American scientists are crazy: planning to burn through the Earth with plasma. What exactly are they trying to do?

The universe’s ultimate source of energy is actually right under our feet.

The Earth’s core reaches temperatures as high as 6,000°C—nearly as scorching as the surface of the Sun. There is primordial accretion heat that has not dispersed for 4.5 billion years, as well as nuclear energy released by the decay of countless radioactive isotopes. However, for decades, the way humans have been tapping geothermal energy has been extremely primitive and limited. We can only, like picking up shells along the seashore, use ultra-thin shallow geothermal resources in extremely rare crustal fractures such as in Iceland and Yellowstone National Park.

But now, a group of crazy scientists and engineers from MIT in the United States have decided not to wait for Earth’s charity anymore. They founded a company called Quaise Energy, completely abandoning traditional mechanical drill bits. They use microwave weapons at the level of nuclear fusion—directing ultra-high-frequency plasma toward the Earth’s core—vaporizing the hard granite directly and forcefully boring through a terrifying abyss up to 20 kilometers deep on the Earth’s surface!

To understand why they use plasma to “burn through” the Earth, we have to first review the heartbreaking history of humanity trying to drill through the planet.

In geology, there is a depressing term: “geothermal gradient.” In most regions, for every 1,000 meters you drill downward, the temperature of the surrounding rock increases relentlessly by about 25°C to 30°C.

In 1970, at the height of the Cold War, Soviet scientists launched what was the largest—and most insane—deep drilling project in human history on the Kola Peninsula. This was the Kola Superdeep Borehole. Their goal was extremely simple and direct: dig downward at any cost, to find out what is actually inside the depths of the Earth.

After more than 20 years of extremely grueling excavation, and breaking countless expensive special steel drill rods, the Soviets were finally forced to permanently halt operations at a depth of 12,262 meters.

Why did they stop?

Was it because they had reached the legendary “door to hell”?

The truth is far more hopeless than any myth. At a depth of 12,000 meters, the temperature underground had already surged to a terrifying 180°C—far higher than scientists expected. Under extreme high temperatures and terrifying lithostatic water pressure, the rocks underground are no longer rigid solids; they become semi-fluid substances with extremely strong plastic rheological characteristics—like plastic.

When conventional tungsten carbide and man-made diamond drill bits spin at high speed, the extra heat produced by friction causes the drill bit to soften instantly, even to melt and fail. Even more terrifying is this: when you pull the drill string out to replace the drill bit, due to extreme pressure, the surrounding mud-like rock rushes in instantly and seals off the borehole you just drilled.

If contact mechanical drill bits are destroyed by the laws of physics, then the answer MIT scientists came up with is extremely sci-fi: use light and plasma to “evaporate” the rock directly.

The absolute core of this technology is an enormous super-high-frequency electromagnetic wave generator called a “circular resonator,” capable of producing extremely powerful high-frequency millimeter waves. These death rays invisible to the naked eye are precisely emitted through an extremely smooth, ultra-long waveguide tube to the very bottom of the borehole.

When ultra-dense microwave energy bombards granite or basalt, the rock simply does not have time to melt into magma. Instead, in an instant, it is vaporized directly by that terrifying energy, turning into a cloud of scorching plasma waste gas.

While emitting microwaves, engineers also inject high-pressure argon or nitrogen into the bottom of the well. On one hand, these inert gases blow the vaporized rock waste gas up to the surface; on the other hand, they cool the waveguide tube.

At the edge where the rock is vaporized, the extremely high temperature instantly melts a tiny surrounding ring of rock and then quickly cools it, forming an extremely strong vitrified inner wall. This means that while the machine vaporizes the Earth, it automatically puts on an ultra-hard glass armor layer for the wellbore wall, completely solving the problem of deep-sea borehole collapse.

With so much extremely massive research and development resource—using microwave weapons at the level of nuclear fusion to burn through the Earth—what exactly are American scientists trying to accomplish?

The goal is extremely clear: at a depth of 20 kilometers underground, search for the Earth’s ultimate fluid with an extremely terrifying energy density—supercritical water.

When water is heated to 373°C and the pressure exceeds 220 standard atmospheres, it crosses the critical point on the phase diagram and enters an extremely bizarre fourth state. In this state, water is neither liquid nor gas. It has the extremely terrifying penetration and diffusion abilities of a gas, allowing it to easily pass through extremely tiny pores in rock. At the same time, it has the astonishing density and dissolving power of a liquid, enabling it to carry enormous amounts of thermal energy.

At a depth of 20 kilometers underground, the temperature of the rock reaches 500°C or even higher, and the pressure there is thousands of times greater than at the surface. If we inject surface water through pipes into this ultra-deep cavern burned through by plasma, the water will instantly be heated and pressurized into a supercritical fluid.

The thermal energy carried by this supercritical fluid is more than 10 times that of ordinary geothermal steam. When this supercritical water—packed with extremely terrifying energy—is drawn up to the surface to drive steam turbines for power generation, a geothermal well that occupies only a few hundred square meters can unleash megawatt- and even gigawatt-level base-load electricity power comparable to that of large nuclear power plants.

At this stage, wind power must be built at windy sites, and solar power must be deployed in deserts. Traditional geothermal energy must find areas along crustal activity zones. But the deep high temperatures of the Earth are distributed uniformly across the globe. As long as you dare to drill downward 20 kilometers with a millimeter-wave drill bit, you can reach the endless energy treasure trove at 500°C—without exception.

At present, across the world there are thousands of coal-fired and natural gas power plants facing retirement. Dismantling them is extremely expensive, yet their huge steam turbines, substations, and high-voltage transmission networks inside are still fully intact. The Americans’ plan is to directly move drilling rigs into the backyards of these old coal power plants, burn a 20-kilometer deep hole with plasma, then connect the extracted supercritical geothermal steam directly into the existing steam turbines.

No need to build ultra-expensive extra-high-voltage power grids. No need for large-scale land acquisition. And no persistent intermittent power problems like “depending on the sky,” as with solar and wind. Deep geothermal energy is absolute base-load power output that is extremely stable for 365 days a year, 24 hours a day.

Faced with such extremely aggressive deep-space-level drilling technology, many people instinctively feel intense fear: if you bombard the Earth’s depths with microwaves at tens of thousands of degrees, could it trigger a supervolcano eruption?

Could it cause the Earth’s crust to fracture, even burning the whole planet like a watermelon?

The answer is: there’s no need to worry.

First, the Earth’s volume and heat capacity are enormous. A borehole a few dozen centimeters in diameter and 20 kilometers deep—compared with the entire lithosphere that is tens or even over a hundred kilometers thick—doesn’t even count as a single extremely fine hair. It is completely impossible to shake the structural stability of tectonic plates.

Second, the Earth’s interior is already under extremely high pressure. Magma will not gush out through needle-sized pores like toothpaste squeezed out. And the vitrified borehole-wall technology has already tightly and thoroughly isolated the borehole from the surrounding formations.

Using a nuclear-fusion plasma blade to extract extremely pure supercritical energy from the Earth’s core is not the act of a villain destroying the planet. Rather, it is an extremely grand act of final resistance by human civilization when faced with two mutually desperate dead ends: runaway greenhouse effect and energy depletion.

The fire of a celestial body that has been burning for 4.5 billion years deep within the Earth is waiting to become the ultimate engine that lights up humanity’s next millennium.

Editor: Chen Fang

First Review: Li Hui

Second Review: Tang Shiming

Third Review: Wang Chao