Context:

Recently, a team of scientists, including researchers from the Bose Institute in Kolkata, proposed a new tabletop experiment aimed at investigating whether gravity follows the laws of quantum mechanics.

• General Relativity and Quantum Mechanics are two major theories in modern physics, but it has not yet been clear how to understand gravity at the quantum level. This research could be an important step toward incorporating gravity into quantum theory, which could accelerate the search for a unified theory of physics.

About the Tabletop Experiment:

• The scientists have proposed a new experiment to investigate the quantum nature of gravity. This experiment will test whether the behavior of gravity is consistent with the principles of quantum mechanics.
• In this experiment, a mass (Test Mass) is placed on two possible paths, known as superposition. Along with this, another mass (Probe Mass) exerts gravitational influence on it, causing the test mass to collapse onto one path. If gravity itself causes the collapse of the mass, it would indicate that the nature of gravity might be quantum.
• Previous experiments studied regions with extremely strong gravity, such as black holes. However, this new experiment focuses on investigating weak gravity, similar to the force exerted by small objects.

Quantum Mechanics and Classical Mechanics Theories:

 Quantum Mechanics and Classical Mechanics are two major theories in physics used to explain the behavior of objects at different scales.

Classical Mechanics:

• Classical mechanics is capable of explaining the motion of objects that we observe in everyday life, such as cars, planets, and balls. Its rules are deterministic and predictable, meaning that if the initial position of an object is known, its motion can be fully measured and predicted.
• Under classical physics, large objects like planets, cars, or balls behave like particles. They do not exhibit wave-like properties or create any wave patterns. For this reason, wave-particle duality applies only at the microscopic level, and it is a significant feature of quantum mechanics.

Quantum Mechanics:

• On the other hand, quantum mechanics was developed to explain the behavior of particles at the atomic and subatomic levels, where classical rules do not apply. One of the most unique features of quantum mechanics is superposition, where a particle can exist in two or more states at the same time. Additionally, entanglement is another quantum phenomenon, where two particles become so deeply connected that a change in one immediately affects the other, even if they are at opposite ends of the universe.
• According to quantum theory, microscopic particles, such as electrons and photons, exhibit dual nature. They sometimes behave as particles and sometimes as waves. For example, when electrons pass through two slits in a thin wall (Double-Slit Experiment), they form a wave-like pattern.