What Makes a Poem Short?

This poem is short and sweet,
It’s that simple, or is it?

I mean, what makes a poem short,
How many characters there are?
If that is so then how can we know,
What the shortest poem is?

There must be another way,
To measure a poem’s length,

What about actual size?
Can you measure a poem in inches?
If you measured like that
Then smallest poem would be the size of an atom,
And that I cannot fathom.

What else could we do
To measure a poem’s length.

How about the time it takes to read?
Is there a way to measure a poem in minutes?
If that was the case,
Then the shortest poem would remain unheard
Because it would be too short to hear.

So it appears that there is no way to measure the length of a poem,
Maybe someday.