China-based Italian cosmologist Cosimo Bambi recently made headlines with his bold proposal to send a tiny spacecraft to a black hole—a mission he believes may take a century to become reality. He is currently a Professor of Physics at the Fudan University in Shanghai, China.

A marathon runner himself, Bambi likens the quest for interstellar travel to a long-distance race, saying his proposal is meant to spark fresh debate on its possibilities.

After completing his PhD in Italy, Bambi worked in the US, Japan, and Germany, before joining the Fudan University in Shanghai. When he first moved to China, he recalls, the community of scientists focusing on black holes was still small.

“But in recent decades, China has invested heavily in research … The overall quality of research has grown tremendously,” he noted.

THE WEEK sat down with Bambi for an exclusive conversation about his proposal and how this ambitious plan could reshape our understanding of physics. Edited excerpts:

Q) You have made a scientific proposal to send a tiny spacecraft to a black hole: a mission that could take around 100 years. Could you explain this to us in simple terms? What exactly is the mission, and what’s the thinking behind sending such a nano-level spacecraft toward a black hole?

First, let me say that people have been studying concepts for interstellar spacecraft since at least the 1960s. Even the idea of using a laser to accelerate a probe goes back that far. Over the past 10–15 years, these ideas have gained renewed interest from a wider scientific community.

The concept of sending small probes is not new. For example, in the exoplanet community, scientists have long discussed the possibility of sending tiny spacecraft to nearby star systems to study planets beyond our solar system.

My article simply asks: if we’re already discussing this for exoplanets, why not also consider black holes?

It’s not that I’m presenting a concrete mission plan. Rather, my work is meant to open a discussion about the possibility. My background is in theoretical physics, not engineering. A mission like this would require expertise from many different fields: materials science for designing the probe, laser technology for propulsion, and advanced communication systems to transmit data back to Earth.

There’s another challenge: we don’t yet know where the nearest black holes are. We expect them to exist, because we know many massive stars collapse into black holes.

Estimates suggest there could be between 100 million and a billion black holes in our galaxy. Yet, so far, we’ve identified fewer than a hundred with certainty. So right now, even before thinking about missions, we first need to know where to send the probe.

Q) What’s the importance of studying black holes? How crucial is it to explore these phenomena, especially when we imagine a future where humanity might look for life or homes beyond Earth and even beyond our galaxy?

I would say that the main scientific goal of a mission to a black hole is not about finding a new home for humanity, but about testing the limits of physics—specifically, finding physics beyond general relativity.

Modern physics rests on a few fundamental pillars, and one of them is general relativity.

Einstein proposed it more than 100 years ago, and remarkably, the theory has remained essentially unchanged since then. That’s very different from particle physics, for example, where experiments have constantly refined models over decades—culminating in the Standard Model, which was developed in the 1960s and confirmed step-by-step until the Higgs boson was discovered in 2012.

In the case of gravity, the problem is that it’s very weak, making it hard to test. That’s why physicists are so interested in black holes: near them, gravity is extremely strong, and we might finally see deviations from Einstein’s predictions.

There’s a general consensus that the structure of black holes as described by general relativity—like the idea of a singularity, a point of infinite density—cannot be the complete picture. However, without direct experiments, it’s difficult to know which alternative models, if any, are correct.

Now, telescopes and gravitational wave detectors are giving us incredibly high-quality data, but the challenge is interpretation.

These signals come from very messy astrophysical environments—black holes surrounded by gas, dust, and stars—so extracting clear answers about fundamental physics is hard. Even with more powerful telescopes in the future, there will still be limits to what we can deduce.

That’s why the idea of sending a probe is so exciting.

Within our solar system, spacecraft have allowed us to make precise tests of general relativity in relatively “clean” environments, even though the gravitational field here is weak. A probe near a black hole could, in principle, do something similar in a regime where gravity is extremely strong.

The stakes go beyond black holes themselves.

These questions are tied to some of the deepest mysteries in physics: the true structure of time, the origin of the universe, and what happened at the “beginning,” in the face of which current theories break down.

In Newtonian physics, time was absolute, the same for everyone. In relativity, time is already relative—different observers can measure different times—but it still has a before and after.

