Chinese Carbon Nanotube Insulator

 

Scientists are searching for new, advanced materials that can block heat while also being thin and lightweight. In a paper published in Advanced Functional Materials, Chinese researchers at Tsinghua University describe how they stacked and wound together very thin, flexible films of carbon nanotubes to create an insulation material called super-aligned carbon nanotube films (SACNT-SF). This revolutionary material blocks heat more effectively than any other known insulator at high temperatures.

The new carbon nanotube insulator can withstand high temperatures up to 2,600°C, outperforming all other materials used for extreme-temperature applications. This breakthrough could be used for heat shields on hypersonic vehicles and spacecraft during re-entry into the atmosphere and in other high-temperature environments.

In addition to its superior insulation, SACNT-SF is also remarkably durable. It can withstand repeated heating and cooling cycles and remains stable up to 3,000°C in an argon atmosphere. And unlike bulky insulation material, this innovative substance is made of paper-thin films that can easily bend around a variety of shapes.

Read more here: Breakthrough carbon nanotube material sets new thermal insulation record

Resilient New Copper Alloy

A cross-section of the new copper alloy, with the orange dots representing copper atoms, the yellow tantalum atoms and the blue lithium atoms. (Image credit: Lehigh University)

An ultra-tough copper alloy that is stronger than steel and can be used to build better airplanes and spacecraft. It can withstand temperatures of 1500 F. This alloy is an excellent candidate to build parts for high-temperature aerospace applications. The researchers published their findings March 27 in the journal Science.

The new alloy, a mixture of copper, tantalum and lithium, was built on nanoscales to withstand extreme temperatures and strains, and will have significant applications for aerospace, defense and industry. 

"This is cutting-edge science, developing a new material that uniquely combines copper's excellent conductivity with strength and durability on the scale of nickel-based superalloys," reports study co-author Martin Harmer, a professor emeritus of engineering at Lehigh University in Bethlehem, Pennsylvania.

Related reading: New material gives copper superalloy-like strength | EurekAlert!; Scientists create ultra-tough copper alloy that is stronger than steel and can withstand temperatures of 1500 F | Live Science

Self-Healing Concrete

 

A section of the First Century BC Roman wall of Empuries (Ampurias) in Spain. 

The base of the wall was made of calcareous rock while the upper portion is of Roman concrete (opus caementicium).  Photo by Mark Cartwright, Creative Commons

Cement is a human-made conglomerate comprised of sand and gravel aggregates with calcined lime and clay. It is mixed with water to form mortar or mixed with sand, gravel, and water to make concrete. Concrete is a mixture of broken stone or gravel, sand, and cement. In ancient times concrete often contained crushed seas shells.

Cement-matrix composites include concrete (containing coarse and fine aggregates), mortar (containing fine aggregate, but no coarse aggregate), and cement paste (containing no aggregate, whether coarse or fine).

The ancient Romans built extremely durable sea walls using a concrete made from lime and volcanic ash to bind with rocks. Rather than eroding in the presence of sea water, the material gained strength from the exposure. Scientists have discovered that elements within the volcanic material reacted with sea water to strengthen the construction.

“Contrary to the principles of modern cement-based concrete, the Romans created a rock-like concrete that thrives in open chemical exchange with seawater,” reports Marie Jackson (University of Utah) in the journal American Mineralogist.

Mixing the concrete with limestone-producing bacteria allowed for cracks to self-heal. The bacteria, either Bacillus pseudofirmus or Sporosarcina pasteurii, are found in highly alkaline lakes near volcanoes, and are able to survive for up to 200 years without oxygen or food. They are activated when they come into contact with water. They then use the calcium lactate as a food source, producing limestone that closes up the cracks.

Related reading: Ancient Roman Concrete was Incredibly Strong

Newly Predicted Superhard Carbon Structures

 

An illustration depicts three of 43 newly predicted superhard carbon structures. The cages colored in blue are structurally related to diamond, and the cages colored in yellow and green are structurally related to lonsdaleite. Credit: Bob Wilder / University at Buffalo

Researchers have used computational techniques to identify 43 previously unknown forms of carbon that are thought to be stable and superhard -- including several predicted to be slightly harder than or nearly as hard as diamonds. Each new carbon variety consists of carbon atoms arranged in a distinct pattern in a crystal lattice.

