&w=3840&q=100)
From myth to reality: Scientists recreate 2000-year-old Chinese quake sensor
About 2,000 years ago, a Chinese scholar named Zhang Heng reportedly created a groundbreaking device called the Houfeng Didong Yi, a seismoscope that allegedly could detect distant earthquakes and even point to their direction.
Though mentioned in ancient texts like The Book of the Later Han, some scholars doubt its existence, calling it a myth, and it was dropped from China's school curriculum in 2017.
Now, a team of researchers in China is working to prove this ancient invention was real by rebuilding it with the help of modern science.
STORY CONTINUES BELOW THIS AD
The device
Imagine a decorative wine jar with eight dragons around it, each holding a bronze ball in its mouth, and toads below waiting to catch them.
When an earthquake's tremors hit, a hidden mechanism would make one dragon drop its ball into a toad's mouth with a loud clang, showing the quake's direction.
According to The Book of the Later Han, it was 'as accurate as the gods.'
Built in 132 AD during the Eastern Han dynasty, this device was allegedly far ahead of its time—Europe didn't have a similar tool until 1856, when Italian scientist Luigi Palmieri made one.
Challenges and determination
Sceptics argue that ancient technology couldn't be that advanced, but others believe it was a remarkable engineering achievement.
Efforts to recreate the device based on old texts have failed to fully match its described abilities.
Xu Guodong, an associate professor at the Institute of Disaster Prevention in Hebei, is leading a team to change that.
Using modern seismic knowledge, they've designed a model with three parts: an excitation structure, a transmission structure, and a shutdown system.
Historical texts describe a 'capital pillar' with eight channels as the device's core.
Xu's team believes this pillar wasn't an unstable rod, as some thought, but a pendulum-like cantilever, similar to a giant chopstick fixed in the ground.
When the ground moved just 1mm, the pendulum's tip would swing at least 5mm, amplifying the tremor. This motion triggered an L-shaped lever system, releasing a bronze ball from a dragon's mouth. Even a tiny 0.5mm tremor could tip the delicate balance, sending the ball into a toad's mouth below.
STORY CONTINUES BELOW THIS AD
A clever locking system ensured only one ball fell. When the first ball dropped, it activated levers that locked the other seven, so only one direction was recorded, matching the historical claim that 'one dragon triggering while seven remained silent.'
Xu calls this design almost prophetic for its time.
The device was built to detect quakes reliably without false triggers, responding to ground movements as small as 0.5mm. However, pinpointing the exact direction of an earthquake's epicentre was tricky and only accurate under specific conditions, like when the device aligned with certain fault lines.
Xu's research, published in Progress in Geophysics in March, aims to restore the Houfeng Didong Yi's place as a marvel of ancient engineering.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Time of India
7 hours ago
- Time of India
Harvard expert reveals jobs that may protect you from Alzheimer's disease
A Harvard Health Publishing highlights a surprising link between certain occupations and a lower risk of dying from Alzheimer's disease (AD). According to research reviewed by Dr. Tired of too many ads? go ad free now Robert H. Shmerling, taxi and ambulance drivers show markedly lower rates of AD-related deaths compared with many other professions. Scientists believe the mental demands of real-time navigation in these jobs may strengthen the hippocampus, a brain region critical for memory and spatial awareness, and one of the first areas affected by Alzheimer's. If confirmed, these findings could open new doors in understanding and preventing the disease. Ambulance and taxi driver jobs may protect against Alzheimer's Earlier studies on London taxi drivers revealed enlargement in specific areas of the hippocampus, the part of the brain responsible for spatial memory. This region is particularly vulnerable to the damage caused by Alzheimer's. Researchers suspect that the constant mental mapping, route planning, and decision-making involved in taxi and ambulance driving help preserve hippocampal health. These jobs often require drivers to process incoming information instantly, adapt to changing traffic patterns, and find the most efficient routes in unfamiliar areas. Over time, this mental workout may strengthen neural connections in the brain, potentially slowing or preventing the deterioration associated with Alzheimer's disease. What the new study found The study examined data from nearly nine million death certificates, focusing on 443 occupations. After adjusting for the average age of death, the researchers discovered striking differences in Alzheimer's-related mortality rates. Alzheimer's