Where does tunneling collide?

In quantum mechanics, tunneling is the passage of a particle through a region that its energy would forbid it to cross under classical rules, because the particle's wavefunction does not stop at the barrier but continues through it with reduced amplitude. Hund's 1927 Zur Deutung der Molekelspektren. III. first treated this barrier penetration, in the flipping of a molecule between two mirror-image shapes separated by an energy hump. Gamow's 1928 Zur Quantentheorie des Atomkernes and Gurney and Condon's 1929 Quantum Mechanics and Radioactive Disintegration applied the same idea to explain how an alpha particle escapes a nucleus. The referent is a physical event at the scale of atoms, scaled as a probability of crossing, and it has nothing to do with value drained from a firm, one network protocol wrapped inside another, or a tube linking two cells.[1][2][3]

Unit

A single barrier-crossing event, scaled as a transmission probability between 0 and 1

Recovery means

Not applicable

Measured by

Inferred from tunneling current, decay rates, or transmission spectra, and modelled from the barrier's height and width

In computer networking, tunneling is carrying one protocol's traffic across a network that does not natively support it, by wrapping each packet inside a packet of the carrier protocol and unwrapping it at the far end. Provan's 1991 Tunneling IPX Traffic through IP Networks (RFC 1234) set out an early instance, placing IPX datagrams inside UDP packets so they could cross an IP internet. Hanks, Li, Farinacci, and Traina's 1994 Generic Routing Encapsulation (RFC 1701) generalised the method to any payload over any delivery protocol. The referent is a data-handling technique inside communication equipment, counted in packets and headers, and it is unrelated to a particle crossing an energy barrier, an owner draining a company, or a bridge between living cells.[4][5]

Unit

One encapsulated packet travelling through the tunnel between its two endpoints

Recovery means

Not applicable

Measured by

Observed by packet capture and by counting encapsulated frames, overhead bytes, and throughput at each tunnel endpoint

In corporate finance, tunneling is the transfer of assets or profits out of a company for the benefit of those who control it, at the expense of minority shareholders. Johnson, La Porta, Lopez-de-Silanes, and Shleifer's 2000 Tunneling named the practice, drawing on European cases, and separated outright removal of assets from subtler forms such as transfer pricing, dilutive share issues, and self-dealing transactions. The referent is a governance and ownership problem inside a firm, gauged in diverted value and lost minority returns, and it bears no relation to a particle passing an energy barrier, packets wrapped for transport, or a physical tube between cells.[6]

Unit

A single value transfer diverted from the firm to its controlling party

Recovery means

Not applicable

Measured by

Estimated from related-party transactions, share-price reactions to expropriation events, and ownership and control structures

In cell biology, a tunneling nanotube is a thin, membrane-bound tube that stretches between two animal cells and forms an open channel along which organelles and other cargo can pass directly from one cell to the other. Rustom, Saffrich, Markovic, Walther, and Gerdes's 2004 Nanotubular Highways for Intercellular Organelle Transport first described these structures and showed vesicles moving through them between cultured cells. The referent is a physical connection built by living cells, measured in nanometres of diameter and micrometres of length, and it is not a particle crossing a barrier, a wrapped network packet, or value drained from a company.[7]

Unit

One nanotube bridging a pair of cells, described by its diameter and length

Recovery means

Not applicable

Measured by

Visualised by fluorescence and electron microscopy, and quantified by tube diameter, length, and the frequency of connected cell pairs