Dear Sourav,

Space is primarily a mental construct arising out of perception of a "gap" between two objects, just as time is a mental construct arising out of the perception of a gap between two events.

Newtonian space is infinite and eternal and hence absolute and immutable.

In Special Relativity, it gets conjoined with time to form a four-dimensional continuum, which is again a mental construct.

In Genaral relativity, space is endowed with curvature and also Torsion. It becomes relative and in cosmological models it may have big-bang and big-crunch singularities at the beginning and at the end of the cosmic evolution.

It gains in dimensionality in Kaluza-Klein theories, supergravity and String theories.

Its principal philosophical significance is that it leads to perception of multiplicity of entitieand is the very basis of all existence..

In physics Free Space is associated with lot of properties through the idea of QFT vacuum.

Regards,

Rajat

In special relativity, space'n'time has a different ontological status from Newtonian Space and time. It isn't a being existing independently from its content. Actually, space and time are variables that can be assigned to measurements performed through a well defined comparision procedure, which defines the concept of space-time. That is, space-time is the mere expression of the relationship between events. That is what the mathematicians of the time, such as Poincaré, couldn't see. This view has been lost in general relativity, where the Riemannian manifold seems to have the ontological status of absolute space and time, but basicly it isn't true. Only the results of space-time measurements obey Riemannian geometry, which isn't Euclidian because of the interaction of light with massive bodies. Actually, the Mach principle that inspired it but is not included in it is relational in nature.

@Rajat Pradhan, Thank you very much for so descriptive answer. This answer contains facts as well as concept both. But is it anything related with space and energy ? if any idea in this regards kindly discuss that:

any relation between space and energy???

Dear Sourav,

It depends on what definition and at what level of complexity you are talking.

Free space as quantum vacuum does have an energy density that unless somehow "renormalized", leads to an infinite energy and leads one in to deep unsolved problems.

Classical Curved space in GTR has energy depending on the curvature.

In Classical theories/Cosmologies, the gravitational and other (e.g. electromagnetic) potential energies are defined at all space points and thus lead to their respective energy densities.

All said and done, one might very well say that space is a manifestation of energy, as per our current understanding.

Regards,

Rajat

Rajat, thank you very much for simplifying the whole talk, actually i was reading just for my query so i thought i should ask to someone who is deep in this field. I really like your concluding line....

With regards