пятница, 24 мая 2019 г.

Extraordinary Materials: Developed for Space, Useful for Just About Everything on Earth

Did

you know technologies developed for space show up all over Earth? Our Technology

Transfer Program
has one major goal: bring our technology down to Earth. We

patent space innovations developed for missions so that companies, startups and

entrepreneurs can spin them off into new commercial products.


Our

engineers and scientists create all sorts of materials and coatings—in fact, it

is one of the most licensed technology categories in our patent portfolio. From

materials that improve industrial and

household products, to coatings and insulations that protect satellites,

machinery and firefighters,

our technologies offer smart solutions for modern challenges.


These are a few of our most in-demand technologies.


Dust-Resistant Coatings


Made

by innovators at our Langley

Research Center
, this tech was first created for exploring dusty, dirty surfaces

like the Moon, Mars and asteroids. Lunar dust has been shown to cause big

problems with mechanical equipment, like clogging filters and damaging seals.

This technology can be used in the production of films, coatings and surface

treatments to create dust-resistant and self-cleaning products for biomedical

devices, aircraft, cars and much more. This tech could be a game-changer when

battling dirt and grime.


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Smart, Environmentally-Friendly Coating System


Looking

for a technology to ward off corrosion that’s also safe for the environment? Developed

to protect our launch pads at Kennedy Space

Center


from extreme heat and exhaust from rockets, this “smart” coating can detect and

prevent corrosion. It can even be painted on damaged surfaces to heal and

protect them going forward. This tech has commercial potential in building

safer bridges, automobiles and machinery.  While it may seem like magic, this technology

will reduce maintenance cost and improve

safety.


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Multilayer

Fire Protection System


Made

to protect astronauts and vehicles during the dangerously hot task of reentry,

scientists at Langley developed a flexible, lightweight and portable thermal

protection system that can serve as a personal emergency fire shelter.


The

flexible technology is made up of multilayer thermal blankets designed to

handle external temperatures of up to 2,000°F – that’s as hot as magma found in

some volcanos! The system can be formed as a sleeping bag, a tent, a blanket, a

curtain, a flexible roll-up doorway or even for

fire protection in housing structures.


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Super-Strength Aluminums


This

award-winning tech

was initially developed by researchers at our Marshall

Space Flight Center
to help reduce vehicle exhaust emissions. This special alloy is

flexible and strong—even at temperatures of over 500°F. That means it can withstand

more wear and tear than other similar materials. Currently, this tech can be

found improving motors on fishing boats as well

as in all kinds of different engines.


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Oil-Free

Lubricants


Not

all lubricants are liquids, for example, the non-stick coating on a frying pan.

Truly in a class of its own, innovators at our Glenn

Research Center
have created solid lubricant materials to reduce friction and wear

in mechanical parts, especially in extremely high heat. This tech could be

useful in large engines, valves, turbines and power generation.


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High-Strength

Super Elastic Compounds


We needed a better material than iron or steel to prevent

corrosion and rust in the International

Space Station
’s wastewater treatment system. Enter: our high-strength, super elastic compounds. Shock-proof, lightweight, durable and immune to rust, this durable tech has

applications in ships, machines, industrial knives and cutters, and engine

bearings here on Earth. They also don’t chemically degrade or break down lubricants, a

common problem with existing bearing materials.


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Interested

in licensing the tech mentioned above? Follow the links to apply through our

website, http://technology.nasa.gov.


You

can also browse our entire materials and coatings portfolio at http://technology.nasa.gov/materials_and_coatings/.


Follow

our NASA Technology Transfer Program on Twitter (@NASAsolutions) for the latest

updates on technologies available for licensing.


Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.


SpaceX — STARLINK Mission Success


SpaceX — Falcon 9 / STARLINK Mission patch.


May 24, 2019



Lift-off

On Thursday, May 23 at 10:30 p.m. EDT SpaceX launched 60 Starlink satellites from Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station, Florida. SpaceX’s Starlink is a next-generation satellite network capable of connecting the globe, especially reaching those who are not yet connected, with reliable and affordable broadband internet services.


Falcon 9’s first stage for this mission previously supported the Telstar 18 VANTAGE mission in September 2018 and the Iridium-8 mission in January 2019. Following stage separation, SpaceX landed Falcon 9’s first stage on the “Of Course I Still Love You” droneship, which was stationed in the Atlantic Ocean.



SpaceX’s first Starlink mission

Approximately one hour and two minutes after liftoff, the Starlink satellites were deployed at an altitude of 440km. They then used onboard propulsion to reach an operational altitude of 550km.


The 60 small satellites, each with a flat-panel design and built by an in-house SpaceX team, will be joined by hundreds more Starlink craft over the next year to fill out the network’s preliminary constellation. Eventually, SpaceX says thousands of Starlink satellites may be launched to provide high-speed Internet services to consumers around the world.



Image above: Artist’s concept of a Starlink satellite with its solar array wing unfurled. Image Credit: SpaceX.


Each satellite carries a krypton ion propulsion system and Ku-band antennas to continue in-orbit demonstrations of SpaceX’s planned broadband network, which may eventually number up to 12,000 small relay stations in low Earth orbit.


Future Starlink satellites will carry Ka-band and V-band radio transmission hardware, along with laser inter-satellite links to allow signals to bounce between spacecraft in orbit, rather than going through a ground station.


For more information about SpaceX, visit: https://www.spacex.com/


Images, Video, Text, Credits: SpaceX/SciNews/Orbiter.ch Aerospace/Roland Berga.


Best regards, Orbiter.chArchive link


2019 May 24 Boulders on Bennu Image Credit: NASA, Goddard Space…


2019 May 24


Boulders on Bennu
Image Credit: NASA, Goddard Space Flight Center, University of Arizona


Explanation: An abundance of boulders litters the surface asteroid 101955 Bennu in this dramatic close-up from the OSIRIS-REx spacecraft. Taken on March 28 from a distance of just 3.4 kilometers (2.1 miles) the field of view is about 50 meters across while the light colored boulder at top right is 4.8 meters tall. Likely a loose conglomerate rubble pile asteroid, Bennu itself spans less than 500 meters. That’s about the height of the Empire State Building. Mapping the near Earth asteroid since the spacecraft’s arrival in December of 2018, the OSIRIS-REx mission plans a TAG (Touch-and-Go) maneuver for July 2020 to sample Bennu’s rugged surface, returning the sample to planet Earth in September 2023. Citizen scientists have been invited to help choose the sample collection site.


∞ Source: apod.nasa.gov/apod/ap190524.html


Predator size is everything

Natural ecosystems are as vulnerable as they are diverse. Environmental changes such as climate change, pollution or the spread of alien species can easily throw an ecosystem off balance. Researchers are therefore investigating how susceptible ecosystems are to disruption. But in their search for answers they face the problem that the complex network of relationships includes innumerable interactions, which are virtually impossible to record comprehensively and convert into measurable data.











