In this episode of StarTalk Radio, co-hosts Chuck and Gary delve into their burning questions about the universe. They explore topics such as the age of the universe, the mysteries of quantum physics, the concept of time, and the significance of energy in civilization. Join Neil deGrasse Tyson and his co-hosts as they navigate through these fascinating subjects.
Chuck recalls a deep discussion about the true size of the universe between Neil and a colleague at Princeton. 20 years ago, the age and size of the universe were uncertain, with estimates ranging from 10 to 20 billion years. However, better data and measurements have led to more accurate estimates. Red shifting, which is the stretching of light waves due to the expansion of the universe, is a key concept in understanding the universe’s size. The correct age of the universe was found to be between the initial estimates of 10 and 20 billion years. Supernovae, which are brighter than the galaxies they’re contained in, serve as a standard candle for measuring distances in the universe based on their brightness and rate of decline. However, discrepancies exist in the measurements of the size and age of the universe obtained from different methods, creating cosmological tension. While the observable universe’s size is nearly 100 billion light years across today, what we see is limited to what the light has reached us, and the actual universe’s size remains unknown.
The mysteries of quantum physics are explored, highlighting the behavior of particles as waves. When electrons are fired through two slits and observed, they behave as particles, but when not observed, they behave as waves, creating an interference pattern on the projection surface. The act of looking at the electrons by shining light on them causes the interference pattern to disappear, and they behave as particles, known as the observer effect. Quantum physics defies common sense but can still be described and predicted. It showcases the complexities of the universe and the alternate possibilities that exist.
Time is a complex concept that is affected by relativity. Kinematic and gravitational time dilation are real phenomena, where movement in space affects the progression of time. In the theory of relativity, the speed of light must be measured as the same for observers moving at different speeds, leading to time dilation. The observer moving faster experiences time slowing down, while the observer at rest experiences time normally. Stronger gravitational fields also cause time to slow down. GPS satellites, due to their distance from Earth’s center, experience time dilation, which is calibrated by the National Institute of Standards and Technology for accurate timekeeping.
The discovery that matter is made of atoms and atoms are made of particles has shaped the world the most. This understanding has led to advancements in electricity, nuclear power, communications, and an understanding of molecules and the periodic table of elements. Professors at MIT have created a comprehensive course and textbook called “Energy and Big Fat Textbook” covering everything about energy and its conversion. Understanding, measuring, harnessing, and transforming energy is essential for modern civilization. The ability to transform energy from one form to another is the backbone of modern civilization.
Exploring the age of the universe, the mysteries of quantum physics, the concept of time, and the significance of energy in civilization, this episode of StarTalk Radio delves into the wonders and complexities of the universe. From the uncertainties of the universe’s size and age to the mind-boggling behavior of particles in quantum physics, these topics highlight the vastness and intricacies of our existence. Understanding these concepts is crucial for unraveling the mysteries of the cosmos and advancing our civilization. As Neil deGrasse Tyson often says, “Keep looking up.”