Conlin 858 M Presentation

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Some philosophers have doubted the role of causation in science. Here I defend the position that causation is part of mature science.

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Conlin 858 M Presentation

  1. 1. Causation: Not Just for Common Folk<br />Luke Conlin<br />1<br />
  2. 2. PREFACE:The importance of mechanism in science is important to convey in science education<br />2<br />
  3. 3. Many philosophers have doubted the need for causal talk in science…<br />3<br />“…the reason why physics has ceased to look for causes is that, in fact, there are no such things. The law of causality…is a relic of a bygone age, surviving, like the monarchy, only because it is erroneously supposed to do no harm.” (Russell, 1913)<br />
  4. 4. …but the function of science seems to hinge upon causal notions.<br />4<br />
  5. 5. Norton says causal talk amounts to folk science, like “force” or “caloric”…<br />5<br />
  6. 6. …but I will show three ways that causal talk contributes to mature science<br />6<br />
  7. 7. I conclude that causation can (and does) play a central role in science.<br />7<br />
  8. 8. Causation can put “direct” causal restrictions on theories<br />As enforced by mathematically expressible principles<br />8<br />
  9. 9. Causal principles can underwrite theoretical derivations and empirical tests<br />9<br />
  10. 10. Fluctuation Theorem: using causality to derive 2nd law of thermodynamics<br />10<br />Evans, D. J., & Searles, D. J. (1996). Causality, response theory, and the second law of thermodynamics. Physical Review E, 53(6), 5808-5815.<br />
  11. 11. Causal Dynamical Triangulations: using causality to recover 4-D spacetime from quantum gravity<br />“Restricted by Principle of Causality: When physicists add the rule that adjacent triangles must have a consistent notion of time—so that cause and effect are unambiguously distinguished—the outcome is a four-dimensional space­time that looks tantalizingly like our universe. (below)”<br />11<br />Jurkiewicz, J., Loll, R., Ambjorn, J., & Concepts, K. (2008). Using causality to solve the puzzle of quantum space-time. Scientific American.<br />
  12. 12. Causation can put “indirect” restrictions on theories<br />By providing warrant for throwing out spurious solutions<br />12<br />
  13. 13. There are more mathematical solutions than there are physical ones<br />13<br />You throw a rock into the air at 10 m/s from 1 m above the ground. How long will it take to hit the ground?<br />Answer #1: <br /> 2.1 seconds<br />Answer #2:<br /> -.096 seconds<br />physically unreasonable!<br />
  14. 14. There are always more solutions to equations than obtain in the real world<br />Banks, T. (1985). T C P, QUANTUM GRAVITY, THE COSMOLOGICAL CONSTANT AND ALL THAT... Nuclear Physics B, 249, 332–360.<br />Burke, W. L. (1970). Runaway solutions: remarks on the asymptotic theory of radiation damping. Physical Review A, 2(4), 1501–1505.<br />Goldberger, M. L., & Treiman, S. B. (1958). Decay of the pi meson. Physical Review, 110(5), 1178–1184.<br />Ishak, M., Chamandy, L., Neary, N., & Lake, K. (2001). Exact solutions with w modes. Physical Review D, 64(2), 24005.<br />Magueijo, J., Albrecht, A., Coulson, D., & Ferreira, P. (1996). Doppler peaks from active perturbations. Physical Review Letters, 76(15), 2617–2620.<br />Mason, J. K., Lund, A. C., & Schuh, C. A. (2006). Determining the activation energy and volume for the onset of plasticity during nanoindentation. Physical Review B, 73(5), 54102.<br />Neary, N., Ishak, M., & Lake, K. (2001). The Tolman VII solution, trapped null orbits and w-modes. Arxiv preprint gr-qc/0104002.<br />Simon, J. Z. (1990). Higher-derivative Lagrangians, nonlocality, problems, and solutions. Physical Review D, 41(12), 3720–3733.<br />
