If Planck's constant were smaller than it is, would quantum phenomena be more or less conspicuous than they are now?

To answer this question, we need to understand the role of Planck's constant in quantum mechanics. Planck's constant (denoted by h) is a fundamental constant in physics that relates the energy of a photon to its frequency. It also plays a crucial role in determining the scale at which quantum effects become noticeable.

Quantum phenomena refer to the behaviors and interactions of particles at the atomic and subatomic level. These phenomena include wave-particle duality, superposition, and quantization of energy levels.

If Planck's constant were smaller than its actual value (6.62607015 × 10^-34 J·s), it would mean that the energy associated with a given frequency of radiation or particles would be decreased. As a result, the effects of quantization and wave-particle duality would become less noticeable. Quantum phenomena would be less conspicuous in this scenario.

Quantum effects become more significant when the energy involved is comparable to Planck's constant. For example, when we observe the behavior of particles at extremely small scales or in experiments involving low energies, the quantized nature of energy levels and the wave-particle duality become evident. Thus, if Planck's constant were smaller, it would imply that the energies required to observe these effects would also be smaller. Consequently, quantum phenomena would be less pronounced and harder to observe.

It's important to note that Planck's constant has a fixed value determined through experimental measurements. It is one of the foundational constants in physics and is considered to be a fundamental property of the universe.