3c/(pi*h^2), where c is the speed of light
2*pi*sqrt(h/g), where g is the gravitational constant
e^(pi*h), where e is the base of the natural logarithm
h/pi
(27*pi^2)/(h*[g^2]*[e*c]^3)

6(pi*r)^3
(4/3)(pi)(r^3)
([2/3]*pi*r)^3
2*pi*r
4*pi*(r^2)

Sir, I send a rhyme excelling
in sacred truth and rigid spelling.
Numerical sprites elucidate
For me the lexicon's dull weight.
Now I, even I, would celebrate
In rhymes inapt, the great
Immortal Syracusan, rivaled nevermore,
Who in his wondrous lore,Passed on before,Left men his guidance
How to circles mensurate.
But a time I spent wandering in bloomy night; Yon tower, tinkling chimewise, loftily opportune.
Out, up, and together came sudden to Sunday rite,
The one solemnly off to correct plenilune.
How I want a drink, alcoholic of course, after the heavy lectures involving quantum mechanics. All of thy geometry, Herr Planck, is fairly hard.
Poe, E. -
Near A Raven

Midnights so dreary, tired and weary,
Silently pondering volumes extolling all by-now obsolete lore.
During my rather long nap - the weirdest tap!
An ominous vibrating sound disturbing my chamber's antedoor.
"This", I whispered quietly, "I ignore".

the laws of reflection and refraction
general relativity
exploding pop-tarts
the photoelectric effect
the uncertainty principle in quantum mechanics

Pi > e.
No pattern exists in pi's digits.
Pi is irrational.
The area of a circle is equal to pi times the square of its radius.
It's fun to recite digits of pi.