Gold actually comes from the universe! Can scientists "produce" gold?

We all know that many substances can be synthesized artificially, such as diamonds. Scientists can use high-tech equipment to create a high-temperature and high-pressure environment and use carbon elements to synthesize them. So where does gold come from, and why can't it be synthesized through high-tech equipment? Let's follow Pang Ke and go to scientists to find the answer!

Fat Ke: Scientists, where does gold come from? Why is it so expensive?

Scientist: It is expensive because the earth cannot produce gold by itself. That is to say, the amount of gold on earth since its birth is the same as today. If we mine more, the "stock" will be less. Isn't it expensive? As for where gold comes from? This is a very long topic. Do you have the patience to listen to it?

Fatko: Of course!

● It turns out that “gold” is an alien product

Scientists: Astrophysicists have found that gold comes from rare stellar catastrophes. When the Earth was first formed 4.6 billion years ago, heavy metals including gold sank to the center of the Earth, and there was almost no metal like gold on the Earth's surface. However, 4 billion years ago, the newly formed Earth was hit hard and experienced a period called the Late Heavy Bombardment. A storm of small celestial bodies hit it, bringing gold and other new metals to the Earth.

First of all, it is worth emphasizing that the elements that make up all matter on Earth actually come from space. We gradually discovered them on Earth and began to arrange them in the famous Mendeleev periodic table from light to heavy starting in 1869; from hydrogen with only one proton to plutonium with 94 protons, but at that time we did not know where they came from...

The two lightest elements, hydrogen and helium, were created spontaneously at the beginning of the universe. They are the raw materials for all early stars. In the subsequent evolution of stars, heavier elements with higher proton numbers are created by nuclear fusion reactions. Soon, we have carbon, nitrogen, oxygen, calcium, and the elements that make up our bodies. Stars spread these elements into the surrounding space, causing their content to increase in the nebula. Finally, the nebula collapsed, and the sun and the earth, as well as other planets and small celestial bodies, were formed.

In short, all the gold on Earth comes from a super catastrophe that occurred in the universe before the birth of the sun.

● The long journey of “looking for gold”

Fat Ke: Gold actually comes from the universe! What happened in the universe to produce gold?

Scientists: For a long time, scientists have wanted to know where the heavy elements such as gold, platinum, and uranium in the universe come from. They have devoted a lot of time and energy to find the answer. The exploration of the unknown is a process of continuous conjecture, verification, and re-examination. The road of scientists' "gold search" is also full of twists and turns.

Scientists once believed that supernova explosions at the end of a star's life could provide enough energy to produce heavy atoms.

However, whether there are other sources is not entirely certain.

This question did not make any progress until 2018.

Neutron stars are the product of the core collapse of giant stars. Researchers have discovered that when two neutron stars revolve around each other due to gravity, they will release turbulent gravitational waves into the universe. The two neutron stars will lose orbital energy due to gravitational waves, gradually approach, collide, and explode. Based on this, researchers have established a neutron star merger model, which shows that an explosion phenomenon called a kilonova will occur, and this process will also generate enough energy to form a large number of new heavy elements: gold, silver, uranium, platinum, and other heavy metals. It is worth mentioning that this "large amount" is enough to be measured in the mass of the earth.

Finally, on August 17, 2017, the US Gravitational Wave Laser Interferometer Observatory first detected the expected gravitational wave signal, and then detected heavy metal components including gold and platinum through optical infrared telescopes. The long-standing theory that heavy metals come from neutron star collisions has finally been preliminarily verified. In addition, this observation found that about 10 Earth masses of gold and platinum were contained.

Fat Ke: Wow! So this is how scientists determined another source of gold atoms.

Scientists: After this verification, scientists have confirmed that neutron star collisions can also produce heavy metals such as gold, silver, uranium, and platinum, but scientists have not yet reached a conclusion on which production mechanism is dominant.

An analysis of galaxy evolution from Australia published in The Astrophysical Journal in 2020 found that neutron star collisions do not produce the amount of heavy elements previously assumed, and even the most optimistic estimates of the frequency of neutron star collisions cannot be achieved. This means that the cosmic content of gold produced by neutron star collisions may only account for a small part of what has been observed so far, and the role of neutron stars may have been greatly overestimated.

Although the origin of gold remains uncertain today, I believe the mystery will be solved in the near future.

● Scientists' attempts to make gold

Pangke: It turns out that scientists have made so many guesses and explorations on the road to finding the source of gold. Such an indomitable spirit of exploration is really admirable! Pangke also has a small question. Humans can create atoms through nuclear reactors or particle accelerators, so have scientists tried to artificially create gold?

Scientists: Of course we have tried, but currently we can only produce gold atoms by colliding atoms through devices such as particle accelerators. But just as it takes millions of years for the gold atoms ejected to the earth to decay and aggregate before they can be mined and used by humans, scientists also need to undergo the same chemical and physical changes to artificially produce gold. The long time required for this process is beyond human efforts.

Fat Ke: So that's how it is! Thank you for answering our questions!

The gold on Earth is not endless, and we who live on Earth cannot wait for the second gift from the universe. It is "valuable" because the resource is non-renewable, and also because of the scientists' unremitting pursuit of knowledge. "Continuous accumulation will lead to leaps and breakthroughs." The universe is vast and boundless, and all the discoveries made today are just the starting point. Human exploration of the universe will never stop.