The study -- published in the journal npj Computational Materials -- combines computational predictions of crystal structures with machine learning to hunt for novel materials. The work is theoretical research, meaning that scientists have predicted the new carbon structures but have not created them yet.

Eva Zurek, a University at Buffalo professor of chemistry, conceived of the study and co-led the project with Stefano Curtarolo, PhD, professor of mechanical engineering and materials science at Duke University.

Superhard materials can slice, drill and polish other objects. They also hold potential for creating scratch-resistant coatings that could help keep expensive equipment safe from damage.

"Diamonds are right now the hardest material that is commercially available, but they are very expensive," says Zurek. "I have colleagues who do high-pressure experiments in the lab, squeezing materials between diamonds, and they complain about how expensive it is when the diamonds break.

She added, "We would like to find something harder than a diamond. If you could find other materials that are hard, potentially you could make them cheaper. They might also have useful properties that diamonds don't have. Maybe they will interact differently with heat or electricity, for example."

The first and second authors of the new study are UB PhD graduate Patrick Avery and UB PhD student Xiaoyu Wang, both in Zurek's lab. In addition to these researchers, Zurek, Curtarolo and Toher, the co-authors of the paper include Corey Oses and Eric Gossett of Duke University and Davide Proserpio of the Universitá degi Studi di Milano.

The research was funded by the U.S. Office of Naval Research, with additional support from the Universitá degi Studi di Milano, and computational support from UB's Center for Computational Research.

Read more here and here.

MIT Engineers Rock the "Impossible"

 

Using a novel polymerization process, MIT chemical engineers have created a new lightweight material stronger than steel. The new substance is the result of polymerizing a material in two dimensions.

The new material is a two-dimensional polymer that self-assembles into sheets, unlike all other polymers, which form one-dimensional, spaghetti-like chains. Until now, scientists had believed it was impossible to induce polymers to form 2D sheets.

The researchers found that the new material’s elastic modulus — a measure of how much force it takes to deform a material — is between four and six times greater than that of bulletproof glass. They also found that its yield strength, or how much force it takes to break the material, is twice that of steel, even though the material has only about one-sixth the density of steel.

Such a material could be used as a lightweight, durable coating for car parts or cell phones, or as a building material for bridges or other structures, says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the new study.

“We don’t usually think of plastics as being something that you could use to support a building, but with this material, you can enable new things,” he says. “It has very unusual properties and we’re very excited about that.”

The researchers have filed for two patents on the process they used to generate the material, which they describe in a paper appearing today in Nature. MIT postdoc Yuwen Zeng is the lead author of the study.

Read more here and here.

Transparent Wood

 

The piece of glass in the photo was made from wood. (Photo: USDA Forest Service)

Forest Products Laboratory (FPL) researcher Junyong Zhu in co-collaboration with colleagues from the University of Maryland and University of Colorado have found a better way to make wood transparent. The conventional method involves a long process using chemicals to remove the lignin. In this new effort, the researchers are able to make wood transparent by changing the lignin rather than removing the lignin.

Wood’s lack of transparency comes from the combination of its two main components, cellulose and lignin. The researchers removed lignin molecules that are involved in producing wood color. First, they applied hydrogen peroxide to the wood surface and then exposed the treated wood to UV light (or natural sunlight). The wood was then soaked in ethanol to further clean it. Next, they filled in the pores with clear epoxy to make the wood smooth.

This method produces transparent wood that is 50 times stronger than the old method. The new method will be used to improve solar technology and window production. 

Transparent wood is one of the most promising new materials. The number of uses and benefits has yet to be fully realized. The production of transparent building materials will have an impact on the architecture of the future. It will be possible to live in a glass house made of wood!

 

Read more here and here.

Writing Surfaces Used by Humans

Alice C. Linsley

Humans have shown great ingenuity in drawing and writing. The earliest written communications involved drawings. The surfaces used included the walls of rock shelters, animal skins, stone and shells. This shell was carved by a human living in Java about 500,000 years ago.

Ostrich egg shells are one of the earliest known surfaces used by humans to draw. Many examples of these have been found at paleolithic sites. These ostrich eggs are an example. They are about 70,000 years old.

Stones with identical markings to those on the ostrich shells have been found in caves in Southern Africa. This Blombos Stone dates to about 70,000 years ago.

