making flour – and by implication, breads, porrages, gruels, etc. Just because they’re called “HUNTER GATHERERs” doesn’t mean that they’re living on mammoth steaks and bronto-burgers exclusively. As modern studies of modern HGs suggests, upwards of 50% of their calories come from the GATHER part of the lifestyle, and very often, it's gathering by the women-folk. Collecting tubers with a waen on the tit is probably less population-risky than mammoth-hunting while giving suck. Less appealing ot the "I wanna eat a mammoth-burger" crowd of Andrew Tate wannabes.
Continiing FTFAbstract : The recovery of starch grains on a Mousterian grindstone at Bombrini suggests that the last Neanderthals not only consumed and processed plants but also made flour 43 - 41,000 years ago. Starch grains attributable to Triticeae on Protoaurignacian grindstones at both sites testify that Sapiens were processing wild cereals at least 41,500 - 36,500 years ago when they expanded into Eurasia, long before the dawn of agriculture.
Does that need expansion? The sites are in Italy, Bombrini cave overlooks the Mediterranean, near the Monaco border ; Castelciveta is in Campania, well inland, and is sealed by the Campanian ignimbrite from the Phlegraean Fields supervolcano in the outskirts of Naples (erupted 39,220 ~ 39,705 BCE). One of the caves (I didn't note which) has plant-preparation tools at two significantly different levels (ages), giving three sites at two locales. There’s no particular reason to believe that proto-Aurignacian in Bombrini cave is close to the same date as at Castelcivita cave ; it may be earlier, overlapping, or later. As always, other actual implements may not have been identified, as always, though the archaeologists have used a fairly broad set of criteria, andone of the tools was identified as such during excavation, allowing immediate "sterile" (dig sites aren't steril ; nor is soil) collection.
The dating at Castelcivetta has a latest-possible date in the sealing Campanian Ignimbrite deposit. The Bombrini specimens had “areas - including an apex - covered by carbonate incrustations formed during their permanence in the cave.” (OK ; clearly not edited by a native-English speaker. Bear in mind. I recently met "permanencia" in my Spanish as somewhat equivalent to "period of residence". Trivial point.) And they got U-series dates from that carbonate, giving a latest possible date there. Why the Campanian Ignimbrite is considered to mark the end of human occupation of Campania for a considerable period is left as an exercise for the reader.
From my PoV, it is interesting to see the morphology of the detected starch grains on the tools. That sort of material wasn't covered in my mineralogy microscopy. I note in particular the pseudo-isotropic bisectrix ficures of the starch grains under XPL ... which implies that their spherical shape makes them quite strong converging lenese in a generally plane (not convergent) polarisation field. I'll have to try to show that to the Microscopy Club if they ever meet again.
The body of the paper had a few worthwhile highlights too :
Half of each sample of B-A2 and B-M1 was also subjected to heavy liquid separation using zinc chloride, according to Mariotti Lippi et al. (2015).
Why? What were they expecting to find? We’d use ZnCl2 to make density columns between about 1.8 and 2.5 SG, so that covers a lot of territory. Obviously looking ... ah, if the ZnCl2 is fairly dense, say 1.8 SG, it would float off starch (organic)grains at ~1 SG, but drop out minerals like calcite (2.7) quartz (2.6), and phyllosilicates (clay-ish, 2.0~2.6 SG) all while keeping the starches in a low-osmosis potential fluid.In Africa a cobble used for grinding plant materials is mentioned from the Early to Middle Stone Age site of Sai Island, Sudan
(Van Peer et al., 2003 “The Early to Middle Stone Age transition and the emergence of modern human behaviour at site 8-B-11, Sai Island, Sudan.” J. Hum. Evol. 45 (2), 187 – 193).” Which gets a Spock-Fascinating.GIF from me, not least because it's very old and a long way from the "Fertile Crescent" associated with the origin of agriculture.New evidence of processed plant food is illustrated by pulse remains from the Late Middle Palaeolithic to Upper Palaeolithic at Shanidar cave (Iraq) and Franchthi cave (Greece)
(Kabukcu et al., 2022 [Cooking in caves: palaeolithic carbonised plant food remains from Franchthi and Shanidar. Antiquity 2023 Vol. 97 (391): 12–28 https://doi.org/10.15184/aqy.2022.143 ]” I know the name of Shanidar – isn’t that the "crippled Neanderthal" cave? These two sites pretty well "bracket" the Fertile Crescent", but again, much eariler than the conventional "origin of agriculture".- From Kabukcu, above,
Almost all sites from these regions dating to the Middle and Upper Palaeolithic and the Epipalaeolithic/ Mesolithic periods, for example, provide evidence for the use of wild almonds, which contain high levels of cyanogenic metabolites that can produce hydrogen cyanide. [...] Several other plants also feature prominently in the regional archaeobotanical record, including tannin-rich wild pistachios (terebinth), wild pulses (some containing neuro-toxic compounds) and astringent wild mustards. Most of these plants require several preparation steps to leach out unpalatable and/or toxic compounds prior to consumption. The long-term and widespread use of almonds, terebinths and pulses therefore suggests that Palaeolithic foragers developed processing technologies and associated food preparation practices that enabled their routine safe consumption.
(Me : That's going to stay right OFF the Palæolithic Diet menus.)… new evidence concerning the long-term histories of Palaeolithic plant food use and associated food preparation practices from two multi-period sites: Franchthi Cave (Greece) and Shanidar Cave (Iraqi Kurdistan). We focus on the analysis of amorphous, charred plant aggregates retrieved from flotation samples from the two sites; … Franchthi Cave is located in the Argolid peninsula of southern mainland Greece. It was excavated between 1969 and 1976 by T.W. Jacobsen of Indiana University and M.H. Jameson of Pennsylvania University, […] Occupation at the site spans the Upper and Final Palaeolithic, Mesolithic and Neolithic (c. 38,000–6,000 cal BP) […] Shanidar Cave, “located on the western flanks of the Zagros Mountains of Iraqi Kurdistan, was originally excavated between 1951 and 1960 […] Since 2015, a team led by Graeme Barker has conducted systematic excavations at the site (Reynolds et al. 2015), during which the fragments analysed in this study were collected. Five charred plant aggregates were recovered from Upper Palaeolithic (Baradostian) and one further fragment from the Middle Palaeolithic (Mousterian) deposits. Various levels there 43 – 30 kyr BP, 54.4 – 46.05 kyr BP, 75 – 70 kyr BP […] based on their broad stratigraphic association with the well-known Neanderthal flower burial and the recently discovered Shanidar Z articulated skeletal remains, dated to c. 73 kyr BP (Pomeroy et al. 2017, 2020).
All of the charred food remains were further examined under a Meiji MT6500 darkfield/ brightfield incident light microscope (magnification ×50–500) and subsequently mounted on SEM aluminium stubs and gold sputter coated (to a thickness of 20nμ) to allow for more detailed observation
nµ ?? nm, surely?Beyond the Eastern Mediterranean and South-west Asia, archaeobotanical studies at sites such as Niah Cave (Sarawak, Borneo) have revealed evidence for the processing of the highly toxic Dioscorea (yam) and Pangium edule nuts from as early as 50 kyr ago, underscoring the complexity and deep ancestry of such food preparation practices
(Barker et al. 2007; Barton et al. 2016). “Niah” rings bells for me. Not hobbits. But … just a few bones, though Palaeolithic.
All, uh, grist to the "Palæolithic Diet" menu's non-existant non-meat part. Not that it ever had any connection ot archaeology.
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