Life is arguably the most intriguing natural occurrence in the universe, with the human brain standing as the most complex structure we know. Despite being a product of nature’s laws, we are still unraveling how it creates the experience of living. To truly understand the meaning of life, we must first delve into the nature of life itself and consciousness, as meaning emerges from consciousness.
In a recent conversation with physicist Brian Cox, we explored what it means to be alive. While our discussion did not focus on cosmic phenomena like the Big Bang or black holes, it centered on the fundamental question: What distinguishes living beings from inanimate objects like rocks? By examining the fundamental rules of the universe through physics, we might gain insights into the meaning of life.
As a biologist, I often ponder why a physicist would be interested in life’s questions. The universe, from swirling galaxies to the shining stars, operates under the laws of physics. Textbooks often describe life with a checklist of attributes, such as cellular organization, growth, reproduction, and energy use. However, exceptions abound, challenging our understanding of what life truly is.
Energy is vital for living organisms. It is a conserved quantity, meaning it changes forms but never disappears. Since the Big Bang, energy has become more disordered, following the second law of thermodynamics. Life represents a local complexity that emerges amidst the universe’s march toward disorder. This complexity is possible as long as there is a price paid in the environment, much like a refrigerator creating order inside by expelling disorder outside.
The original order in the universe, stemming from the Big Bang, allowed complex structures to form over billions of years. Our Sun, like every star, is a pocket of complexity, releasing energy over time as sunlight, which powers life on Earth. Living organisms absorb this ordered sunlight energy and return less ordered energy as heat, contributing to the universe’s overall disorder.
One commonality among all living things is their management of energy, particularly through proton pumping across membranes. This universal trait may offer clues about life’s origins, possibly in deep-sea hydrothermal vents where natural proton gradients exist. The transition from geochemistry to biochemistry marks the origin of life, where chemistry becomes complex enough to store and copy information.
DNA, carrying life’s instructions, allows organisms to extract meaning and perform functions. Although individual organisms die, life continues through the information stored in DNA, shared across species. Understanding life’s origin may be easier on Mars, where evidence could be more pristine due to less geological activity.
In live discussions, I often begin with the question of what it means to live a finite life in an infinite universe. While the answer remains elusive, embracing uncertainty can lead to excitement and curiosity, driving us to explore the unknown.
If you’re interested in learning more about Professor Brian Cox and his science communication work, check out the links provided. Additionally, consider supporting educational content through platforms like Patreon.
Before you go, ponder these intriguing questions: What can someone who is completely blind teach you about video games? How did anime become a $25 billion industry? And why are some people putting underwear on goats? These questions and more are explored in “Subcultured,” a new documentary series from PBS. Check it out on “PBS Voices,” and let them know Joe sent you.
Engage in a structured debate with your classmates on what constitutes life. Use the attributes mentioned in the article, such as cellular organization and energy use, as starting points. Consider exceptions and challenge each other’s views to deepen your understanding of life’s complexity.
Conduct a lab experiment to observe energy transformation in living organisms. Measure the energy input and output in a simple biological system, such as a plant or yeast culture, to understand how living beings manage energy and contribute to the universe’s entropy.
Work in groups to research the origins of life, focusing on theories such as those involving deep-sea hydrothermal vents. Present your findings on how proton gradients might have played a role in the transition from geochemistry to biochemistry.
Participate in a seminar discussing the possibility of life beyond Earth. Use the concepts of energy management and complexity from the article to hypothesize about the conditions necessary for life elsewhere in the universe.
Write a reflective essay on the theme of embracing uncertainty in scientific exploration. Consider how the unknown drives curiosity and innovation, as discussed in the article, and relate it to your personal experiences in learning and discovery.
Here’s a sanitized version of the provided YouTube transcript:
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Thank you to Policygenius for supporting PBS. I think that life is the most fascinating naturally occurring phenomenon in the universe, and I believe that’s widely accepted. Clearly, the human brain is the most complex structure we know of. It is a product of the laws of nature, but we are still far from understanding how it produces the experience of living. If we want to ask about the meaning of life, we first need to understand life itself and consciousness, as meaning emerges from consciousness.
