Fire Part III: The creation of the Sun on Earth

The quest to develop thermonuclear fusion is the apogee of humanity’s ongoing struggle to control and utilise fire and energy

“the ‘control of nature’ is a phrase conceived in arrogance, born of the Neanderthal age of biology and philosophy when it was supposed that nature exists for the convenience of man.”
Rachel Carson, the author of The Modern Environment Movement,
quoted from her 1962 classic Silent Spring

In charting the relationship between mankind and fire, we have seen how the gradual mastery of a natural phenomenon transformed mankind and enabled the production of technologies, fuels, and forms of energy that have shaped and still determine our world today.

But before we examine nuclear fusion and the quest for a limitless supply of clean and safe energy, it is worth noting another development which remains arguably one of the most critical technological advances humanity has ever created: welding – a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence.

The modern world’s infrastructure, architecture, manufacturing and consumer goods rely upon welding, which remains hidden in plain sight.

The arc of familiarity: when welding was ‘New Tech’

Over 6,000 years ago, humans had already learned how to harness controlled fire to smelt ore and make tools and weapons from metal, spurring an industrial revolution that transformed man and life.

The early creation of fire tools and kiln technology enabled early humans to make pottery under controlled fire conditions, creating ceramic vessels to store or cook food and intricately decorated pottery vessels as art forms. But metalworking was of a different order. Controlled fire was used to extract metal from ore deposits, creating tools and weapons which furthered our place within nature. It enabled a massive shift from wooden tools to more robust metal implements due to fire control.

The earliest examples of welding date back to the Bronze and Iron Ages, with forge welding (hammering heated metal together) being the primary method. The Iron Pillar of Delhi, erected around 310 AD, is a testament to the early mastery of forge welding. Ancient Greece also claimed a place in the history of welding: Greek historian Herodotus mentions Glaucus of Chios as an early innovator in iron welding.

However, the real potential of welding was realised in the 19^th century, particularly during the Industrial Revolution. In 1800, for example, Humphry Davy (1778-1829), a British chemist and inventor considered one of the founders of electrochemistry (who also discovered elements like sodium, potassium, calcium, and barium), discovered the electric arc, laying the groundwork for arc welding. In 1836, British chemist Edmund Davy discovered acetylene gas when attempting to produce potassium metal and came up with potassium carbide, which reacted with water to produce a gas. Calcium carbide was identified in 1862, and like potassium carbide, it reacted with water to form acetylene. In 1881-82, Russian engineer and inventor Nikolai Benardos (1842-1905) and his Polish inventor assistant, Stanisław Olszewski (1852-1898), collaborated to develop carbon arc welding, the first practical arc welding method. In 1890, an American inventor, C.L. Coffin (1850-1916), was granted a patent similar to modern shielded metal arc welding (SMAW), which laid the groundwork for one of the most widely used welding processes today.

This brief glimpse of some of the people involved in the development of welding are the hidden heroes of a phenomenon hidden from view but which makes the modern world possible. The unassuming steel fence encircling a backyard or field is so commonplace, its construction so familiar, that we rarely pause to consider the ingenuity behind its creation. Yet, this seemingly mundane object owes its structural integrity to a technological marvel: SMAW – shielded metal arc welding. Without SMAW, we would not have the buildings we live in, the cars we drive, the aeroplanes we fly in, nor the consumer goods like refrigerators, smartphones and computers we rely upon.

Hidden in plain sight, woven into the fabric of our modern marvels, are countless technological breakthroughs mankind created through the mastery of fire.

Nuclear fusion: the control of nature

As essential and remarkable as SMAW is, the quest for thermonuclear fusion as an energy supply is of a different order. It is no exaggeration to state that the quest for nuclear fusion represents one of the most ambitious and challenging crusades our species has ever undertaken. This quest unites mankind’s power of imagination and abstraction with our learned engineering prowess. Indeed, for nuclear fusion to become a reality, mankind’s inherent problem-solving ethos will have to be raised to unimaginable heights.

