A somewhat sarcastic, self-flagellating term used to explain why some interesting, possibly fruitful areas of scientific research are not pursued and don't get funding. They have a high giggle factor. Anyone considering submitting a grant applications is immediately discouraged by imagining politicians, purse string holders, or even editors of scientific journals giggling over the application/paper.

"Coddlesworth, my God, these SETI people want a $1 million so E.T. can phone home!"

"Ha ha! ET phone home. That's a good one Senator Proxmire! You slay me!"

As my small dialog reveals, "giggle factor" probably came into play in the '80s by things like Senator William Proxmire's Golden Fleece Award, which tended to criticize areas of science that made for easy pickings in newspaper headlines, but rarely delved into the underlying theory of why it might be a beneficial area of study. It might sound silly to research the mating habits of South American poisonous tree frogs but if the research reveals why said frogs don't kill each other off with their poison while mating, it might lead to interesting human drugs.

Its origin might actually come from a famous rejection letter Antonie van Leeuwenhoek received from Henry Oldenburg, Secretary of the Royal Society:
Dear Antonie van Leeuwenhoek,

Your letter of October 10th has been received here with amusement. Your account of myriad "little animals" seen swimming in rainwater, with the aid of your so-called "microscope," caused the members of the society considerable merriment when read at our most recent meeting. Your novel descriptions of the sundry anatomies and occupations of these invisible creatures led one member to imagine that your "rainwater" might have contained an ample portion of distilled spirits--imbibed by the investigator. Another member raised a glass of clear water and exclaimed, "Behold, the Africk of Leeuwenhoek." For myself, I withhold judgment as to the sobriety of your observations and the veracity of your instrument. However, a vote having been taken among the members -- accompanied I regret to inform you, by considerable giggling -- it has been decided not to publish your communication in the Proceedings of this esteemed society. However, all here wish your "little animals" health, prodigality and good husbandry by their ingenious "discoverer".

Modern day areas of research with high giggle factors tend to be anything with any kind of Star Trek tie in (antimatter, transporter-like technology). As mentioned, the search for alien life, because of its association with tinfoil-hat wearing UFO nuts, has a high giggle factor. Teaching apes and chimps language still has a high giggle factor. One too many bad asteroid disaster movies has tended to make research into defense against Earth orbit crossing bodies a high giggle factor endeavor.

Naturally, lots of research into sex is loaded with giggle factor roadblocks. How long, for example, before sex in space is ever officially researched? Why the very notion conjures up images of the closing scenes of Roger Moore and Dr Holly Goodhead getting' zero-g jiggy in Moonraker!

Even if the science is sound, say basic physics, a researcher can come with his own built in giggle factor. Einstein, a humble patent clerk, had to over come something of a giggle factor. Lots of researchers/inventors outside of academia, cooking up stuff in their garage, also have to escape the giggle factor inherent in their association with perpetual motion proponents and those on the weird science fringe.