system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is special about light that makes it so fast?

is it something special about the photon? This seems like such a basic fundamental question, i feel like I should know but have no idea.
gpt
It's actually a pretty sophisticated topic.

What's special about a photon is that it has *no resting mass.* In other words, it's not made by taking an existing particle and then speeding it up and shooting it off in some direction. Instead, it is initially created at its full speed (the speed of light, or "c" for short). That's crucial because it's physically impossible to accelerate a particle up to c, because its mass would keep increasing up toward infinity as it got faster and faster.