light barrier n. 2

The speed of light. Pluto and back. That was only the test. That was only a quick run and the light barrier would be crossed for only a few seconds during the trip.

Me—the first guy to take a ship through the light barrier, even if it did disintegrate.

Thirty-three seconds of gut-tearing, bone-straining agony, during which their craft was slipped through the light-barrier to be hurled at superluminal velocities across the galaxy.

We broke the sound-barriers, and we’ll break the light-barrier. You scientists are just stupid and dogmatic.

Here, you had no relativity theory. But you did have the kernels, and you discovered relativity experimentally, by driving your kernel ships up against the light barrier, and finding out the hard way that the clocks slow and the relativistic mass piles up.