Predator size is everything
The difference in size between a predator — like this leopard — and its prey is the decisive factor
 for Ulrich Brose’s method [Credit: Bernd Adam]

Data set with information from 290 food webs


In an effort to overcome this obstacle, a team lead by ecologist Prof. Ulrich Brose of Friedrich Schiller University in Jena (Germany) and of the German Centre for Integrative Biodiversity Research (iDiv) has developed a new approach. The special feature of the method is that only limited information is needed about the characteristics of ‘predators’ that hunt prey animals.


These data enable researchers to determine the structure and stability of a habitat, without the need for a comprehensive examination of the relationships to other organisms. The scientists were able to confirm the value of their method using a large dataset of 220,000 interactions from 290 food webs. They had collected the data from research partners throughout the world over a period of more than 10 years.


Larger hunters with smaller prey are ideal for the ecosystem


«The decisive characteristic of a predator is the relationship between its body mass and that of its prey,» explains Brose, who was recently awarded the Thuringian Research Prize. «If there is a big difference, this has a positive effect on the equilibrium of the energy flows of the food web and, by extension, on the stability of the ecosystem.» Large hunters with small prey, such as mouse-hunting martens, therefore have an important positive effect on the organisms’ habitats.


With the help of the data they had collected, Brose and his team were able to predict precisely which animals play a key role within a food web. The prediction is even more precise if, in addition to body mass, additional features such as the mode of locomotion or the metabolic type are considered. The analysis showed that, depending on the nature of the habitat, different species of predator maintain the equilibrium of an ecosystem. In three-dimensional biotopes (air, water), very large predators have a stabilising effect, whereas in two-dimensional spaces (land), this is done by smaller predators.


Food web theory provides stimulus for practical nature conservation


Brose and his team now wish to study the reasons for these differences. For their next step, they want to supplement the existing data on food webs with additional physical factors, such as the gravitational force or the viscosity of the medium in which the organisms live.


«Our aim is to uncover the fundamental laws of the architecture of biodiversity,» says Brose, who makes his data available to other research teams through the iDiv database. His latest findings might also help to close the gap between food web theory and practical nature conservation.


«If we understand nature conservation to be a way of cushioning nature against disturbance from outside, we will have most success if we protect large hunters such as whales and sharks in water and large birds of prey in the air. In contrast, on land we should prioritise small mammals such as weasels or polecats.»


The study is published in Nature Ecology & Evolution.


Source: Friedrich Schiller University [May 20, 2019]



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More detailed picture of Earth’s mantle

The chemical composition of the Earth’s mantle is a lot more variable and diverse than previously thought, a new study has revealed.











More detailed picture of Earth's mantle
A mineral map of a cumulate mineral sample [Credit: Sarah Lambart/
University of Utah]

According to a new analysis of cores drilled through the ocean crust, the mantle is made up of distinct sections of rock each with different chemical make-ups.


The chemical composition of the mantle has been notoriously difficult to determine with a high degree of certainty because it is largely inaccessible.


Scientists have traditionally relied on lava that erupts on the ocean floor to give them some idea of what the mantle is made up of, and so far studies have suggested that it’s chemically mostly the same everywhere on the planet.


However in their new study, the team of researchers led by scientists at Cardiff University have studied the very first minerals that begin to form when lava first makes contact with the crust at mid-ocean ridges.


In particular they looked at variations in isotopes of neodymium and strontium, which can indicate different chemistries of mantle material that come from different types of rocks.


Results showed that the amount of isotope variability in the minerals was seven times greater than that in the mid-ocean ridge lavas.


The team believe that this variability could be linked to the process whereby old ocean crust spreads away from mid-ocean ridges until it’s shoved beneath a continent and sinks back into the mantle.


«Our results show that recycled oceanic crust is much more abundant in the mantle than we thought,» said principal investigator of the study Dr Johan Lissenberg from Cardiff University’s School of Earth and Ocean Sciences.


«This recycled crust melts again, along with the surrounding mantle, but the chemically different melts remain isolated during their transport to the crust. Only after they reach magma chambers in the crust do they mix to produce the homogeneous lavas we observe on the seafloor.»


So rather than a gradient of yellow and orange that we regularly see represented as the mantle in textbooks, the true picture could be quite different.


«If you look at a painting from Jackson Pollock, you have a lot of different colours,» said lead author of the study Dr Sarah Lambart, who undertook the work at Cardiff University and is now based at the University of Utah.


«Those colours represent different mantle components and the lines are lava produced by these components and transported to the surface.»


The study has gone some way to helping the scientists understand the processes that are taking place below our feet, and trying to explain the chemical composition of the rocks that we see today.


The study has been published in the journal Nature Geoscience.


Source: Cardiff University [May 20, 2019]



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Germany returning 15th century stone cross to Namibia

The German Historical Museum in Berlin announced Friday that it is returning to Namibia a 15th century artifact known as the Stone Cross of Cape Cross. The country has called for the object’s return since June 2017.











Germany returning 15th century stone cross to Namibia
The Cape Cross was originally put up by the Portuguese
[Credit: Picture-Alliance/dpa/P. Zinken]

«The rapprochement with Namibia is clearly, and visibly taking place,» said Monika Grütters, Germany’s State Secretary for Culture and Media. She said that dealing with its colonial legacy in Namibia had been a «blind spot» for Germany for too long.


For Grütters, the restitution planned for August, is a «clear signal that we want words to be followed by deeds.»


Namibia’s Ambassador to Germany, Andreas Guibeb, sees the return as a «significant progress» which however, does not end the chapter. «The origin of the column is inseparably connected with the history of Namibia,» said Guibeb in Berlin. He said that this reconciliation for the colonial era would allow his country to concentrate on its future.


The restitution, sparked in part by a 2018 symposium the museum held on the history of the object, is part of Germany’s desire to face up to the moral responsibility of its colonial past.


The museum says that although the object is not an African artwork, it nevertheless highlights how «descendants from Europe and Africa can engage in dialogue that does historical justice» to it.


The museum acknowledged the «outstanding significance which an artifact like this pillar has to the people of Namibia and the special contribution it can make on site in the future to understanding Namibia’s history.»


Marking Portuguese territorial claims


The artifact was originally erected by explorer Diogo Cao in 1486 on the coastline of present-day Namibia to signify Portuguese territorial claims, as well as serve as a navigational marker.











Germany returning 15th century stone cross to Namibia
The Stone Cross was placed by the Portuguese in 1486 and features
the country’s crest [Credit: AFP/Getty]

The 1.1 ton, 3.5-meter (11-foot) Stone Cross is emblazoned with the Portuguese coat of arms as well as inscriptions in Portuguese and Latin. Its presence, alongside other such crosses, was so significant that maps at the time — such as Martin Waldseemüller’s world map from 1500 — featured images of them. The crosses also gave rise to the coast’s present-day name, Cape Cross.


The artifact came into Germany’s possession in 1893, when seafarer Gottlieb Becker discovered it and ordered it removed and returned with it to Germany, where it made its way from Wilhelmshaven to Berlin.


The object was presented to Kaiser Wilhelm II, who used it to serve his propaganda purposes regarding the empire’s naval superiority. The kaiser also ordered a new cross, emblazoned this time with the German imperial eagle and a German inscription, to replace the original.


