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How the last meal of a 3,000-year-old crocodile was brought back to life using science
In a recent study, my colleagues and I revealed extraordinary details about the final hours in the life of a crocodile that was mummified by the ancient Egyptian embalmers. Using a CT scanner, we were able to determine how the animal died and how the body was treated after death.
To the Egyptians, animals served an important religious function, moving between the earthly and divine realms. Hawks were associated with the sun god, Horus, because they flew high in the sky, closer to the sun (and therefore to the god himself). Cats were linked to the goddess Bastet, a brave and ferociously protective maternal figure.
Most animal mummies were created as votive offerings or gifts.
Animal mummies provide a snapshot of the natural world, taken between approximately 750BC and AD250. Some of these mummified species are no longer found in Egypt.
For example, ancient Egyptians would have seen sacred ibises, long-legged wading birds with curved beaks, along the banks of the Nile every day. The birds were mummified in their millions as offerings to Thoth, the god of wisdom and writing. The birds are no longer in Egypt as climate change and the effects of desertification have made them move south to Ethiopia.
Another commonly mummified animal was the crocodile. Although crocodiles lived in the Nile during ancient times, the completion of the Aswan Dam in 1970 prevented them from moving northwards towards the delta in lower Egypt.
Crocodiles were associated with Sobek, Lord of the Nile and the god whose presence signalled the annual Nile flood which provided water and nutrient-rich silt to their agricultural land.
Crocodiles were mummified in huge numbers as offerings to Sobek. They were used as talismans throughout pharaonic Egypt to ward off evil, either by wearing crocodile skins as clothing, or by hanging a crocodile over the doors of homes.
Most crocodile mummies are of small animals, which suggests that the Egyptians had the means to hatch and keep the young alive until they were required. Archaeological evidence reinforces this theory, with the discovery of areas dedicated to the incubation of eggs and rearing of hatchlings. Some were pampered as cult animals and allowed to die a natural death.
As the crocodiles grew larger, the risk to crocodile keepers increased, suggesting perhaps that larger specimens were captured in the wild and hastily dispatched for mummification. Research on the mummified remains of larger animals has revealed evidence of skull trauma inflicted by humans probably as an attempt to immobilise and kill the animal.
What we found
The crocodile mummy in our study holds evidence to suggest how these animals might have been caught. The mummy is held in the collection of Birmingham Museum and Art Gallery, UK, and measures 2.23 metres long. In May 2016, the large crocodile mummy, which formed part of a wider study by a team of researchers I work with from the University of Manchester, was transported to the Royal Manchester Children’s Hospital to undergo a series of radiographic studies.
Medical imaging techniques allow researchers to study ancient artefacts without destroying them, the way that studies of mummies once did.
X-rays and CT scans showed that the animal’s digestive tract was filled with small stones known as “gastroliths”. Crocodiles often swallow small stones to help them digest food and regulate buoyancy. The gastroliths suggest the embalmers did not carry out evisceration, the process of removing the internal organs to delay putrefaction.
Among the stones, the images also showed the presence of a metal fish hook and a fish.
The study suggests that large, mummified crocodiles were captured in the wild using hooks baited with fish. It adds weight to the account of Greek historian, Herodotus, who visited Egypt in the 5th century BC and wrote about pigs being beaten on the banks of the river to lure the crocodiles, which were caught on baited hooks placed in the Nile.
Unlike many aspects of life in ancient Egypt, little information was recorded relating to animal worship and mummification. Classical writers who travelled to the country remain some of our best sources of information.
Colleagues from the Birmingham School of Jewellery helped replicate the hook in bronze, the metal most likely to have been used to create the ancient original, for display alongside the crocodile mummy.
Modern technology is helping us to learn more and more about our ancient past. I can only imagine what secrets technology might help reveal in the future.
Lidija M. Mcknight, Lecturer in Biomedical Egyptology, University of Manchester
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Iceland’s recent volcanic eruptions driven by pooling magma are set to last centuries
One of our findings suggests that magma from the first eruption pooled just under the island’s surface, where it built up the energy to spectacularly erupt. This initial burst of volcanism made it easier for more eruptions to follow after it.
Why is Iceland called the land of fire?
