Why do the Cardinals uses smoke signals to indicate the selection of a new Pope?

Because they lock themselves in a room and they are not supposed to have any contact with anyone outside of the room until a new Pope is chosen.

I thought they used them to signal the bullpen to warm-up a relief pitcher!

They burn the ballots before they unlock the door so no recount can take place.

they add "stuff" to create the color so folks on the outside can keep track of the number and result of votes taken...

I also release smoke signals instead of turn signals. Two puffs mean left, one right.

A fine question but kind of minor. You should ask "If current prophecy and from the saints of old states Our Lord is returning soon, please does anyone know what He is going to show the world?"

Oooh, oooh, I have the answer.

Protestant and Catholic prophecy reveals the Remnant is Roman Catholic. God is going to show every soul on the earth this Truth, non-Christians too.

Time is short, Protestant prophecy is saying the same, right now Jesus is telling Protestants His presence in the holy Eucharist is true.

"Eat of Me"...their prophetic Word.

[link to www.danaleipold.com]

I don't know but I think they'll win the World Series.

It probably has a lot to do with how news was spread before modern communications. The whole idea of a secret meeting and secret vote with no one knowing why the decision was made probably came from the dangerous position the church was in with political pressures from nobility and to try to fend off corruption.