Guess Me riddle #3

View the last part here

Guess the word

Sir, I bear a rhyme excelling
In mystic force and magic spelling
Celestial sprites elucidate
All my own striving can't relate

What am I?

• I'm not sure this is really a puzzle. (For the avoidance of doubt: yes, I know the answer.) Nov 19 '18 at 17:34
• Or locate they who can cogitate and so finally terminate. finis. pages.intnet.mu/cueboy/education/maths/pi/england.htm
– user66207
Mar 16 '20 at 0:00

This is

a well known mnemonic for the digits of $$\pi$$. (Count the letters in each word.)

I got

hocus pocus

but I feel like I'm missing something.

It rhymes and it is used to invoke magical effects.

Well, it made me think of

Light

But, if @GarethMcCaughan is correct, then this is pretty moot.

Sir, I bear a rhyme excelling

Not a rhyme unfortunately, but a synonym for excel is shine

In mystic force and magic spelling

This statement along with the mathematics tag makes me think of a math formula relevant to light. Perhaps one related to Electromagnetic ration specifically?

Celestial sprites elucidate

Celestial: Of the sky
sprite: a faint flash, typically red, sometimes emitted in the upper atmosphere over a thunderstorm owing to the collision of high-energy electrons with air molecules.
elucidate: make (something) clear; explain
This makes me think of a star, and thus the light emitted from one.

All my own striving can't relate

We still struggle to fully understand all the states of light. Also, we aren't capable of travel at the speed of light yet.