The island nation of Iceland is sometimes called “the land of ice and fire.” Early settlers witnessed several great “fires” – or volcanic eruptions – along the Reykjanes Peninsula.
After about 800 years without a volcanic event on the Reykjanes Peninsula, the Fagradalsfjall volcano roared to life on March 19, 2021. Then, two more discrete volcanic events occurred at Fagradalsfjall in 2022 and 2023. Subsequently, four more eruptions have taken place to the west at the Sundhnúkur fissure system in 2023 and 2024.
While these eruptions provide an incredible spectacle, they also have the power to wreak havoc. The recent Sundhnúkur eruptions threatened the fishing town of Grindavík, the geothermal power plant at Svartsengi and Iceland’s premier tourist destination: the geothermal spa the Blue Lagoon. Lava erupted within the town limits of Grindavík, and only human-made berms have prevented further destruction.
What makes Iceland so volcanically active?
Iceland is a unique place on Earth. It is part of a huge chain of volcanoes submerged in the center of the Atlantic Ocean, with Iceland being exposed above the ocean’s surface. This volcanic chain is known as the Mid-Atlantic Ridge, and it plays an essential role in plate tectonics.
Plate tectonics describes how the vast, rigid plates that make up Earth’s crust slide past, into and under one another. Their behavior slowly reshapes Earth’s surface. In some locations, the plates collide to form mountain ranges like the Himalayas. In other locations, one plate slides under another, creating volcanoes and earthquakes, like in Japan.
On the Mid-Atlantic Ridge – which stretches between the South Atlantic and Arctic Ocean – the plates pull apart, allowing molten magma to pour through. This magma solidifies into volcanic crust and creates new parts of the tectonic plates.
Geologists have also found a buoyant, hot plume of rocky material rising from deep in the Earth that intersects with the Mid-Atlantic Ridge under Iceland. This plume, along with several other similar plumes in the central and southern Atlantic, may have triggered the formation of the Atlantic Ocean basin more than 200 million years ago.
The plate tectonics associated with the Mid-Atlantic Ridge and the hot, rocky plume under Iceland together form Iceland’s volcanoes.
Scientists have been able to show that previous eruptions on the Reykjanes Peninsula are not random in time or space. Instead, they occur in periods that last centuries and along the same volcanic zones. These patterns indicate that these volcanic periods happen when vast tectonic forces pull apart the Reykjanes Peninsula. It appears that, while the plates pull apart evenly, volcanism along the Reykjanes ridge segment pulses with time.
What’s driving the eruption?
Many groups, including my colleagues from Iceland, have been collecting the erupted lavas on a near-daily basis. The collected samples provide a vital scientific time series of the eruptions.
Taking a volcanic time series is like regularly drawing someone’s blood to understand their medical condition. In this case, though, the blood is red-hot lava.
An initial study by another team in 2022 suggested that the mantle – the solid geological layer beneath the Earth’s crust – was melting to feed the lavas in Iceland, and that the lavas’ chemical makeup was changing over time. They suggested that these changes had to do with where and when the melting was happening in the mantle.
In July 2024, my research team and I published a longer time-series of the lavas from the eruption using a sensitive chemical method that helped us understand the lavas’ composition and origin.
The layer of basaltic rock that people live on in Iceland extends to a depth of about 9 miles (15 kilometers). It’s part of Earth’s crust. The mantle that lies directly beneath this crust is distinct – it’s made mostly of minerals like olivine that form a rock called peridotite. The magmas feeding these volcanic eruptions come from mantle peridotite.
The chemical method that my team used revealed that the first magmas feeding these eruptions rose from the mantle, but got stuck beneath the surface in a magma chamber for as long as a year. The rocks in the chamber walls melted into the magma, and we could see traces of them in our analyses.
Our research also suggests that the magmas gained water, carbon dioxide and other gases from sitting in the magma chamber. This water and gas allowed the magma to build up enough pressure to break through the surface and erupt as lava.
Magma pooling in the crust can trigger explosive eruptions – the beginnings of eruptions like those in Iceland or in La Palma in the Canary Islands in 2021 may require this type of pooling.
What might we expect in the future?
History tells researchers that these eruptions will likely last a long time. The volcanoes will erupt periodically every few years, for days to months at a time, for up to several hundred years into the future.
