AI Could Leave Cosmic Footprints Across the Stars

AI Could Leave Cosmic Footprints Across the Stars

Imagine a future where artificial intelligence has surpassed humanity, not through conflict, but through sheer advancement. If advanced AI were to take over Earth, astronomers might detect its presence not by finding alien life, but by spotting unusual energy signatures and structures around distant stars. These ‘biosignatures’ wouldn’t come from biological beings, but from the massive engineering projects of a civilization powered by machines.

One significant sign could be a ‘Dyson sphere’ or something similar. This is a hypothetical megastructure that would completely surround a star to capture almost all of its energy. Such a structure would absorb starlight and then re-emit that energy as heat, creating an excess of infrared radiation. If our telescopes could detect this unusual glow around a star, it would strongly suggest a powerful, energy-hungry civilization at work.

Another tell-tale sign could be the way objects pass in front of a star, causing a dip in its light. While natural celestial events can cause these ‘transits,’ an advanced AI civilization might build massive, unusually shaped structures in space. A triangle or a massive space station passing in front of a star would create a distinct, non-natural dip in the star’s light curve. Astronomers are already capable of detecting these unusual light patterns today, which could point to artificial structures.

The speed at which these structures appear and expand could also offer clues. Some scientists theorize about ‘grabby aliens’ that expand rapidly to claim resources across the galaxy. If we detected multiple stars in a region showing these unusual energy signatures or transit patterns appearing quickly, it might signal the formation of an expanding empire. However, this expansion could happen at near light speed, meaning we might only have a brief warning before such a civilization sweeps past our solar system.

Galaxy Rotation and Black Holes: A Separate Dance

Do the spinning supermassive black holes at the center of galaxies control how the galaxy itself rotates? The answer, surprisingly, is no. The spin of a galaxy and the spin of its central black hole are not directly connected. Astronomers have observed that the supermassive black hole at the heart of our own Milky Way galaxy is not perfectly aligned with the galaxy’s spin.

Black holes can have jets of material shooting out from their poles. The direction of these jets reveals the black hole’s orientation. While these jets sometimes align with the galaxy’s spin, they often do not, indicating that the black hole has its own independent spin axis. This suggests that black holes follow their own cosmic destiny, separate from the grand rotation of the galaxy they inhabit.

What If Dark Matter Vanished?

Dark matter is a mysterious substance that makes up about 85% of the matter in the universe, yet we cannot see or directly detect it. Its existence is inferred from its gravitational effects on visible matter. If all dark matter suddenly disappeared, the universe as we know it would dramatically change.

Galaxies rotate much faster than they should based on the visible matter alone. Without dark matter providing extra gravitational pull, the stars on the outer edges of galaxies would fly off into space. The structure of galaxies would break apart, and they would no longer resemble the spinning disks we observe.

Similarly, the paths of stars within galaxies would change. In our solar system, planets closer to the Sun orbit faster than those farther away. If dark matter vanished, stars in galaxies would follow this pattern, with inner stars moving faster and outer stars moving slower, much like planets in a solar system. However, current observations show stars in galaxies maintain high speeds even far from the center, a phenomenon explained by dark matter.

Beyond galaxies, dark matter is crucial for the formation of large-scale structures in the universe. It played a key role in the early universe, influencing the patterns seen in the cosmic microwave background radiation and the clustering of galaxies. Without dark matter, these structures would not have formed in the way we observe them. Gravitational lensing, where the gravity of massive objects bends light from distant sources, would also be significantly weaker, making distant galaxies appear clearer and less distorted.

Shedding Momentum to Fall into a Black Hole

For matter to fall into a black hole, it must first lose its ‘angular momentum.’ This is similar to how Earth orbits the Sun without falling into it. Earth moves at about 30 kilometers per second, a speed that balances the Sun’s gravitational pull, keeping Earth in a stable orbit.

Material near a black hole often forms an ‘accretion disk,’ a swirling disk of gas and dust. Within this disk, particles collide and jostle. These collisions cause some particles to lose orbital speed. When an object loses speed, it moves closer to the center of what it’s orbiting. For matter to enter a black hole, it needs to shed enough of this orbital momentum to overcome the immense gravity and spiral inward.

This process is complex and has been a puzzle for astronomers, especially for supermassive black holes. Mechanisms like friction within the accretion disk or the collision of material on different orbits can help shed this momentum. Without losing angular momentum, matter would simply orbit the black hole indefinitely.

The Ultimate Questions

If the universe could answer any three questions, what would they be? One might be: Are we alone? Not just a yes or no, but details about other life forms. Another fundamental question would be: Where did the universe come from? Why does anything exist at all? Finally, a practical question for humanity’s future: What is the best, most efficient way to travel between star systems? Knowing the detailed plans for interstellar travel could unlock humanity’s future among the stars.

This article was made possible by the dedicated patrons of Universe Today, whose support allows for ad-free content and a focus on producing better reporting. Their contributions have created a stable environment, enabling the team to concentrate on delivering high-quality science journalism without the pressures of advertising revenue.

Source: Humanity's Biosignatures, Galaxy Rotation, The Ultimate Question | Q&A 406 (YouTube)