Do Laws of Physics Cause or Describe?
Audio Brief
Show transcript
In this conversation, biologist Denis Noble explores whether the laws of physics are the causal forces of nature or simply mathematical descriptions of how the universe behaves.
There are three key takeaways. First, physical laws describe observations rather than cause them. Second, we must distinguish between actual forces and the equations representing them. Third, emergent laws in biology and thermodynamics are highly reliable for practical engineering.
While physicists treat forces like gravity as causes, equations remain descriptive tools. A pragmatic approach focuses on predictive accuracy rather than philosophical debates. This allows scientists to use high-level system rules with confidence to solve real-world problems.
Ultimately, balancing practical application with deep inquiry maximizes the utility of scientific models.
Episode Overview
- This episode explores a fundamental philosophical question in science: do the laws of physics act as the causal forces behind natural phenomena, or do they simply describe how the universe behaves?
- Featuring renowned biologist and physiologist Denis Noble, the discussion navigates the tension between mathematical description and physical causation.
- The conversation helps viewers understand how scientists view the utility of physical laws, balancing pragmatic application in engineering with deep philosophical inquiry.
Key Concepts
- Descriptive Nature of Physics: The primary function of physical laws, dating back to Galileo, is to describe observations, particularly through the language of mathematics.
- Causality vs. Description: While equations (like those of Newton, Einstein, or Maxwell) are descriptive tools, the physical forces themselves (like gravity or electromagnetism) are intuitively perceived as the "causes" of actions in the real world.
- Emergent Laws: Laws at higher levels of organization, such as thermodynamics or biological metabolism, are emergent rather than fundamental. They are caused by underlying physical effects but are still accurately described by these higher-level laws.
- Pragmatic Realism: From an engineering perspective, the ultimate validation of physical laws is their extreme accuracy and reliability in predicting real-world outcomes, regardless of the underlying philosophical debate about causality.
Quotes
- At 0:10 - "There's no question whatever that they describe it... in most cases they can be discovered mathematically." - explaining the fundamental descriptive and mathematical nature of physical laws pioneered by Galileo.
- At 0:49 - "As a physicist, it feels to me that gravity causes things to happen, electromagnetism causes things to happen... and those are described by Newton's equations, Einstein's equations, Maxwell's equations." - highlighting the pragmatic perspective of treating physical forces as causes while using equations as descriptions.
- At 1:40 - "My own way of thinking about it is that they are caused by physical effects which we can describe by those laws." - clarifying the relationship between physical realities (the effects/causes) and the human-derived laws that represent them.
Takeaways
- Adopt a pragmatic approach when utilizing scientific models: focus on their descriptive accuracy and predictive power rather than getting bogged down in ontological debates about what "causes" reality.
- Maintain a clear distinction between a physical force itself (e.g., gravity) and the mathematical representation of that force (e.g., Einstein's equations).
- Use emergent laws (such as those in thermodynamics or biology) with confidence, recognizing that higher-level system rules are highly reliable and practical for real-world application and engineering despite not being "fundamental" laws.
