Throughout Hindu philosophy (in particular the Samkhya, Yoga, Vaisheshika darshanas), runs the theme of the holographic nature of the universe, i.e. the microcosm mirrors the macrocosm (similar in concept to quantum-cosmology of modern physics). These were not just theories, but backed by validation by keen meditative insight by yogis.
The kundalini is one such discovery. The kundalini is a cosmic energy, quantum-cosomological connection to the fabric of the universe, that lies at the base of your spinal axis, and represents the very core of your spiritual being.
For most people it lies dormant (coiled up like a spring). Through the practice of yoga, this cosmic energy awakens, as the kundalini sakthi, and travels up the spinal axis, activating each of 7 major chakras (cosmic/spiritual energy centers along the axis), till it reaches the most brilliant chakra, the sahasrara chakra (“the thousand petaled lotus) upon which one attains Enlightenment (Self-Realization or Full-Revelation). One’s spiritual journey is often measured in terms of the level of kundalini awakening.
The kundalini current is composed of three currents that run along the spinal axis right to the brain – the ida, pingala, and sushumna. During spiritual progress of the individual, the ida and pingala currents (the left and right currents in the spine) join unified as the sushumna current (in the center), and travel up the spine.
In modern physiology also it is known that thousands of nerves criss-cross along the spine at certain junctions, forming nerve bundles (ganglia) at these junctions. Considering that nerve cells communicate with each other through electricity (in the form of ionic exchange), and considering the huge number of nerves that meet at each ganglia, they can be considered as centers of millions of sparks of energy.
Someday using a future technology one might be able to take scan of the energy distribution (like an MRI) along the spinal column, and one might be able to see this energy flow like the great yogis saw it with their “third eye”: as two glowing serpent-like energies twisting and flowing on either side of the spinal axis with brilliant activity at the major intersection points (the 7 chakras) and a brilliant stream of energy in the center of the spinal axis, the main kundalini current.
That the ancients were able to have this vision at a time when most of the world was in the Stone Age or Iron Age (i.e. several millennia before modern science) is astounding. The ancient sages even go further in detail for each chakra: its form, function, color, mantra or mode of vibration, what part of physiology it governs, what form of subconscious desires and higher conscious or deity it is associated with, and the type of siddhis (powers) that can be manifest.
The vision of these twisting streams of luminous liquid light of energy around the spinal axis, is probably what led to the symbolism of the serpent. It is also represented as a serpent laying coiled and dormant at the base of the spine, awakening and making its way to the top with spiritual progress. Ancient Hindu texts are replete with tens of thousands of articles and pictorial representations of Kundalini.
In tantra, the left-hand and right-hand currents (ida and pingala) of the Kundalini are treated as the Lunar (Siva Conscious) and Solar (Narayana Conscious) currents. The Ida current rules over our nerves, hormones, emotions, intuition, and the Pingala current rules over our circulatory system, heart, intellect. The cool liquid light, the Soma energy from the Moon works on our intuition and manas, while the bright energy light from the Sun works on our buddhi and actions.
In Hindu cosmology, the microcosm reflects the macrocosm, so the kundalini current or yoga (the actuator of the kundalini current) can also be seen as the amritam (“nectar of immortality”) obtained during the churning of the Ocean of Milk. The kundalini current is also described as brilliant white luminosity, and the Ocean of Milk is considered as pure energy/consciousness, and it is also churned by using a snake. Yoga is considered as the right-hand path, and upon Enlightenment one attains “immortality” (i.e. beyond any meaning of life/death). Another part of the same story goes that a drop of this amritam fell to the ground and became garlic. The asura’s took the garlic, and the devas took the amritam (in this case, yoga).
The symbol of modern medicine, the caduceus, is derived from this kundalini symbolism. The irony, considering how modern medicine discredits anything ancient as backward, while at the same time constantly expropriating knowledge from it.