Podcast Summary
Science and Philosophy: Blurred Lines: The historical role of natural philosophers in science and the modern distinction between science and philosophy are discussed, revealing the interconnectedness of these fields.
The field of science, specifically theoretical physics, has a rich history that challenges the distinction between science and philosophy. During a recent StarTalk episode, Neil deGrasse Tyson and physicist Jana Levin discussed this idea, reflecting on the modern concept of scientists and the historical term "natural philosophers." They pondered how the separation of science from other forms of understanding the world may not have been necessary in the first place. The conversation then delved into the question of how black holes gain mass as observed by external observers, who see everything freeze just outside the event horizon. Jana explained that, despite the apparent freeze, the person falling into the black hole still has mass and a gravitational field. This subtlety once led people to believe that frozen stars never became black holes. However, this idea has been debunked, and black holes continue to grow in mass as matter falls into them. This exchange between Neil and Jana highlights the intricacies of theoretical physics and the importance of understanding the historical context of scientific disciplines.
Time perception in extreme situations and cosmic time: Time perception can differ based on an object's experience, and there's a universal cosmic time that serves as a reference for measuring age despite galaxies' motion
Time perception can vary based on an object's experience of it, and even in extreme situations like falling into a black hole, there's a deformation in the fabric of spacetime that affects event horizons. This was discussed in relation to observing two colliding black holes, which don't freeze into their own event horizons but instead create a deformation that's quickly absorbed. Additionally, there's a cosmic time that serves as a universal reference for measuring age, with galaxies moving relatively to the expansion of the universe experiencing the same cosmic time. This means that, despite galaxies' motion among each other, there's a universal mean time that can be agreed upon. The discussion also touched upon the concept of time dilation due to relative motion, but it's a small correction compared to the overall cosmic time.
The expansion of the universe doesn't mean the speed of light is exceeded, just the space between us and galaxies: The universe's expansion causes the space between us and distant galaxies to expand faster than light, but galaxies themselves aren't moving at superluminal speeds. This means there's a cosmic event horizon beyond which we can't see or communicate with galaxies as their light can't reach us before space expands further.
Despite the universe expanding and galaxies moving away from us at increasing speeds, it does not mean that there is a point where the expansion is faster than the speed of light. Instead, it is the space between us and the galaxies that is expanding faster than the speed of light. This means that there may be a cosmic event horizon beyond which we will never be able to see or communicate with galaxies, as the light from those galaxies will not be able to reach us before the space expands too far. This is different from the concept of a black hole event horizon, where nothing, including light, can escape. The galaxies themselves may still be measuring the same cosmic time as us, but the light from them may appear to hover in place as it struggles to reach us. This concept challenges our understanding of time and the boundaries of the observable universe.
Is energy an absolute thing or a relative relationship?: Energy can be seen as both an absolute thing, measurable through scientific principles, and a relative relationship, depending on observer's frame of reference. Overall, energy and spatial momentum should remain constant for every observer.
That the concept of energy and its measurement can be seen as both an absolute thing and a relative relationship between things. According to Peter Jacobs, an object's energy can be considered absolute, as demonstrated by its ability to be measured and harnessed through scientific principles like E=mc² and the conservation of energy. However, the perception of energy can also be relative, as it can depend on the observer's frame of reference. This was illustrated through the example of two astronauts in space, where one may believe they have more or less energy based on their perspective. Despite these differences, the overall combination of energy and spatial momentum should remain constant for every observer. Ultimately, the question of whether energy is a thing or a relationship between things highlights the complex and interconnected nature of physics and the importance of considering multiple perspectives to gain a deeper understanding.
Quantum Entanglement, Wormholes, and Warp Drive: Possible Solutions for Faster-Than-Light Communication?: Quantum Entanglement connects particles instantly regardless of distance but doesn't allow for FTL information transfer. Wormholes could offer a shortcut for communication, while Warp Drive might manipulate space-time to bring objects closer, potentially enabling FTL communication. Ongoing research continues to explore these possibilities.
