  Time, space, and matter are categories of our reasoning, whose properties
appear to be fundamental. However, these require a scrutiny as in the extreme
regime of the primordial universe these present quantum properties. What does
it mean for time to be quantum? What does it mean for space? Are space and time
disappearing, or what is disappearing are simply the categories we have been
using to understand them? Concepts such as the superposition of causal
structures or the quantum granularity of space require our attention and should
be clarified to understand the physics of the primordial universe. The novelty
that this brings requires us to reflect on matter as well: How can matter be
defined on a granular space? Is quantum gravity hinting us toward considering
new types of matter? The answers to these questions, that touch the foundations
of physics and the very concepts with which we organize our understanding of
reality, require in the end of the journey to confront ourselves with empirical
data. And for that, the universe itself provides us with the best of possible
laboratories.