accounted for just 0.91 percent of deaths among taxi drivers and 1.03 percent among ambulance drivers. Tired of too many ads? go ad free now This was more than 40 percent lower than the general population average and significantly lower than the 1.82 percent observed among chief executives. Pilots and ship captains had some of the highest rates, with 2.34 percent and 2.12 percent respectively. The findings suggest that the level of active navigation required in a job could be an important factor, although the benefit was not observed for other types of dementia. Why other navigation jobs are not equally protective While jobs like piloting an aircraft, captaining a ship, or driving a bus might seem similar in navigational demands, researchers explain that these roles often follow fixed routes or rely heavily on automated systems. Pilots can depend on autopilot and air traffic control, ship captains may navigate pre-determined sea routes, and bus drivers typically repeat the same path daily. As a result, the cognitive challenge is less intense and less varied compared to taxi and ambulance drivers, who must constantly adapt to new road conditions, passenger destinations, and emergency scenarios. This constant need for flexible problem-solving may be key to the observed brain benefits. Could everyday activities have the same effect? Experts believe it may be possible to gain similar brain benefits outside of professional driving. Activities that demand spatial reasoning and complex navigation skills could potentially help maintain hippocampal function. Examples include orienteering, geocaching, and hiking in unfamiliar terrain using a map and compass. Even indoor activities such as jigsaw puzzles, solving Rubik's Cubes, or playing spatially challenging video games like Tetris and Minecraft might provide cognitive stimulation. However, researchers caution that there is still no definitive proof that such activities reduce Alzheimer's risk in the same way these occupations appear to. Further studies will be needed to confirm whether these recreational tasks have long-term protective effects. The takeaway While this research does not conclusively prove that driving a taxi or ambulance prevents Alzheimer's disease, it adds weight to the theory that mentally challenging and spatially demanding activities can help protect brain health. Harvard experts recommend that people interested in lowering their Alzheimer's risk should combine mentally stimulating activities with other proven lifestyle measures. These include maintaining regular physical activity, eating a nutrient-rich diet, managing cardiovascular health, staying socially connected, and ensuring good sleep quality. Together, these strategies offer the best chance of reducing the likelihood of developing Alzheimer's and other forms of dementia.
Economic Times
11 hours ago
- Economic Times
Wolbachia transinfection: China's plan to mate lab mosquitoes with wild ones to tackle chikungunya
TIL Creatives The Chinese government has taken prevention and control measures to try to curb the spread of chikungunya, a virus that often causes fever and joint pain. The Chinese government has taken prevention and control measures to try to curb the spread of chikungunya, a virus that often causes fever and joint pain. The steps initiated by the communist regime have caused concerns among medical professionals and the people. As the chikungunya outbreak continues to engulf China, Guangdong Province reported 1,387 new chikungunya cases between August 3 and August 9, 2025, The EPOCH Times reported, citing a notice by the provincial Centers for Disease Control and Prevention (CDC). According to state media, the cumulative number of chikungunya cases as of July 29 in Foshan, Guangdong, where the first cases of the outbreak were reported on July 8, had crossed the 6,000 mark. The measures taken by the Chinese authorities amid the chikungunya outbreak include mandatory blood tests and mosquito breeding. Residents in various locations in the Guangdong Province shared on social media platforms that mandatory blood tests are being implemented for PCR testing for chikungunya, the EPOCH TIMES reported. It is different from the saliva tests for largest mosquito breeding facility in the Huangpu District of Guangzhou city, Wolbaki, was running at full capacity and releasing 5 million specially treated male mosquitoes per week, The EPOCH TIMES reported, citing Chinese state media. The step was taken in the hopes of them mating with the wild female mosquito population to produce unviable eggs in a population control technique known as Wolbachia transinfection, where the reproductive compatibility of male mosquitoes is altered by an infection with the common naturally occurring Wolbachia bacterium. Unviable eggs are eggs that, for various reasons, cannot develop into viable offspring. Wolbachia transinfection is a method where the reproductive compatibility