According to buddhism, there exists 31 "planes of existence".
Theravada Buddhist cosmology describes the 31 planes of existence in which rebirth takes place. The order of the planes are found in various discourses of the Gautama Buddha in the Sutta Pitaka. For example, in the Saleyyaka Sutta of the Majjhima Nikaya the Buddha mentioned the planes above the human plane in ascending order.1 In several sūtras in the Anguttara Nikaya, the Buddha described the causes of rebirth in these planes in the same order. In Buddhism, the devas are not immortal gods that play a creative role in the cosmic process. They are simply elevated beings who had been reborn in the celestial planes as a result of their words, thoughts, and actions. Usually, they are just as much in bondage to delusion and desire as human beings, and as in need of guidance from the Enlightened One. The Buddha is the "teacher of devas and humans (satthadevamanussanam). The devas come to visit the Buddha in the night. The Devatasamyutta and the Devaputtasamyutta of the Samyutta Nikaya gives a record of their conversations. The devaputtas are young devas newly arisen in heavenly planes, and devatas are mature deities.
There are more than 10,000 crore (100 billion) solar systems in our Galaxy, and more than 10,000 crore (100 billion) galaxies in our Universe. There are many Universes in space. Past and future lives may occur on other planets. The data for the 31 planes of existence in samsara are compiled from the Majjhima Nikaya, Anguttara Nikaya, Samyutta Nikaya, Digha Nikaya, Khuddaka Nikaya, and others. The 31 planes of existence can be perceived by a Buddha's Divine eye (dibbacakkhu) and some of his awakened disciples through the development of jhana meditation. According to the suttas, a Buddha can access all these planes and know all his past lives as well as those of other beings.
Hence the question: Are these 31 planes of existence actually existing all around us RIGHT HERE where we are (as in 31 'dimensions' per se), or are they belonging in different planets and galaxies far apart from each other? Since 'planes' can also mean 'dimensions' if viewed from such a perspective.
Please verify! Thanks for your patience! IMAGE: 31 planes of existence - Ven.Suvanno Mahathera