Vesto Slipher

Vesto Melvin Slipher was born November 11, 1875, and spent his career as an American astronomer chasing light from objects most thought were static. He performed the first measurements of radial velocities for galaxies, a technical feat that revealed something stranger: distant galaxies were redshifted, their light stretched as they moved. He was the first to relate those shifts to actual velocity, turning a spectral curiosity into a kinematic fact. That work laid the empirical foundation for the idea that the universe expands. He died November 8, 1969, three days shy of his ninety-fourth birt…