I think it’s a bit unfair that everything sounds so much better with your accent when you explain concepts about the origin of the universe and life. So, are you saying it’s not the inherent poetry in my sentence construction or the ideas I convey, but just the accent? Let’s call it 60/40. I’ll take that.
I recently sat down with science communicator Brian Cox. He is a physicist, but our conversation didn’t focus on the Big Bang, alien worlds, or black holes. Instead, we talked about what it means to be alive. Life is one of those things where you know it when you see it, but what exactly makes me different from a rock? By looking to physics and asking questions about the fundamental rules of the universe, we might understand the meaning of life.
Hey smart people, Joe here. You might know this already, but I’m a biologist, a doctor of biological sciences to be exact. So why would I need to call up a physicist to talk about life? Next to questions like why are we here? and where is here? What is life? is one of the biggest questions out there. People have asked this in various ways throughout history, often involving supernatural answers. It’s a relatively new idea to look only to nature for answers, inspired by the dawn of modern physics.
Every living thing that has ever existed is a product of the universe, and every process in the universe, from the swirling of galaxies to the fusion that makes stars shine, to life itself, follows the laws of physics. In textbooks, life is often described with a checklist of attributes: organized into cells, capable of growth, reproduction, and energy use. However, as you study, you realize there are exceptions. For example, crystals can grow and replicate, soap bubbles exhibit cellular order, and the ocean can maintain stability. Even a simple flame can reproduce, use energy, and grow, but we wouldn’t argue that a candle is alive.
Biology, as I’ve learned from talking to biologists, is the science of exceptions. This makes me think that what we learn in school about life is insufficient for truly describing what it is. I’m curious why a physicist would be interested in questions about life. Ultimately, cosmology and astronomy raise profound questions. When I discuss the size and scale of the universe, the first question I get is, “What does it all mean?” That word, meaning, doesn’t sound scientific, but it clearly exists in the universe because it means something to us.
Our great hero, Carl Sagan, once celebrated our civilization on “Cosmos,” showing how arts, music, and architecture are products of hydrogen atoms over 15 billion years of cosmic evolution. Life is fundamental to understanding the universe. Let’s look at life through Sagan’s perspective, as atoms doing interesting things, and see what we can learn.
This view of life as interesting physics goes back to physicist Erwin Schrödinger, who published “What Is Life?” in 1944. He asked if we could use physics and mathematics to describe how atoms form complex structures like us. This approach differs from Charles Darwin’s view, which focused on ecosystems. My conversation with Brian touched on ideas from physics that help us understand what makes life different from other atoms in the universe.
Energy is crucial for living things. We can define energy mathematically, but it’s also a conserved quantity. From the Big Bang to today, all energy that ever was still exists, changing forms but never disappearing. Since the beginning of time, energy has been getting more disordered, following the second law of thermodynamics. The universe started in a highly ordered state at the Big Bang and is moving toward a more disordered state.
This brings us to the question of how life fits into this. Life can be seen as a local complexity that emerges in the universe’s march toward disorder. While it may seem that complexity should decrease, local complexity can emerge as long as there’s a price paid in the environment. For example, a refrigerator creates order inside by expelling disorder outside.
The original order in the universe comes from the Big Bang, which allowed complex structures to exist over billions of years. Our Sun, like every star, is a tiny pocket of complexity in an increasingly disordered universe. It takes some of that original order and releases it over time as sunlight, which powers life on Earth.
Life absorbs sunlight energy, which is more ordered than the infrared radiation it emits. When a leaf absorbs sunlight, it uses that order to perform functions like splitting water and making sugars, returning less ordered energy as heat. In essence, while we live and process information, we contribute to the universe’s disorder.
