Quantum mechanics is not something that creeps most people’s thoughts on any given day. In fact, if you are like me and you don’t really have a full understanding of how it works, here’s a (slightly) simplified explanation.

The word quantum derives from the Latin ‘how much’ whilst mechanics explains ‘how things move’ – a layman’s definition to those words in this complex and puzzling form of physics. 

According to science, quantum mechanics (or physics) explains how our universe works at a scale smaller than atoms…. Atoms being the building blocks of ordinary matter, which mold together to form molecules… which in turn make up most of the objects around us. These atoms are formulated from even smaller particles called protons, electrons and neutrons. Quantum mechanics explains how these work. (1)

Winger’s Friend

‘Winger’s friend’ thought experiment was a theory first outlined in 1961 by Hungarian-American Nobel Prize winning physicist Eugene Wigner. The experiment demonstrated a little-known contradiction of quantum physics, where two observers (in this case), Winger and Winger’s friend, experienced conflicting actualities.

The theoretical experiment began with a particle of light – or photon. Winger’s friend, isolated in a laboratory, measures the photon and takes note of its findings.

Winger, from outside the laboratory, reports the situation using the same equation of quantum mechanics. 

Without knowing each other’s results, both observers report different outcomes, yet neither of those contradictory observations – according to quantum mechanics – was thought to be incorrect. (2)

The results of Winger’s thought experiment have been the subject of much debate over the years, but now physicists have used advanced technology to recreate the test in a real experiment.

Is Objective Reality Real?

Proving there’s no such thing as objective reality has been a long time in the making. Until recently there has been little progress. 

Caslav Brukner, at the University of Vienna, Austria, has recently modeled a way to recreate the Winger’s friend thought experiment in a laboratory using techniques involving the entanglement of different particles at the same time. (3)

Now, Massimiliano Proietti and colleagues at Heriot Watt University in Edinburgh, Scotland have performed this experiment for the first time, creating different realities and comparing them. They have concluded that Wigner was correct.

The test was performed on a small-scale quantum computer made up of three pairs of entangled photons. The results have suggested there is no such thing as objective reality. (4)

So what does this mean? 

Conclusion or Confusion?

Martin Ringbauer, a researcher with the Department of Experimental Physics at the University of Innsbruck, Austria, said of the study:

“Quantum mechanics describes how the world works at a scale so small that the normal rules of physics no longer apply; over many decades, experts who study the field have offered numerous interpretations of what that means.

However, if measurements themselves aren’t absolutes – as these new findings suggest – that challenges the very meaning of quantum mechanics.

It seems that, in contrast to classical physics, measurement results cannot be considered absolute truth but must be understood relative to the observer who performed the measurement. The stories we tell about quantum mechanics have to adapt to that”. (5) 

The new reality is – we could observe the same thing, but see or hear something different…. and both be correct in our observations. For example, if a balloon pops and one of us hears it and the other doesn’t, does it make a bang… or not? It seems it’s all down to the eye (or ear) of the beholder.