The object entered the collection of East Germany’s Museum of German History in 1953, and then the German Historical Museum after reunification. It has been part of the museum’s permanent exhibition since 2006.


Namibia, which was previously known as German South-West Africa, was a German colony from 1884 to 1915.


Germany has been slow to fully acknowledge the darkest chapters of its colonial past, but has made recent efforts in that direction. Though the German government announced a planned apology for the genocide of tens of thousands of Herero and Nama men, women, and children between 1904 and 1908, it has refused to pay reparations, pointing to the millions that it has given Namibia in development aid over the years.


Record of Namibia’s colonial past


Raphael Gross, the president of the museum’s foundation, said the return of the object was an «important gesture» and the «recognition of a historical injustice».


Writing in the Frankfurter Allgemeine Zeitung daily newspaper, Gross called the cross «one of the very few objects that documents the occupation of the country by the Portuguese and with that the slow beginning of colonial rule in present-day Namibia.»


Author: Jon Shelton | Source: Deutsche Welle [May 20, 2019]



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Stellar waltz with dramatic ending

Astronomers at the University of Bonn and their colleagues from Moscow have identified an unusual celestial object. It is most likely the product of the fusion of two stars that died a long time ago. After billions of years circling around each other these so-called white dwarfs merged and rose from the dead. In the near future, their lives could finally end — with a huge bang. The researchers are now presenting their findings in the journal Nature.











Stellar waltz with dramatic ending
The infrared nebula of J005311 [Credit: Vasilii Gvaramadse/Moscow University]

The extremely rare merger product was discovered by scientists from the University of Moscow. On images made by the Wide-field Infrared Survey Explorer (WISE) satellite they found a gas nebula with a bright star in its center. Surprisingly, however, the nebula emitted almost exclusively infrared radiation and no visible light. «Our colleagues in Moscow realized that this already argued for an unusual origin», explains Dr. Götz Gräfener from the Argelander Institute for Astronomy (AIfA) at the University of Bonn.
In Bonn, the spectrum of the radiation emitted by the nebula and its central star was analyzed. In this way, the AIfA researchers were able to show that the enigmatic celestial object contained neither hydrogen nor helium — a characteristic typical for the interiors of white dwarfs. Stars like our Sun generate their energy through hydrogen burning, the nuclear fusion of hydrogen. When the hydrogen is consumed, they continue burning helium. However, they cannot fuse even heavier elements — their mass is insufficient to produce the necessary high temperatures. Once all helium is used up, they cease burning and cool down turning into so-called white dwarfs.


Usually their life is over at this point. But not for J005311 — this is how the scientists named their new find in the constellation Cassiopeia, 10,000 light-years from Earth. «We assume that two white dwarfs formed there in close proximity many billions of years ago,» explains Prof. Dr. Norbert Langer from AIfA. «They circled around each other, creating exotic distortions of space-time, called gravitational waves.» In the process, they gradually lost energy. In return, the distance between them shrunk more and more until they finally merged.


Only five of these objects in the Milky Way


Now their total mass was sufficient to fuse heavier elements than hydrogen or helium. The stellar furnace started burning again. «Such an event is extremely rare,» stresses Gräfener. «There are probably not even half a dozen such objects in the Milky Way, and we have discovered one of them.»











Stellar waltz with dramatic ending
WISE 22 micron infrared images at different intensity scales (panels a and b) compared with an optical IPHAS
H alpha image where the nebula is not visible (panel c) [Credit: Vasilii Gvaramadse/Moscow University]

An extreme stroke of luck. Nevertheless, the researchers are convinced that they are right with their interpretation. For one, the star in the center of the nebula shines 40,000 times as bright as the sun, far brighter than a single white dwarf could. In addition, the spectra indicate that J005311 has an extremely strong stellar wind — this is the stream of material that emanates from the stellar surface. Its engine is the radiation generated during the burning process. Only, at a speed of 16,000 kilometers per second, the wind of J005311 is so fast that this factor alone is not enough to explain it. However, merged white dwarfs are expected to have a very strong rotating magnetic field. «Our simulations show that this field acts like a turbine, which additionally accelerates the stellar wind,» says Gräfener.
Sadly, the resurgence of J005311 will not last long. In only a few thousand years the star will have transformed all elements into iron and fade again. As its mass has increased to more than 1.4 times the mass of the Sun in the merger process, it will suffer an exceptional fate. The star will collapse under the influence of its own gravity. At the same time, the electrons and protons building up its matter will fuse into neutrons. The resulting neutron star has only a fraction of its previous size, measuring only few kilometers in diameter, while it is weighing more than the entire solar system.


J005311, however, won’t leave without a final salute. Its collapse will be accompanied by a huge bang, a so-called supernova explosion.


Source: University of Bonn [May 21, 2019]




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Water formation on the moon demonstrated

For the first time, a cross-disciplinary study has shown chemical, physical, and material evidence for water formation on the Moon. Two teams from the University of Hawai?i at Manoa collaborated on the project: physical chemists at the UH Manoa Department of Chemistry’s W.M. Keck Research Laboratory in Astrochemistry and planetary scientists at the Hawaii Institute of Geophysics and Planetology (HIGP).











Water formation on the moon demonstrated
Water and their precursors were stored in lunar silicates and released into the gas phase by (micro)meteorite
impact [Credit: Molecules and data courtesy of Cheng Zhu and Ralf I. Kaiser; background image
courtesy of NASA/Goddard/Conceptual Image Lab]

Although recent discoveries by orbiting spacecraft such as the Lunar Prospector and the hard lander Lunar Crater Observation and Sensing Satellite suggest the existence of water ice at the poles the Moon, the origin of this water has remained uncertain. Lunar water represents one of the key requirements for permanent colonization of the Moon as a feedstock for fuel and energy generation (hydrogen, oxygen) and also as «drinking water.»


The breakthrough research is outlined in «Untangling the formation and liberation of water in the lunar regolith,» lead-authored by UH Manoa postdoctoral fellow Cheng Zhu and colleagues in the Proceedings of the National Academy of Sciences.


Chemistry Professor Ralf I. Kaiser and HIGP’s Jeffrey Gillis-Davis designed the experiments to test the synergy between hydrogen protons from solar wind, lunar minerals, and micrometeorite impacts. Zhu irradiated samples of olivine, a dry mineral that serves as a surrogate of lunar material, with deuterium ions as a proxy for solar wind protons.


Deuterium irradiated only «experiments did not reveal any trace of water formation, even after increasing the temperature to lunar mid-latitude daytime temperatures,» Zhu explained. «But when we warmed the sample, we detected molecular deuterium, suggesting that deuterium — or hydrogen — implanted from the solar wind can be stored in the lunar rock.»











Water formation on the moon demonstrated
Image shows the pits and lids on the irradiated sample
[Credit: University of Hawaii at Manoa]

Kaiser added, «Therefore, another high-energy source might be necessary to trigger water formation within the Moon’s minerals followed by its release as a gas that can be detected.»


