Who Discovered the Finite Speed of Light?
Ole Romer, a Danish astronomer, discovered that light is not instantaneous. He observed that the emergence of Io from behind Jupiter varied depending on the position of the two planets in the sun's orbit. This led him to realize that light takes time to travel from Jupiter to Earth, causing the observed differences in emergence time.
Understanding the Speed of Light
The speed of light is a fundamental constant, moving through space at a finite speed of 299,792,458 meters per second.
Exploring Light Years and Galaxies
A light year is both a measure of distance and time, representing the distance light travels in one year. Andromeda, a spiral galaxy, is nearly the same size as the Milky Way and is home to millions of old red stars.
Color of Young Stars and the Expanding Universe
Young stars appear blue due to their high mass and temperature. The red glow of the farthest galaxies is a result of the universe's expansion, supporting the Big Bang Theory.
The Big Bang and Invisible Light
The Big Bang was not an explosion but a simultaneous event that occurred everywhere. Beyond the visible spectrum, the Cosmic Microwave Background (CMB) provides crucial insights into the universe's origins.