Kṛṣṇa explains the ‘breathing’ of the universe. When Brahmā’s day begins, all living entities become manifest from an unmanifest state. When his night falls, they are all merged back into that unmanifest condition. The universe is like a giant machine that is switched on and off in cycles. This means that our current bodies and our current world are just one ‘waking’ phase of the cosmos. When the ‘night’ comes, everything we see will dissolve into a dormant state, like seeds waiting for the next spring. We have been through this cycle of appearing and disappearing countless times before. This cycle is automatic and mechanical. It shows that material existence is a series of temporary flashes. Kṛṣṇa is teaching Arjuna that what he sees as ‘life’ and ‘death’ on the battlefield is just a micro-version of this cosmic pulse. Real life is found only when we break free from this rhythmic inhalation and exhalation of material energy.