The Science Behind Black Hole Interactions

In any scientific investigation, merely proving that something can happen isn't enough. We must also understand how it happens, under what conditions, and at what rate. For any mass that isn't massive enough to collapse into a black hole, we need to assess two main probabilities: the chance of colliding with another black hole or gravitationally spiraling into one.

An active black hole, which accumulates matter and ejects jets of energy, exemplifies how quasars function. It’s essential to note that black holes do not actively 'suck' in matter from their surroundings.

Galactic Dynamics and Long-Term Predictions

The Milky Way, with its spiral shape and central bulge, contains around 400 billion stars. Only about 0.1% of stars end up as black holes, most being between 4 and 40 solar masses. However, some can grow exponentially, culminating in supermassive black holes containing millions of solar masses.

Statistically, a planet like Earth is unlikely to encounter a substantial mass like a black hole. The nearest star, aside from our Sun, has remained over 500 times farther from us than the Earth-Sun distance for most of cosmic history. Projections suggest that it would take approximately 10²⁰ years before a black hole might approach Earth.

The Role of Gravitational Waves

Another critical aspect is the orbital decay caused by gravitational waves, as described by General Relativity. When masses move through curved space, they emit gravitational radiation, losing energy and drawing closer together. Over immense timescales, stars and other celestial bodies will eventually merge due to these interactions.

For instance, in about 10²⁶ years, Earth will spiral into the remnants of the Sun. Similarly, over even longer periods, the supermassive black hole at the center of our galaxy will consume surrounding stars.

Competing Processes and Cosmic Outcomes

The potential for black holes to consume the Universe hinges on understanding all competing processes. If faster and more frequent events occur, they will likely dictate the Universe's fate. Calculations show that while black holes might seem to be on a collision course with everything, alternative outcomes are more probable.

After merging, large spiral galaxies eventually evolve into giant elliptical galaxies. As stars exhaust their fuel, they will interact with one another gravitationally, leading to a significant number of them getting ejected from their systems.

The Fate of the Universe

In the grand scheme, it's projected that around 10¹⁹ years from now, approximately 99% of stars will be ejected into intergalactic space, never to return to another galaxy. Rather than being consumed by black holes, these stars will wander the cosmos as runaway stars.

Despite the minuscule number of stars that might fall into a black hole, this is less than 0.1% of the total matter in the Universe. Furthermore, as time progresses, even black holes will eventually decay due to Hawking radiation.

In conclusion, while black holes may seem ominous, they will not devour the Universe. If something you cherish does happen to fall in, don’t lose hope; with enough time, you may very well recover its energy and possibly its information.

Ethan Siegel, author of "Beyond The Galaxy" and "Treknology: The Science of Star Trek from Tricorders to Warp Drive," explores these themes in depth in his writings.