No, all the subatomic particles of a macroscopic object cannot undergo quantum tunneling simultaneously. Quantum tunneling is a phenomenon that occurs at the quantum level and is typically observed for individual particles or small systems. When a particle encounters a potential barrier, there is a small but finite probability that it can tunnel through the barrier and appear on the other side, even though classically it does not have enough energy to overcome the barrier.
However, for a macroscopic object, such as a solid, composed of a large number of particles, the individual quantum behaviors of its constituent particles generally average out and do not manifest on macroscopic scales. This is due to a process called decoherence.
Decoherence refers to the loss of quantum coherence or the entanglement between particles and their environment. As particles interact with their surroundings, they undergo continuous interactions and exchange information with the surrounding environment, which leads to a loss of quantum superposition and the emergence of classical behavior. The environment effectively "measures" the particles and forces them into specific states, destroying their quantum coherence.
As a result, the macroscopic object behaves according to classical physics, where particles are treated as classical entities with well-defined positions and velocities. The probabilities associated with quantum tunneling at the individual particle level do not extend to the macroscopic scale.
Quantum tunneling phenomena are generally observed and studied in controlled laboratory settings or in specific systems where quantum effects dominate, such as in certain electronic devices or in quantum systems at extremely low temperatures. However, for everyday macroscopic objects, the quantum tunneling of their constituent particles does not manifest in a coherent and observable manner.