Practical Applications of Entanglement in our Nonlocal Universe

Quantum mechanics shows that our universe is best described by wavefunctions that obey the laws of physics. This is quite different from most people’s understanding of our universe being made of little balls of matter. What do you think of when someone asks you what you are made of?

The first picture that would come to my mind would show little atoms made of electrons, protons and neutrons. Maybe I would go further and see that protons and neutrons are made of quarks and I might imagine some little photons and gluons zipping around.

But the last decades have shown more and more that everything in our universe is described much more precise by quantum mechanical wavefunctions than by little particles. The time evolution of this wavefunction has been incredibly successful in predicting how everything in our universe works (1). What is a wavefunction? I visualize it as a very blurred version of a particle that is wobbling around in space and time. Here are some important properties of wavefunctions:

Wavefunctions can be somewhat localized but have a decaying tail that can spread out through the whole universe.

The particle or particle system that is represented by a wavefunction is de-localized and exists at every position of the wavefunction simultaneously.

Not only the position of a particle represented by a wavefunction can be undetermined but also other properties like the spin. I imagine this as a particle that spins clockwise and counter-clockwise at the same time.

Very important classes of wavefunctions are so-called entangled states. I visualize an entangled state as two blurry wavefunction-particles that share their decaying tail (2). Entangled states have the very important feature that they can represent two particles that are spatially separated but have linked properties.

Let’s think about two entangled particles (particle 1 and particle 2) that simultaneously spin clockwise and counterclockwise. Now let’s assume the only way to find out the direction of spinning is to touch a particle. Interestingly, as soon as your body-wavefunction touches for example particle 1, you will feel that the particle is spinning in only one well defined direction.

Even more surprisingly, the other particle 2 that can be far away will instantaneously decide to spin in opposite direction of particle 1 just at the instance in time when you touched particle 1. This means we live in a non-local universe in which remote things can be instantaneously linked to each other. Note that it is impossible to transmit information using this effect because you cannot control in which direction particle 1 spins without destroying the entanglement.

Let’s have a short break here. There are a few things that I learned in physics that simply overwhelmed me and made me cry. Realizing that we are living in a non-local universe in which entangled states can be instantaneously linked to each other is one of them.

Known applications for entangled states are quantum key distribution and secure communication. Here I want to talk about a more emotional and maybe a bit philosophical application of entangled states which will lead us to the Quantum-Ballerina.

Assume it is the year 2050 and mankind finally made it to Mars. You are one of the lucky space travelers that live on Mars but unfortunately your most loved person had to stay back on earth. The fastest way to communicate is with the speed of light, meaning 20 minutes of delay for a signal between Mars and Earth, which is a very sad situation.

Fortunately we have our Quantum-Ballerina that allows you and your loved one to have unique and shared emotional experiences without delay. Here is how it works:

A stream of entangled particle twins is generated on Mars, always sending one of them to Earth The spin direction of the particles on Mars is measured with a 20 minute delay (enough time for the other particle to arrive at earth) Your loved one on Earth measures his twin particle and knows instantaneously your unpredictable measurement result Both of you feed the results to a little mechanical Quantum-Ballerina that starts to perform a unique dance

This would allow you and your loved one to simultaneously see the same ballerina dance and have a shared experience even though you are so far apart that it is physically impossible to directly communicate (3). A slightly modified version would use the random but shared measurement results to simultaneously display the same random photo slideshow from your pre-defined photo album both on Earth and on Mars. Thinking a step further, this would even allow for a simultaneous and unique sex experience with someone many lightyears away.

Footnotes

(1) Quantum mechanics doesn’t describe gravity so far but let’s assume there will be a quantum mechanical description of gravity in the near future.

(2) Importantly the entangled state is a combined wavefunction that represents simultaneously two or more particles.

(3) Given that you arranged previously to look at the ballerina at a certain time.