Quantum decoherence (also known as dephasing) is the mechanism by which quantum systems interact with their environments to exhibit probabilistically additive behavior. Decoherence can be viewed as the loss of information from a system into the environment.

I'm guessing you are asking why we do not see quantum behaviour in the normal world? Well if it is then because of the a effect called decoherence (the interference of air and other mediums) that wipe out quantum behaviour in macroscopic objects

It's the study of very small particles... so small that quantization becomes a noticeable factor in their behavior.

Adding to the answer above you would also see quantum behaviour in macroscopic objects if it was not for a phenomena called decoherence - an

interaction with the wider environment that wipes out quantum behavior

The cast of Decoherence - 2006 includes: Dave Huber as Professor Allan Rosenberg

Decoherence - 2006 was released on:

USA: 15 September 2006 (Big Bear Lake International Film Festival)