Do you play the Piano? I'm self-taught, learned while working nights at a hotel on the lobby piano.. 
I wish I could play the piano, it is so beautiful! Has it been around for long?
They were invented in Italy in1700 so in the big picture no. No better time to learn then now. 
That seems like a long time haha, but I guess not in the span of all things. Is it hard to learn
The earth is 4.5 billion years old so it's not that old.  The word "piano" is a shortened form of "pianoforte" so it still hold's some of it's original flavor. 
Who came up with the piano
Only the third coolest man ever Bartolomeo Cristofori 
Haha that is an awesome name, are there any instruments similar to the piano
the stronger the attack. The name was created as a contrast to harpsichord, a musical instrument that does not allow variation in volume. The first fortepianos in the 1700s had a quieter sound and smaller dynamic range.
An acoustic piano usually has a protective wooden case surrounding the soundboard and metal strings, which are strung under great tension on a heavy metal frame. Pressing one or more keys on the piano's keyboard causes a padded hammer (typically padded with firm felt) to strike the strings. The hammer rebounds from
said, 
“You want to play some jazz at my home?” I said sure. So we got my drum-set to his place. We rehearsed a couple nights a week – drums and piano. These sessions were my lessons with Sal. Then came Ben Johnston. I knocked at his studio door. I went in. There was silence everywhere. He was in his rocking chair, staring out the window. I showed Ben the score I was working on. I played through it on his piano