New research: Tiny electric sparks from waves hitting the shore may be the spark of the origin of life on Earth

In science fiction, the birth of life is sometimes accompanied by lightning and thunder, such as the Frankenstein monster awakened by lightning. Interestingly, one of the explanations of the origin of life in the past by the scientific community also involved thunder and lightning.

However, a new study suggests that a tiny electrical spark may be enough to give rise to life.

When you spray water mist into the air, tiny water droplets can generate weak electric charges in the process of splashing, which is called " micro lightning " by scientists. According to the latest discovery by researchers at Stanford University in the United States, these "micro lightning" can promote the conversion of inorganic matter in the primitive Earth's atmosphere into organic matter, even including uracil, a key component of DNA and RNA.

Schematic diagram of the Miller-Urey experiment. Image source: Wikipedia

Traditional theory: Lightning creates the "seeds of life"

70 years ago, scientists Stanley Miller and Harold Urey conducted a famous experiment in which they simulated the early Earth environment by mixing methane, ammonia, hydrogen and water and then passing an electric current through it.

A few days later, these inorganic substances miraculously turned into organic molecules that constitute life, such as amino acids. This discovery gave birth to the Miller-Urey hypothesis that "lightning created life": ancient lightning struck the ocean, triggered chemical reactions, and sowed the seeds of life on Earth.

However, this hypothesis has been controversial. Some scientists believe that lightning on early Earth was so rare that it might not have produced enough organic matter, and that the chemicals in the ocean were too dispersed to produce an effective reaction. This is like trying to ignite an entire forest with an occasional match, with a very low success rate.

Micro-lightning produced by water droplets

Therefore, scientists from Stanford University found a more reasonable explanation through their experiments. So what kind of experiments did they conduct?

The research team first experimented with the charge generated by water droplets that were sprayed or splashed. They observed that larger droplets generally had a positive charge, while smaller droplets had a negative charge.

When two oppositely charged water droplets come close together, tiny sparks are created - a process similar to how energy builds up in clouds and is released as lightning, only on a much smaller scale.

Although these micro-lightning flashes are difficult to observe directly, researchers used high-speed cameras to capture them. Although the micro-lightning is small in size, it carries enough energy.

Schematic diagram of the experiment in which researchers sprayed water into a simulated primitive Earth atmosphere.

The researchers then experimented with spraying water into a gas mixture containing nitrogen, methane, carbon dioxide and ammonia. These gases are thought to have existed on the early Earth and could be used to simulate the Earth's primitive atmosphere. Eventually, the experiment produced the crucial organic molecules: hydrocyanic acid, uracil and the simplest stable amino acid, glycine.

The researchers believe that the experimental results show that the synthesis of life molecules can be completed with only the tiny electric charges generated by the friction between water mist and air, without the need for spectacular lightning.

Why the "micro-lightning" theory is more reasonable

Compared with the traditional lightning hypothesis, the "micro-lightning" theory of Stanford University researchers has two major advantages.

First, the phenomenon of "micro lightning" is more common. In the early days of the Earth, there was water mist everywhere - waves hitting rocks, waterfalls hitting the water surface, and even raindrops hitting the ground would produce charged water mist. These micro reactors can work almost around the clock.

Second, the reaction is more efficient : high-speed cameras show that micro-lightning can release energy in a concentrated manner in a local area, just like using a laser pen to focus light to ignite paper, which is more efficient than lightning that casts a wide net.

The researchers said that the micro-lightning experiment can produce all the key organic substances in the Miller-Urey experiment 70 years ago, but the process is more gentle and controllable. As Professor Zare, one of the members of the research team, said: "This solves many problems of the traditional hypothesis and makes the story of the origin of life more reasonable."

The study of water droplet micro-lightning may rewrite the script of the origin of life, but it also reminds us that the mysteries of nature are often hidden in seemingly ordinary phenomena. The next time you see the mist of a fountain glittering in the sun, you might as well imagine that the magic of life chemistry 4 billion years ago is being performed there. Those fleeting glimmers may be the first sparks of life.

Reference Information:

[1]https://phys.org/news/2025-03-microlightning-droplets-life-earth.html

[2]https://www.science.org/doi/10.1126/sciadv.adt8979

Compiled by: Wen Xing

Planning: Liu Ying, Zhang Chao, Li Peiyuan, Yang Liu

Reviewer: Ma Runlin, researcher at the Institute of Genetics and Developmental Biology, Chinese Academy of Sciences

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