The second set of deuterium irradiation experiments was followed by laser heating to simulate the thermal effects of micrometeorite impacts. A burst of ions with mass-to-charge ratios matching that of singly ionized heavy water was observed in the gas phase during the laser pulses. «Water continued to be produced during laser pulses after the temperature was increased, suggesting that the olivine was storing precursors to heavy water that were released by laser heating,» said Zhu.


To image these processes and interpret the broader impact on the Moon and other bodies, HIGP’s Hope Ishii and John Bradley used focused ion beam-scanning electron microscopy and transmission electron microscopy in the Advanced Electron Microscopy Center. They observed sub-micrometer-sized surface pits, some partially covered by lids, suggesting that water vapor builds up under the surface in vesicles until they burst, releasing water from lunar silicates upon micrometeorite impact.


«Overall, this study advances our understanding on the origin of water as detected on the Moon and other airless bodies in our Solar System such as Mercury and asteroids and provides, for the first time, a scientifically sound and proven mechanism of water formation,» HIGP’s Jeffrey Gillis-Davis concluded.


Source: University of Hawaii at Manoa [May 21, 2019]




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2-metre sea level rise ‘plausible’ by 2100: study

Global sea levels could rise by two metres (6.5 feet) and displace tens of millions of people by the end of the century, according to new projections that double the UN’s benchmark estimates.











2-metre sea level rise 'plausible' by 2100: study
The vast ice sheets of Greenland and Antarctica contain enough frozen water to lift
the world’s oceans dozens of metres [Credit: Mario Tama/AFP]

The vast ice sheets of Greenland and Antarctica contain enough frozen water to lift the world’s oceans dozens of metres. The expansion of water as oceans warm also contributes to sea level rise.


But predicting the rates at which they will melt as the planet heats is notoriously tricky.


The United Nations’ Intergovernmental Panel on Climate Change (IPCC) said its 2013 Fifth Assessment Report that under current emissions trajectories — a «business-as-usual» scenario known as RCP8.5 — would likely rise by up to one metre by 2100.


That prediction has since been viewed as conservative, as the levels of planet-warming greenhouse gas emissions continue to rise year on year, and satellites showing accelerated rates of melt-off from massive ice sheets atop Antarctica and Greenland.


A group of the world’s leading ice scientists this week released a expert judgement on the situation, drawing on their own experience and observations.


While there was still a significant margin of error, they found it «plausible» that under the business-as-usual emissions scenario, sea-level rises could exceed two metres by 2100.


The authors said the area of land lost to the ocean could be equivalent to that of France, Germany, Spain and Britain combined and would displace more than 180 million people.


«A sea-level rise of this magnitude would clearly have profound consequences for humanity,» they said.


The Paris climate deal, struck between nations in 2015, aims to limit global temperature rises to well below two degrees Celsius (3.6 Farenheit), and encourages countries to work towards a 1.5C cap.


In October the IPCC released a landmark climate report that called for a drastic and immediate drawdown in coal, oil and gas consumption in order to arrest the rapid rise in the levels of greenhouse gases in the atmosphere.


That report, however, did not include revised estimates of sea level rise.


Earth has already heated 1C since pre-industrial times, contributing roughly 3mm to sea levels each year.


The authors of the new study, released in the journal Proceedings of the National Academy of Sciences, argue that the IPCC’s sea-level rise prediction was too constrained by focusing on what was «likely» to happen.


At wider probabilities — 5-95 percent likelihood — they found that under 2C of warming seas could rise 36-126 cm by 2100.


In world that has warmed by 5C — unlikely but certainly not impossible given projected fossil fuel demand in the coming decades — they calculated a five percent risk of sea levels surpassing two metres higher, topping out at 238 cm.


Willy Aspinall, from the University of Bristol’s School of Earth Sciences, said he hoped the study could provide policymakers with a more accurate worst-case scenario «crucial for robust decision making.»


«Limiting attention to the ‘likely’ range, as was the case in the IPCC Fifth Assessment Report, may be misleading and will likely lead to a poor evaluation of the true risks,» he added.


Source: AFP [May 21, 2019]



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Eastern US forests shaped more by Native Americans’ burning than climate change

Native Americans’ use of fire to manage vegetation in what is now the Eastern United States was more profound than previously believed, according to a Penn State researcher who determined that forest composition change in the region was caused more by land use than climate change.











Eastern US forests shaped more by Native Americans' burning than climate change
Low numbers of Native Americans were capable of burning large areas of the eastern U.S. and did so repeatedly,
according to the researcher. Native Americans, he says, knew that to regenerate plant species that they wanted
 for food, and to feed game animals they relied on, they needed to burn the forest understory regularly
[Credit: © Getty Images/William Sherman]

«I believe Native Americans were excellent vegetation managers and we can learn a lot from them about how to best manage forests of the U.S.,» said Marc Abrams, professor of forest ecology and physiology in the College of Agricultural Sciences. «Native Americans knew that to regenerate plant species that they wanted for food, and to feed game animals they relied on, they needed to burn the forest understory regularly.»


Over the last 2,000 years at least, according to Abrams — who for three decades has been studying past and present qualities of eastern U.S. forests — frequent and widespread human-caused fire resulted in the predominance of fire-adapted tree species. And in the time since burning has been curtailed, forests are changing, with species such as oak, hickory and pine losing ground.


«The debate about whether forest composition has been largely determined by land use or climate continues, but a new study strongly suggests anthropogenic fire has been the major driver of forest change in the East,» said Abrams. «That is important to know because climate change is taking on an ever larger proportion of scientific endeavour.»


But this phenomenon does not apply to other regions, Abrams noted. In the western U.S., for example, climate change has been much more pronounced than in the East. That region has received much more warming and much more drought, he explained.


«Here in the East, we have had a slight increase in precipitation that has ameliorated the warming,» said Abrams.











Eastern US forests shaped more by Native Americans' burning than climate change
Pollen and tree survey map [Credit: Marc Abrams, Penn State]

To learn the drivers of forest change, researchers used a novel approach, analyzing both pollen and charcoal fossil records along with tree-census studies to compare historic and modern tree composition in the forests of eastern North America. They looked at seven forest types in the north and central regions of the eastern United States. Those forest types encompass two distinct floristic zones — conifer-northern hardwood and sub-boreal to the north, and oak-pine to the south.


The researchers found that in the northernmost forests, present-day pollen and tree-survey data revealed significant declines in beech, pine, hemlock and larches, and increases in maple, poplar, ash, oak and fir. In forests to the south, both witness tree and pollen records pointed to historic oak and pine domination, with declines in oak and chestnut and increases in maple and birch, based on present-day data.


«Modern forests are dominated by tree species that are increasingly cool-adapted, shade-tolerant, drought-intolerant pyrophobes — trees that are reduced when exposed to repeated forest burning,» Abrams said. «Species such as oak are largely promoted by low-to moderate-level forest fires. Furthermore, this change in forest composition is making eastern forests more vulnerable to future fire and drought.»


