Enlarge / Experiments yield fresh evidence to support controversial hypothesis about the formation of the Great Sphinx of Giza. (credit: MusikAnimal/CC BY-SA 3.0 )

Leif Ristroph, a physicist and applied mathematician at New York University, was conducting experiments on how clay erodes in response to flowing water when he noticed tiny shapes emerging that resembled seated lions—in essence, miniature versions of the Great Sphinx of Giza in Egypt. Further experiments provided evidence in support of a longstanding hypothesis that natural processes first created a land formation known as a yardang , after which humans added additional details to create the final statue. Initial results were first presented last year as part of the American Physical Society's Gallery of Fluid Motion, with a full paper being published this week in the journal Physical Review Fluids.

"Our results suggest that Sphinx-like structures can form under fairly commonplace conditions," Ristroph et al. wrote in their paper. "These findings hardly resolve the mysteries behind yardangs and the Great Sphinx, but perhaps they provoke us to wonder what awe-inspiring landforms ancient people could have encountered in the deserts of Egypt and why they might have envisioned a fantastic creature."

In 2018 , Ristroph's applied mathematics lab fine-tuned the recipe for blowing the perfect bubble based on experiments with soapy thin films, pinpointing exactly what wind speed is needed to push out the film and cause it to form a bubble, and how that speed depends on parameters like the size of the wand. (You want a circular wand with a 1.5-inch perimeter, and you should gently blow at a consistent 6.9 cm/s.)

Enlarge / Drawing of a trade expedition to Punt during the reign of Queen Hatshepsut. Note the presence of baboons on board the lower ship. (credit: Nastasic )

One of the most enduring mysteries within archaeology revolves around the identity of Punt, an otherworldly “land of plenty” revered by the ancient Egyptians. Punt had it all—fragrant myrrh and frankincense, precious electrum (a mixed alloy of gold and silver) and malachite, and coveted leopard skins, among other exotic luxury goods.

Despite being a trading partner for over a millennium, the ancient Egyptians never disclosed Punt’s exact whereabouts except for vague descriptions of voyages along what’s now the Red Sea. That could mean anywhere from southern Sudan to Somalia and even Yemen.

Now, according to a recent paper published in the journal eLife, Punt may have been the same as another legendary port city in modern-day Eritrea, known as Adulis by the Romans. The conclusion comes from a genetic analysis of a baboon that was mummified during ancient Egypt’s Late Period (around 800 and 500 BCE). The genetics indicate the animal originated close to where Adulis would be known to come into existence centuries later.

Enlarge / The Pyramid of Sahura in Abusir, Egypt. (credit: Mohamed Ismail Khaled)

Over a century after a British archaeologist noted a blocked passageway in the ruins of Sahura's Pyramid in Egypt and suggested it might lead to additional rooms, a team of Egyptian and German archaeologists have cleared out that passageway to prove the archaeologist right. They discovered several previously undocumented storage rooms and used 3D laser scanning to produce a map of the interior, shedding additional light on the structure's architecture.

Sahura ("He who is close to Re ") was the second ruler of Egypt's Fifth Dynasty and reigned for roughly 13 years in the early 25th century BCE. Egyptologists believe he was the son of the first Fifth Dynasty founder, Userkaf , and Queen Neferhetepes II. When the time came for Sahura to build his pyramid complex, he chose to do so at a site called Abusir instead of Saqqara or Giza, where prior pharaohs had constructed their edifices. Archaeologists have suggested this might have been because Userkaf had built a sun temple at Abusir. Regardless, Sahura started a new trend: Abusir became the main acropolis for three other pharaohs of the early Fifth Dynasty.

The decorative carved reliefs of Sahura's Pyramid are widely considered to be unparalleled in Egyptian art, and the architectural design was a milestone in its use of palmiform columns, among other innovations; it became a template for subsequent pyramid/temple complexes in the Old Kingdom. The pyramid was smaller than the great monuments at Giza and Saqqara and more cheaply constructed, indicative of the decline in pyramid building in Egypt. For instance, the inner core was made of roughly hewn stones packed with a fill of limestone chips, pottery shards, and sand, held together with a thick clay mortar; only the outer casing was built with high-quality limestone. It might have made the pyramid faster and cheaper to build, but it also meant the pyramid deteriorated more over time.

