Solar System, i.e. BRAHMA
Brahma represents solar system, he is worshiped by all terrestrial Gods.
From His body emerged personalities - Brahman, Kshatriya, Vaishya, Shudra, and from soul, Kayastha in them. He is Prajapati and directs the earthly Gods.
Galaxy, i.e. VISHNU
Vishnu represents Galaxy and his chakra Blackholes, lives in Ksheer Sagar the ocean of milk, rests on spiral beds of snakes. Brahma was born of His naval. He represents Adityan, the hordes of Suns in the galaxy. He creates and preserves.
Universe, i.e. MAHESH
Shiva is Universe, as a creator god, His one day equals thousands days and nights of Vishnu. Shivalinga represents theory of big bang from infinitesimal source, the PARA, the formless originator creator.
1,000 days and nights of Brahma= 1 day of Vishnu
1,000 days and nights of Vishnu = 1 day of Shiva
Solar System, i.e. Brahma
Brahma represents solar system. He is worshiped by all terrestrial Gods like water, air, fire etc. From his body emerged human personalities like Brahman, Kshatriya, Vaishya, Shudra and from soul, Kayastha. Shiva beheaded his fifth head to save humanity. This was the Sanatan Dharam way to state the facts about solar system ejecting a planet to stabilize it. Lord Brahma is subordinate to lord Vishnu, the galaxies. Lord Brahma got Birth from Vishnu's Naval.
Galaxy, i.e. Vishnu
Vishnu, represents Galaxy and his chakra represents the cyclical motion. Being a devourer, he is attributed to Blackholes and creations via Supernova. Its process of creation and dissolution represented by clockwise and anticlockwise Swastika. His symbolic seat on spiralling snake on ocean of Milk, represent Milky way and similar galaxies. His one day equals several thousands of days and nights of Brahma, while his thousands of days and nights equal a day of Shiva.
Universe, i.e. Mahesh
Bell-shaped creations of cosmos in Big Bang is symbolized as Shivalinga. This created physical and metaphysical existences known as Prakriti, and Purusha, represented by Parvati and Shiva (or Uma-Mahadev), whose marriage was important for creation to go forth, as scriptures narrate. Lord Vishnu subordinates to Mahadev. Lord Vishnu was devoured by Andhaka, a Blackhole, said to be Son of Lord Shiva. Shiva's sons and daughter represent emotions, attitudes, good, evil, and valour such other metaphysical qualities.
Millions of days and nights of Brahma= 1 day of Vishnu
Thousands of days and nights of Vishnu = 1 day of Shiva