The energy crisis is not just a global problem. If there are civilizations in the Universe that are thousands or millions of years ahead of us, their appetite for energy should be enormous. Instead of building thousands of thermonuclear reactors in an attempt to reproduce the processes inside stars, they could have taken a simpler and more logical approach: take a ready-made star and “wrap” it in a giant solar battery. New research by astronomers suggests that such objects should be sought not near bright giants, but near the modest “babies” of our Universe.

The Legacy of Freeman Dyson

Dyson sphere through the eyes of Copilot AI

The very idea of megastructures surrounding stars belongs to the outstanding theoretical physicist Freeman Dyson. Back in the 1960s, he suggested that any sufficiently developed civilization would sooner or later face a shortage of resources on its planet. One solution could be a “Dyson sphere” — a colossal structure made of mirrors or solar panels rotating around the sun, intercepting almost 100% of its radiation. 

Interestingly, Dyson himself initially referred to his idea as a “little joke” in conversations with journalists. However, over the years, he changed his mind, recognizing the concept as entirely viable and logical from a thermodynamic point of view. Today, the search for such structures is one of the priorities of SETI (the Search for Extraterrestrial Intelligence project), since a Dyson sphere is the most striking “technosignature” that can be detected from a distance of many light years.

Why are white and red dwarfs ideal candidates? 

In a new study published in Nature, astronomer Amirnezam Amiri from the University of Arkansas has revisited traditional views on where exactly to look for these megastructures. Most previous theories have focused on solar-type stars, but Amiri suggests turning our attention to low-mass stars: white dwarfs and red dwarfs.

Red dwarfs are the most common stars in our galaxy. They burn extremely slowly, providing energy to the surrounding space for trillions of years. White dwarfs are the remains of stars that have already “retired,” but they continue to steadily emit heat over enormous periods of time. 

According to Amiri’s calculations, these stars are the best sources for long-term energy supply to megastructures. They are stable, not prone to frequent catastrophic outbursts (like some massive stars), and allow for the creation of an energy system that will operate almost indefinitely. 

Compactness – the key to saving resources

One of the main problems with building the Dyson sphere is the incredible amount of materials required. To encircle the Sun at the distance of Earth’s orbit, it would be necessary to literally break down several planets the size of Jupiter into atoms. However, the rules of the game change for red and white dwarfs.

The habitable zone (where temperatures allow water to remain liquid) around a red dwarf is located very close to the star, typically between 0.05 and 0.3 astronomical units. For a highly developed civilization, this is the ideal place:

  • Material savings. The sphere will have a much smaller radius, which means it will require significantly fewer resources to build.
  • Efficiency. The closer the panels are to the light source, the more compact and manageable the entire energy farm is.
  • Stability. A compact sphere is more easily held in place by the star’s gravity, reducing the risk of structural failure.

James Webb in search of alien engineers

The most practical part of Amiri’s research is devoted to how we can detect such objects from Earth. According to the laws of physics, the Dyson sphere cannot simply absorb energy — it has to release it somewhere (discharge excess heat), otherwise it will simply melt. This heat is emitted in the form of infrared light.

To an outside observer, a star in a “wrapper” will look very strange:

  1. Abnormal dimness. The star will appear significantly fainter than it should be based on its mass.
  2. Spectrum change. Instead of visible light, the observer will see a uniform “black” spectrum of infrared radiation.
  3. Artificial signals. If the sphere consists of separate panels (a so-called “Dyson swarm”), they can create unusual flickering or radiation bursts that cannot be explained by natural processes.
  4. No dust. Building the sphere requires a huge amount of matter, so the aliens will most likely “clean” the system of dust and asteroids, using them as raw materials.

Amiri claims that modern observatories, such as the James Webb Space Telescope (JWST), already have sufficient sensitivity to detect such infrared anomalies. We already have the tools to detect aliens — we just need to know what to look for.

Are we alone in the Universe?

Of course, Dyson spheres remain pure theory for now. Any such prediction is based on a number of assumptions: that aliens exist, that they develop according to similar physical laws, and that they want to build such large-scale objects in the first place. Perhaps they have found even more sophisticated ways of obtaining energy that we cannot even imagine.

However, such studies make us think about the future of humanity. If we want to survive as a species in the long term, we will have to become a “Type II civilization” on the Kardashev scale — one that completely controls the energy of its star. Studying possible Dyson spheres around white dwarfs is not only a search for “little green men,” but also an attempt to glimpse our own future millions of years from now.

Freeman Dyson once said that “The Universe is far more interesting than we can imagine.” And if somewhere in the depths of the Milky Way a red dwarf suddenly began to shine unusually dimly, it is possible that someone’s giant energy farm has been operating there for millions of years.

We previously reported that Jupiter should be destroyed to build a Dyson sphere around the Sun.