In his very accurately formulated question ”How can the events in space and time which take place within the spatial boundary of a living organism be accounted for by physics and chemistry?”, Schrödinger focused on (at least) these significant points
’events’ Unlike non-living matter, living matter is dynamic, changing autonomously by its internal laws; we must think differently about it, including making hypotheses and testing them in the labs. Those laws are non-ordinary ’because the construction is different’, but its principles must not differ from the ones we already know.
’space and time’ Those characteristic points are significant changes resulting from processes that have material carriers, which change their positions with finite speed, so (unlike in classical mechanics) the events also have the characteristics ’time’ in addition to their ’position’. In biology, the spatiotemporal behavior is implemented by slow ion currents. The meticulous observations must describe the events by using special ’space-time’ coordinates (to distinguish it from the one used in theories of relativity, we call it ’time-space’ coordinate). In other words, instead of ’moments’ we must consider ’periods’ and define the ’events’ that define the beginning and the end of those periods.
’within the spatial boundary’ Laws of physics are usually derived for stand-alone systems, in the sense that the considered system is infinitely far from the rest of the world; also, in the sense that the changes we observe do not significantly change the external world, so its idealized disturbing effect will not change it. The ’construction’ also results in constraint forces. Furthermore, we must consider the issue of finite resources.
’accounted for by physics’[by extraordinary laws] We are accustomed to abstracting and testing a static attribute, and we derive the ’ordinary’ laws of motion for the ’net’ interactions. In the case of physiology, nature prevents us from testing ’net’ interactions. We must understand that some interactions are non-separable, and we must derive ’extraordinary’ laws. The forces are not unknown, but the known ’ordinary’ laws of motion of physics are about single-speed interactions.
’living matter’ To describe its dynamic behavior, we must introduce a dynamic description. Processes happen inside it, and we can observe some characteristic points. The internal processes also manifest in changing physical quantities which are inseparable from the ones the experimenter intended to change.
’yet tested in the physical laboratory’[including physiological ones] We test those ’constructions’ in laboratories, in their actual environment, and in ’working state’. As we did with inanimate matter, we must develop and gradually refine the testing methods as well as the hypotheses. Moreover, we must not forget that our methods refer to ’states’, and this time, we test ’processes’. Not only in measuring them (including measurement design and evaluation) but also in handling them computationally, we need more or less different thinking and algorithms.
Quotation: “in thinking about the physical basis of the action potential perhaps the most important thing to do at the present moment is to consider whether there are any unexplained observations which have been neglected in an attempt to make the experiments fit into a tidy pattern” [87], page 70.