Quantum theory describes nature at a subatomic scale – provides us a different conception.

So far, we’ve been looking at what’s observable to the naked eye, and for the most part what we see around us is all normal and explainable. But if we could see what is going on around us at the subatomic level, where quantum theory rules, things wouldn’t seem so normal.

One of the most important tenets of quantum physics is the uncertainty principle, established in 1926 by the German physicist Werner Heisenberg.

Heisenberg believed that it was impossible to simultaneously measure, with any precision, the position and velocity of a particle.

Once we try to zero in on a particle’s speed, we lose the ability to measure its position, and vice versa. And with an infinite number of possibilities, it’s impossible to predict where a particle has been and where it will be in the future.

The best you can do is measure the probability of the various places a particle is likely to be.

Another key principle of quantum theory states that we cannot passively observe something. Rather, by making an observation, we are affecting what we are observing.

For example, if we open a refrigerator to see what’s inside, we’re changing the temperature of the contents and exposing the food and drinks that are in there to photons of light.

While shining a light on something as big as an apple isn’t going to do much, shooting photons, or particles of light, will greatly affect the movement and direction of other tiny particles.

So, as you can see, the disruption that simple light can cause makes it quite difficult to conduct experiments on the quantum level.