This explanation is the wrong intuition for why space can expand FtL. It’s an understandable one to infer, but the balloon one further down is correct and the one most commonly used by cosmologists for a lay audience.
Our current understanding of recessional velocity works by Hubble’s law, and that linear equation imposes no such 2x cap.
Well duh. When a thing moves away from another thing, that is moving at the speed of light, at the speed of light, you have speed of light time two!
You still have one speed of light, that’s the Lorentz transformation
This explanation is the wrong intuition for why space can expand FtL. It’s an understandable one to infer, but the balloon one further down is correct and the one most commonly used by cosmologists for a lay audience.
Our current understanding of recessional velocity works by Hubble’s law, and that linear equation imposes no such 2x cap.