Researchers also included human population data for the region, going back 2,000 years, to bolster their findings, which recently were published in the Annals of Forest Science. After hundreds of years of fairly stable levels of fire caused by relatively low numbers of Native Americans in the region, they report, the most significant escalation in burning followed the dramatic increase in human population associated with European settlement prior to the early 20th century. Moreover, it appears that low numbers of Native Americans were capable of burning large areas of the eastern U.S. and did so repeatedly.


After 1940, they found, fire suppression was an ecologically transformative event in all forests.


«Our analysis identifies multiple instances in which fire and vegetation changes were likely driven by shifts in human population and land use beyond those expected from climate alone,» Abrams said. «After Smokey Bear came on the scene, fire was mostly shut down throughout the U.S. and we have been paying a big price for that in terms of forest change. We went from a moderate amount of fire to too much fire to near zero fire — and we need to get back to that middle ground in terms of our vegetation management.»


Author: Jeff Mulhollem | Source: Pennsylvania State University [May 21, 2019]



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Life in evolution’s fast lane

Most living things have a suite of genes dedicated to repairing their DNA, limiting the rate at which their genomes change through time. But scientists at Vanderbilt and University of Wisconsin-Madison have discovered an ancient lineage of budding yeasts that appears to have accumulated a remarkably high load of mutations due to the unprecedented loss of dozens of genes involved in repairing errors in DNA and cell division, previously thought to be essential.











Life in evolution's fast lane
This is Hanseniaspora uvarum, one of the budding yeast species living without many genes
otherwise thought to be essential for life [Credit: University of Ljubljana]

In a new study published in the open-access journal PLOS Biology, graduate student Jacob L. Steenwyk, working in the laboratory of Professor Antonis Rokas at the Department of Biological Sciences at Vanderbilt University in Nashville, Tennessee discovered that a group of budding yeasts in the genus Hanseniaspora, which is closely related to the baker’s yeast Saccharomyces cerevisiae, has lost large numbers of genes related to cell cycle and DNA repair processes.
These losses are particularly surprising not only because these genes are broadly conserved across living organisms but also because mutations in the human versions of many of these genes dramatically increase the rates of different types of mutations and lead to cancer.


Steenwyk’s analyses show that the genomes of Hanseniaspora budding yeasts have lost hundreds of genes, including dozens involved in DNA repair, cell cycle, and metabolism. «It appears that, in genomic terms, Hanseniaspora are the yeast with the least,» said Steenwyk, adding: «They have very small genomes and among the smallest numbers of genes of any species in the lineage. These dramatic losses of so many genes are reflected in the biology of these yeasts.»


«The speed with which the genomes of these yeasts have mutated is unprecedented and their cell division appears to be extremely fast but also somewhat erratic — a quantity-over-quality approach, so to speak», said Rokas.


Due to the loss of these genes, Hanseniaspora yeasts have experienced many more changes in their DNA than their relatives and bear numerous ‘genomic scars’ from natural mutagens from within (e.g. oxidative damage) and from outside (e.g. UV radiation).


«We’re excited to continue studying Hanseniaspora yeasts», said Steenwyk. «There’s a lot we can learn about life’s basic processes from these humble yeasts».


Source: Public Library of Science [May 21, 2019]



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A unique experiment to explore black holes


ESA — LISA Mission patch.


23 May 2019


What happens when two supermassive black holes collide? Combining the observing power of two future ESA missions, Athena and LISA, would allow us to study these cosmic clashes and their mysterious aftermath for the first time.



Black holes after a merger

Supermassive black holes, with masses ranging from millions to billions of Suns, sit at the core of most massive galaxies across the Universe. We don’t know exactly how these huge, enormously dense objects took shape, nor what triggers a fraction of them to start devouring the surrounding matter at extremely intense rates, radiating copiously across the electromagnetic spectrum and turning their host galaxies into ‘active galactic nuclei’.


Tackling these open questions in modern astrophysics is among the main goals of two future missions in ESA’s space science programme: Athena, the Advanced Telescope for High-ENergy Astrophysics, and LISA, the Laser Interferometer Space Antenna. Currently in the study phase, both missions are scheduled for launch in the early 2030s.



Merging black holes

“Athena and LISA are both outstanding missions set to make breakthroughs in many areas of astrophysics,” says Günther Hasinger, ESA Director of Science.


“But there is one extremely exciting experiment that we could only perform if both missions are operational at the same time for at least a few years: bringing sound to the ‘cosmic movies’ by observing the merger of supermassive black holes both in X-rays and gravitational waves.


“With this unique opportunity to perform unprecedented observations of one of the most fascinating phenomena in the cosmos, the synergy between Athena and LISA would greatly increase the scientific return from both missions, ensuring European leadership in a key, novel area of research.”


Athena will be the largest X-ray observatory ever built, investigating some of the hottest and most energetic phenomena in the cosmos with unprecedented accuracy and depth.


It is designed to answer two fundamental questions: how supermassive black holes at the centre of galaxies form and evolve, and how ‘ordinary’ matter assembles, along with the invisible dark matter, to form the wispy ‘cosmic web’ that pervades the Universe.


“Athena is going to measure several hundreds of thousands of black holes, from relatively nearby to far away, observing the X-ray emission from the million-degree-hot matter in their surroundings,” says Matteo Guainazzi, Athena study scientist at ESA.


“We are in particular interested in the most distant black holes, those that formed in the first few hundred million years of the Universe’s history, and we hope we’ll be able to finally understand how they formed.”


Meanwhile, LISA will be the first space-borne observatory of gravitational waves – fluctuations in the fabric of spacetime produced by the acceleration of cosmic objects with very strong gravity fields, like pairs of merging black holes.


Gravitational-wave astronomy, inaugurated only a few years ago, is currently limited to the high-frequency waves that can be probed by ground-based experiments like LIGO and Virgo. These experiments are sensitive to the mergers of relatively small black holes – a few times to a few tens of times more massive than the Sun. LISA will expand these studies by detecting low-frequency gravitational waves, such as the ones released when two supermassive black holes collide during a merger of galaxies.





Two merging supermassive black holes

“LISA will be the first mission of its kind, looking primarily for gravitational waves coming from supermassive black holes smashing into one another,” explains Paul McNamara, LISA study scientist at ESA.


“This is one of the most energetic phenomena we know of, releasing more energy than all the quiescent Universe does at any time. If two supermassive black holes merge anywhere in the cosmos, LISA will see it.”


The first few gravitational wave events detected by LIGO and Virgo between 2015 and 2017 all originated from pairs of stellar-mass black holes, which are known to not radiate any light upon coalescence. Then, in August 2017, gravitational waves coming from a different source – the merger of two neutron stars – were discovered.


This time, the gravitational waves were accompanied by radiation across the electromagnetic spectrum, readily observed with a multitude of telescopes on Earth and in space. By combining information from the various types of observations in an approach known as multi-messenger astronomy, scientists could delve into the details of this never-before-observed phenomenon.


