Does the Big Bang prevent us from being in two places at once?

Physics Department Spring Seminar presents Miles Blencowe from Dartmouth College.

Quantum mechanics tells us that atoms and even molecules can display both particle-like and wave-like properties. By wave-like properties, we mean for example that an atom can be in two different places at once. Only when we probe the atom does its position "collapse" into having one value or the other, and we have no way of knowing beforehand which value it will be. However, there is nothing in the theory of quantum mechanics that rules out larger objects, such as a ball or even you, being in two places simultaneously. So why don't we observe everyday objects in such bizarre quantum states? We shall argue that the answer may ultimately lie in the presence today of a largely invisible, leftover remnant from the Big Bang that created our Universe.