Enlarge / One of the limestone canopic jars that once held mummified organs of the Egyptian noblewoman Senetnay (c. 1450 BCE). (credit: Museum August Kestner, Hannover/Christian Tepper)

Trying to recreate the scents and smells of the past is a daunting challenge, given the ephemeral nature of these olfactory cues. Now scientists have identified the compounds in the balms used to mummify the organs of an ancient Egyptian noblewoman, according to a recent paper published in the journal Scientific Reports, suggesting that the recipes were unusually complex and used ingredients not native to the region. The authors also partnered with a perfumer to recreate what co-author Barbara Huber calls "the scent of eternity."

“'The scent of eternity’ represents more than just the aroma of the mummification process,” said Huber , an archaeologist at the Max Planck Institute of Geoanthropology in Jena, Germany. “It embodies the rich cultural, historical, and spiritual significance of Ancient Egyptian mortuary practices. Our methods were also able to provide crucial insights into balm ingredients for which there is limited information in contemporary ancient Egyptian textual sources.”

As previously reported , Egyptian embalming is thought to have started in the Predynastic Period or even earlier, when people noticed that the arid heat of the sand tended to dry and preserve bodies buried in the desert. Eventually, the idea of preserving the body after death worked its way into Egyptian religious beliefs. When people began to bury the dead in rock tombs, away from the desiccating sand, they used chemicals like natron salt and plant-based resins for embalming.

Enlarge / Portrait of Ramesses II in Nakhtamun tomb, Chief of the Altar in the Ramesseum (possibly 20th Dynasty, circa 1100 BCE). (credit: Martinez et al./CC-BY 4.0 )

Researchers have discovered evidence of earlier versions of two ancient Egyptian paintings located in tomb chapels in the Theban Necropolis , according to a new paper published in the journal PLoS ONE. In one, there is a ghostly third hand partially hidden under a white overprinted layer; the other has adjustments to the crown and other royal items in a portrait of Ramesses II . These discoveries were made with a portable macro-X-ray fluorescence (MA-XRF) imaging device that enabled the researchers to analyze the paintings on site, with no need for taking physical samples.

X-rays are a well-established tool to help analyze and restore valuable paintings because the rays' higher frequency means they pass right through paintings without harming them. X-ray imaging can reveal anything that has been painted over a canvas or where the artist may have altered his (or her) original vision. For instance, Vermeer's Girl Reading a Letter at an Open Window was first subjected to X-ray analysis in 1979 and revealed the image of a Cupid lurking under the overpainting. In 2020, a team of Dutch and French scientists used high-energy X-rays to unlock Rembrandt's secret recipe for his famous impasto technique, believed to be lost to history.

In 2021, scientists used macro-X-ray fluorescence imaging to map out the distribution of elements in the paint pigments of Jean-Louis David's famous portrait of 17th-century chemist Antoine Lavoisier and his wife Marie-Anne—including the paint used below the surface—to create detailed elemental maps for further study. Earlier this year , scientists used X-ray powder diffraction mapping and synchrotron micro X-ray analysis to study Rembrandt van Rijn 's 1642 masterpiece The Night Watch , and found rare traces of a compound called lead formate .

Enlarge / An Egyptian drinking vessel in the shape of Bes head contained traces of Syrian rue and blue water lily, among other compounds. (credit: Tampa Museum of Art, Florida)

An ancient Egyptian vase in the shape of the deity Bes showed traces of chemical plant compounds known to produce hallucinations, according to a recent preprint posted to Research Square. The authors suggest that members of the cult of Bes may have consumed a special cocktail containing the compounds to induce altered states of consciousness.

There is ample evidence that humans in many cultures throughout history used various hallucinogenic substances in religious ceremonies or shamanic rituals. That includes not just ancient Egypt but also ancient Greek, Vedic, Maya, Inca, and Aztec cultures. The Urarina people who live in the Peruvian Amazon Basin still use a psychoactive brew called ayahuasca in their rituals, and Westerners seeking their own brand of enlightenment have also been known to participate.

Lacing the beer served at their feasts with hallucinogens may have helped an ancient Peruvian people known as the Wari forge political alliances and expand their empire, according to a 2022 study . As previously reported , the use of hallucinogens, particularly a substance derived from the seeds of the vilca tree, was common in the region during the so-called Middle Horizon period, when the Wari empire thrived.

