What a fascinating question!

Proponents of the multiverse theory do indeed propose that there may be an infinite number of universes beyond our own. This idea is based on various lines of reasoning and evidence from cosmology, theoretical physics, and mathematics.

To clarify, the concept of infinity in this context is not meant to imply a finite countable set of universes, but rather an unbounded, uncountable set. In other words, there may be no upper limit to the number of universes, and new ones could be created or arise spontaneously at any moment.

Now, you might wonder why anyone would propose such an extraordinary idea. There are several reasons:

1. Mathematical necessity: Some theories, like eternal inflation or string theory, naturally lead to the prediction of multiple universes. These theories aim to describe the fundamental laws of physics and the behavior of space-time at very small scales (quantum gravity). The multiverse hypothesis arises as a consequence of these mathematical frameworks.
2. Cosmological observations: Certain features of our universe, such as its uniformity and the value of physical constants, can be explained by assuming that our universe is just one of many bubbles in an infinite multidimensional space. This idea helps to address long-standing problems in cosmology, like the fine-tuning problem.
3. Philosophical and probabilistic considerations: If we assume that our universe is just a random draw from an ensemble of all possible universes, it’s likely that there are many others with different properties. This perspective helps to explain why our universe appears so finely tuned for life.

While some critics might argue that the multiverse hypothesis is a convenient excuse or a way to avoid difficult questions about the nature of reality, proponents would counter that:

1. The multiverse is not an ad hoc explanation: The concept arises from well-established theories and observations, rather than being invented solely to explain away difficulties.
2. It’s testable and falsifiable: Scientists are actively working on experimental searches for evidence of other universes or signs of the multiverse (e.g., gravitational waves, cosmic microwave background anomalies). If these efforts fail to yield results, the hypothesis could be discredited.

In conclusion, proponents of the multiverse theory genuinely propose that an infinite number of universes might exist, driven by mathematical and theoretical reasoning, cosmological observations, and philosophical considerations. While it’s a mind-boggling idea, it’s not simply a convenient excuse; rather, it’s a well-motivated hypothesis that continues to inspire research and debate in the scientific community.

Would you like me to elaborate on any specific aspect of the multiverse theory or its implications?