With Athena and LISA together, we would be able to apply multi-messenger astronomy to supermassive black holes for the first time. Simulations predict that their mergers, unlike those of their stellar-mass counterparts, emit both gravitational waves and radiation – the latter originating in the hot, interstellar gas of the two colliding galaxies stirred by the black holes pair when they fall towards one another.



The merger of supermassive black holes

LISA will detect the gravitational waves emitted by the spiralling black holes about a month before their final coalescence, when they are still separated by a distance equivalent to several times their radii. Scientists expect that a fraction of the mergers found by LISA, especially those within distances of a few billion light years from us, will give rise to an X-ray signal that can be eventually seen by Athena.


“When LISA first detects a signal, we won’t know yet where exactly it’s coming from, because LISA is an all-sky sensor, so it works more like a microphone than a telescope,” explains Paul.


“However, as the black holes inspiral towards each other, the amplitude of their gravitational wave signal increases. This, coupled with the motion of the satellites along their orbits, will allow LISA to gradually improve the localisation of the source in the sky, up until the time when the black holes finally merge.”


A few days before the final phase of the merger, the gravitational wave data will constrain the position of the source to a patch on the sky measuring about 10 square degrees – roughly 50 times the area of the full Moon. This is still pretty large, but would allow Athena to start scanning the sky to search for an X-ray signal from this titanic clash. Simulations indicate that the two spiralling black holes modulate the motion of the surrounding gas, so it is likely that the X-ray signature will have a  frequency commensurate to that of the gravitational wave signal.


Then, just a few hours before the final coalescence of the black holes, LISA can provide a much more precise indication in the sky, roughly the size of the field of view of Athena’s Wide Field Imager (WFI), so the X-ray observatory can directly point towards the source.


“Catching the X-ray signal before the black holes become one will be very challenging, but we are pretty confident that we can make a detection during and after the merger,” explains Matteo.


“We could see the emergence of a new X-ray source, and perhaps witness the birth of an active galactic nucleus, with jets of high-energy particles being launched at close to the speed of light above and beyond the newly formed black hole.”



Negative photo of the 1919 solar eclipse

We have never observed merging supermassive black holes – we do not yet have the facilities for such observations. First, we need LISA to detect the gravitational waves and tell us where to look in the sky; then we need Athena to observe it with high precision in X-rays to see how the mighty collision affects the gas surrounding the black holes. We can use theory and simulations to predict what might happen, but we need to combine these two great missions to find out.


One hundred years ago this month, on 29 May 1919, observations of the positions of stars during a total eclipse of the Sun provided the first empirical evidence of the gravitational bending of light predicted a few years earlier by Albert Einstein’s general theory of relativity.


This historic eclipse inaugurated a century of gravity experiments on Earth and in space, setting the stage for inspiring missions like Athena and LISA, and more exciting discoveries.


Notes for editors:


Athena was selected as the second large (L2) mission in ESA’s Cosmic Vision programme in 2014, and LISA as the third large (L3) mission in 2017. The additional science that could be performed with both missions operating jointly is described in a 2019 white paper by the Athena-LISA synergy working group.


Athena is an ESA-led mission with important contributions from NASA and JAXA. The WFI instrument is provided by an international consortium led by the Max Planck Institute for extraterrestrial Physics in Germany, involving several ESA Member States and the US. Under the management of CNES, the X-IFU instrument is provided by an international consortium led by France, The Netherlands, and Italy, furthermore involving several ESA Member States, Japan and the US.


LISA is an ESA-led mission with important contributions from NASA. The LISA Consortium, led by the Max Planck Institute for Gravitational Physics in Germany, involves several ESA Member States and the US.


Note:


On Earth, we deal with gravity every day. We feel it, we fight it, and – more importantly – we investigate it. Space agencies such as ESA routinely launch spacecraft against our planet’s gravity, and sometimes these spacecraft borrow the gravity of Earth or other planets to reach interesting places in the Solar System. We study the gravity field of Earth from orbit, and fly experiments on parabolic flights, sounding rockets and the International Space Station to examine a variety of systems under different gravitational conditions. On the grandest scales, our space science missions explore how gravity affects planets, stars and galaxies across the cosmos and probe how matter behaves in the strong gravitational field created by some of the Universe’s most extreme objects like black holes. Join the conversation online this week following the hashtag #GravityRules


Related links:


Athena: http://sci.esa.int/athena/


LISA: http://sci.esa.int/lisa/


Athena-LISA paper: https://www.cosmos.esa.int/documents/678316/1700384/Athena_LISA_Whitepaper_Iss1.0.pdf


Images, Animation, Text, Credits: ESA/Markus Bauer/Paul McNamara/Matteo Guainazzi.


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Clocks, gravity, and the limits of relativity


ESA — Columbus Space Lab patch.


23 May 2019


The International Space Station will host the most precise clocks ever to leave Earth. Accurate to a second in 300 million years the clocks will push the measurement of time to test the limits of the theory of relativity and our understanding of gravity.


Albert Einstein’s general theory of relativity predicted that gravity and speed influences time, the faster you travel the more time slows down, but also the more gravity pulling on you the more time slows down.



European space laboratory Columbus where ACES will be installed

On 29 May 1919 Einstein’s theory was first put to the test when Arthur Eddington observed light “bending” around the Sun during a solar eclipse. Forty years later, the Pound-Rebka experiment first measured the redshift effect induced by gravity in a laboratory – but a century later scientists are still searching for the limits of the theory.


“The theory of relativity describes our Universe on the large scale, but on the border with the infinitesimally small scale the theory does not jibe and it remains inconsistent with quantum mechanics,” explains Luigi Cacciapuoti, ESA’s Atomic Clock Ensemble in Space (ACES) project scientist. “Today’s attempts at unifying general relativity and quantum mechanics predict violations of the Einstein’s equivalence principle.”



Negative photo of the 1919 solar eclipse

Einstein’s principle details how gravity interferes with time and space. One of its most interesting manifestations is time dilation due to gravity. This effect has been proven by comparing clocks at different altitudes such as on mountains, in valleys and in space. Clocks at higher altitude show time passes faster with respect to a clock on the Earth surface as there is less gravity from Earth the farther you are from our planet.


Flying at 400 km altitude on the Space Station, the Atomic Clock Ensemble in Space will make more precise measurements than ever before.


Internet of clocks


ACES will create an “internet of clocks”, connecting the most accurate atomic timepieces the world over and compare their timekeeping with the ones on humankind’s weightless laboratory as it flies overhead.


Comparing time down to a stability of hundreds femtoseconds – one millionth of a billionth of a second – requires techniques that push the limits of current technology. ACES has two ways for the clocks to transmit their data, a microwave link and an optical link. Both connections exchange two-way timing signals between the ground stations and the space terminal, when the timing signal heads upwards to the Space Station and when it returns down to Earth.



ACES clock

The unprecedented accuracy this setup offers brings some nice bonuses to the ACES experiment. Clocks on the ground will be compared among themselves providing local measurements of geopotential differences, helping scientists to study our planet and its gravity.