Generations of geologists and volcanologists are likely to forge their careers in Iceland, and millions of geo-tourists will get to experience the hauntingly beautiful eruptions.
German Typhoon jets fly in formation over the 2023 Litli-Hrútur eruption. James Day/SIO
With all these eruptions, Icelanders will have to adapt. Lava flows can disrupt infrastructure such as the Svartsengi geothermal plant, and volcanic gases can cause health problems.
The Fagradalsfjall and Sundhnúkur eruptions have already provided scientists with a treasure trove of data and insight into how volcanoes work. Continued study of volcanism on the Reykjanes Peninsula will help scientists understand how, when and why eruptions take place, and to better manage the hazards associated with living with volcanoes.
James Day, Professor of Geosciences, University of California, San Diego
This article is republished from The Conversation under a Creative Commons license. Read the original article.
NASA smacked a spacecraft into an asteroid – details on its 12-million-year history
By gathering lots of data on approach and after the impact, we would also get a better idea of what we’d be in for if such an asteroid were to hit Earth.
Five new studies published in Nature Communications today have used the images sent back from DART and its travel buddy LICIACube to unravel the origins of the Didymos-Dimorphos dual asteroid system. They’ve also put that data in context for other asteroids out there.
DART’s last complete image of Dimorphos, about 12km from the asteroid and 2 seconds before impact. NASA/Johns Hopkins APL
Asteroids are natural hazards
Our Solar System is full of small asteroids – debris that never made it into planets. Those that come close to Earth’s orbit around the Sun are called Near Earth Objects (NEOs). These pose the biggest risk to us, but are also the most accessible.
Planetary defence from these natural hazards really depends on knowing their composition – not just what they’re made of, but how they’re put together. Are they solid objects that will punch through our atmosphere if given the chance, or are they more like rubble piles, barely held together?
The Didymos asteroid, and its tiny moon Dimorphos, are what’s known as a binary asteroid system. They were the perfect target for the DART mission, because the effects of the impact could be easily measured in changes to Dimorphos’ orbit.
They are also close(ish) to Earth, or are at least NEOs. And they’re a very common type of asteroid we haven’t had a good look at before. The chance to also learn how binary asteroids form was the icing on the cake.
Quite a few binary asteroid systems have been discovered, but planetary scientists don’t exactly know how they form. In one of the new studies, a team led by Olivier Barnouin from Johns Hopkins University in the United States used images from DART and LICIACube to estimate the age of the system by looking at surface roughness and crater records.
They found Didymos is roughly 12.5 million years old, while its moon Dimorphos formed less than 300,000 years ago. That may still sound like a lot, but it’s much younger than was expected.
A pile of boulders
Dimorphos is also not a solid rock as we’d typically imagine. It is a rubble pile of boulders that are barely held together. Along with its young age, it shows there can be multiple “generations” of these rubble pile asteroids in the wake of larger asteroid collisions.
Sunlight actually causes small bodies like asteroids to spin. As Didymos started to spin like a top, its shape became squashed and bulged in the middle. This was enough to cause large pieces to just roll off the main body, with some even leaving tracks.
These pieces slowly created a ring of debris around Didymos. Over time, as the debris started sticking together, it formed the smaller moon Dimorphos.
How the spin of Didymos could have produced its tiny moon Dimorphos. Video by Yun Zhang.
Another study, led by Maurizio Pajola from Auburn University in the US used boulder distributions to confirm this. The team also discovered there were significantly more (up to five times) large boulders than have been observed on other non-binary asteroids humans have visited.
Another of the new studies shows us that boulders on all asteroids space missions have visited so far (Itokawa, Ryugu and Bennu) were likely shaped the same way. But this excess of larger boulders on the Didymos system could be a unique feature of binaries.
The locations of 15 suspected boulder tracks on the surface of Didymos. Bigot, Lombardo et al., (2024)/Image taken by DRACO/DART (NASA)
Lastly, another paper shows this type of asteroid appears to be more susceptible to cracking. This happens due to the heating–cooling cycles between day and night: like a freeze–thaw cycle but without the water.
This means if something (such as a spacecraft) were to impact it, there would be much more debris thrown up into space. It would even increase the amount of “shove” it could have. But there is a good chance that what lies underneath is much stronger than what we’re seeing on the surface.