At the most fundamental level, even that might not be true. To uncover what time and the universe really are, we need to go beyond general relativity. Studying black holes may be one of the best ways to do that.

Q) Your proposal mentions sending a nano-spacecraft propelled by Earth-based lasers. Could you explain how this propulsion system would work? And what kind of technological advances would you like to see in the coming decades—not just from your side, but from engineers and scientists around the world—so that such a mission can become a reality?

The very first step is actually to identify a nearby black hole—ideally within 20 to 25 light-years from us. If we can find one, then the scientific community will have a real motivation to develop the technology needed for such a mission.

Without that motivation, it’s difficult to push technology forward. A common misconception is that technology automatically improves with time. In reality, it advances only when there is focused effort and a clear reason to pursue it.

Now, the basic idea of the propulsion system is this: you have a very small spacecraft, and you fire powerful lasers from Earth onto a reflective sail attached to it.

The photons from the laser exert pressure, accelerating the probe to very high speeds. In principle, we already have the technology to do this today—but with current systems, it would be prohibitively expensive.

The encouraging part is that, over the last 20 years, laser technology has advanced rapidly while costs have fallen significantly. If you look at this trend and project it forward, there’s good reason to believe that in 20 or 30 years, lasers powerful and affordable enough for such missions could become available.

So, while there are many technological challenges, the laser system is the key bottleneck at the moment. We’ll need sustained global effort in laser research and engineering to make this concept viable.

Q) How did you estimate that such a mission could be possible within the next 100 years?

The timeline comes from two parts. First, developing the necessary laser technology might take 20 to 30 years, based on current progress and cost trends. After that, the time depends on two factors: the distance of the target black hole and the speed of the probe.

In my paper, I assumed the probe could reach about one-third the speed of light. This is a reasonable assumption: technically, it may be possible to push closer to the speed of light, but the cost doesn’t scale linearly with velocity. Accelerating a probe to higher speeds would increase the cost dramatically or require more advanced technology.

So, with current projections, a century-long timeline is a realistic estimate.

Q) How does your proposal compare to other past initiatives, like Breakthrough Starshot?

Well, the concept is not entirely new. In the exoplanet community, scientists have already discussed interstellar missions using nano-craft.

The main difference is the target. Breakthrough Starshotfor example, is aimed at reaching nearby exoplanets to take images and study their atmospheres.

In my proposal, the destination is a black hole, and the goal is very different: to study its gravitational field. That means instead of focusing on imaging, we would be observing how particles move around the black hole.

One possible approach would be for the probe to separate into a “mothership” and smaller sub-probes as it nears the black hole. These sub-probes would exchange electromagnetic signals with each other and with the mothership. By studying how those signals propagate and by reconstructing the probes’ trajectories, we could directly measure the effects of the black hole’s gravity.

This setup is similar to what has already been done in solar system experiments, where a spacecraft communicates with Earth-based stations to study gravitational effects. The principle is the same, but here it would be applied in the extreme environment around a black hole.

Q) Do you believe China will emerge as a leader in ambitious fields like astrophysics and cosmology, just as it has in many other critical technologies?

I would say it’s difficult for any country today to be the absolute leader in science. Modern research requires too many different areas of expertise, and no single country can realistically dominate them all. What China can do—and is already doing—is to become a very important contributor.

The real trend, in my view, is toward greater international collaboration.

Fields like astrophysics and cosmology are so broad and complex that no one nation can cover everything. So instead of thinking in terms of absolute leadership, it makes more sense to think in terms of building strong contributions within global collaborations.

How do you see the contributions from the Indian research community in your field? Are there interesting developments coming from there?

Honestly, I have very good connections with India. Typically, about half of my PhD students are from China, and the rest are from nearby countries—often from India or Kazakhstan. India’s system is, of course, evolving differently and on a different time scale. But I’m optimistic: for instance, India’s space programme is making significant and rapid progress.

Historically, India has had a stronger tradition in astrophysics. Even ten years ago, the Indian community was larger than China’s. Now, perhaps it’s growing a bit more slowly, but I’d still say there’s real promise.

Even though relations between China and India can sometimes be complicated, scientists don’t care about those political issues—we can build good collaborations.

In fact, every year I organise a China–India workshop on high-energy astrophysics, and over the past ten years these connections have only grown stronger.