When a branch of science based on incoherent, false or phoney theories is serving a useful but non-scientific purpose it may be kept-going by continuous transfusions of cash from those whose non-scientific interests it serves.

For example, if a branch of pseudo-science based on a phoney theory is nonetheless valuable for political purposes (e.g. to justify a government intervention such as a new tax) or for marketing purposes (to provide the rationale for a marketing campaign) then real science expires and a 'zombie science' evolves.

Zombie science is science that is dead but will not lie down. It keeps twitching and lumbering around so that (from a distance, and with your eyes half-closed) zombie science looks much like real science.

But in fact the zombie has no life of its own; it is animated and moved only by the incessant pumping of funds.

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Real science is coherent - and testable (testing being a matter of checking coherence with the result of past and future observations).

Real science finds its use, and gets its validation, from common sense evaluation and being deployed in technology.

Real science is validated (contingently) insofar as it leads to precise predictions that later come true; and leads to new ways of solving pressing problems and making useful changes in the world.

But zombie science is not coherent, therefore cannot be tested; its predications are vague or in fact retrospective summaries rather than predictions.

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In a nutshell, zombie science is supported because it is useful propaganda; trading on the prestige which real science used-to have and which zombie science falsely claims for itself.

Zombie science is deployed in arenas such as political rhetoric, public administration, management, public relations, marketing and the mass media generally. It persuades, it constructs taboos, it buttresses rhetorical attempts to shape opinion.

Furthermore, most zombie sciences are supported by moral imperatives - to doubt the zombie science is therefore labelled as wicked, reckless, a tool of sinister and destructive forces.

To challenge zombie science is not merely to attack the livelihoods of zombie scientists (which, considering their consensus-based power, is itself dangerous) - but opens the attacker to being labelled a luddite, demagogue, anti-science, a denialist!

For all its incoherence and scientific worthlessness, zombie science therefore often comes across in the sound bite world of the mass media as being more plausible than real science; and it is precisely the superficial face-plausibility which in actuality is the sole and sufficient purpose of zombie science.