At the Upper Paleolithic site of Ohalo II near the Sea of Galilee, archaeologists found wooden objects on brush-hut floors that appear to have symbolic markings. One incised wooden object (c. 23,000 BC) is identical in size and incision pattern to a gazelle bone implement found in a grave.

Prehistoric populations left marks on the walls of caves to provide directions to people passing that way. Some of these marks are recognized today as letters. Many words that share a similar meaning begin with an ancient mark. Consider the V. This mark indicates a parting of water ways. It suggests a place that spreads out, like a valley or a vale. It might signify a washout or a deposit of sediment, like a glacial varve. Or something that opens, like a vagina or a valve.

Typical marks include concentric circles, parallel lines (both vertical and horizontal), Y, V, X, and O and sometimes an X inside an O. The Y suggests a fork in the route ahead. The X indicates a place to cross or an intersection of routes. The O represented a day's time, or the solar arc from east to west.

One of the oldest known scripts is that of the Vinča Culture of present day Serbia and parts of Bulgaria and Romania, dated to the period 5700–4500 BC. This inscribed amulet was discovered in 1961 by archaeologist Nicolae Vlassa at a Neolithic site in the village of Tărtăria in modern Romania.

Papyrus reeds and wood were also used as writing surfaces. The wood document below dates to the reign of Amenhotep I, c. 1514-1493 BC.

The scribe’s tablet above shows hieratic script. Text is an excerpt from The Instructions of Amenemhat (12th Dynasty, 1991-1778 BC). It reads: “Be on your guard against all who are subordinate to you …Trust no brother, know no friend, make no intimates.”


Related reading: Symbols of Archaic Rock Shelters; Early Written Signs; The Edwin Smith Papyrus; How Parchment is Made

War Armour

This is the war armour of Lord Buckhurst, made in 1587 at the Royal Armourers’ Workshops in Greenwich, England. The Royal Armourers’ Workshops was set up by Henry VIII at the beginning of the 16th century to provide himself and his Court with the finest quality armour. Read more here.

Iron armour could be carburized or case hardened to give a surface of harder steel.


Related reading: Materials 1 (metals); Materials 2 (ores), Materials 3 (resins)

A History of Glass

Glass is a material of great interest to archaeologists and materials experts. Because of its fragile nature, many of the oldest glass artifacts are no longer intact.

The oldest known glass manufacturing site was in Egypt. It dates to around 1350 B.C. The glass items produced there were for nobles and high kings. The Egyptians set the early standard in glass-making. They created blue glass beads, beads with embedded amber, and vessels with narrow necks used to store perfume or other precious liquids. They also used glazes of glass to decorate objects made of other materials.

A glass bottle bearing the sign of King Thutmose III, of the eighteenth dynasty of Egypt, is on display in the British Museum in London.

The artisans of Mesopotamian also produced glass. A victory inscription from an Egyptian king claimed that he had brought back skilled glass workers from Mesopotamia.

Decorated glass was produced 1000 years ago at Igbo-Olokun, an archaeological site in the Yoruba city of Ile-Ife in southwestern Nigeria.

The Glastonbury Abbey Project has been reevaluating data from previous excavations at that ancient site. One of the discoveries involves glass making. A reassessment of the Glastonbury glass-producing furnaces proved that Saxon workers were recycling Roman glass imported from Europe, and that the furnaces are nearly 300 years older than expected. They date to about A.D. 700 and are associated with the construction of the earliest stone churches in England. According to archaeologist Roberta Gilchrist (University of Reading) this makes the site’s glass production complex among the earliest and most substantial in Saxon England.

Ancient Greek and Roman glass

Glass is made from sand. Early humans probably discovered this when they built bonfires on the sand. The fire's intense heat turned the sand into liquid. When the liquid sand cooled, they noticed that it was hard. It had turned into glass.

The technique of glass blowing made glass less costly and more accessible to the average person of the Roman Empire.

Watch this video.

Here is another account of the history of glass.

Related reading: Egyptian Glass in Ancient Nordic Graves; The Origin of Libyan Desert Glass

Materials (Part 4)

Conglomerates are of interest to geologists and materials specialists. A conglomerate is a coarse-grained sedimentary rock that is composed of gravel-size clasts, e.g., granules, pebbles, cobbles, and boulders. Conglomerates form through different processes that cause the particles to consolidate and harden into rock. The finer materials such as sand, silt, or clay fill the interstices or gaps. This filler is called "matrix" by geologists. The matrix and other particles are often cemented by calcium carbonate, iron oxide, silica, or hardened clay.

Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. In cases where the rocks are composed of consolidated angular gravel-sized particles of rubble (usually from run off), the rock is called "Breccia."

Epiclastic conglomerates are produced by the physical disintegration (weathering) of preexisting rocks. The matrix is usually composed of clay, sand, particles of quartz, calcite, feldspar, hematite and clay cement.

Cataclastic conglomerates are formed by local earth movements, often along fault lines. or by the collapse of breccias into a sinkhole or in cave development.

Pyroclastic conglomerates are produced by the explosive activity of volcanoes. The heat and pressure fuse the particles. Volcanic rocks that have been transported and reworked through the action of wind or water are termed "volcaniclastic."

Phaneritic rock

This rock shows large interlocking crystals characteristic of intrusive 
rocks that cool slowly.

Cement is a human-made conglomerate comprised of sand and gravel aggregates with calcined lime and clay. It is mixed with water to form mortar or mixed with sand, gravel, and water to make concrete. Concrete is a mixture of broken stone or gravel, sand, and cement. In ancient times concrete often contained crushed seas shells.

Cement-matrix composites include concrete (containing coarse and fine aggregates), mortar (containing fine aggregate, but no coarse aggregate), and cement paste (containing no aggregate, whether coarse or fine).

The ancient Romans built extremely durable sea walls using a concrete made from lime and volcanic ash to bind with rocks. Rather than eroding in the presence of sea water, washed and wind, the material gained strength from the exposure. Scientists have discovered that elements within the volcanic material reacted with sea water to strengthen the construction.

Related reading: Scientists explain ancient Rome's Long-lasting concrete; How Ancient Rome's Concrete Has Survived 2000 Years

Materials (Part 3)

Besides metals and ores, biblical peoples used resins and oils. A resin is a sticky organic substance that does not dissolve in water (insoluble). Resins are exuded by some trees and plants. The sap of pine and fir trees is a resin. Resins tend to be flammable.

The hard transparent resins, such as the copals, dammars, mastic, and sandarac, are used for varnishes and adhesives. These are especially flammable and require careful storage away from heat and flame.

Oleoresins are a naturally occurring combination of oil and resin that can be extracted from plants. The softer oleoresins include turpentine, frankincense, elemi, and copaiba. Most oleo-resins are extracted from spices such as capsicum, cardamon, cinnamon, and the vanilla bean. Vanilla oleoresin is used in non-food products to provide a vanilla fragrance. Cinnamon oleoresin is used in cinnamon scented candles.

Gum resins like ammoniacum, asafoetida, gamboge, scammony, and myrrh are used to create essential oils. Essential oils were used by biblical peoples for perfumes, medicines, incense, and for purification and anointing.

Myrrh

The gum resin myrrh is extracted from a number of small, thorny trees of the genus Commiphora. The myrrh used by biblical peoples came from trees in Africa, the Arabian Peninsula, and India. Biblical peoples used myrrh to make perfume, incense, and medicine. It was also used to treat sore throats, cramps, inflammation, colic, and digestive problems. Myrrh was used to anoint people in dedication services and in preparation for death. The women who came to the tomb very early in the morning to finish preparing Jesus' body likely had myrrh with them. But He was not there. He had risen!

Frankincense

Frankincense resin and the oil produced from it have been used for thousands of years. Frankincense oozes out of the Bosellia tree bark as a gummy sap that hardens into the chucks shown above. These chunks of resin are used to make incense. Many Christians use incense in their services of worship.

There are over 52 references to frankincense in the Bible. Frankincense and myrrh were among the gifts presented to Jesus Christ by the Magi.

The Chinese have used frankincense as a medicine since at least 500 BC. Ancient Egyptian records make frequent reference to this aromatic resin, including some of its medical uses. It was used to make salves for wounds and sores, and it was a key ingredient in the embalming process. The Phoenicians used the smoke from burning frankincense as an insect repellent.

Hyssop

Hyssop is a small bushy aromatic plant of the mint family. The bitter leaves are used in cooking and herbal medicine (phytomedicine). The biblical peoples used hyssop for purification rites. This is what is meant by these words: "Purge me with hyssop and I shall be clean." (Psalm 51:7)

Hyssop oil has an antispasmodic property that may help relieve spasms in the respiratory system, nervous system, muscles, and intestines. Biblical peoples used it on wounds to prevent infection.

