Appeal to ridicule, also called appeal to mockery, the Horse Laugh, or reductio ad ridiculum (Latin: "reduction to the ridiculous"), is a logical fallacy which presents the opponent's argument in a way that appears ridiculous, often to the extent of creating a straw man

Straw man

A straw man is a component of an argument and is an informal fallacy based on misrepresentation of an opponent's position, twisting his words or by means of [false] assumptions...

 of the actual argument, rather than addressing the argument itself. For example:

• "If Einstein's theory of relativity
  Introduction to special relativity
  In physics, special relativity is a fundamental theory concerning space and time, developed by Albert Einstein in 1905 as a modification of Galilean relativity...
  
   is right, that would mean that when I drive my car it gets shorter
  Length contraction
  In physics, length contraction – according to Hendrik Lorentz – is the physical phenomenon of a decrease in length detected by an observer of objects that travel at any non-zero velocity relative to that observer...
  
   and more massive the faster it goes. That's crazy!" (This is, in fact, experimentally verifiable, but the effects are so minuscule that a human observer will not notice them at speeds far less than the speed of light.)
• "Evolution is ridiculous! If evolution were true, that would mean that all the apes wouldn't be here any more, since they all would have evolved into humans!" (This is not implied by the theory of evolution, thus the argument is invalid.)
• A real man never puts vegetables on his pizza, and doesn't eat quiche
  Quiche
  Quiche is a savory, open-faced pie of vegetables, cheese, or meat in custard, baked in a pastry crust.The quiche is sometimes regarded as the savoury equivalent ofegg custard tart.- Etymology:...
  
  . It implies that masculine
  Macho
  Macho typically refers to machismo. Other uses include:*Macho , a short-lived disco group in the late 1970s*Pique macho, Bolivian dish*Macho Man , a 1978 disco song performed by the Village People...
  
   men don't eat their vegetables.

This is a rhetorical tactic that mocks an opponent's argument, attempting to inspire an emotional reaction (making it a type of appeal to emotion

Appeal to emotion

Appeal to emotion is a potential fallacy which uses the manipulation of the recipient's emotions, rather than valid logic, to win an argument. The appeal to emotion fallacy uses emotions as the basis of an argument's position without factual evidence that logically supports the major ideas endorsed...

) in the audience and to highlight the counter-intuitive aspects of that argument, making it appear foolish and contrary to common sense

Common sense

Common sense is defined by Merriam-Webster as, "sound and prudent judgment based on a simple perception of the situation or facts." Thus, "common sense" equates to the knowledge and experience which most people already have, or which the person using the term believes that they do or should have...

. This is typically done by demonstrating the argument's logic in an extremely absurd way or by presenting the argument in an overly simplified way, and often involves an appeal to consequences

Appeal to consequences

Appeal to consequences, also known as argumentum ad consequentiam , is an argument that concludes a premise to be either true or false based on whether the premise leads to desirable or undesirable consequences...

.

Appeal to Ridicule is often found in the form of challenging one's credentials or maturity;

• "Nobody believes in capitalism
  Capitalism
  Capitalism is an economic system that became dominant in the Western world following the demise of feudalism. There is no consensus on the precise definition nor on how the term should be used as a historical category...
  
   after college! Grow up."

The argument is ridiculed on the basis that having a view commonly associated with youth is somehow invalid.

Although they appear very similar, this fallacy should not be confused with reductio ad absurdum

Reductio ad absurdum

In logic, proof by contradiction is a form of proof that establishes the truth or validity of a proposition by showing that the proposition's being false would imply a contradiction...

, which is a valid type of logical argument.