Humanities newbie learning lightning-fast science with GPT: Why can’t aliens and humans make contact? Why does the Dark Forest Theory in *The Three-Body Problem* have flaws? Why can’t we break the speed of light? 'The universe might be full of civilizations, but we may never see each other.' **Fermi Paradox**: If there are countless civilizations in the universe, why haven’t we seen any of them? One mainstream answer is: the universe is too vast, the speed of light is too slow, and civilizations are isolated 'islands.' This is called the 'speed-of-light prison.' According to Einstein’s theory of relativity: nothing with mass can exceed the speed of light. Civilizations might only exist for 10,000 years, but even a simple communication exchange could take thousands or tens of thousands of years. It’s like sending an email to a civilization still in the Tang Dynasty—by the time they reply, you’d already be extinct. The universe is like a dark forest, but not because everyone wants to shoot each other—it’s because no one can hear each other. The distance between civilizations isn’t spatial; it’s temporal. Liu Cixin’s 'Dark Forest Theory' is a literary hypothesis: civilizations in the universe remain silent or hunt each other out of mutual distrust. But most scientists believe the Dark Forest isn’t the mainstream explanation. Here’s why: The real universe is harsher than fiction. The distances are too vast, the speed is too slow—there’s no need to hunt others because they’re 10,000 light-years away. If you launch an attack, it would take 20,000 years for it to reach them and return. By then, they might already be extinct, or your civilization might be. This isn’t a strategic issue; it’s a physical one. The universe is too cold, too vast, and too slow—not too dangerous. The 'Dark Forest' is more like a projection of human fears. Why is the speed of light the ultimate speed limit in the universe? In relativity: the speed of light isn’t just a speed—it’s a conversion factor that links 'distance' and 'time.' It’s like having a constant that converts 'centimeters' into 'seconds.' That constant is the speed of light. If the speed of light were different, the structure of space-time would change, the laws of physics would change, and the universe might not even be stable. That’s why the speed of light is a fundamental parameter of the universe.