Logical Inconsistencies

The second major difference between quantum physics is the uncomfortable notion that in the microscopic world, you cannot always rely on ordinary logic. Physicists find this especially troubling since logic plays such an important role in science as a whole. When inconsistencies arise, it begins to cast doubt on the notion that a coherent framework of physical law exists in the first place.

For example, how often have you wished you could be at the championship game when your favorite team is playing, but also at the big family wedding at the same time? In our daily lives, it’s just not possible to be in two places at one time. This prohibition applies to both people and things. In the quantum realm, however, it’s possible for objects to be in multiple places simultaneously. The reason for this has to do with probability.

In quantum physics, probability takes on greater importance than it does in ordinary situations. Generally speaking, you are at work or school Monday through Friday, and at home on Saturday and Sunday. This means that if you pick a future date at random, there will be a 71 percent chance (5 out of 7) that you’ll be found at work or school, and a 29 percent chance (2 out of 7) that you’ll be at home. When the day actually comes, though, you’ll be in one place or the other for sure.

QUANTUM QUOTE

Those who are not shocked when they first come across quantum theory cannot possibly have understood it.

—Quantum pioneer Niels Bohr

Things are a little less clear in quantum physics. In this case it is possible to be in both places at once. At least, that is, until somebody phones you up and detects that you are in one place or the other. Once you pick up the phone, your location will be revealed and you’ll be exclusively in that location from that moment forward. The moment before you picked up the phone, though, you would have literally existed in both locations at once. We know this sounds strange, but it is simply the way it is according to quantum physics.

This is not the only type of paradox that arises in quantum physics. Quantum objects can exist in places that are physically forbidden, they can suddenly appear out of thin air, and they can exhibit mutually exclusive properties depending on how you look at them. For better or for worse, all of this is perfectly allowed according to the bizarre rules of quantum physics.