Bdellium

Bdellium (shown below) is a semi-transparent oleo-gum resin extracted from Commiphora wightii and from Commiphora africana. These trees grow in Ethiopia, Eritrea and other parts of sub-Saharan Africa. 

Did the manna eaten by the Israelites in the wilderness look like this?

Bdellium, onyx, and gold are listed as being plentiful in the land of Havilah in Genesis 2. Havilah was at the source of the Nile, in the region that came to be called Nubia. Bdellium also is mentioned in Numbers 11:7, where the manna is described as tasting like coriander seed and looking like bdellium resin.

Among the biblical peoples, bdellium was used medicinally, and as perfume and incense. In Hebrew this resin is called bedolach.


Related reading: Tar as an Adhesive and Sealant; Nubia in Ancient History; Materials (Part 1 - Metals); Materials (Part 2 - Ores)

Materials (Part 2) - Ores

Ores are naturally occurring rocks that contain metal or metal compounds in sufficient amounts to make extracting them worth the effort. The method used to extract a metal from its ore depends upon the reactivity of the metal and so how stable the ore is.

This chart shows the "reactivity" of these elements.

Some ores of importance to biblical peoples include carbon and hematite.

Carbon is a nonmetal that has two main forms (diamond and graphite) and that also occurs in impure form in charcoal, soot, and coal. It was ground to make pigment by biblical peoples and the black powder was used to imprint hands on the wall of caves by prehistoric peoples.

This "show of hands" is in the Cueva de las Manos (Cave of the Hands) located in Perito Moreno, Argentina. The cave art dates between 13,000–9000 BC.


Red ochre was ground into powder from red hematite. Because of its earthly red color, red ochre was used as a pigment by prehistoric peoples. It was used in human burial for over 40,000 years. An incised red ochre stone dating to 100,000 years was found at Blombos Cave, Western Cape, in South Africa. (See "Artifacts of Great Antiquity")

Related reading: Materials (Part 1); Mining Blood; Red Ochre and Red Deer

Materials Science (Part 1)

Materials scientist Changhong Ke believes boron nitride nanotubes (BNNTs) will revolutionize the construction of future spacecraft (Photo credit: Jonathan Cohen at Binghamton University, UK)


The interdisciplinary field of materials science, also termed "materials science and engineering" involves the design and discovery of new materials, particularly solids. Material science is related to metallurgy, the branch of science and technology concerned with the properties of metals and their production and purification.

Materials scientists have been responsible for the development of plastics, new alloys, and in the space industry they have created radiation shielding materials containing Hydrogen, Boron and Nitrogen.  

Changhong Ke's team working at Binghamton University in the UK found that boron nitride nanotubes (BNNTs) form stronger interfaces with epoxy and other polymers than comparable common carbon nanotubes (CNTs).

Metallurgists are materials scientists who specialize in metals such as steel, aluminum, iron, and copper. They often work with alloys, that is, metals that are mixed with each other metals or with other elements, to create materials with specific desirable properties.

One of the most important properties is tensile strength, or the resistance of a material to breaking under tension.

Another concern is corrosion, a natural process that converts a refined metal to a more chemically-stable form, such as its oxide, hydroxide, or sulfide. Corrosion is the gradual destruction of materials (usually metals) by chemical and/or electro-chemical reaction with their environment.

Copper slag found in the region of Edom, Abraham's territory

Among the biblical peoples there were clans that worked with metals and came to understand their properties. They were able to work these metals into useful objects such as knives, spear heads, sacred vessels for the temples, crown, and jewelry. The metal working clans kept their skills and knowledge a secret. By this means they had job security.

The metals worked by biblical metal workers included copper, gold, tin and silver. The oldest copper artifacts date to c. 9000 BC. They learned to alloy tin and copper to produce bronze.

Piles of waste material, called copper slag, have recently been discovered in ancient Edom, indicating large-scale mining operations there.

Royal metal workers created beautiful objects of gold, silver, cooper, and bronze. They made jewelry, knives, crowns, sacred vessels for the temples and shrines, and the gold ephod of the High Priest. They made the gold calves that King Jeroboam placed at the entrances to the shrines in Dan and Bethel in Israel. Moses fashioned a bronze serpent (Numbers 21) and Aaron fashioned a calf of gold (Exodus 32).


