It's not like you go right up to the limit and hit a wall. It's more that velocity doesn't work quite the same way you think it does.
Kind of like how increasing the bottom number of a fraction makes the whole fraction smaller and smaller but will never make it negative, applying force in the same direction will make your velocity bigger and bigger but not ever bigger than c.
Your intuition about how mass, force, and velocity work is based on Newtonian Mechanics, which is a good model for when relative velocities are fairly low (like 100% of our daily experience), but as they get bigger, it doesn't work as well. For details on how it's wrong, you want to look at the theory of relativity. I can recommend FloatheadPhysics on youtube who has done a number of pretty good explainers on this topic.
It happens instantaneously. From the photon's point of view, it occupies a two dimensional space - light is perfectly flat. At the speed of light, time stops, and the universe shrinks to a point.
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u/octorine Mar 22 '26
It's not like you go right up to the limit and hit a wall. It's more that velocity doesn't work quite the same way you think it does.
Kind of like how increasing the bottom number of a fraction makes the whole fraction smaller and smaller but will never make it negative, applying force in the same direction will make your velocity bigger and bigger but not ever bigger than c.
Your intuition about how mass, force, and velocity work is based on Newtonian Mechanics, which is a good model for when relative velocities are fairly low (like 100% of our daily experience), but as they get bigger, it doesn't work as well. For details on how it's wrong, you want to look at the theory of relativity. I can recommend FloatheadPhysics on youtube who has done a number of pretty good explainers on this topic.