The Ruins of the Ramessueum at Thebes, Egypt
Several meanings of 'space' in different parts of speech are available under various categories, ranging from commerce to narcotics. However, in architecture, the idea of space can be explained through the concept of time.
Patrick Schumacher suggests in 'Concept of Space in Architecture' that historically, the idea of space emerged as the essential goal of the architect; that architecture is the art of space making. This notion changed over the course of time, not literally but conceptually, and is still debatable.
A space exists when it can be experienced in time, and thus depends on time for its manifestation. As rightly expressed by Jeremy Till in 'Architecture in Space-Time', our experience of space is conditioned through time and memory.
Time is an abstract container of events. As we experience a space physically, we acknowledge the passage of time through our actions: sitting, walking, climbing. The evident aspect of time in architecture is the aging of a building.
However, the most important aspect, that forms the interrelationship of time and space, is as described by Karsten Harris, the 'terror of time' i.e the fear of mortality. He sees architecture as one of the ways to address that fear.
The poem Ozymandias, by P.B Shelly, is a classic example of the fear of impermanence. This fear can easily be seen in architecture, where we tend to capture a building in its most glorious visage while forgetting that eventually it has to deal with the wrath of time. By hoping for it to remain static, it gets distanced from truth, or as we can call in today's lingo, 'expectation vs reality.'
The presumption of permanence of monumental weighty structures is misleading. We can no longer take space as well as time to be granted. The idea of space being static in itself leads to monotony. To glorify space as it changes with time, rising above mere aesthetics is integral, for sustainability and to remain in reality.