The frequencies of the laser and microwave links will help understand how light and radio waves propagate through the troposphere and ionosphere thus providing information on climate. Finally, the internet of clocks will allow scientists to distribute time and to synchronise their clocks worldwide for large-scale Earth-based experiments and for other applications that require precise timing.




Columbus module with ACES

“The next generation of atomic clocks and the link techniques that we are developing could one-day be used to observe gravitational waves themselves as ESA’s proposed LISA mission,” adds Luigi, “but right now ACES will help us test as best we can Einstein’s theory of general relativity, searching for tiny violations that, if found, might open a window to a new theory of physics that must come.”


The clocks have been tested and integrated on the ACES payload and the microwave link for ACES is undergoing tests before final integration with the full experiment. ACES will be ready for launch to the Space Station by 2020.


Related links:


European space laboratory Columbus: http://www.esa.int/Our_Activities/Human_and_Robotic_Exploration/Columbus


Pound-Rebka experiment: https://en.wikipedia.org/wiki/Pound%E2%80%93Rebka_experiment


International Space Station Benefits for Humanity: http://www.esa.int/Our_Activities/Human_and_Robotic_Exploration/International_Space_Station_Benefits_for_Humanity


Images, Text, Credits: ESA/D. Ducros/NASA/Royal Astronomical Society/CNES.


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3-million-year-old fossilized mouse reveals evolutionary secrets of colour

The evolutionary use of colour for mammal’s survival in the wild is evident from, red foxes, to zebras. Today an international team, led by researchers from The University of Manchester, publish research revealing the evidence of colourful pigments from ancient mouse remains.











3-million-year-old fossilized mouse reveals evolutionary secrets of colour
Using SLAC’s Stanford Synchrotron Radiation Light Source, researchers were able to untangle the story of key pigments
in ancient mouse fossils. The researchers showed that the mouse likely had reddish and brown fur on its back and sides
and a white tummy, as shown in Stuart Pond’s artist’s conception on the left. The bottom image on the right
is a photograph of the key fossil examined in this study. Above that is a false colour synchrotron X-ray
image of the fossil chemistry [Credit: Gregory Stewart/SLAC National Accelerator Laboratory]

Colour plays an important role in the evolution of life on Earth, it has also played a role in the selective processes that have steered evolution for hundreds of millions of years.


The paper, ‘Pheomelanin pigment remnants mapped in fossils of an extinct mammal’ is published in the journal Nature Communications. The work marks a major scientific breakthrough in our ability to define fossilised colour pigments in long extinct species for the first time.


This new study applied X-ray imaging to several 3 million year old fossils in order to untangle the story of key pigments in ancient animals and reveal how we might recognise the chemical signatures of specific red pigments in long extinct animals to determine how they evolved.


Professor Phil Manning, the lead palaeontologist on the paper explained: «The fossils we have studied have the vast potential to unlock many secrets of the original organism. We can reconstruct key facets from life, death and the subsequent events impacting preservation before and after burial. To unpick this complicated fossil chemical archive requires an interdisciplinary team to combine their efforts to crack this problem. In doing this, we unlock much more than just palaeontological information.»


Professor Roy Wogelius, co-author and geochemist said: «This was a painstaking effort involving physics, palaeontology, organic chemistry, and geochemistry. By working as a team, we were able, for the first time, to discover chemical traces of red pigment in fossil animal material. We understand now what to look for in the future and our hope is that these results will mean that we can become more confident in reconstructing extinct animals and thereby add another dimension to the study of evolution.»











3-million-year-old fossilized mouse reveals evolutionary secrets of colour
A false colour synchrotron X-ray image of the fossil chemistry. Blue represents calcium in the bones, green is the element
zinc which has been shown to be important in the biochemistry of red pigment and red is a particular type of organic
sulfur which cannot be imaged by traditional methods. This type of sulfur is enriched in red pigment. When combined,
 regions rich in both zinc and sulfur appear yellow on this image, showing that the fur on this animal was rich in
the chemical compounds that are most probably derived from the original red pigments produced by the mouse
[Credit: Manning et al. 2019]

The new research reveals that not only may chemical traces of dark black pigments be present within exceptionally preserved soft tissues, but that traces of the much more elusive red animal pigment may be resolved. The chemical residue of black pigment, which colours such animals as crows, was first resolved by this team in a previous study nearly ten years ago. But the red pigment, characteristic of animals such as foxes, is far less stable over geological time and proved much more difficult to detect.


Professor Wogelius went on to say: «We had data which suggested red pigment residue was present in several fossils, but there was no useful data available to compare this to in modern organisms. So we needed to devote several years to analysing modern tissue before we could go back and review our results from some amazing fossil specimens. In the end, we were able to prove that detailed chemical analysis can resolve such pigment residue, but along the way we learned so much more about the chemistry of pigmentation throughout the animal kingdom.»


To unlock the fossil patterns, the Manchester team collaborated with scientists at some of the brightest sources of light on the planet, using synchrotron radiation at the Stanford Synchrotron Radiation Lightsource (USA), and also at the Diamond Light Source (UK) to bathe the fossils in intense x-rays. It is the interaction of these x-rays with the chemistry of these fossils that enabled the team to be the first to recognise the chemistry of red (pheomelanin) pigmentation in fur from exceptionally well preserved 3 million year old mouse fossils.


The key to their work was identifying trace metals incorporated by ancient organisms into their soft tissues, and comparing these to the modes of incorporation into living species. The chemistry shows that the trace metals in the mouse fur are bonded to organic chemicals in exactly the same way that these metals are bonded to organic pigments in animals with high concentrations of red pigment in their tissue.











3-million-year-old fossilized mouse reveals evolutionary secrets of colour
The key fossil examined in this study is a 3-million-year-old extinct species of field mouse from Germany.
The mouse is approximately 7 cm long ]Credit: University of Göttingen]

The scientists have also translated the chemical findings into sound waves so people are able to hear frequencies of sound associated with differing pigment colours present in the fossils.


In order to make absolutely sure of their findings, modern comparison standards were analysed both by synchrotron radiation and by specialists in pigment chemistry based at the Fujita Health University in Japan.


Prof. Manning finally added: «Palaeontology offers research that is more than relevant to our everyday life. Information gleaned from the fossil record is influencing multiple fields, including; climate research, the burial of biowaste and radwaste, the measure of environmental impact of oil spills on living species with techniques developed on fossil organisms. Whilst our research is firmly anchored in the past, we set our sights on its application to the future.»


Source: University of Manchester [May 21, 2019]



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Origins of cannabis traced back 28 million years to Tibetan Plateau

The origin of marijuana has finally been discovered and it dates back 28 million years to the Tibetan plateau, 10,700ft (3km) above sea level.











Origins of cannabis traced back 28 million years to Tibetan Plateau
Credit: CBD School

Researchers analysed pollen fossils of the plant and found it slowly dispersed over millennia to Europe, China and India.


It has long been known cannabis originated in Central Asia but its exact location had remained a mystery until now.


Archaeological evidence of its use as a drug dates back to to 2,700 BC in the nearby Xinjiang region north west of China.


