Peter Kahl · Lex et Ratio
Research
Research in quantum information, quantum error correction and the philosophy of physics, examining the limits of observation, representation and scientific inference.
Research programme
Representation, observation and physical knowledge.
The central question is what a system can establish about physical conditions from its observations. Accurate predictions and reliable records do not necessarily provide the distinctions needed to identify an underlying state or certify that its representation is adequate.
The research combines philosophical analysis, formal models and computational experiments. It develops Representational Sealing Theory (ReST) and investigates observational limits through quantum information, quantum error correction and selected problems in the foundations of physics.
Theoretical framework
Representational Sealing Theory
Representational Sealing Theory (ReST) examines conditions under which a system can successfully represent a target without possessing the resources needed to certify that its representation is adequate. It distinguishes reference, representation and certification as separate achievements.
A central distinction is between a target identified by its role and the underlying condition that realises that role. Different realisers may support the same accessible structure, leaving the system unable to establish which one obtains.
This limitation is relative to the operative representational law. ReST does not claim that reality is generally unknowable or that successful representations are unreliable. It identifies the conditions under which adequacy cannot be certified from within a specified regime.
Formal epistemology · Observability
Interface Closure and the Limits of Inquiry
An observation interface determines which distinctions between underlying conditions become accessible. If two conditions generate identical distributions of observations, no procedure using only those observations can distinguish them reliably. More sophisticated downstream inference cannot recover information the interface never transmitted.
What Conceptual Change Cannot Recover develops this result through formal analysis and computational examples. It also examines approximate closure, where observation distributions differ but discrimination may require substantial evidence. Quantitative bounds clarify the limits of adaptive inquiry and certification.
These limits apply to specified interfaces and assumptions. New measurement channels or interventions may make previously inaccessible distinctions observable.
Quantum information
Quantum Information and Physical Distinguishability
Quantum information theory provides a precise mathematical setting for investigating the relationship between physical states, measurements and accessible information. What an observer can establish depends on the available quantum channels, measurement procedures and permitted operations.
Research examines state discrimination, observational equivalence and the relationship between information acquisition and disturbance. It distinguishes limits imposed by a particular measurement architecture from those arising from more general constraints of quantum theory.
Quantum error correction · Formal and computational research
Quantum Error Correction and Functional Blindness
Quantum error correction (QEC) protects encoded information by detecting faults without directly measuring the logical quantum state. Its measurement procedures must reveal enough to support recovery while preserving the information they protect.
In Blind by Design, Kahl distinguishes three forms of blindness: limitations of the interpretive model, limitations of the available observations, and limitations required to preserve a system's function. Formal results examine what function-preserving inquiry can reveal about an unknown encoded state, including approximate bounds on distinguishability.
Computational investigations use quantum error-correction models and Python simulations to examine syndrome statistics, correlated errors, decoder assumptions and recovery performance. The practical question is whether a diagnostic limitation calls for a better decoder, a different measurement architecture, or recognition of a constraint intrinsic to protecting quantum information.
Philosophy of physics · Developing research
Joint Physical Descriptions and Their Limits
When two successful physical descriptions resist combination, several questions must be separated: whether a mathematically consistent joint description exists, whether it is physically admissible, and what evidence could certify its adequacy.
Developing research investigates these distinctions through established cases, including quantum contextuality, before considering the relationship between quantum mechanics and general relativity. Particular questions concern time, reference frames, clocks and the physical distinctions accessible to observers.
The objective is to clarify the meaning and evidential consequences of claims about theoretical incompatibility, not to claim an established unification of quantum mechanics and general relativity.
Philosophy of physics · Developing research
Physical Parameters and the Scope of Insensitivity
A parameter may be physically meaningful while remaining inaccessible to a particular class of experiments. Its absence from one set of observables does not establish that it is irrelevant to every physically admissible process.
Developing work investigates this distinction through rephasing invariance and neutrino physics. If neutrinos are Majorana particles, additional phases in the lepton mixing matrix cancel from ordinary oscillation probabilities, although that cancellation alone does not establish their irrelevance to other processes.
The broader question is how claims of unobservability or physical redundancy depend on the transformations, processes and observables over which they are asserted.
Earlier research
Technology, Agency and Institutional Governance
Earlier work examined technological capability, artificial agency, evaluative authority and institutional accountability. It investigated how organisations recognise new capabilities, establish standards and remain answerable when consequential decisions depend on complex technical systems.
This research draws on experience in semiconductor engineering, international technology businesses and law. It remains part of the scholarly record but is no longer the principal focus of the current programme.