Life runs on order that we borrow and then pay back. To understand how we use order to perform work, consider a water wheel. If water is moving in one direction, it can do work. Living things tap into sources of highly ordered energy, like protons, to power molecular machines. When we burn food, we borrow ordered energy to create a useful flow of protons.
One commonality among all living things is how they manage energy, particularly through proton pumping across membranes. This universal trait may provide clues about how life began, possibly in deep-sea hydrothermal vents where natural proton gradients exist.
The origin of life represents a transition from geochemistry to biochemistry, where chemistry becomes complex enough to store and copy information. Information is another key ingredient that separates living from nonliving things. DNA carries the instructions for life, allowing us to extract meaning and perform life’s functions.
Eventually, all living things will die, but life itself continues through the information stored in DNA. This information is shared across species, creating a vast genetic database on Earth. However, determining the first living thing is complex and somewhat semantic, akin to debates in astronomy about planetary classification.
Understanding life’s origin may be easier on Mars, where evidence could be more pristine due to less geological activity. Some believe that science can answer these profound questions about our existence. Living things are structures created by the laws of nature, just like stars. Understanding the origin of living things is a profound question.
In live shows, I often start with the question of what it means to live a finite life in an infinite universe, but I admit I don’t know the answer. When we distill life down to protons and energy movement, it can feel uncomfortable, but nature often challenges us. Embracing uncertainty can lead to excitement and curiosity, pushing us to explore the unknown.
If you enjoyed this episode and want to learn more about Professor Brian Cox and his science communication work, check him out through the links in the description. Thank you to Policygenius for supporting PBS. Policygenius is an insurance marketplace that combines experience with online tools and guidance to help you find coverage. For more information, click the link in the description.
And a huge thank you to everyone who supports the show on Patreon. If you’d like to find out more about how you can support the show, check the links in the description.
Before you go, consider these intriguing questions: What can someone who is completely blind teach you about video games? How did anime become a $25 billion industry? And why are some people putting underwear on goats? These questions and more are explored in “Subcultured,” a new documentary series from PBS. Check it out on “PBS Voices,” and let them know Joe sent you.
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This version maintains the essence of the original transcript while removing any informal language or potentially sensitive content.
Life – The condition that distinguishes living organisms from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death. – The study of life encompasses a wide range of biological disciplines, from molecular biology to ecology.
Energy – The quantitative property that must be transferred to an object in order to perform work on, or to heat, the object, often manifested in various forms such as kinetic, potential, thermal, and chemical energy. – In physics, energy conservation is a fundamental principle that states energy cannot be created or destroyed, only transformed from one form to another.
Complexity – The state or quality of being intricate or complicated, often used to describe systems with many components and interactions, such as biological organisms or ecosystems. – The complexity of cellular processes is a major focus of systems biology, which seeks to understand how various components interact to produce life.
Biology – The scientific study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy. – Advances in molecular biology have revolutionized our understanding of genetic diseases.
Physics – The natural science that studies matter, its motion and behavior through space and time, and the related entities of energy and force. – Quantum physics explores the behavior of matter and energy at the smallest scales, where classical physics no longer applies.
Consciousness – The state of being aware of and able to think about one’s own existence, sensations, thoughts, and surroundings, often studied in neuroscience and psychology. – The biological basis of consciousness remains one of the most intriguing questions in neuroscience.
DNA – Deoxyribonucleic acid, the molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses. – DNA sequencing has become a crucial tool in biology for understanding genetic variation and evolution.
Origins – The point or place where something begins, arises, or is derived, often used in the context of the origin of life or the universe. – The study of the origins of life on Earth involves interdisciplinary research across biology, chemistry, and geology.
Thermodynamics – The branch of physics that deals with the relationships between heat and other forms of energy, and, by extension, the relationships between all forms of energy. – The laws of thermodynamics are essential for understanding energy transfer in biological systems.
Organization – The structured arrangement of components in a system, often referring to the hierarchical structure of biological organisms or the systematic arrangement of physical systems. – The organization of cells into tissues and organs is a fundamental concept in developmental biology.
