QUES: One of the problems of the standard electric light bulb is filament notching due to evaporation of the filament. Small variations in resistivity along the filament cause "hot spots" to form at points of higher resistivity; a variation of diameter of only 1% will cause a 25% reduction in service life. These hot spots evaporate faster than the rest of the filament, which increases the resistance at that pointthis creates a positive feedback that ends in the familiar tiny gap in an otherwise healthy-looking filament. Irving Langmuir found that an inert gas, instead of vacuum, would retard evaporation. General service incandescent light bulbs over about 25 watts in rating are now filled with a mixture of mostly argon and some nitrogen, or sometimes krypton. Lamps operated on direct current develop random stairstep irregularities on the filament surface which may cut lifespan in half compared to AC operation; different alloys of tungsten and rhenium can be used to counteract the effect.

Who discovered that inert gas could slow evaporation?
What is the answer?
ANS: Irving Langmuir
QUES: Cubism began between 1907 and 1911. Pablo Picasso's 1907 painting Les Demoiselles d'Avignon has often been considered a proto-Cubist work. Georges Braque's 1908 Houses at L'Estaque (and related works) prompted the critic Louis Vauxcelles to refer to bizarreries cubiques (cubic oddities). Gertrude Stein referred to landscapes made by Picasso in 1909, such as Reservoir at Horta de Ebro, as the first Cubist paintings. The first organized group exhibition by Cubists took place at the Salon des Independants in Paris during the spring of 1911 in a room called 'Salle 41'; it included works by Jean Metzinger, Albert Gleizes, Fernand Leger, Robert Delaunay and Henri Le Fauconnier, yet no works by Picasso or Braque were exhibited.

What painting did Picasso paint in 1908?
What is the answer?
ANS: unanswerable
QUES: Melinda Gates has stated that the foundation "has decided not to fund abortion". In response to questions about this decision, Gates stated in a June 2014 blog post that she "struggle[s] with the issue" and that "the emotional and personal debate about abortion is threatening to get in the way of the lifesaving consensus regarding basic family planning". Up to 2013, the Bill & Melinda Gates Foundation provided $71 million to Planned Parenthood, the primary U.S. abortion provider, and affiliated organizations.

Who decided not to fund basic family planning?
What is the answer?
ANS:
unanswerable