Related reading: The Afro-Asiatic Metal Workers, The Religious Symbolism of Gold, The Gold of Ophir; Humans Have Created 208 Species of Materials

Geologic Studies Confirm Biblical Data

Mysterious keyhole structures at Al Wadi, in the Saudi Arabian desert, observed by archaeologist David Kennedy from a helicopter.


Three regions are named in the Bible as being rich in minerals like copper and gold: Havilah at the source of the Nile in Kush (Genesis 2:11); Dedan in southwestern Arabia, and Ophir, south of Dedan.

The region of Dedan and Ophir is riddled with lava caves dating to many thousands of years ago. The archaic populations of Dedan and Ophir lived in these caves and collected epithermal gold. This is gold that is mined close to the surface because it has been brought up by volcanism.

Scientists have been studying this area. They are especially interested in the lava caves of Harrat Khaybar. Here researchers have found hundreds of stone walls surrounding large basaltic lava fields. The largest of the walls reaches almost 1,700 feet long. The stone walls were built during active volcanism. The structures at Harrat Khaybar are regarded as “works of the old men” by the Bedouin. The Bible calls them the "mighty men of old."

The lava caves and walls of Harrat Khaybar (Arabic for "White Mountain") are in the news today. Scientists have known about this region for 30 years. This is the region of biblical Dedan and Ophir, described as rich in precious metals. This is probably the oldest known site of recovery of copper and gold, and the miners lived in the caves, many of which collapsed long ago. Ophir was one the sons of Joktan (Gen. 10:26-28). The Joktanite clans still live in this region of Arabia.

This area of Saudi Arabia and Yemen is a site for porphyry copper and epithermal gold deposits captured by people living in the caves.

In 1946 an inscribed pottery shard was found at Tell Qasile (Tel Aviv) dating to the eight century BC. The Paleo-Hebrew inscription says, "gold of Ophir for Beth-Horon [...] 30 shekels." This, and other such finds, confirm that gold was exported from Ophir. 

Every three years Solomon received tribute of gold, silver, sandalwood, precious stones, ivory, apes and peacocks from Ophir. Solomon's navy traveled to Ophir, taking "four hundred and twenty talents of gold from there" (1 Kin. 9:26-28; 22:48; 2 Chr. 8:17-18; 9:10).

Related reading: Marvelous Stones at Harrat Khaybar; The Afro-Arabian Dedanites; The Gold of Ophir; Kushite Gold; The Lava Caves of Khaybar in Saudi Arabia; The Religious Symbolism of Gold; The Lava Fields of Saudi Arabia

How Heavy Elements are Produced

An artist’s illustration of merging neutron stars.

Credit: Robin Dienel; Carnegie Institution for Science

Monday's (Oct. 16) historic announcement of the detection of gravitational waves produced by two colliding neutron stars has provided explanation as to where in the elements heavier than iron are synthesized.

Until astrophysicists were able to observe the merger of two neutron stars, there only had theories about how heavy elements like gold, platinum and lead are created in the cosmos.

Neutron stars are the corpses of massive stars whose cores collapsed in supernova explosions. While they’re not that big, they’re incredibly dense, packing a sun’s worth of mass into the size of a city. A teaspoon of neutron-star stuff weighs around a billion or so tons.

Neutron stars contain some of the building blocks of atomic nuclei. If these neutrons are somehow released from a neutron star, they undergo reactions that allow them to stick together, creating elements heavier than iron. All of the post-iron elements are formed in these supernova explosions. So much energy is released during a supernova explosion that the freed energy and copious free neutrons streaming from the collapsing core drive massive fusion reactions, past the formation of iron.

Researchers are witnessing a distant heavy-element factory synthesizing "maybe hundreds of Earth masses' [worth] of gold and … maybe 500 Earth masses' worth of platinum," astrophysicist Daniel Kasen said in a new video.

Related reading: New Era of Astronomy; The Collision of Two Neutron Stars; Gold from Neutron Star Crashes

Tar as an Adhesive and Sealant

For thousands of years tar has been used as an adhesive and a sealant. This material is mentioned in Genesis 11:3 in connection with the construction of buildings made of brick. The bricks were mortared together using tar. The substance they used is called bitumen and is also known as asphaltum. It is a black, oily form of petroleum that occurs in nature as a byproduct of decomposed plants.

