The line in the complex plane
on which the Riemann hypothesis asserts that
all nontrivial (complex) Riemann zeta function
zeros lie. The plot above shows the first few zeros of the Riemann
zeta function, with the critical line shown in red. The zeros with
and
that do not line on the critical line are the trivial
zeros of
at
,
, .... Although it is known that an infinite
number of zeros lie on the critical line and that these comprise at least
40% of all zeros, the Riemann hypothesis is
still unproven.

An attractive poster plotting the Riemann zeta function zeros on the critical line together with annotations for relevant historical information, illustrated above, was created by Wolfram Research (1995).
In the Season 1 episode "Prime Suspect" (2005) of the television crime drama NUMB3RS, math genius Charlie Eppes discusses the critical line after realizing that character Ethan's daughter has been kidnapped because he is close to solving the Riemann hypothesis, which allegedly would allow the perpetrators to break essentially all internet security.