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Researchers Are Reconstructing Zhang Heng’s Legendary Seismoscope From 132 AD.

— July 27, 2025 | By Christopher McFadden

Modern Reconstruction of the Houfeng Didong Yi. The Chinese Museum Calgary Alberta/Wikimedia Commons

Chinese scientists are exploring the possibility of recreating a modern, more sophisticated version of an ancient earthquake sensor allegedly invented nearly 2,000 years ago.

The original, called the Houfeng Didong Yi, was, according to Chinese lore, invented in 132 AD by the famous Chinese polymath Zhang Heng. This is widely considered the world’s first dedicated seismoscope (Earthquake Detector).

However, claims around the existence of this device have been questioned in recent years, with many citing that it was too advanced for the time.

The Houfeng Didong Yi (meaning “instrument for measuring seasonal winds and Earth’s motion”) supposedly consisted of a bronze jar with eight dragons facing eight compass directions. Each of these dragons held a ball in its jaws and sat above a toad with an open mouth.

When an earthquake happens, the dragon facing the quake’s direction drops its ball into the toad’s mouth, acting as a kind of ancient directional indicator.

World’s First Seismoscope

Despite being historically praised, many modern scholars have dismissed the device as a legend. To this end, textbooks in China removed any reference to it in 2017.

A researcher named Xu Guodong, from the Institute of Disaster Prevention in China, has re-examined the historical texts and attempted a realistic reconstruction using modern seismic science and engineering knowledge.

His new model features a central pendulum (like a weighted stick anchored in the ground) that swings when an earthquake occurs. It also has an L-shaped lever system that transfers the pendulum’s motion to one of the dragons’ ball-release mechanisms.

The reconstruction also features a locking system that ensures only one ball drops per quake, preserving directional accuracy. The new detector works by allowing the pendulum to swing when an earthquake occurs.

This pendulum, in turn, triggers a lever that makes one dragon drop its bronze ball. Like the original, the ball falls into the waiting toad’s mouth, indicating the direction of the quake.

The device’s locking system stops the other dragons from reacting, so only one direction is shown. According to Xu’s calculations, the device could detect tiny tremors as small as 0.5mm of ground movement.

To this end, it effectively amplified ground motion via the pendulum to increase sensitivity. While it couldn’t always determine the exact epicentre (modern wave science shows some limitations), its directionality was likely reliable under the right conditions.

Rediscovering Ancient Knowledge

According to historical records, the device was not just a curiosity, but it actually worked. For example, a real historical case from 138 AD reports that the device detected an earthquake 528 miles (850 km) away before anyone in the capital felt anything.

Later records show that after 132 AD, Luoyang (the capital at the time) began to record many more earthquakes, likely due to the device’s increased sensitivity. The physical device and its plans have since been lost to time.

“The loss of the seismoscope [original device, diagrams and notes missing] was [likely to have been] directly caused by war and chaos. It was also linked to powerful noble families who [might have] coveted, fought over, and hid the device and its technical records,” Xu explained.

“In Chinese history, only two bronzes were ever deified: the Xia dynasty’s Nine Tripod Cauldrons … and this – a testament to its extraordinary historical significance,” he added.

Following this research, Xu’s team plans to rebuild the device using only Han dynasty methods and materials. By doing so, they plan to restore a lost legacy and acknowledge early Chinese contributions to science that predate the West by over 1,700 years.

The Darvaza Gas Crater Has Been Burning Since 1971, When Soviet Scientists Accidentally Hit a Gas Pocket and Set It Alight.

— June 09, 2025 | Georgina Jedikovska

The Darvaza Gas Crater or the Door To Hell, a Burning Natural Gas Field, in the Karakum Desert in Turkmenistan. Photograph Teresa Otto

One of Turkmenistan’s most iconic landmarks, the infamous ‘Door to Hell’, a fiery natural gas crater which has been raging on for more than half a century has finally started to lose its steam, according to scientists monitoring the site.

The Darvaza Gas Crater, also referred to as the Gates of Hell or the Shining of Karakum, is located in the heart of Turkmenistan’s Karakum Desert and has been consuming millions of cubic meters of natural gas each year.

The 230-foot-wide, 100-foot-deep crater, which reaches temperatures exceeding 1,832 degrees Fahrenheit (1,000 degrees Celsius), has long been a subject of debate, with the country’s government repeatedly calling for its closure to prevent the ongoing loss of valuable natural gas.

However, officials may finally be seeing an end to their long-standing concerns, as researchers from Turkmengaz, the country’s state-run gas company, revealed the flames have visibly weakened on June 5.

A major Drop In Flame Activity

Turkmengaz scientists reportedly presented the new data showing a significant decline in the crater’s methane-fueled blaze at the International Scientific and Practical Conference on Environmental Aspects of Innovative Technologies in Hydrocarbon Development (TESC 2025).

Speaking at the conference held in Turkmenistan’s capital, Ashgabat, which focused on cutting emissions in hydrocarbon production and advancing the global energy transition, the research team revealed that the drop in flame activity is due to most of the flammable gas in the crater being nearly depleted.

According to officials, the fire’s strength has noticeably diminished, with flames now reduced to nearly a third of their original size and visible only up close. This marks a clear contrast to previous years when the fire could be seen from miles across the desert.

“The reduction is nearly threefold,” Irina Luryeva, director of the state-owned energy company, said, adding that recent engineering efforts have focused on drilling numerous containment wells around the site to capture the methane before it escapes into the atmosphere.

“Before, a huge glow from the blaze was visible from several kilometres away, hence the name ‘Gateway to Hell,'” continued Luryeva. “Today only a faint source of combustion remains.”

Tracing The Pit’s Origins

While the exact origins of the massive sinkhole remain a matter of speculation, it is widely believed to have been ignited in 1971, when a group of Soviet geologists accidentally drilled into an underground pocket of gas.

They then set it on fire to prevent toxic gases from spreading into the air, aiming to avoid a potential environmental disaster that could have poisoned the nearby locals. They reportedly expected the fire to burn out within a couple of weeks.

However, the flames continued to burn for more than 54 years, turning the gas crater into one of Turkmenistan’s most popular tourist attractions, drawing more than 10,000 visitors annually who come to witness the hundreds of flames burning inside its depths.

Seaweed – the Modern Day Superfood That Got Everyone Talking — Interesting Engineering

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— by Kashyap Vyas: You might have heard of the new fad in healthy eating – The Seaweed. The term seaweed is very board because seaweed comes in a variety of shapes and types.

Basically, seaweed is a term often used to describe a group of plants and algae that grow in the oceans, rivers, as well as in lakes and other water bodies. They are highly nutritious and…

Excuse the poor English on the site, it's obviously a translation, or written by someone for whom English is not his/her first language.