  15. 15. Causality can provide warrant for rejecting spurious solutions<br />Clapp, R. E. (1968). Enforcing causality in numerical solutions of Maxwell&apos;s equations. Proceedings of the IEEE, 56(3), 329-329.<br />Fowler, M., & Maki, K. (1967). Conditions for Bound States in a Superconductor with a Magnetic Impurity. Physical Review, 164(2), 484-488.<br />Peebles, G. H., & Clapp, R. E. (1968). Comments on&quot; Enforcing causality in numerical solutions of Maxwell&apos;s equations. Proceedings of the IEEE, 56(8), 1365-1365.<br />Pi, T. W., Hong, I. H., Cheng, C. P., & Wertheim, G. K. (2000). Surface photoemission from Si (100) and inelastic electron mean-free-path in silicon. Journal of Electron Spectroscopy and Related Phenomena, 107(2), 163-176.<br />Wismer, M. G., & Ludwig, R. (1995). An explicit numerical time domain formulation to simulate pulsed pressure waves in viscous fluids exhibiting arbitrary frequency power law attenuation. Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, 42(6), 1040-1049.<br />Worster, M. G. (2006). Solidification of an alloy from a cooled boundary. Journal of Fluid Mechanics Digital Archive, 167, 481-501.<br />15<br />
  16. 16. Norton’s dome is a prime example of using causation to reject spurious solutions<br />16<br />A ball of unit mass sits at rest on top of a dome. What happens?<br />initial conditions:<br />initial conditions:<br />Answer #1: Nothing.<br /> r(t) = 0, for all T<br />Answer #2: It slides down the side after an arbitrary time T<br /> r(t) = 0, for t ≤ T<br /> r(t) = (1/144)(t-T)4 for t ≥ T<br />physically unreasonable!<br />
  17. 17. Causation can put “semantic” restrictions on scientific theories<br />By constraining the directionality of the causal model & thus the kinds of problems that can be solved with it.<br />17<br />
  18. 18. Pinker shows how causation can put semantic restrictions on language<br />Foregrounding is syntactical…<br />…But Foregrounding is semantically constrained<br />18<br />
  19. 19. Lorentz causal model places semantic restrictions on physics<br />“A-Problems”<br />“B-Problems”<br />19<br />
  20. 20. Einstein’s derivation of G.R. hinged on Lorentz causal model<br />20<br />OP*(POTENTIAL)=SOURCE<br />Core Operator, Entwurf Operator, <br />Ricci Tensor, <br />Einstein Tensor, etc…<br />(Renn et al., 2007)<br />
  21. 21. Have we satisfied the first horn of Norton’s argument?<br />21<br />
  22. 22. Potential objection: no universally exceptionless principle of causation…<br />22<br />
  23. 23. Norton calls causation “folk science” because it makes no real difference<br />23<br />We know that in classical physics vacua have no active powers, yet we routinely attribute to them<br />the ability to draw things in—to suck.<br />
  24. 24. …but I have shown three ways that causation is more than folk science.<br />24<br />
  25. 25. THANK YOU!!<br />Thanks to Lindley Darden & all of you in PHIL 858m for hearing me out!<br />Thanks to Matthias Frisch, as well as the UMD physics education research group for helpful discussions<br />25<br />
  26. 26. References<br />26<br />Clapp, R. E. (1968). Enforcing causality in numerical solutions of Maxwell&apos;s equations. Proceedings of the IEEE, 56(3), 329-329.<br />Fowler, M., & Maki, K. (1967). Conditions for Bound States in a Superconductor with a Magnetic Impurity. Physical Review, 164(2), 484-488.<br />Peebles, G. H., & Clapp, R. E. (1968). Comments on&quot; Enforcing causality in numerical solutions of Maxwell&apos;s equations. Proceedings of the IEEE, 56(8), 1365-1365.<br />Pi, T. W., Hong, I. H., Cheng, C. P., & Wertheim, G. K. (2000). Surface photoemission from Si (100) and inelastic electron mean-free-path in silicon. Journal of Electron Spectroscopy and Related Phenomena, 107(2), 163-176.<br />Renn, J., Janssen, M., Norton, J. D., Sauer, T., Stachel, J., Divarci, L., et al. (2007). The Genesis of General Relativity. The Genesis of General Relativity, in 4.<br />Russell, B. (1957). Mysticism and logic. Garden City, N.Y.: Doubleday.<br />Wismer, M. G., & Ludwig, R. (1995). An explicit numerical time domain formulation to simulate pulsedpressure waves in viscous fluids exhibiting arbitrary frequency powerlaw attenuation. Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, 42(6), 1040-1049.<br />Worster, M. G. (2006). Solidification of an alloy from a cooled boundary. Journal of Fluid Mechanics Digital Archive, 167, 481-501.<br />

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