BLOGS

Topics: African Studies, Civil Engineering, Civilization, Diaspora, History

A personal note:

I am mandated to drive into my office daily, which for me is a one-hour and ten-minute commute if the traffic is optimal. Two of my colleagues opted to separate from government service as their commutes were two hours for one and two and one-half hours ONE WAY for each of them, respectively. It was obviously not sustainable. So you will forgive me as my posts have not been as frequent as I would have liked them to be. I also find myself self-editing, before posting, thinking out loud, "can I say that," and not raise the ire of what amounts to a surveillance state that can bring misery to anyone for something we used to take for granted: The First Amendment.

That being said, this post resonated with me because, as a young man, I believed in the "ancient astronauts" conspiracy theory not so much from Erich Von Daniken's "Chariots of the Gods" as from the Afrofuturistic renderings of Earth, Wind, and Fire, influenced by Sun Ra ("Space is the Place"). Ironically, it allowed a lot of us to buy into the claptrap and bury the fact that Africans (or, inhabitants of Alkebulan) were just as capable of grasping engineering principles as were their European descendants, and they would have done it earlier since the continent is the cradle of our "intelligent species," which in current demonstration, that remains to be seen true.

The Neolithic farmers and herders who built a massive stone chamber in southern Spain nearly 6,000 years ago possessed a good, rudimentary grasp of physics, geometry, geology, and architectural principles, according to a detailed study of the site.
Using data from a high-resolution laser scan, as well as unpublished photos and diagrams from earlier excavations, archaeologists pieced together a probable construction process for the monument known as the Dolmen of Menga. Their findings, published on 23 August in Science Advances, reveal insights into the structure and its Neolithic builders’ technical abilities ( J. A. Lozano Rodríguez et al. Sci. Adv. 10, eadp1295; 2024).
The dolmen pre-dates the main stone circle at Stonehenge in the United Kingdom by about 1,000 years, but the construction process described in the study would have involved similar techniques and demanded a similar level of engineering.

Nature Vol 633 | 5 September 2024

Are the pyramids too awesome to have been the work of the mere mortals of ancient Egypt? If so, does that mean they were built by aliens? Rob Attar speaks to Professor Joyce Tyldesley about the origins of the pyramid conspiracy, and unveils what evidence we have for how these monuments were really constructed.

Of all the examples of pyramids in Egypt, the most famous is certainly the Great Pyramid of Giza. It was the oldest of the Seven Wonders of the Ancient World and the only one still surviving, and for nearly 4,000 years it stood as the tallest human-made structure in the world.

Now, more than 50 pyramids remain in Egypt: colossal feats of architecture and lasting monuments to the ancient civilization of the pharaohs.

But the complexity of the pyramids poses a significant challenge to archaeologists studying ancient Egypt. How, exactly, did this civilization construct such magnificent and technically precise monuments? As with the likes of Stonehenge, there are many challenging theories that seek to answer these questions of who built the pyramids, and how. A pyramid conspiracy even exists, and poses the provocative question: did aliens build the ancient Egyptian pyramids?

Archaeological evidence strongly suggests that the pyramids of ancient Egypt were built not by aliens, but by large groups of Egyptian laborers equipped with effective tools, directed by an impressive organizational ability.

“If we take the Great Pyramid of Giza, we know that it was built by gangs of workers summoned under a sort of national service or corvée system,” explains Professor Joyce Tyldesley, Egyptologist at the University of Manchester. They had fairly basic but effective tools, and the workers were able to cut blocks of stone, transport them to the construction site and gradually erect the pyramid. “There are parts of the technology we can’t see today – for example, the ramps – but basically, it was the sheer amount of person power that made it all possible.”

Did aliens build the pyramids? The real history that debunks the conspiracy, Jonny Wilkes, History Extra dot com, January 14, 2025

Keeping the carbon: Biochar can be added to cement to sequester carbon within concrete. (Courtesy: Sabbie Miller)

Topics: Biomass, Civil Engineering, Environment, Global Warming, Green Tech

Replacing conventional building materials with alternatives that sequester carbon dioxide could allow the world to lock away up to half the CO₂ generated by humans each year – about 16 billion tons. This is the finding of researchers at the University of California Davis and Stanford University, both in the US, who studied the sequestration potential of materials such as carbonate-based aggregates and biomass fiber in brick.

Despite efforts to reduce greenhouse gas emissions by decarbonizing industry and switching to renewable energy sources, humans will likely continue to produce significant amounts of CO₂ beyond the target “net zero” date of 2050. Carbon storage and sequestration – at source or directly from the atmosphere – are therefore worth exploring as an additional route towards this goal. Researchers have proposed several possible ways of doing this, including injecting carbon underground or deep under the ocean. However, all these scenarios are challenging to implement practically and pose their own environmental risks.

Modifying common building materials

In the present work, a team of civil engineers and earth systems scientists led by Elisabeth van Roijen (then a PhD student at UC Davis) calculated how much carbon could be stored in modified versions of several common building materials. These include concrete (cement) and asphalt containing carbonate-based aggregates; bio-based plastics; wood; biomass-fiber bricks (from waste biomass); and biochar filler in cement.

The researchers obtained the “16 billion tons of CO₂” figure by assuming all aggregates currently employed in concrete would be replaced with carbonate-based versions. They also supplemented 15% of cement with biochar and the remainder with carbonatable cement; increased the amount of wood used in all new construction by 20%; and supplemented 15% of bricks with biomass and the remainder with carbonatable calcium hydroxide. A final element in their calculation was to replace all plastics used in construction today with bio-based plastics and all bitumen with bio-oil in asphalt.

“We calculated the carbon storage potential of each material based on the mass ratio of carbon in each material,” explains van Roijen. “These values were then scaled up based on 2016 consumption values for each material.”

“The sheer magnitude of carbon storage is pretty impressive”

While the production of some replacement materials would need to increase to meet the resulting demand, van Roijen and colleagues found that resources readily available today – for example, mineral-rich waste streams – would already let us replace 10% of conventional aggregates with carbonate-based ones. “These alone could store 1 billion tonnes of CO₂,” she says. “The sheer magnitude of carbon storage is pretty impressive, especially when you put it in context of the level of carbon dioxide removal needed to stay below the 1.5 and 2 °C targets set by The Intergovernmental Panel on Climate Change (IPCC).”

Indeed, even if the world doesn’t implement these technologies until 2075, we could still store enough carbon between 2075 and 2100 to stay below these targets, she tells Physics World. “This is assuming, of course, that all other decarbonization efforts outlined in the IPCC reports are also implemented to achieve net-zero emissions,” she says.

Alternative building materials could store massive amounts of carbon dioxide, Isabelle Dumé, Physics World