A team of researchers led by the University of Vermont in the US examined 155 existing fossil pollen studies from Asia in order to ‘to reconstruct the evolutionary and human related history of Cannabis in Asia’, said the authors in the report.


By looking at genetic analysis and fossils of cannabis pollen, they pinpointed the origins of its growth to 28 million years ago to the area of Qinghai lake on the Tibetan plateau.


They mapped the fossil data and found the oldest pollen fossil dates to 19.6 millions BC where it was likely cultivated by humans, given that both hem crop and fruits seeds fossils were also found at archaeological sites.


The plateau in the southwest of China measures 14,800 ft (4,500 m) above sea level at its peak and the lake sits at 10,700ft (3km) up the range.


The area overlaps with the first hunter and gatherer community that evolved in Asia, although no link has been made between the two.


Based on their analysis, the researchers found evidence the cannabis strain of hemp first disseminated to Europe and then East to China followed by India due to tectonic movements in the Earth that caused land mass to move closer to each other.


The flowering tops of cannabis strains such as hemp plant produce cannabinoids, which have been used to make the cannabis drug.


One reason the origins of the plant have been so hard to trace is because the leaves of cannabis plants — such as hemp — don’t create very good print fossils, and only two collections of the plant fossil exist.


In contrast, hundreds of pollen fossils have been found and analysed, which the current study reviewed.


While widely known as a drug, the cannabis plant in fact had may functions for communities that used its plant fibres, for providing cordage and textiles, for example.


Carbonised hemp fibres, found with silk and spinning wheels, date to 5,600 BC, in Henan Province, China.


Scientists also put down the appearance of cannabis elsewhere in the world down to tectonic movements of the earth, rather than humans migrating with it.


The researchers wrote: ‘Early floristic exchanges between India and Asia were shaped by plate tectonics,’ the researchers wrote in their paper.


‘As the Indian plate migrated towards the Asian plate, it made a ‘glancing contact’ with Sumatra 57 [million years ago], followed by Burma, and then a ‘hard collision’ with Tibet 35 [million years ago].


‘The glancing contact between continents resulted in floristic exchanges during the Eocene.’


‘Cannabis holds significance in human history and life today as a triple-use crop. First, its fruits (seeds) provide valuable protein and essential fatty acids’, wrote the researchers.


Archaeological evidence in a food context dates back to 10,000 BC in Japan.


The full report was published in the journal Vegetation History and Archaeobotany.


Author: Yuan Ren | Source: Daily Mail [May 21, 2019]



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Facial reconstruction breathes new life into ancient citizens of Sagalassos

A look into the past. It’s usually just a metaphor, but archaeologists Jeroen Poblome and Sam Cleymans have made it a physical reality. Together with the University of Burdur, Turkey, they have reconstructed the faces of two centuries-old residents of Sagalassos.











Facial reconstruction breathes new life into ancient citizens of Sagalassos
«A facial reconstruction is a combination of science and creativity,» according to Professor Poblome
[Credit: Bruno Vandermeulen & Danny Veys/Sagalassos Archaeological Research Project]

For over thirty years, KU Leuven researchers have been examining the archaeological site of Sagalassos with an international and interdisciplinary team. Layer by layer, they’re reconstructing the past of this ancient city in what is now Turkey.


From now on, the Sagalassos Archaeological Research Project literally has a face. On the basis of skeletal remains, the researchers have reconstructed two lifelike faces – one of a Roman-era man (early third century CE) and one of a Middle-Byzantine woman (11th-13th century CE). The researchers have called them ‘Rhodon’ and ‘Eirènè’, respectively, as their real names are unknown.


“As the director of the Sagalassos Archaeological Research Project, I’ve always had the ambition to get a better picture of everyday life in Sagalassos,” says Professor Jeroen Poblome. “Archaeologists are often obsessed with superlatives – the first, the biggest, the most beautiful – but our research focuses on the life of everyday men and women. These facial reconstructions fit in perfectly with this approach.”


“Eirènè’s skeleton was found in 1995 by a research team led by my predecessor, Marc Waelkens. Her final resting place was in a graveyard surrounding a chapel. We discovered Rhodon’s remains on the final day of the excavations in 2016. He was found in a brick burial chamber that is part of a larger complex of several graves. Both skeletons were nearly complete and well preserved.”


Two life stories


Their burial places and skeletons offer more insight into the lives of these citizens. “We estimate that the ‘Roman’ man was older than fifty when he died,” says postdoctoral researcher Sam Cleymans. “His burial place tells us that he came from a middle-class family. We found some beautiful grave goods, for instance: an epistomion – a golden leaf placed on the mouth of the deceased – decorated with the image of a bee, and a gilded bronze ring.”











Facial reconstruction breathes new life into ancient citizens of Sagalassos
Professor Jeroen Poblome (middle) and PhD Sam Cleymans have reconstructed the faces of two
 centuries-old residents of Sagalassos [Credit: © KU Leuven/Rob Stevens]

“The remains show that the man has had a physically hard life. We found several joint lesions and bone fractures. His age plays a role, of course, but physical labour in a difficult landscape with many differences in height has clearly had an impact on his body.”


“For the Byzantine woman, fewer clues are available. Estimates put her between 30 and 50 years old when she died. She had fewer joint lesions, perhaps because of her younger age. Compared with that of the Roman man, her burial place was also a lot more sober, which fits with the Christian traditions in the Middle-Byzantine period.”


Beauty and the beast


The researchers wanted to know how the citizens lived, but also what they looked like. The first stage of the reconstruction was a completely digital process. A research team from the University of Burdur created a 3D scan of the skulls. The face shape was calculated on the basis of the form of the skull and the muscle origins. Layer by layer, the face was reconstructed: first the muscles and the layer of fat, and finally the skin. The size and shape of the nose, eyes, and ears were calculated as well. The digital facial reconstruction has an accuracy of 75 per cent.


The next steps involved a bit more educated guesswork, says Jeroen Poblome. “A facial reconstruction is a combination of science and creativity. We cannot deduce the skin tone or the colour of the eyes and hair from the skull, so we have to determine these on the basis of other sources. That’s why we based our decisions on the contemporary population of Ağlasun, where the archaeological site is located. Most citizens have brown eyes there, dark brown hair, and fairly light skin. So these seemed the best choices for Rhodon and Eirènè as well.”


For the hairstyle and beard shape, the researchers turned to historical sources. Sam Cleymans: “Physical appearance was important in the Roman age. The Romans could be quite vain. Written sources teach us that men generally didn’t like being bald, for instance. The beauty ideal for Roman men in the second century CE is based on Emperor Hadrian. That’s why we gave Rhodon relatively short hair and a well-groomed beard.”


“In the Byzantine period, the average population paid less attention to physical appearance. Modesty and simplicity were the norm. The limited descriptions and images suggest that women typically wore their hair long – loose or braided. For Eirènè, we chose loose hair with a thin braid.”


Author: Bregt Van Hoeyveld (trsl. Katrien Bollen] | Source: Katholieke Universiteit Leuven [May 21, 2019]



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