When US physicist Lyman Spitzer stated in the 1950s that nuclear fusion was the ‘most difficult challenge ever taken up by mankind’, he was not exaggerating.

Nuclear fusion involves combining light atomic nuclei—typically isotopes of hydrogen like deuterium and tritium—to form a heavier nucleus, releasing vast amounts of energy. Creating nuclear fusion on Earth without the Sun’s gravity requires heating gases to 150 million degrees Celsius inside a vacuum, producing a plasma ten times hotter than the Sun’s core, temperatures so high that no wall can contain them.

Fusion is much safer than nuclear fission, which powers today’s reactors by splitting atoms and producing long-lived radioactive waste. The byproducts are minimal, and the fuel sources, such as hydrogen from water, are abundant. Yet the core challenge has always been re-creating the conditions necessary for fusion: temperatures exceeding 100 million degrees Celsius and sufficient pressure to force nuclei to overcome their repulsion. Only by engineering mighty magnets to corral the superheated gas away from the sides can fusion on Earth take place.

Yet, for five seconds in December 2021, scientists created the Sun on Earth. In a device developed at a U.K. facility in Oxfordshire, an experiment produced the highest sustained nuclear-fusion energy ever recorded – 59 megajoules of fusion energy – roughly the equivalent to the energy required to run a kettle in everyday use for two months.

In an experiment earlier that year at Lawrence Livermore National Laboratory, researchers reported that by using 192 gigantic lasers to annihilate a pellet of hydrogen, they were able to ignite a burst of more than ten quadrillion watts of fusion power — energy released when hydrogen atoms are fused into helium, the same process that occurs within stars. Mark Hermann, Livermore's deputy program director for fundamental weapons physics, says this is about 10 per cent of the 170 quadrillion watts of sunshine that bathe the Earth’s surface. Mindbogglingly, all the fusion energy produced by the lasers emanated from a hot spot about as wide as a human's hair.

In May 2024, the WEST (Tungsten Environment in Steady-state Tokamak) reactor in France sustained a plasma at 50 million degrees Celsius for six minutes, setting a new world record for a tungsten tokamak (a machine that confines a plasma using magnetic fields in a doughnut shape that scientists call a torus). This achievement is a significant step toward maintaining the high-temperature plasma necessary for continuous fusion reactions. 

OK, the numbers are still small. Six minutes or running a kettle for two months is not something to get too excited about. But it is. In those small windows of time, what has been demonstrated is that this particular fuel mix – the same combinations engineers plan to use in commercial fusion power plants – produces sustained energy. This is a crucial step towards realising a future powered by thermonuclear fusion – a nearly limitless energy source. This is truly something to celebrate.

For physicists, this means that to achieve thermonuclear fusion energy, the challenge is engineering, not physics. And that’s not as easy as it may sound. Engineers like to point out that the same observation could have been made about the engineering of rockets going to the moon after seeing a fireworks rocket. The challenges are immense.

Nuclear power—responsible for about 10% of the world’s electricity—is generated by fission, splitting atoms like uranium creating radioactive waste that lasts thousands of years. This involves significant risks, too. All the world’s major nuclear reactor accidents, such as 3 Mile Island, Chornobyl, and Fukushima, have occurred because reactors have overheated, causing a meltdown with a subsequent release of radioactive material into the environment. But even this inherent risk is being overcome.

Chinese engineers have made a nuclear safety breakthrough by shutting off power to the cooling systems of two large-scale nuclear reactors and showing their design can’t melt down because it passively cools itself.[1] This means we now have atomic reactors that will cool naturally without needing electro-mechanical or human intervention. This is a real breakthrough in the current management of risk and the generation of energy with enormous potential for the future. But nuclear fusion is another planet, and this time on Earth.