Tar pits are found all over the world. Genesis 14:10 reports that "the valley of Siddim [in Israel] was full of tar pits." The La Brea Tar Pit in California is a tourist attraction. Tar deposits are found in Africa, the Dead Sea, at various sites along the Indus River (Isa Khel), in Central and South America, in Switzerland, and in northeastern Alberta, Canada.

Throughout the biblical world, bitumen was used for the construction of buildings and water-proofing of reed boats like the one shown in the image above. The earliest known reed boat to date that was coated with bitumen, was found at the site of H3 at As-Sabiyah in Kuwait. The boat dates to about 5000 BC. 

According to Genesis, Noah's ark was made of reeds (gopher). Noah was a great Proto-Saharan ruler. He would have had boat builders (shipwrights), household servants, and gardeners. He is remembered for having a vineyard (Gen. 9:20). As a king, Noah had access to the best and the most plentiful supply of boat building materials.

The historicity of Noah’s concern for animals is supported by the discovery that Proto-Saharan rulers kept royal menageries of exotic animals. The oldest known zoological collection was found during the 2009 excavations at Nekhen on the Nile. The royal menagerie dates to about 3500 BC and included hippos, elephants, baboons, and wildcats. 

Noah would have known about the shrine city of Nekhen. It was one of the earliest worship centers for the Horite Hebrew.

The Neanderthals used bitumen at sites such as Gura Cheii Cave (Romania) and Hummal and Umm El Tlel in Syria. Here archaeologists have found stone tools with bitumen adhesive to fasten handles to tools and blades to spears used for hunting. The tar adhesive helped to strengthen and waterproof bindings made of sinew, hide, or plant fibers used to attach bone or stone tools and weapons to handles. The technique is known as hafting with tar.

Related reading: The Archaeological History of Black Goo; The Animals on Noah's Ark

Lead Contamination of Water

Lead pipes in Rome

Lead is harmful to humans. In recent years, the water supplies of some American cities has been found to have high concentrations of lead. Flint, Michigan made the news when it was discovered that the water wasn't properly treated. Lead from aging service lines began leaching into the Flint water supply after the city tapped into the Flint River as its main water source.

The problem of lead contamination is not a new problem. The water systems of ancient Rome used lead pipes. These pipes disintegrated, leaving lead residue in the soil. Researchers can use these lead trails to figure out the urban expansion around 33 BC.

Here is a report:

Just as modern cities struggle with lead pollution, so may have ancient Rome. And muddy waters preserved the city’s legacy of lead pipes, a new study suggests.

Researchers examined lead levels in dirt drilled from two Roman harbor sites, Ostia and Portus, on the Tiber River. The samples spanned 1000 B.C. to A.D. 1000. Up until around 200 B.C., harbor waters were pristine, but then contamination started to creep in.

The most likely source of lead would have been runoff from pipes in the city’s water system. The timing supports the idea that before aqueducts went in around 300 B.C., Rome’s water system initially employed terra-cotta or wooden pipes that were replaced with lead ones at least a century later. The researchers also link the ups and downs of lead levels to the expansion of the pipe system around 33 B.C. and periods of neglect beginning around A.D. 250.

Read more here.

Textiles of the Ancient World

Credit: Dailymail.UK

Textile technology is at least 77,000 years old. The world's oldest known mattress is an example. It was unearthed in South Africa at the Sibudu Cave site in KwaZulu-Natal. The mattress consists of layers of reeds and rushes. This mattress was discovered at the bottom of a pile of bedding made from compacted grasses and leafy plants. The bedding had accumulated over a period of 39,000 years, with the oldest mats dating to 77,000 years ago. (Read more here.)

Because fibers disintegrate, it is difficult to find intact samples of human-fabricated textiles from archaic times. Often the evidence of textiles is indicated by impressions left in burned clay. The earliest evidence of string appears about 40,000 years ago. Twined fibers were used to string beads.

Early cloth was made with string. The earliest known string-making was at the Ohalo II site in Galilee in Israel. There three fragments of twisted and plied plant fibers were discovered that date to 19,000 years ago.

