Modern Astronomy

Edwin Hubble

Hubble's most significant achievement was the observation of the redshift of galaxies, which provided compelling evidence for the expansion of the universe. By meticulously measuring the distances to galaxies and their recessional velocities, Hubble formulated Hubble's Law, demonstrating that galaxies are moving away from each other, and that the universe is expanding. Hubble's work not only expanded the scale of the known universe but also laid the foundation for modern cosmology, earning him a legacy as one of the most influential figures in the history of astronomy. In honor of his groundbreaking contributions, the Hubble Space Telescope, launched in 1990, was named after him and continues to provide invaluable insights into the distant reaches of our expanding universe.

Albert Einstein

In 1915 Einstein presented his equations of general relativity, which fundamentally transformed our understanding of gravity and the structure of spacetime. One of the key predictions of general relativity was the bending of light around massive objects, known as gravitational lensing. This phenomenon has practical implications in astronomy, as it affects the apparent positions and shapes of distant celestial objects. General relativity also influenced our understanding of the expansion of the universe, and its equations are crucial for describing the behavior of massive objects such as black holes.

Penzias and Wilson

In 1964, while working at Bell Labs, Penzias and Wilson were investigating radio signals using a large horn antenna. Despite meticulous efforts to eliminate sources of interference, they encountered a persistent noise in their measurements. They realized that they had stumbled upon the faint, uniform radiation pervading the entire universe—the afterglow of the Big Bang. This discovery provided crucial evidence for the Big Bang theory, supporting the idea of an expanding universe, and offering profound insights into the early moments of cosmic history. Penzias and Wilson were awarded the Nobel Prize in Physics in 1978.

Vera Rubin

Rubin's observations provided compelling evidence for the existence of dark matter—a mysterious, invisible substance that exerts gravitational forces on visible matter. In the 1970s, her research challenged existing theories that suggested visible matter alone could account for the observed rotation of galaxies. By demonstrating that galaxies rotate as if they contain more mass than is visible, Rubin's work fundamentally altered our understanding of the composition of the universe. Her dedication to advancing our knowledge of the universe paved the way for further research into the nature of dark matter and its role in shaping the large-scale structure of the cosmos.

Perlmutter, Schmidt, and Riess

Their collaborative efforts, conducted independently by two research teams, provided compelling evidence that the rate of the universe's expansion is increasing over time. Using observations of distant supernovae, these scientists demonstrated that the distant galaxies were receding at a faster pace than anticipated, challenging the prevailing notion of a decelerating expansion. Perlmutter, Schmidt, and Riess's work not only reshaped our understanding of the cosmos but also suggested the presence of dark energy—a mysterious force driving the accelerated expansion. Their efforts marked a transformative moment in cosmology, shedding light on the dynamics of the universe and earning them the prestigious Nobel Prize in Physics.