Ep 5. Discovery of the Accelerating Universe

Deep Space Mysteries season 2 episode 5, titled "Discovery of the Accelerating Universe," delves into one of the most fascinating and game-changing discoveries in modern cosmology. The episode explores the mystery of the universe's accelerating expansion, which defies the laws of gravity and our understanding of the world around us.

The episode begins by setting the stage for the discovery of the accelerating universe. It takes us back to the late 1990s when two independent research teams were studying a type of exploding star called a supernova. These supernovae were used as "standard candles" - objects of known luminosity - to measure distances across the universe. The teams expected to find that the expansion of the universe had slowed down over time, as gravity pulled galaxies together.

Instead, they found the opposite. They discovered that the light from these supernovae was actually weaker than expected, and the universe was expanding at an ever-accelerating rate. This finding was a bombshell for cosmology, as it suggested there was some unknown force or energy that was causing this expansion.

The episode then tracks the efforts of scientists to understand this new phenomenon. We see how they used telescopes to observe distant galaxies and cosmic microwave background radiation - the afterglow of the Big Bang - to gather data. They also used theoretical models to try and explain the accelerating expansion, including the possibility of a "cosmological constant" - an energy that permeates all of space.

We then witness the major breakthroughs that eventually led to a clearer understanding of the accelerating universe. One such breakthrough was the Wilkinson Microwave Anisotropy Probe, which mapped the cosmic microwave background radiation with unprecedented detail. It showed that the universe was flat - meaning that space was uniformly curved - which was a key prediction of the theory of inflation.

Another breakthrough came from the study of supernovae, which were used to measure not just their distance, but also their redshift - the apparent shift in the wavelength of light caused by the expansion of space. This data enabled scientists to create a "Hubble diagram," which showed that the acceleration of the universe was real and not just an observational error.

The episode also touches on the significance of the discovery of the accelerating universe. It opened up a whole new field of cosmology - dark energy - and raised profound questions about the nature of space, time, and the universe as a whole. It also challenged our understanding of the fundamental forces of nature and prompted scientists to develop new theories and models to explain it.

Overall, Deep Space Mysteries season 2 episode 5 is a fascinating and illuminating exploration of one of the most significant discoveries in modern cosmology. It provides a clear and engaging overview of the science behind the discovery, as well as the impact it has had on our understanding of the universe. Anyone with an interest in space and astrophysics will find this episode an enlightening and enjoyable watch.