I can travel from there to here by disappearing, and here to there by reappearing. What am I?

Answer: The letter "T

More What am I ? with answers

More What am I ?

I can wake you up in the morning but I require no electricity or winding. What am I?
I can wave my hands at you, but I never say goodbye. You are always cool when with me, even more so when I am high! What am I?
I can’t be seen, found, heard or smelled. I lie behind stars and under hills, I fill empty holes, come first and follow after. What am I?
I can’t go left, I can’t go right. I am forever stuck in a building over three stories high. What am I?
I can’t go right, I can’t go left. I’m forever stuck going only up and down. What am I?
I can't see yet I know your there. I'm not a cow but I'm leather. I'm a rare find but follow paths. I can fly but I'm not a bird. What am I?
I cannot be bought, cannot be sold, even if I’m sometimes made of gold. What am I?
I cannot be burned by fire or drowned in water. What am I?
I cannot be burned in fire or drowned in water. What am I?
I cannot be felt or moved, but as you come closer, I get more distant. What am I?
I cannot hear or even see, But sense light and sounds there may be, Sometimes I end up on a hook, I can be combined with a book. What am I?
I cannot speak but I have great knowledge, I’m not a tree but I have leaves. I have hinges but I am neither a door nor a window. What am I?