What Does the Star Hamal Reveal About Cosmic Time? - The Shifting Equinox and the Star That Marked Spring | Sleepy Facts About the Universe
Sleepy Facts About the Universe by sciflix.one - Sleepy Astronomy
Episode notes
Tonight, if you look up and find that steady orange light in the northern sky, you are receiving photons that left their source when your grandparents were young. The object sending them, however, has already burned through three and a half billion years of existence. This episode explores the star Hamal, the brightest light in the constellation Aries, and the profound contrast between a human lifetime and a stellar one. We examine how ancient Babylonian astronomers used this warm, hearth-like star as a landmark to mark the vernal equinox, and how Greek observers like Hipparchus later realized the equinox point slowly drifts due to Earth's axial wobble.
As measurement improved across centuries, the celestial sphere dissolved into physical depth. Hamal was recast from a permanent fixture to a distant wanderer possessing proper motion, and sp ...