Graduate Research Course
Feline Biophysics & Biochemistry
From the righting reflex to Turing coat patterns — biomechanics, sensory physics, obligate carnivore metabolism, and the molecular basis of feline life.
Key Equations of Feline Biophysics
Righting Reflex
\( I_1\omega_1 + I_2\omega_2 = 0 \quad \text{(zero angular momentum)} \)
Tapetum Lucidum
\( I_{retinal} = I_0(1 + R \cdot e^{-2\alpha d}) \)
Purring Frequency
\( f = \frac{1}{2\pi}\sqrt{\frac{k_{laryngeal}}{m_{membrane}}} \approx 25\text{–}50\,\text{Hz} \)
Metabolic Scaling
\( P = P_0 M^{0.75} \quad \text{(Kleiber's law)} \)
Turing Pattern
\( \frac{\partial u}{\partial t} = D_u \nabla^2 u + f(u,v) \)
Predator-Prey Capture
\( E_{capture} = \frac{1}{2}m v_{pounce}^2 \cdot P_{success}(\theta) \)
About This Course
The domestic cat (Felis catus) is a masterwork of evolutionary engineering. A falling cat can right itself in under 0.3 seconds with zero initial angular momentum — a feat that puzzled physicists from Maxwell to Kane. A cat's tapetum lucidum reflects photons back through the retina, effectively doubling sensitivity in near-total darkness. Its purr oscillates at 25–50 Hz, a frequency range associated with bone-density preservation and tissue healing.
This course dissects the physics and biochemistry behind every aspect of feline biology: the biomechanics of the righting reflex and retractable claws, the optics of slit pupils and night vision, the obligate carnivore metabolism that demands taurine and arachidonic acid, and the Turing reaction-diffusion patterns that paint tabby stripes and calico patches.
Every module includes thorough MathJax derivations, SVG diagrams, and Python simulations. Cross-links to our Avian Biophysics and Tree Biophysics courses for comparative biology.
Nine Modules
M0
Physical Foundations
Scaling laws, allometry, semi-digitigrade mechanics
M1
Locomotion & Biomechanics
Righting reflex, gallop, claw retraction
M2
Vision & Sensory Biophysics
Tapetum lucidum, slit pupil, whiskers
M3
Purring & Vocalization
Laryngeal oscillation, osteogenic effects
M4
Metabolism & Thermoregulation
Obligate carnivore, taurine, gluconeogenesis
M5
Olfaction & Chemical Sensing
Jacobson’s organ, Flehmen, catnip
M6
Coat & Pigmentation
MC1R, agouti, Turing patterns
M7
Neuroscience & Behavior
Sleep, vestibular, predatory circuits
M8
Evolution & Domestication
Felis lybica, breed genomics
Recommended Textbooks
- [1] Bradshaw, J.W.S. (2013). Cat Sense: The Feline Enigma Revealed. Allen Lane.
- [2] Turner, D.C. & Bateson, P. (2014). The Domestic Cat: The Biology of its Behaviour, 3rd ed. Cambridge University Press.
- [3] Vogel, S. (2003). Comparative Biomechanics: Life's Physical World, 2nd ed. Princeton University Press.
- [4] Murray, J.D. (2003). Mathematical Biology II: Spatial Models and Biomedical Applications. Springer. (Turing patterns, Chapter 2–3)
- [5] Case, L.P. (2003). The Cat: Its Behavior, Nutrition, and Health. Iowa State Press.
- [6] Kitchener, A.C. et al. (2017). A revised taxonomy of the Felidae. Cat News, Special Issue 11.