Handwave

{{logicnav}}{{hatnote|Not to be confused with an [[escape hatch]].}}
{{Sources needed}}
'''Handwaving''' is the act of glossing over a difficult or superfluous component in an [[argument]], by ignoring or distracting from it, and hence treating it as a [[black box]] for the purpose of a discussion. It is a metaphor derived from the sleight-of-hand of a conjuror who relies on flamboyant hand movements to distract the audience.<ref name=wp>{{wpa|Hand-waving}}</ref>

The assumption is that the component in question is either [[Red herring|outside the scope of the current discussion]] or simply doesn't need to be understood by the listener; as a result, while there may be legitimate reasons not to bother with the handwaved topic, handwaving can sometimes be used as a form of [[deceit|misdirection]] or outright [[bullshit]] in order to advance a faulty argument. The term is used in mathematical contexts where important steps are left out so that something is assumed to be true without any rigorous demonstration, which can lead to things being assumed to be true that are in fact unproven and false. In literary or film criticism, it refers to a technique where an author ignores a plot hole and hopes the audience won't notice or tries to get around a plot hole by distraction.<ref name=wp/>

==Examples==
===What we are ''really'' interested in...===

{{quotebox|
'''[[Woo]]-defender:''' [[Magnetic field therapy|Magnet therapy]] has been proven to work in so many cases.

'''Scientist:''' Well-designed clinical testing has shown no correlation between the use of magnetic therapy and any improvement in health.

'''Woo-defender:''' Clinical trials may be fun to chat about, but we are talking about the thousands of real-life successes here. There are millions of them. It is the billions of real-life cases of success with magnetic therapy in real-life magneto-medicine that we are interested in.}}

==="Just a theory" gambit===
{{main|Just a theory}}

{{quotebox|
'''[[Creationism|Creationist]]:''' As we can see, if [[evolution]] really worked, then pilots who fly a lot would have grown wings by now.

'''[[Scientist]]:''' That's not how evolution works. Evolution is based on [[natural selection]] from traits over time. As [[human]]s, we don't have any sort of gene that allows us to fly, since we don't ''need'' to. We can't even grow our own wings at will. It's not genetic at all. Unless a flood covers the Earth and we're forced to live above ground, then maybe, over hundreds or thousands of generations of natural selection, we may sprout wings.

'''Creationist:''' That mumbo-jumbo is [[just a theory]]. [[One single proof|Show me a pilot with feathered wings!]]}}

==Skinner constant==
'''Skinner’s Constant''' (also known as '''Flannegan's Finagling Factor''') denotes:

{{cquote|That quantity which, when multiplied by, divided into, added to, or subtracted from the answer you got, gives you the answer you should have gotten.}}

There's a great many ideas that ''would'' work, if just one important item wasn't completely unknown. For such things, we have the Skinner constant — the [[mathematical]] equivalent of a handwave.

==Left as an exercise==
Usually, the term "left as an exercise" (originated in and largely used in mathematical and [[computer]] [[science]] circles) implies that part of a [[proof]] or algorithm is sufficiently elementary as to be either obvious or readily worked out by the reader or student. However, it can be used in two less-than-sensible ways:

#As a potholed introduction to an exceptionally difficult or unsolved problem
#As part of an argument by intimidation

==See also==
*[[Moving the goalposts]]
*[[Escape hatch]]
*[[Reiki]]
*[[Therapeutic Touch]]
*[[Quantum touch]]

==External links==
*[http://www.catb.org/~esr/jargon/html/H/handwave.html The canonical definition at the Jargon File]

==References==
{{reflist}}

{{logfal}}

[[Category:Ad hoc]]

Categories: Ad hoc