Archaeologists have found 35,000-year-old flax fibers (Linum usitatissimum) at the Dzudzuana rockshelter in the former Soviet state of Georgia. The flax fibers had been twisted, cut and dyed a range of colors.

Archaic populations made foot coverings of animals hides. Bodies buried about 27,000 years ago at the Sunghir Upper Paleolithic sites in Russia appear to have had foot protection. A moccasin-type shoe was discovered at the Areni-1 Cave in Armenia that dates to 5500 years ago.

Sandals dating to between 12,000 and 6500 years have been found at several sites in the American southwest.

Silk proteins were found in 8500-year-old tombs at Jiahu in the Henan Province in central China. Silk was produced in significant amounts during the Longshan period in China (BC 3500-2000). Silk is made by extracting fibers from the cocoons of silkworms.

Evidence of silk has been found at ancient sites such as Palmyra in the Syrian Desert and in Egyptian tombs. Silk fibers were found in the hair of an Egyptian female mummy found in Thebes. The mummy has been dated to the twenty-first dynasty (c.1069-945 B.C.).

Related reading: Silk Production 8000 Years Ago; Stone Age String

Brick Making in the Ancient World

Unexcavated brick wall at Harappa in India.

Brick makers were a skilled class of people in the ancient world. They served the regional chiefs who constructed fortifications, palaces, and pyramids. 

Mud bricks date back to Mehrgarh (4500 B.C.), and baked bricks were a hallmark of the Indus Valley Civilization. Archaeologists have found clay or mud brick structures, often in ruins, dating to as early as 4800 B.C.

The bricks were pressed into molds and then dried in the sun or baked in ovens (kilns). The molds made it possible to produce bricks that were uniform in size and shape.

Baked bricks form this fortification wall. The strength and height are increased by alternating rows of bricks running in different directions.

Kiln-baked bricks were stronger and were used for the outer defensive walls and for structures near flood zones. 

Brick kilns (shown below) were discovered at Egyptian Teudjoi (Ankyronpolis) south of Beni Suef, on the east bank of the Nile. 

Genesis 11:3 tells us that the towers in Mesopotamia were built of fired brick. Mud or clay bricks were used to build temples, palaces, entrances to royal tombs, houses, walls, and pyramidal towers called ziggurats. The Mesopotamian ziggurats were built with a core of sun-dried mud brick and an exterior covered with kiln-baked brick. The term "ziggurat" comes from the Akkadian word ziqqurratu, which is translated as "rising building" (from the ancient Akkadian zaqâru, "to rise high").

The Sumerians used bricks to create arched entrances to royal tombs. Sumerian arches were made by stacking bricks on top of each other in steps that met in the center. Around 3000 B.C, builders created a special wedge-shaped brick mold that allowed the bricks to fit even more closely together above a doorway.

The Sumerians used natural bitumen ("black gold") as a waterproof mortar to bind sun-dried and kiln-fired bricks. This added to the structural strength and durability of the temples, city walls, and homes and protected against floods.

The Sumerians and ancient Egyptians built shrine cities and fortifications using clay bricks mixed with straw. According to Exodus 5:7, Pharaoh ordered the Egyptian taskmasters: "You are no longer to supply the people with straw for making bricks; let them go and gather their own straw."

To increase the brick production teams of brick makers competed against each other. This image (above) of men making bricks appears on the wall of the tomb of Rekmara, a ruler of the Eighteenth Dynasty (1550-1292 BC). 

The land of Canaan and its principal cities, such as Hazor, Kadesh, and Jerusalem, were under Egyptian rule during the Eighteenth Dynasty. Cities under Egyptian rule were fortified with walls many feet thick. The north wall protecting Lachish was 17 feet thick and the outer walls of Gezer were 14 feet thick. These fortified shrine cities are called the "high places" in the Bible. Jerusalem was named Jebus because it was the city of the Jebusites who built their royal complex on the south-eastern hill of Jerusalem. The old Jebusite wall was made of stone. Most monuments and fortification walls built by high kings were made of stone.

Bricks were used to lay out the structure of a new building. Stacked bricks served as markers. Some buildings contained bricks that were inscribed with prayers and dedications, as is done today on the corner stones of many public buildings and churches.

Related reading: Bricks and Urbanization in the Indus Civilization Rise and Decline; The High Places; Ancient Twin Cities; The Tower of Babel; Tar as an Adhesive and Sealant; Pharaoh's Brick Makers