The following excerpt is about spiritual light and heat.
Swedenborg saw the correspondences (or parallels) between the spiritual and the natural.
For example, I can see that light represents wisdom and heat represents warmth. In the winter you have light, but no heat. But in the spring, light plus heat will awaken the seeds to sprout.
Frequency times wavelength equals the speed of light. Light is an electromagnetic wave that moves along, with a changing electric field causing a changing magnetic field, and then the changing magnetic field causes the changing electric field. And so on.
Can you see the correspondence with love and wisdom. Faith without works is dead says the Bible. You need works to complete the action. Thought is not enough, we must walk the walk. A good thought, based in faith and love, leads to action. Without the works, the faith is not complete.
The electrostatic field represents wisdom (light) and the magnetic field represents love (in the form of attraction). One could view the light as the love (warmth) and magnetic field as the wisdom which arranges and orders things in its field. Love and wisdom work so closely together that you cannot have one without the other. And so it is in the natural realm, you have electricity and magnetism working hand in hand.
Maxwell added a little something to his fourth equation (Ampere's equation) to help the electromagnetic wave keep moving in space. Could it be that in spiritual terms, that little something is the spark of inspiration from God--could it be that this spark, or perhaps a rapport with our Creator is what permits our words and deeds to continue to a good fruition, despite the persecution and opposition we must bear?
We humans must act in love out of wisdom (what we know in our heart is right). When our action flows directly from wordless inspiration, you have a flow. This flow, or movement, is good for us and for others. it is only when we do not flow, but instead analyze the consequences that the flow is broken and we them move out of self interest, self protection or fear, not out of love.
Now Emanuel Swedenborg:
FROM THAT SUN PROCEED HEAT AND LIGHT; THE HEAT PROCEEDING FROM IT IS IN ITS ESSENCE LOVE, AND THE LIGHT FROM IT IS IN ITS ESSENCE WISDOM.
It is well known that in the Word, and thence in the common language of preachers, the Divine Love is expressed by fire; as when prayer is offered that heavenly fire may fill the heart, and kindle holy desires to worship God: the reason is that fire corresponds to love, and thence signifies it. Hence it is that Jehovah God appeared before Moses as a fire in the bush, and in like manner before the children of Israel on Mount Sinai; and that it was commanded for fire to be kept perpetually upon the altar, and for the lights of the lamp stand in the tabernacle to be lighted every evening: these commands were given because fire signified love.
[2] That such fire has heat proceeding from it appears plainly from the effects of love: thus a man is set on fire, grows warm, and becomes inflamed, as his love is exalted into zeal, or into the glow of anger. The heat of the blood, or the vital heat of men and of animals in general, proceeds solely from love, which constitutes their life. Neither is infernal fire anything else than love opposed to heavenly love. Thence it is, as was stated above, that the Divine Love appears to the angels in their world as the sun, fiery, like our sun; and that the angels enjoy heat according to their reception of love from Jehovah God by means of that sun.
[3] It follows from this that the light there is in its essence wisdom; for love and wisdom, like Being (esse) and Manifestation (existere), are indivisible, since love is manifested by means of wisdom and according to it. This is as it is in our world: at the time of spring heat unites itself with light, and causes germination, and at length fruit. Moreover, every one knows that spiritual heat is love and spiritual light is wisdom; for a man grows warm as he loves, and his understanding is in light as he becomes wise.
[4] I have often seen that spiritual light. It immensely exceeds natural light in brightness and splendour, for it is as brightness and splendour in their very essence: it appears like resplendent and dazzling snow, such as the garments of the Lord appeared when He was transfigured (Mark 9:3; Luke 9:29). As light is wisdom, therefore the Lord calls Himself the light which enlightens every man (John 1:9); and says in other places that He is light itself (John 3:19; 8:12; 12:35, 36, 46); that is, that He is the Divine Truth itself, which is the Word, thus wisdom itself.
[5] It is believed that natural light [lumen], which also is rational, proceeds from the light of our world: but it proceeds from the light of the sun of the spiritual world; for the sight of the mind flows into the sight of the eye, thus also the light of the spiritual world into the light of the natural world, but not the other way round: were it otherwise, there would be physical and not spiritual influx.