Set theory is a branch of mathematical logic that studies sets, which informally are collections of objects. Although any type of object can be collected into a set, set theory is applied most often to objects that are relevant to mathematics. The language of set theory can be used in the definitions of nearly all mathematical objects. 

The modern study of set theory was initiated by Georg Cantor and Richard Dedekind in the 1870s. After the discovery of paradoxes in naive set theory, such as the Russell's paradox, numerous axiom systems were proposed in the early twentieth century, of which the Zermelo–Fraenkel axioms, with or without the axiom of choice, are the best-known. 

Set theory is commonly employed as a foundational system for mathematics, particularly in the form of Zermelo–Fraenkel set theory with the axiom of choice. Beyond its foundational role, set theory is a branch of mathematics in its own right, with an active research community. Contemporary research into set theory includes a diverse collection of topics, ranging from the structure of the real number line to the study of the consistency of large cardinals. 

Mathematical topics typically emerge and evolve through interactions among many researchers. Set theory, however, was founded by a single paper in 1874 by Georg Cantor: "On a Property of the Collection of All Real Algebraic Numbers".

Based on the article and the following list of answers, write a list of questions.

1. Georg Cantor and Richard Dedekind
2. in the 1870s
3. branch of mathematical logic
4. collections of objects
5. On a Property of the Collection of All Real Algebraic Numbers
6. 1874
7. Georg Cantor
8. structure of the real number line
9. yes
10. objects that are relevant to mathematics
11. emerge and evolve through interactions among many researchers

Numbered questions:
1. who started the study of set theory?
2. when?
3. what is set theory?
4. what are sets?
5. what paper founded set theory?
6. when was it written?
7. by who?
8. what is a current topic in set theory?
9. can any object be in a set?
10. what objects are usually part of set theory?
11. how do math topics usually start?