Why Is the Universe Exactly 13.8 Billion Years Old?#Space #Astronomy #Universe #Science #Cosmos

Added: 2026-05-17

[00:00:00]13.8 billion years. Imagine you're sitting in a time machine, not moving forward but backward. You pass a thousand years, then a million, then a billion. Galaxies start [music] disappearing. Stars blink out.

[00:00:16]Everything gets quieter.

[00:00:17]>> [music] >> And then, you reach a moment where time itself just stops. No before, [music] no earlier, just the beginning. So, here's the question. How do we even know where that moment is?

[00:00:30]>> [music] >> Because the number we always hear, 13.8 billion years, it's weirdly specific.

[00:00:37]>> [music] >> Not 10 billion, not 20 billion, 13.8, which is oddly precise for something as chaotic as the universe. So, what kind of cosmic ruler are we using to measure something like time itself? Hold that thought because the answer is way more layered than it sounds. Okay. So, when we talk about the beginning of time, we're talking about the Big Bang.