1. Introduction

    1. Background

    2. Some hints

  2. How to understand circadian clock, magneto-sensing and gravitaxis in TGD framework?

    1. Basic problems and basic principles

    2. Could circadian rhytms be analogous to EEG rhythms in TGD Universe?

    3. Trying to figure out the general mechanism

    4. More concrete model for the mechanism of magnetoreception and circadian rhythms

    5. Gravitaxis and $h_{eff

  3. TGD view about magneto-reception and circadian rhythm: few years later

    1. Magneto-receptor as quantum compass

    2. The simplest pace-keeper mechanism does not explain the slowing down of the circadian rhythm

    3. A model based on cell membrane as a generalized Josephson junction (GJJ)

    4. Quantitative formulation of the model

  4. Appendix: What TGD is?

    1. Why TGD?

    2. TGD and GRT

    3. TGD and string models

    4. TGD based ontology

    5. TGD, quantum measurement theory, and consciousness