Knowledge of eternity is sometimes termed as the knowledge of Supreme light. It remains an enigma and is sought out as the ultimate destination by all seekers of truth.
A reasonable understanding of the science of light began with Newton, whose concept of light converged with the concept proposed by Einstein more than 200 years later, of the particle nature of light - although Einstein's light quanta are different from Newton's corpuscles. In between the two, there is continuity, a wave, also a nature of light. This is the wave-particle duality of modern physics. Light interacts with matter as particle but propagates as wave.
Shining light on philosophical aspects of knowledge also has several aspects. The cosmic form is the Supreme light, the guide as well as destination of all knowledge.
In ultimate consciousness, we are the illuminator of all light, beyond darkness of all ignorance, and therefore Supreme Knowledge, knowing which, there would be nothing to be known further.
Knowledge is continuous; it pervades space and time; it is also discrete, as it is there in every being, all the time. It is the duality of knowledge, in conformity with the duality of light.
The beginning of light as well as knowledge remains as much of a mystery as the beginning of space, the universe, and time. The more one explores, the more the mystery. It's worth the quest as it signifies progress and expands the territory of knowledge. Knowledge liberates the mind and knowledge of the ultimate enables eternal liberation. On a similar note, ordinary light de-localises a localised particle; focused and high intensity light can liberate the particle from the system itself. This is the essence of Einstein's photoelectric effect.
In Quantum Theory, a material body can emit light when excited. The excitation can be done by absorption of light. Emission of light can take place also by mechanical, chemical, thermal and even biological excitations. However, all bodies cannot absorb light. Some transmit it and others reflect it. Similarly, not everyone is capable of absorbing knowledge.
It is said that knowledge is power. It can make one strong by positively influencing the thought process and willpower. It can distinguish the good from the bad. Hence, in the spiritual context, knowledge is also a form of energy; and it can do and undo things.
Both light and knowledge cannot be absolutely confined, although they could be effectively localised. But one should not lose sight of the fact that while light is a physical entity governed by and conforming to physical laws, knowledge is a transcendental perception.
What are the possible areas of convergence between the material and the spiritual? Synergy is essential for finding meaningful solutions to challenges of life and time. It would be instructive to recollect here the words of Ralph Waldo Emerson: "A man should learn to detect and watch that gleam of light which flashes across his mind from within."