How We Know the Universe Had a Beginning

Miacademy & MiaPrep Learning Channel

This educational video provides a clear and engaging overview of cosmology, focusing on the scientific evidence that supports the Big Bang theory. It begins by exploring the historical debate between a static universe and one with a beginning, highlighting the contributions of George Lemaître and his interactions with Albert Einstein. The narrator explains how the initial concept of a singularity was controversial but eventually accepted due to overwhelming observational evidence. The video details two primary pillars of evidence for the Big Bang: Cosmic Background Radiation (CBR) and the redshift of distant galaxies. Using accessible analogies like glowing hot coals and the Doppler effect of a passing car, complex physics concepts are broken down for student understanding. The video visually demonstrates how light waves stretch as sources move away, connecting this phenomenon to the expansion of the universe. Finally, the lesson introduces the mysterious concept of dark energy. It explains that while the universe is expanding, it is doing so at an accelerating rate—a discovery that implies the existence of an unknown energy source. The video concludes with a review quiz to check understanding, making it an excellent resource for physics and astronomy classrooms to discuss the origins and future of our universe.