The Physics of Fire Explained by Richard Feynman

Описание: In The Physics of Fire, Richard Feynman brings his signature clarity, curiosity, and enthusiasm to one of the most familiar yet fascinating phenomena in nature: fire. What appears to be a simple flame becomes, under Feynman’s explanation, a rich interplay of physics, chemistry, and energy transformation.

Feynman begins by stripping away the everyday assumptions we have about fire. Rather than treating it as a “thing,” he explains that fire is a process—a rapid chemical reaction known as combustion. This reaction occurs when a fuel, such as wood or gas, combines with oxygen in the air, releasing energy in the form of heat and light. Fire, therefore, is not matter itself, but the visible evidence of energy being released as chemical bonds rearrange.
He delves into the molecular scale, describing how atoms in the fuel are bound together and how these bonds store energy. When combustion begins, oxygen molecules collide with fuel molecules at high enough temperatures to break existing bonds. New bonds then form—primarily carbon dioxide and water—and these new bonds are more stable. The excess energy from this rearrangement is emitted as heat and light, which is what we perceive as flame.
Feynman also explains why flames have different colors and shapes. The color of a flame depends on the temperature and the specific atoms involved in the reaction. For example, a blue flame indicates complete combustion and high temperatures, where excited molecules emit light at specific wavelengths. Yellow or orange flames, on the other hand, often come from glowing soot particles heated until they radiate light. Through this, Feynman shows how fire becomes a natural laboratory for understanding atomic behavior and radiation.
Another key concept he explores is the role of heat feedback. Fire sustains itself because the heat it produces ignites more fuel, creating a self-perpetuating cycle as long as fuel and oxygen are present. This leads naturally to the classic “fire triangle”: fuel, oxygen, and heat. Remove any one of these, and the fire goes out. Feynman uses this idea to connect everyday experiences—like blowing out a candle or smothering a fire—with fundamental physical principles.
Feynman also touches on the flow of energy in fire, emphasizing that the energy released was originally stored elsewhere, often from the Sun. In the case of burning wood, the energy was captured millions of years earlier through photosynthesis, stored in chemical bonds, and released again through combustion. Fire thus becomes part of a much larger cosmic story, linking sunlight, plant growth, chemistry, and human technology.
Throughout the explanation, Feynman’s approach is not merely to provide facts, but to cultivate scientific thinking. He encourages curiosity about ordinary phenomena and demonstrates how deep understanding arises from asking simple questions: Why does fire rise? Why does it need oxygen? Why does it stop? His explanation of fire exemplifies his belief that physics is not about memorizing equations, but about understanding how nature actually works.
Ultimately, The Physics of Fire is a reminder that even the most common experiences can reveal profound truths about the universe. Through Feynman’s lens, fire becomes more than a flame—it becomes a gateway to understanding atoms, energy, and the fundamental laws that govern the physical world.