Enlarge / Archaeologists have discovered the first physical evidence of the so-called "gold of honor" ceremony in Ancient Egypt, in which the severed hands of defeated foes were presented to the Pharaoh in exchange for a collar of golden beads. (credit: J. Gresky et al., 2023/CC BY 4.0 )

There is evidence that ancient Egyptian soldiers would sever the right hands of foes and present them to the Pharaoh. That evidence comes in the form of tomb inscriptions of prominent warriors, as well as inscriptions and iconography on temple reliefs. Archaeologists have now discovered the first physical evidence of such a trophy-taking practice, according to a recent paper published in the journal Scientific Reports. The severed right hands of 12 individuals were excavated from pits within a courtyard of a 15th Dynasty palace in northeastern Egypt.

The 15th Dynasty (circa 1640-1530 BCE) rulers were known as Hyksos ("rulers of foreign lands"), although they did not control all of Egypt from their seat of power in the city of Avaris—the pharaohs of the 16th and 17th Dynasties ruled from Thebes during the same time period. Historians disagree about whether the Hyksos came to Egypt as invaders or gradually settled in the Nile delta before rising to power. But by the late 17th Dynasty, the Hyksos and the pharaohs were at war, leading to the former's defeat by Ahmose I, who founded the 18th Dynasty.

But the Hyksos nonetheless left their mark on Egyptian culture in the form of certain technological advances and customs, including the practice of presenting the severed right hands of defeated foes in a so-called "gold of honor" ceremony in exchange for a collar of golden beads. Per the authors, the Egyptians seem to have adopted the custom during Ahmose I's reign at the latest, based on a relief showing a pile of hands in his temple in Abydos. Tomb inscriptions and temple reliefs from the 18th to the 20th Dynasties "consistently depict hand counts on the battlefield following major battles," the authors wrote. However, there was no physical evidence of the custom beyond iconographic and literary sources—until now.

Enlarge / Map of the known corridors and rooms inside the Great Pyramid of Giza. Evidence of a secret corridor was detected in 2016 behind the famed chevron blocks on the north face (h). Another mysterious large void (i) was discovered in 2017—a possible hidden chamber. (credit: Procureur et al., 2023)

In 2016, scientists using muon imaging picked up signals indicating a hidden corridor behind the famous chevron blocks on the north face of the Great Pyramid of Giza in Egypt. The following year, the same team detected a mysterious void in another area of the pyramid, believing it could be a hidden chamber. Two independent teams of researchers, using two different muon imaging methods, have now successfully mapped out the corridor for the first time, according to a new paper published in the journal Nature Communications. Zahi Hawass, Egypt’s former antiquities minister, called it "the most important discovery of the 21st century."

As we've reported previously , there is a long history of using muons to image archaeological structures , a process made easier because cosmic rays provide a steady supply of these particles. An engineer named E.P. George used them to make measurements of an Australian tunnel in the 1950s. But Nobel-prize-winning physicist Luis Alvarez really put muon imaging on the map when he teamed up with Egyptian archaeologists to use the technique to search for hidden chambers in the Pyramid of Khafre at Giza. Although it worked in principle, they didn't find any hidden chambers.

There are many variations of muon imaging, but they all typically involve gas-filled chambers. As muons zip through the gas, they collide with the gas particles and emit a telltale flash of light, which is recorded by the detector so scientists can calculate the particle's energy and trajectory. It's similar to X-ray imaging or ground-penetrating radar, except with naturally occurring high-energy muons rather than X-rays or radio waves. That higher energy makes it possible to image thick, dense substances like the stones used to build pyramids. The denser the imaged object, the more muons are blocked, casting a telltale shadow. Hidden chambers in a pyramid would show up in the final image because they blocked fewer particles.

Enlarge / Illustration of an embalming scene in an underground chamber. (credit: Nikola Nevenov)

Most of what we know about ancient Egyptian mummification techniques comes from a few ancient texts. In addition to a text called The Ritual of Embalming, Greek historian Herodotus mentions the use of natron to dehydrate the body in his Histories . But there are very few details about the specific spices, oils, resins, and other ingredients used. Fortunately, science is helping fill in the gaps. A team of researchers used molecular analysis to identify several basic ingredients used in mummification, according to a new paper published in the journal Nature.

Egyptian embalming is thought to have started in the Predynastic Period or even earlier, when people noticed that the arid heat of the sand tended to dry and preserve bodies buried in the desert. Eventually, the idea of preserving the body after death worked its way into Egyptian religious beliefs. When people began to bury the dead in rock tombs, away from the desiccating sand, they used chemicals like natron salt and plant-based resins for embalming.

The procedure typically began by laying the corpse on a table, removing the internal organs—except for the heart. Per Herodotus, "They first draw out part of the brain through the nostrils with an iron hook, and inject certain drugs into the rest" to liquefy the remaining brain matter.