We do not really know what time is. What is the nature of its "flowing," the manner in which it creates changes and presents something new to the world? What forbids the world to be invariable or static for even a single instant (and, indeed, how would we know whether there were such durations in which the world remained invariable)? All we can do when speaking of the causes of changes, or of the "nature" of time, is to identify, or put into correspondence, the "flow" of time with some natural process (let us call it a "time reference") which is changing monotonically with respect to what we feel or understand as time. A mechanician would say that time is motion; an astrophysicist, that it is the expansion of the Universe; a thermodynamics researcher, that it is entropy growth; a biologist that it is life; an historian, that it is death; a psychologist, that it is consciousness...
Maybe time is a specific substance, one that permeates our world, but one that cannot be directly detected by modern research technologies. On the other hand, such a substance might be unnecessary - like the thermogen once postulated by scientists - that the moving matter with which we are more directly familiar should suffice for an understanding of the nature of time. Perhaps, "time" itself is an extraneous element that originates solely from the way scientists think about it.
How do the concepts of time depend on one's perspective of the world? Is time then determined by the predominent culture of one's society? What are the trends and stages of the development of the Universe, the biosphere, the society, the individual?
Why do the most difficult problems in natural science require for their solution, as a rule, that serious changes be made to the notion of time?
Is time reversible or unidirectional? Is it discrete or continuous? What is its true dimensionality? Is its course uniform? What is the relationship between time and causality?
How might we derive, rather than guess, the fundamental equations of "generalized motion" in various spheres of cognition? How do we measure time correctly, taking into account that different reference processes - i.e., clocks - can have absolutely divergent natures, such that their readings may be strictly irreducible to each other? What distinguishes the proper times of natural systems from processes?
How are concepts of time related to other fundamental concepts of natural science: e.g., space, matter, motion, charges, interaction, energy, entropy, life, consciousness, etc.?
Can one control time? Is it possible to master it? In which sense is a "time machine" possible? Is it possible to be "outside" time?
If some of the questions like these enumerated above do not leave you indifferent, then the Institute for Time Nature Exploration is for you.