This is where the European Space Agency’s Hera mission will step in. It will not only be able to provide higher-resolution images of the DART impact sites, but will also be able to probe the asteroids’ interiors using low-frequency radar.
The DART mission not only tested our ability to protect ourselves from future asteroid impacts, but also enlightened us on the formation and evolution of rubble pile and binary asteroids near Earth.
Eleanor K. Sansom, Research Associate, Curtin University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
How a futuristic material is able to change its properties from soft to rigid, and back
But imagine if an object as soft as a pillow could transform into an object as stiff as a rolling pin. With a simple switch, that object could acquire the properties and functions of a stiff material and, with another click, those of a soft material.
A material that could do this would allow an object to have multiple functions. This multifunctionality would inherently bring a substantial drop in the use of our resources. It would represent a paradigm shift for the sustainable future of everyday technologies.
Future materials
Along with other material scientists, physicists and engineers, my research investigates what we describe as reconfigurable mechanical metamaterials. These are a class of re-programmable multipurpose metamaterials with a transformable internal architecture.
These materials have three antagonist — seemingly counteractive — properties: floppiness, rigidity and multistability. This means that a user can re-program, on demand, their properties to be either stiff or soft or, if needed, even multistable.
An object made by this all-in-one class of metamaterials can become rigid to resist the application of external forces as a stiff structure, shape morph as a floppy mechanism, or trap and absorb energy as a multistable material.
After fabrication
A material that can acquire — post-fabrication — the traits of either a structure, a mechanism or a multistable matter does so because of the arrangements of its building block, in this case, a meta-hinge.
Reconfigurable building block, namely a metahinge. Applying a pair of forces to the rigid structure on the left can form a flexible hinge, generating a flopping mechanism (right) that can rotate around the central pivot. (D. Pasini and L. Wu), CC BY
This rearrangement can be triggered through the application of forces at particular pressure points. During the reconfiguration process, their edges come into contact, eventually merge, and close the central void, forming a flexible hinge. In one configuration, the building block is rigid because the metal hinge is not formed, whereas, in the other, the activation of the meta-hinge generates local rotation around the central pivot, making it floppy.
The metahinge activation can turn a structure into a floppy mechanism: on the left, a rigid curved beam withstands the applied load with negligible deformation, while on the right, the same beam becomes extremely floppy and sag in the opposite direction under the application of the identical load. (D. Pasini and L. Wu), CC BY
The reconfigurable building block can be used to create multifunctional structures with re-programmable properties. For example, a one-dimensional beam can be made to behave as either a stiff or floppy structure under a load applied at its midspan.
On the other hand, tessellating the building block in two dimensions allows the creation of three types of reconfigurations, each corresponding to a given class of macroscopic solids, either rigid, floppy or multistable at the verge between the two. Extensions to three dimensions are also possible.
The selective activation of metahinges enables a single metamaterial to acquire seemingly conflicting mechanical properties: rigidity (left), floppiness (right) and multistability when between the two states (middle). (D. Pasini and L. Wu), CC BY
Applications of metamaterials
Multifunctional products that can benefit from property reprogrammability span multiple sectors. In addition to physical properties, other geometric properties can be re-programmed. For example, the reconfigurability of the unit cells can bring overall changes in the size and shape of a product.
Fostering sustainability through multifunctional products, such as this reconfigurable coat hanger in different states: fully deployed with a width of 52 cm, and condensed, with a width of 16 cm. (D. Pasini, L. Wu and A. Sitbon), CC BY
A multifunctional coat hanger is just one example. By selectively activating certain hinges, the coat hanger can collapse for space-saving and ease of transportation, as well as be deployed when needed in different sizes and forms to accommodate clothing of different sizes. This provides an unprecedented level of multifunctionality, leading to sustainable resource use.
This all-in-one class of metamaterials helps create multipurpose products. This multifunctionality promises to reduce the use of resources, open a sustainable pathway to our future technology and contribute to attaining the sustainability targets our world has set, thereby paving the way for a greener and more resilient future.
Damiano Pasini, Professor of Mechanics and Materials, McGill University
This article is republished from The Conversation under a Creative Commons license. Read the original article.