Energies in the Vedas

Modern science mainly deals with three kinds of energy: heat, light, and electricity.

Veda also talks about three kinds of energy — Agni, Prakasha or Jyoti, and Vidyut.

Agni is at the level of earth — on earth.
Light is in the Dyuloka or Swargaloka, whose in-charge is Indra.
Indra is one of the 12 sons of Aditi, called the Dwadasha Adityas.
These 12 brothers are among the 33 Devas, the rest being 8 Vasus, 12 Rudras, and the two Vishwedevas or Ashwins.

The energy in Surya Mandala is called Indra.
He is the ruler among the Adityas.
That's why he is Devaraja Indra.

These 12 Adityas represent the twelve different aspects or functions of Surya — like Indra is the ruling aspect, Pusha is the nourishing aspect.

इन्द्रो ज्योतिर्ज्योतिरिन्द्रः — says Veda.
Indra is light itself.
Light is Indra.

How many horses are there in Surya's chariot?
Seven.
How many components are there in light?
Seven — VIBGYOR.

Now the third form of energy is in the atmosphere — in the clouds — Vidyut, the lightning, electricity.

The atmosphere is considered as filled with water — it is an ocean — because of the humidity or water vapor present there.
So lightning is called अपां ज्योतिः in the Veda — विद्युत् वा अपां ज्योतिः.

Lightning in Veda is called स्तनयित्नु.
Veda says this is also Indra — स्तनयित्नुरेवेन्द्रः.

It is established at several places in the Veda that Agni and Surya are one and the same.
Light is an effect of heat.

Agni on earth is called Agni.
Agni in the sky is called Aditya or Surya.
Agni in the atmosphere is called Vidyut.

Essentially, they are one and the same.

Veda recognizes gravitational force — starting with the one which makes the earth revolve around the Dhruva Nakshatra through the Kranti Vritta.

Upanishad talks about the gravitational pull applied by the Prithvi Devata upon everything on her surface so that they don't fly away — they have some amount of locational permanence, stability.

Veda considers mind as a form of Vidyut — compares mind with electricity.
Like a flash of lightning, mind can also breach the limits of the sensory organs and go wherever it wants.
But like the lightning, this is also short-lived.
It doesn't stay anywhere, remain anywhere for long.

So mind is also an energy.

Heat, light, electricity, mind, energy of the mind — then energy in the food — that keeps the body heated, that supplies energy to the body for various actions, that converts itself into tissues by replacing dead cells and building new cells.

But Veda considers all these as different forms of one single energy, and you would see these terms being used interchangeably.

Like you will see gravitation being called ध्रौव विद्युत्,
The energy in the food called as सौम्य विद्युत्,
The sunlight being called as सौर विद्युत्.

Ramaswamy Sastry and Vighnesh Ghanapaathi