The Quantum Age will be Powered by Fusion

by Simon Mansfield
Gerroa, Australia (SPX) Dec 19, 2025

From the first stars to any future interstellar civilization, fusion is the energy process that makes complex structure, long-lived stars, and chemically rich worlds possible. It is also the only known energy source that can scale from the galactic to the planetary to the quantum-technological without exhausting matter or destabilizing environments.

Long before life, long before planets, fusion shaped the universe's basic architecture. In the early cosmos, gravity gathered hydrogen and helium into immense clouds that collapsed into the first stars; within those stellar cores, nuclear fusion lit up space and set the clock on cosmic evolution.

Inside main-sequence stars like the Sun, light nuclei - principally hydrogen - are forced together under colossal pressure and temperature, fusing into helium and releasing energy in accordance with E = mc^2. This process defines a star's luminosity, lifetime, size, and color; in effect, the fusion regime at its core writes the operating manual for the entire stellar system. For billions of years, the balance between inward-pulling gravity and outward-pushing fusion pressure stabilizes stars, allowing long spans of calm conditions in which planets can form and orbits can settle.

Fusion does more than shine; it manufactures matter in the form required for chemistry and, ultimately, biology. In successive generations of stars, fusion reactions build heavier nuclei: helium into carbon, carbon into oxygen, and onward up to iron in the cores of massive stars. Beyond iron, explosive events and neutron-capture processes complete the periodic table, but these too depend on fusion-grown seeds and fusion-driven stellar evolution to set the conditions for those cataclysms. When stars shed their outer layers or die in supernovae, they distribute these fusion-forged elements into interstellar space, enriching the gas and dust that will form new stars, planets, and, in time, biospheres.

The simple fact that Earth has liquid water, carbon-based molecules, and an atmosphere with oxygen is a direct consequence of billions of years of stellar fusion and stellar death before the Solar System existed. The rocks beneath our feet, the air we breathe, and the biochemistry of every cell are, in a literal sense, stabilized ash from ancient fusion furnaces.

Even on the scale of an individual habitable world, fusion sets the terms of existence. The Sun's continuous fusion output fixes the energy balance at Earth's orbit, determining climate zones, atmospheric circulation, and the overall range of temperatures within which liquid water and complex organic chemistry can persist. Photosynthesis, the metabolism that powers almost all known ecosystems, is nothing more than the capture and re-packaging of solar fusion photons into chemical form. Fossil fuels, hydro power, wind, and much of biomass are essentially historical or redistributed sunlight - a long-term bookkeeping record of fusion energy integrated over time and weather.

Seen from this angle, fusion is not a special technology or a niche physical process; it is the background engine of the visible universe. It governs star lifetimes, galaxy light output, the distribution of elements, and the energy flows that make planetary climates and biochemistries possible. Any universe with long-lived stars, rich chemistry, and a chance at life is, almost by definition, a universe in which fusion plays the central role.

Mastering Fusion: Life's Total Victory

Human civilization already runs on fusion, but only indirectly. Every watt of solar power, every gust of wind turning a turbine, every barrel of oil is a downstream expression of stellar fusion that began in the Sun's core millions of years ago. The crucial step before us is to bring fusion "upstream": to replicate controlled fusion reactions on Earth and use them as a primary, dispatchable energy source for a technological civilization that is pushing into what can be called the Quantum Age.

The Quantum Age is defined by devices and infrastructures that exploit quantum-scale behavior as a resource: quantum computers, exquisitely sensitive quantum sensors, secure quantum communication networks, and materials whose properties are engineered from the atomic level up. All of this rests on two requirements: sustained, high-quality energy and extreme control over matter and environment across many scales. Fusion is uniquely matched to both conditions.

First, fusion offers energy density that dwarfs chemical fuels and even conventional fission. A small volume of fusion fuel - deuterium and tritium, or more advanced mixtures - can in principle yield gigawatt-scale power with no carbon emissions and with fuel resources that are, on human timescales, effectively inexhaustible in the oceans and crust. Because the physics of fusion does not rely on rare isotopes or fragile supply chains, a mature fusion infrastructure could give civilizations a baseline of abundant energy largely decoupled from geography and weather.

Second, fusion's byproducts and waste profile are well-suited to a civilization that must manage intricate quantum systems over centuries. In most leading designs, fusion does not produce long-lived, high-level radioactive waste; activation products exist, but they decay on much shorter timescales than traditional nuclear waste and can be planned for within durable material cycles. This matters in a world where quantum devices, cryogenic systems, and precision manufacturing facilities cannot function in the shadow of chronic contamination and large-scale environmental instability.

There is also a structural, systemic argument for fusion in the Quantum Age. As computation, sensing, and communication move deeper into quantum regimes, energy demand will not only grow but also become more timing-sensitive and quality-sensitive: stable power for large cryogenic plants, steady supply for exascale and post-exascale computing centers, and the ability to run complex, energy-intensive fabrication processes without interruption. Intermittent renewables, even with advanced storage, can cover a large share of demand, but the system still needs a firm backbone - an energy substrate that is always on, always available, and scalable by design. Fusion, if realized at industrial scale, can supply that backbone without replicating the carbon and resource burdens of fossil fuels or the political and waste challenges of legacy nuclear technologies.

On longer horizons, fusion enables capabilities that transcend the surface of a single planet. High-specific-power fusion systems are natural candidates for deep-space propulsion, off-world industry, and large-scale resource processing on asteroids and icy moons. A civilization that has mastered both quantum engineering and fusion energy can imagine not just local optimization but an extended sphere of activity that includes self-sustaining habitats, distributed manufacturing, and scientific infrastructure far from any star. In that context, fusion ceases to be merely an energy choice and becomes a condition for maintaining complex activity away from the narrow habitable zones of stellar systems.

There is a philosophical symmetry here. In the natural cosmos, fusion is the process that turns simple, uniform matter into complex, structured, chemically diverse environments where life and intelligence can arise. In a technological cosmos, controlled fusion is the process that can turn limited, fragile, localized civilizations into robust, long-lived, and expansive ones, capable of sustaining quantum technologies, advanced ecologies, and cultural complexity without quickly exhausting their planetary base.

The Quantum Age will not arrive solely through more capable algorithms, more coherent qubits, or better materials. Those advances require a foundational energy layer that is as stable, scalable, and long-lived as the stars themselves. Fusion already plays that role at the cosmic scale; to fully enter the Quantum Age, a civilization must learn to make it the central engine of its own world as well.