J. Rogers, SE Ohio
Lesson 1 (Deconstruction): "Constants are bookkeeping."Lesson 2 (Reconstruction): "The real physics is in the simple ratios."Lesson 3 (Generation): "All simple ratios are interconnected in a predictive grid."
Materials:
Projector to display the planck_equivalence_grid.html file. Handout with a blank version of the grid for students to fill in.
Lesson Structure & Instructor Notes
Quickly recap the previous lessons. "We've proven that constants are bookkeeping and that the real physics lies in simple, dimensionless ratios." Write the key invariant laws from the last class on the board:
E_nat = m_nat = f_nat = T_nat = 1/l_nat = E_nat = p_nat = F_nat"But look at this. If Energy is equivalent to Mass, and Energy is equivalent to Frequency, what does that imply about Mass and Frequency?" Guide the class to the transitive property: m_nat = f_nat. "This means they are all part of a single, unified Chain of Equivalence . This is the deep structure of the universe."Write the full chain on the board (or reveal it on the slide): T/T_P = f·t_P = m/m_P = l_P/l = E/E_P = p/p_P = F/F_P
= some process in space time that scales all our measurements in lock step with each other"This chain is the 'source code' of reality. Every fundamental law in physics is just a statement comparing two links in this chain." These are scaled to si units using the non reduced planck units and with the tautology of measurement. Every pair of equivalences is a real law.
This section builds the final conceptual bridge. It moves from a collection of individual ratios to a single, interconnected system. The term "Chain of Equivalence" is powerful and intuitive. It emphasizes the interconnectedness. You are establishing a single, foundational axiom from which all the laws will be derived. This is a moment of profound simplification.
"If every law is just a pairwise comparison of links in this chain, we can organize them. What happens if we make a multiplication table, but for physical laws?" Display the planck_equivalence_grid.html file on the projector. Point out the rows and columns (T, f, m, l, E, p, F...). "This is the Periodic Table of Physics. Each cell represents the physical law that connects the quantity in the row with the quantity in the column." Walk through a few known cells (highlighted in green).Row: Mass (m), Column: Energy (E). "What connects mass and energy? We look at the cell." Point to E = mc². "It's right there. This grid organizes what we already know."Row: Length (l), Column: Momentum (p). "What connects length (wavelength) and momentum?" Point to p = h/l. "The de Broglie relation. It lives here."
Now, point to a predicted cell (highlighted in yellow).Row: Temperature (T), Column: Mass (m). "The grid is telling us theremust be a direct relationship between Temperature and Mass. The structure demands it. Has anyone heard of the 'Temperature-Mass Law'?" (They haven't)."It doesn't have a famous name, but the law is real. It's been sitting here for a century, waiting for us to ask. Let's derive it."
The "Periodic Table" analogy is the central metaphor. It immediately conveys the idea of organization, structure, and predictive power. By showing how known laws fit perfectly into the grid, you build credibility for the structure. The dramatic reveal of the "predicted" but unnamed laws is the hook. It shows the students that the grid is not just a filing cabinet for old laws, but a machine for generating new ones.
Hand out the blank grid worksheet. "We are now going to do what Mendeleev did. We are going to use the structure of the table to predict what must exist in the empty spaces." Demonstrate the algorithm for the T-m cell from the previous step. Write the Equivalence. "From our chain, we know T_nat = m_nat.""Multiply both sides by 1, T_nat (1) = m_nat (1)."- "One is different ratios, T_nat (T_P/T_P) = m_nat (m_P/m_P)."
This is the tautology of measurement. We knowT_nat = T / T_Pandm_nat = m / m_P. Let's substitute those definitions back into our invariant law. - Scale to SI units, T/T_P = m/m_P
Solve for the Target. "Let's solve for T in SI units: T = m · (T_P / m_P)."Find the Constant. "The constant is the term in parenthesis. Let's substitute the Planck definitions: T_P / m_P = (k_B/h · t_P)⁻¹ / (h/c² · t_P)⁻¹... this is messy. Let's do it the easy way. What are the units of T_P/m_P? [K/kg]. What combination of c, h, G, k_B gives us K/kg? The answer is c²/k_B." (Or use the dimensional imbalance algorithm).Write the Final Law. T = m · c²/k_B. "We have just derived a physical law."
Assign students, in pairs, to derive the law for a specific "predicted" cell. For example: "You two, find the law that connects Force and Frequency. You two, find Thermal Momentum." Have teams present their derived laws.
This is the active discovery phase. The students are no longer just analyzing; they are generating physics .The algorithm is simple and powerful. It shows that deriving these "new" laws is not an act of creative genius, but a mechanical process of extraction . The law is already there in the structure.This solidifies the idea that physics is not a collection of disconnected facts, but a single, coherent mathematical structure.
Bring the full, color-coded grid back up on the screen. "Look at this grid. Out of 21 fundamental relationships, we only gave famous names to about 8 of them. The rest were always there, implied by the structure, but we never bothered to look because we were focused on the 'known' laws as separate discoveries." "This is the true map of physics. It shows us not only the territory we have explored but also all the territory that is waiting. Some of these predicted laws, like p=hf/c, turn out to be things we already knew but just wrote differently. Others, like the relationships involving Force, might point to new avenues of research." Deliver the final takeaway: " A hundred years ago, we were explorers wandering in a forest, stumbling upon amazing discoveries (E=mc², E=hf) and thinking they were all unique. Today, you have seen the satellite map of the entire forest. You see that all the paths are connected. You see the structure. Your job is no longer to be an explorer. Your job is to be a cartographer. To map this structure, understand it, and use it to navigate anywhere you want to go. "
This conclusion reframes the history of science. The great "discoveries" are recast as the first explorations of a territory that the students can now see in its entirety. The "Explorer vs. Cartographer" analogy is a powerful redefinition of the student's role. It gives them a sense of mastery and higher perspective. They are not just learning the old discoveries; they are learning the system that generates all discoveries, past and future.This lesson completes the journey. It leaves the students with a tangible, predictive tool that embodies the entire philosophy of the three-class arc. They now have their own "LawForge."
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