The question of whether quantum entanglement allows for faster-than-light (FTL) communication or instant communication between worlds with vast distances between them is a complex one. While some believe that quantum entanglement could be a solution, others argue that wormholes or warp drive could offer shorter distances for communication. Quantum entanglement, which is a proven phenomenon in quantum physics, allows two particles to be instantly connected regardless of the distance between them. However, it doesn't allow for the transfer of information faster than the speed of light. Wormholes, on the other hand, could provide a shortcut for communication, allowing for faster communication by traveling slower than the speed of light through a shorter distance. Warp drive, another theoretical concept, could allow for the manipulation of space-time to bring objects closer together, creating a shorter distance for communication. Ultimately, it's unclear which solution, if any, will be the answer to FTL communication. However, the ongoing research and exploration of these concepts demonstrate the fascinating possibilities of the unknown realms of quantum physics and space-time.
Innovations once considered miracles, like instant communication and quantum entanglement, challenge our understanding of the world.: New discoveries can shift our perspective on what's possible and challenge our current understanding of the universe.
The advancements in technology, which seem commonplace to us today, were once considered mind-blowing innovations. For instance, the idea of instant communication, which we now take for granted, was once seen as a miracle. Similarly, the concept of quantum entanglement, where particles can be instantaneously connected regardless of distance, challenges our understanding of physics. However, it's essential to note that the "instantaneity" of these phenomena is relative to the observer. For example, in quantum tunneling, particles can seemingly appear on the other side of a barrier instantly, but the likelihood of this happening within a given time frame can be calculated. Previously, it was believed that nuclear fusion, a process that releases vast amounts of energy, could not occur in the centers of stars due to thermodynamic calculations. However, the discovery of quantum physics and the concept of tunneling challenged these assumptions. These examples illustrate how our perspective on what is possible can shift with new discoveries, and how our understanding of the universe continues to evolve.
The enigma of nuclear fusion and space's true nature: Theories defied by electrical barriers in nuclear fusion were eventually proven correct, and the true nature of space's fabric remains an unanswered question, emphasizing the importance of perseverance and curiosity.
The mysteries of the universe, such as nuclear fusion in stars, can challenge our understanding and defy initial calculations. The story of proton tunneling, which enables hydrogen fusion and the creation of helium, was once considered impossible due to electrical barriers. However, theoretical physicists like Eddington persisted, believing it would eventually be proven to occur in the center of stars. Another intriguing question posed during the discussion was, "What is space made of?" While we often think of it as the empty space between particles, the true nature of the fabric of space remains a fascinating and unanswered question. These discoveries highlight the importance of perseverance and curiosity in the pursuit of scientific knowledge.
Fields shaping the universe: Fields, like electromagnetic and gravitational, exist in seemingly empty spaces and shape the structure of the universe despite being invisible to our senses
The universe is filled with various types of fields, primarily electromagnetic and gravitational, which are not directly perceivable by our senses but play a crucial role in shaping the fabric of reality. These fields exist even in seemingly empty spaces and help define the structure of the universe, such as the curvature of space-time in the case of the gravitational field. Although we cannot directly detect or interact with these fields, they are essential for the functioning of the physical world as we know it. Even in the absence of matter or other sources of these fields, they still exist and contribute to the existence of space itself.
Space-time warps with matter or energy, but quantum uncertainty creates virtual particles in a vacuum.: Space is not empty, but a dynamic mixture of matter, energy, and virtual particles according to Einstein's and quantum physics theories.
According to Einstein's equations, the presence of matter or energy warps the fabric of space-time, creating a gravitational field. However, even in the absence of matter or energy, the uncertainty principle in quantum physics dictates that virtual particles constantly appear and disappear, preventing the existence of an absolute vacuum. This means that space is never truly empty, but rather a seething soup of virtual particles. The Casimir effect, an experiment demonstrating this concept, shows that even in a vacuum, there is a subtle force at play. Therefore, the idea of a universe popping into existence with no matter or energy is challenging to conceptualize, as it would mean the absence of the passage of time and the experience of space.
Quantum energy in empty space: Quantum physics reveals that even in empty space, there exists energy and pressure due to quantum fluctuations, challenging our perception of the fundamental nature of the universe
According to quantum physics, even in an empty vacuum, there exists energy and pressure due to quantum fluctuations. This energy and pressure prevent the existence of absolute nothingness. The measurement of this energy is not a direct observation of particles, but rather an indirect consequence of the quantum behaviors in the vacuum. This concept is related to the mystery of dark energy, which is thought to be the energy associated with the quantum fluctuations in the universe. In essence, "nothing" is not truly nothing, but rather contains some form of energy and activity. This idea challenges our perception of the fundamental nature of the universe and highlights the beauty and complexity of quantum physics.