The biggest unsolved problem (Larry´s blog)

["Josemar" <vjosemar@ufscar.br>]

Caros redistas,

Recentemente, Larry Wasserman formulou em  seu blog um critério para definir um bom problema em aberto (ver abaixo). O que os caros redistas pensam sobre isso? Abs, Josemar

1. It can be stated succinctly.

2. You can quickly explain it to a non-specialist and they will get the gist
of the problem.

3. It is sexy. In other words, when you explain it to someone they
think it is cool, even if they don't know what you are talking about.

Having sexy open problems is more than just an amusement; it helps raise
the profile of the field.

Can anyone suggest a good open problem that satisfies the three criteria?