In the sixteenth century, Galileo Galilei performed a scientific experiment on which he threw two balls of different weight from the top of the leaning tower of Pisa. Such experiment showed how any object, regardless of their weight, would all fall in the same way when subject to gravity.
Now, almost four hundred years after such experiment, a team of scientists from the University of Florence and Rome's Istituto Nazionale di Fisica Nucleare or National Institute for Nuclear Physics applied the same principle on a quantum version.
They used a novel scientific method proposed by the University of Queensland ARC Centre of Excellence for Engineered Quantum Systems Dr Magdalena Zych and Austrian Academy of Science researcher Professor Časlav Brukner; a principle described by Albert Einstein and was famously known as "Einstein's equivalence principle" or EEP.
Specifically, the researchers conducted a Leaning Tower Test on a quantum level and relied on superposition. Superposition or quantum superposition is a system that can occupy two different energy states at the same time. This means that a quantum system may occupy different mass-energies simultaneously. Dr Zych said, “The spheres in Galileo’s Leaning Tower example were replaced by rubidium atoms.” And “the tower was replaced by a scheme developed by Professor Tino’s team that is based on Bragg atom interferometry."
Results showed that "the total inertial and gravitational mass of any objects are equivalent, meaning all bodies fall in the same way when subject to gravity." This validates Einstein's equivalence principle with a relative precision of a few parts per billion.
The findings could lead to different technologies, from predicting earthquakes and volcanic eruptions to telling the time with precision accuracy and even to navigate the stars, Zych said.