of male mosquitoes is altered by an infection with the common naturally occurring Wolbachia bacterium.'When the [infected] male mosquitoes carrying the Wolbachia bacterium mate with wild female mosquitoes that do not carry the bacteria, the eggs produced cannot develop normally due to cytoplasmic incompatibility and cannot hatch into mosquito larvae,' Gong Juntao, the head researcher at Guangdong's Wolbaki company that produces the mosquitoes, told Chinese media, as quoted by THE EPOCH method has loopholes. For instance, if infected lab females are not separated and instead released into the wild, they can continue to successfully breed and spread disease. Chikungunya is a disease caused by a virus of the same name. The chikungunya virus was first identified in people sickened during an outbreak in Tanzania in 1952. Its name is derived from a word in the Makonde language, which means 'that which bends up,' due to the severe pain it can is transmitted by infected mosquitoes and mostly causes mild symptoms. The majority of people who get chikungunya recover without needing medical attention after one to two typically produces symptoms including fever, muscle pain, nausea, fatigue, and a rash. But in rare cases, it can cause debilitating joint pain that persists for months or even years. Patients who get severely ill often require hospitalization because of the risk of organ damage. The World Health Organization says severe cases and deaths are rare and mostly occur in babies or elderly people with underlying health is no specific treatment for chikungunya, but health workers can treat the symptoms by giving medicines to lower fevers or ease muscle pain. Two vaccines have been approved in several regions, including Britain, Brazil, Canada, and Europe. Those are mostly targeted at travelers and are not widely available in the countries most affected by chikungunya.
Economic Times
18 hours ago
- Economic Times
China unveils ‘gunpowder-powered' space debris catcher that could covertly disable enemy satellites
Live Events How does the launcher work? Addressing the space junk crisis Possible military implications? (You can now subscribe to our (You can now subscribe to our Economic Times WhatsApp channel Chinese researchers have developed a new space-debris catcher that quietly launches a net to capture dangerous debris orbiting Earth. A team of aerospace engineers from Nanjing University of Science and Technology and collaborators in Shanghai and Shenyang have introduced a compact launcher capable of capturing space device propels a capsule containing a net toward floating debris like defunct satellites and spent rocket parts. Once caught, the debris can be safely pulled out of orbit to burn up in Earth's traditional projectile systems, this launcher operates silently, producing no smoke, flash, or strong vibrations. Its innovative design prevents the destabilization of the host spacecraft and allows for precise and safe operation in per the South China Morning Post, this technology was unveiled last month in the peer-reviewed Chinese journal Acta Aeronautica et Astronautica system uses a small gunpowder charge to generate high-pressure gas that drives a piston forward. A specially designed weak section breaks at a preset pressure to release the net capsule.A unique 35-degree angled ring acts like a collapsing flower, absorbing most recoil energy and reducing thrust impact by over 9 per cent compared to earlier SCMP explains that this careful engineering minimizes barrel movement, ensuring sensitive satellite instruments remain unharmed. The sealed design also traps gas, preventing contamination of the space debris has become a critical threat to satellites and spacecraft, with growing amounts of defunct equipment posing collision risks. This new launcher is compact, requires no external power, and can be mass-produced, offering an efficient solution to help clean up dangerous orbital the primary goal is debris management, experts warn that the technology could be adapted for covert military use. Unlike visible missile strikes or explosions, this system could disable or capture an adversary's satellite silently, leaving it to appear as though it failed naturally.A Beijing-based space scientist, speaking anonymously to the South China Morning Post, said, 'There would be no explosion, no visible attack, only a satellite that ceases to respond.'The launcher's emergence comes amid intensifying geopolitical competition in space. The 1967 Outer Space Treaty bans nuclear weapons in orbit and requires peaceful use of space, but does not explicitly forbid conventional kinetic weapons like China's debris catcher is currently operational or still in development remains unclear. Yue Shuai, the project lead and associate professor at Nanjing University of Science and Technology, is noted as an expert in space weapon systems and has already launched two payloads into orbit, with more planned.