One of the most extraordinary things about nuclear fusion is that it does not produce waste
or greenhouse gases like carbon dioxide generated by burning fossil fuels. The promise of
a limitless source of energy on Earth that does not harm the environment is no longer a utopian dream.

This success will only speed up the race for commercial nuclear fusion. Climate change worries have propelled private companies to pursue fusion research. The Wall Street Journal reports that around 35 firms globally are racing to be the first to create net-energy machines and to commercialise them by delivering electricity to the power grid. Fusion companies have raised at least $4.3 billion toward the effort, according to company announcements and data tracked by the Fusion Industry Association and the U.K. Atomic Energy Authority. The establishment of Pacific Fusion, a Silicon Valley startup led by geneticist Eric Lander, aims to achieve commercial fusion energy by the 2030s, focusing on pulsed magnetic fusion techniques. And don’t forget the Chinese: its investment in fusion research at around $1.5 billion annually is nearly double the US budget. The battle for fusion energy is heating up.

Human hubris or ingenuity?

Standing back from the immediate fray and the competitive struggle over the future of energy now underway, it is clear that something notable has happened: the relationship between man and nature has been altered fundamentally.

When our ancestors climbed down from the trees, stood upright and grasped the material world around them, they were captives of their biology and environment, imprisoned by the limits of nature. Yet, the example of fire demonstrates how humanity has moved from an object to the subject of history. From the control and production of fire, from the application of this to materials and food, through science and practical engineering, we have shaped modern man and society.

From nuclear fission to fusion, particularly the ability to create the Sun on Earth, mankind has assumed the mantle we assigned to God in the past. Human beings, not God, have become the creator of an energy paradise on Earth (although there remain significant challenges to realise this).

Marie Curie, whose contribution to this quest should not be under-estimated captured the spirit driving such a quest when she wrote in 1916 about the importance of science for mankind: ‘[I]t is by…daily striving after knowledge that man has raised himself to the unique position he occupies on earth, and that his power and well-being have continually increased’.[2]

Nuclear fusion is a man-made accomplishment. The science and engineering applied to achieve this outcome should remind us that human intelligence and imagination are not a finite resource.

A poetic opposable symmetry is at play in the development of nuclear fusion. While our brains are as terrestrial earthbound as any other part of the human body, our innate power of imagination and abstraction has enabled us to lift the human mind out of Earth's gravitational field. Freed from such constraints, we have explored our ignorance by looking down upon our planet from some point in the universe. The result? The ability to reproduce the gravitational power of the Sun on Earth not to bathe our planet in sunlight but to power human life in the future.

This is not hubris. It is not mankind arrogantly playing at God. This is majestic humanity opening doors through exploring our ignorance to help solve problems on Earth.

Science, the ongoing battle with ignorance, the quintessential quality of what makes us human, has always ensured we are a future-oriented species. Unlike today’s presentists who regard the past as another country best forgotten or ignored, mankind has always fought a battle between what we knew and what we didn’t. Historically, those who sought to suggest that what we knew was all there was to know have constantly been challenged by those who questioned orthodoxy, who embraced the unimaginable, the unforeseen, the accidents to go beyond what was known and to explore our ignorance. This anti-fatalist embrace has pushed humanity beyond what were always incorrectly perceived as unassailable limits.

Nuclear fusion is an outcome of a journey that began with a natural phenomenon—fire. The aspiration to control this sparked imaginations to the point where we could conceive the creation of an unlimited energy supply for the future—a supply under our control and management, not of God.

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[1] ‘Eliminating nuclear metldowns: Chinese reactor completes world-first passive cooling test’, The Chemical Engineer, September 2024, Issue 999, p8.

[2] Marie Curie. Opening paragraph of 'Memorandum by Madame Curie, Member of the Committee, on the Question of International Scolarships for the Advancement of the Sciences and the Development of Laboratories' published by the League of Nations, Committee on Intellectual Co-operation, Geneva (16 Jun 1926).