The Frictionless Current: Lesson Plan
Overview
This lesson uses the discovery of superconductivity to explore how observation precedes explanation in science, and how "impossible" results at the frontier of physics become transformative technologies. Students compare Onnes's 1911 discovery with the 2025 Dirac fluid observation in graphene to understand how scientific paradigms evolve.
Subject areas: Physics, Chemistry, History of Science, Materials Science Grade levels: 10-12, AP Physics, AP Chemistry Duration: 1-2 class periods (45-90 minutes)
Essential Questions
- What happens when experimental results contradict established theory?
- Why did it take 46 years to explain superconductivity after it was observed?
- How do "laboratory curiosities" become technologies that change the world?
- What role does instrumentation play in scientific discovery?
Learning Objectives
Students will be able to:
- Explain the basic concept of electrical resistance and why superconductivity was unexpected
- Describe the role of extreme conditions (cryogenic temperatures) in revealing new physics
- Trace the path from observation to explanation to application in superconductivity
- Compare historical and contemporary examples of laws of physics being violated
- Evaluate the relationship between technological capability and scientific discovery
Key Vocabulary
- Superconductivity: Zero electrical resistance in certain materials below a critical temperature
- Cryogenics: The science of producing and studying very low temperatures
- Wiedemann-Franz law: The ratio of thermal to electrical conductivity is constant for metals
- Dirac fluid: An exotic state where electrons flow collectively as a nearly frictionless liquid
- BCS theory: The quantum mechanical explanation of superconductivity (1957)
- Quark-gluon plasma: The primordial state of matter in the early universe
Activities
Activity 1: The Prediction Game (15 min)
Present students with the 1911 scenario. Two theories exist:
- Kelvin: resistance increases to infinity near absolute zero
- Dewar: resistance decreases smoothly to a small residual value
Ask students to vote on which prediction they think is correct, and explain their reasoning using what they know about electron behavior. Then reveal: both were wrong. Resistance dropped to exactly zero. Discuss why neither theory predicted this.
Activity 2: From Curiosity to Technology (20 min)
Create a timeline of superconductivity applications:
- 1911: Discovery (laboratory curiosity)
- 1957: BCS theory (first explanation)
- 1960s: Superconducting magnets for particle accelerators
- 1977: First MRI scan of a human body
- 1990s: Maglev train prototypes
- 2019: Google claims quantum supremacy using superconducting qubits
Discuss: at each stage, could anyone have predicted the next application? What does this suggest about dismissing "impractical" discoveries?
Activity 3: Breaking the Law (20 min)
Compare the two law-breaking discoveries: | | Superconductivity (1911) | Dirac Fluid (2025) | |---|---|---| | Law violated | Expected resistance behavior | Wiedemann-Franz law (1853) | | Material | Mercury | Graphene | | Temperature | 4.2 Kelvin | Cryogenic | | Magnitude of violation | Infinite (zero resistance) | 200x deviation | | Explanation arrived | 46 years later (BCS, 1957) | Still emerging | | Known applications (so far) | MRI, LHC, maglev, quantum computing | Quantum sensors (theoretical) |
Activity 4: The Notebook Entry (15 min)
Show students Onnes's actual notebook page with "Kwik nagenoeg nul." Discuss:
- Why five words in Dutch changed physics
- The importance of careful record-keeping in science
- How the notebook was "deciphered" a century later
- What would the modern equivalent look like? (A screenshot of a data plot? A Slack message?)
Assessment Options
- Essay: "When electrons start behaving in ways that break the textbook, the textbook is about to get a new chapter." Evaluate this claim using at least two examples from the history of physics.
- Research project: Investigate one application of superconductivity (MRI, maglev, quantum computing) and trace the chain of discoveries that made it possible.
- Prediction exercise: Based on the pattern of superconductivity (observation → decades of mystery → transformative applications), write a speculative but scientifically grounded prediction for what the Dirac fluid in graphene might enable by 2070.
Extension Activities
- Research high-temperature superconductors (discovered 1986 by Bednorz and Muller). Why was this discovery so shocking, and why hasn't it led to room-temperature superconductors yet?
- Investigate the role of graphene in modern materials science. How is it made? What other unusual properties does it have?
- Compare Onnes's cryogenics lab (1904) with a modern materials science lab. What has changed about how frontier science is done?