Los Angeles is experiencing the most destructive fire in history. Why are the wildfires in California so severe? | Expo Daily

35 fires in 6 days! Why are California wildfires so severe?

Just six days into the new year, 35 wildfires have broken out in California. Why are there so many wildfires in California?

This is the latest in a series of extreme climate and weather events. Climate change caused by human activities has led to more frequent high temperatures. The rainy season of 2025 has not yet arrived, but the vegetation has dried up and is ready to burn. In addition, because the wet winter of 2023 promoted the growth of vegetation, and the heat and drought throughout 2024 dried it out, there is more vegetation available for fuel.

Strong winds are also an important factor in the frequent occurrence of local wildfires. For example, the Santa Ana wind monsoon that appears in the southern California valley every autumn and winter can reach wind speeds of 129 kilometers per hour. This will not only make the area drier, but also blow away the burning sparks, further expanding the scope of the fire. When drought and strong winds combine, it leads to a series of catastrophic fires.

Even if the external conditions for a fire are in place, people still need to light it. California has a large population, and people are increasingly moving to areas closer to forests, which are often more prone to fire. According to the U.S. Forest Service, about 85% of wildfires are caused by humans.

Noah Diffenbaugh, a professor at Stanford University, said, "Wildfires have been around in California for much longer than cities have existed. The key to coexisting with wildfires is how we humans manage the risks."

Liu Yeyao:

A foreign engineer spent my annual income in 3 days

The following content is from the speech of Liu Yeyao, senior engineer of the Institute of Acoustics, Chinese Academy of Sciences, at Gezhi Lundao

I remember in 2010, we conducted an acoustic system experiment at sea, and one of the equipment purchased from abroad had some problems. We asked the foreign manufacturer through the agent, but the manufacturer replied to us three days later, telling us that the engineer of the equipment was on vacation. During the vacation, he would not do these work for us.

So we had to wait for about a week before the equipment engineer came back. He said he could help us analyze the problem, but he had a requirement that he must come to the site to solve it. So we had to wait for him again, and it took about half a month for him to arrive at the site.

In fact, he only came for three days. I calculated that his three-day food and lodging, airfare, and his travel allowance of more than a thousand dollars were basically equivalent to my annual income at the time.

But this is not the most important thing. The most important thing is that our experiment was stalled for two weeks. During these two weeks, nearly 100 people on the ship could only wait and there was nothing we could do. So, at that time, we realized how important it was to master the core technology in our own hands.

Image source: Gezhi Lundao Forum

Why can stainless steel be used to make soap?

As a unique deodorizing tool, stainless steel soap works and is used in a way that is completely different from traditional soap.

When it is usually used, it needs to be "half immersed in water and half exposed to air". When used for the first time, it takes 5 to 6 hours to work properly.

This is because stainless steel soap deodorizes by decomposition. When the surface of the stainless steel alloy comes into contact with oxygen and water molecules in the air at the same time, a thin oxide film is formed.

This oxide film can produce a catalytic effect under certain conditions, decomposing odor molecules through chemical reactions and converting them into odorless small molecules.

In addition, there are many tiny pores on the surface of stainless steel soap, which enables it to absorb odor molecules and further achieve the deodorizing effect.

Image source: Generated by AI

Does climate change affect the Earth's rotation?

The Chandler Wobble is a small free swing of the Earth's rotation axis, an important signal of the Earth's rotation. In recent years, astronomers have observed an increase in the variation of the Earth's rotation, speculating that it may be related to climate change, but the specific impact is still unclear.

Research from the Shanghai Astronomical Observatory of the Chinese Academy of Sciences found that changes in the cryosphere caused by global climate change are related to the "Chandler Wobble" phenomenon, and this relationship is strengthening.

In 2022, the contribution of ice sheet glacier changes to the Chandler Wobble is about 20%, four times that of 2006. In addition, the Earth's rotation is complex and changeable, affected by heterogeneities such as internal structure, elasticity and anisotropy.

Modern astronomical and space geodetic techniques have improved the measurement accuracy, making it possible to monitor even the smallest movements of the Earth. Although the physical mechanism of the Chandler Wobble is still controversial, it is generally believed to be related to atmospheric, oceanic and terrestrial hydrological processes.

The melting of glaciers caused by climate change may have exacerbated the Chandler Wobble. This research result provides new evidence for the impact of climate change on the Earth's rotation and also provides a new way to improve the accuracy of prediction of the Earth's rotation parameters. The result was published in Geophysical Research Letters and reported in Nature Climate Change.

Global climate change affects the Earth's rotation

China develops clock with error of less than 1 second in 60 million years

The National Time Service Center of the Chinese Academy of Sciences houses an atomic clock independently developed by China. This is the most advanced timing device currently in use in the world. If it can run continuously for 60 million years, the accumulated error will be less than 1 second. Chinese scientists are currently building a "super clock" covering the sky and the earth. Experts say that this will be a national time service system that crosses the sky and the earth. After completion, it can support the development of China's 6G and 7G communications.

The content is compiled from China Science Popularization Expo Weibo, Gezhi Lundao Forum, Institute of Physics, Chinese Academy of Sciences, Voice of Chinese Academy of Sciences, CCTV Records

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