Trayam Va idam - Nama Roopa Karma
                 - Brhadaaranyaka Upanishad
This objective universe is made up of three folds- Name, Form and Action

Everything that we experience in the objective world is a dynamic flux of name, form and process or action, which makes our Anubhuti relative.

The objective world is what is accessible to our five senses and jnanendriyas. Vision, Smell, taste, touch and hearing.

(Panchashiki)

But there is a subjective world too that is intangible but very much present and palpable, the world of ideas, thoughts and feelings that are accessed through Antahkarana or the inner instruments. Manas, Chitta, Ahamkara , Buddhi Vac and Prana.

Modern Science divides the universe as observable and non observable universe based on their assumptions and premise of how they define knowledge and knowable universe.

What they have focused on so far is the search in the objective world, physical material world.

What they have focused on so far is the search in the objective world, physical material world.

And that search has inevitably  led them to a point where they now are asking the question- Who is the knower?

And here in this realm  is where our Shastras and Vijnanas have thrived as Sanatana. While we explored the diverse  objective relative world through Astronomy, Rasayana,Boogola etc, our Rishis of yore were also equally interested in the vast realms of the non observable universe

The tragedy of modern science of studying nature excluding oneself is almost comical! 
Can you observe the observer? This question or inquiry blindsided them. For a reason. It's the limitation of Bhauthika Shastra of Carvakas.

Dwarf Darwinism is my phraseology for this

The inner search light to understand the nature of mind led to further questions on " what is that which cannot be objectified ?"

The Subject object relationship and its nuanced exploration and inquiry is the focus of Para vidya or Upanishads.

Para-Apara- Parapara