If I asked you to describe what your body is made of, your response might be that it is made of particles or atoms. But did you know that it is equally accurate to describe yourself as being made of waves? A particle can be any object, big or small. In its simplest description, waves are things that vibrate periodically. It seems non-intuitive, but there is a physical relationship between the two.

Waves can be imagined as ripples in a pond. When a rock is dropped in the water, you would observe circular ripples, or waves, propagating from a source. If two rocks are dropped at the same time, you will see two waves interfere with each other.

Light can be imagined in the same way except propagating through space in all directions. Say you have a flat plate with a single slit and a detector screen behind it. If you pass light through the slit, you will see a single bright line on the screen. But if you have a plate with two slits, you will see multiple bright lines on the screen. This is called an interference pattern, and it is analogous to two waves of water interfering with each other.

A famous physics experiment called the double-slit experiment performed by Thomas Young, revealed the relationship between particles and waves. Electrons, real particles with mass, were first fired through a single slit. The screen behind the slit detected where the electrons landed. As we would intuitively expect, a single line of electrons were detected on the screen. When the electrons were fired through two slits, it was expected that two lines of electrons would be detected by the screen. But what was observed was multiple lines of electrons separated by narrow gaps, much like the interference pattern observed from the experiments with light. This led physicists to believe that matter exhibits wave-like properties as well. It changed the way they thought about matter. Now, matter cannot be thought of as solely particles, but as waves too. This is known as the wave particle duality.

These waves of matter represent the probability of a particle being at a particular location in space. If you calculate mathematically how large these waves are, the larger the wave is at a particular location, the greater probability the particle has of being found there. What this means is that all particles, including the ones in our body, have a probability of being anywhere in the universe. So there is a probability of you right now spontaneously appearing on Jupiter. However, the probability of this is so small and rare that it will take a take a time greater than the lifetime of the universe for it to happen.

The world of atoms and subatomic particles, the “small,” is known as the quantum world. The field of studying how things behave in the quantum world is called Quantum Mechanics. When you enter the quantum world, strange and spooky things happen. Common sense logic does not apply and what you experience is not what you would expect. The wave properties of matter are much more noticeable and apparent in small objects than large. That is why we do not notice the wave properties of everyday objects that we interact with. While Quantum Theory is indeed strange and confusing, the reason it is powerful is that it works. It makes accurate predictions of systems and behaviors in the quantum world. It is also responsible for the birth of the Informational and Technological Age.

Feeling confused? Don’t worry. It took me a while to get my head around this idea. But it is amazing to think about nonetheless. No one really knows yet why things behave this way. They just do. As the great physicist Richard Feynman once said, “If you think you understand Quantum Mechanics, you don’t understand Quantum Mechanics.”

Watch a fun explanation of the Double Slit Experiment.