The origin of the universe is discussed in the Nasadiya Sukta – the hymn of creation, the 129th hymn (sukta) in the tenth book (mandal) of Rigveda.
Nasadiya Sukta with translation
नासदासींनॊसदासीत्तदानीं नासीद्रजॊ नॊ व्यॊमापरॊ यत् ।
किमावरीव: कुहकस्यशर्मन्नभ: किमासीद्गहनं गभीरम् ॥१॥
Then even nothingness was not, nor existence,
There was no air then, nor the heavens beyond it.
What covered it? Where was it? In whose keeping
Was there then cosmic water, in depths unfathomed?
The Veda says that neither non-existence nor existence existed in the beginning. This is possible if there is no time. Veda says there was no time before the creation. Modern science also agrees with this hypothesis. According to Stephen W. Hawking, there was no time before the big bang and time began at the moment of the Big Bang.
The second line talks about the absence of the sky and atmosphere. The third line puts on the question, What covered this “Timeless” things? Where and Who/What is responsible for this?
The fourth line puts another question regarding cosmic water. (Some scholars claim that this fourth line regarding a question about “Cosmic Water” is later additions to Vedas during estimated 900 BCE )
न मृत्युरासीदमृतं न तर्हि न रात्र्या।आन्ह।आसीत् प्रकॆत: ।
आनीदवातं स्वधया तदॆकं तस्माद्धान्यन्नपर: किंचनास ॥२॥
Then there was neither death nor immortality
nor was there then the torch of night and day.
The One breathed windlessly and self-sustaining.
There was that One then, and there was no other.
Veda says there is no death nor immortality before the creation and there was no night, no day. This means there was no biological life, no light or darkness, no Sun/Moon/Stars or any other planets. The third line talks about the causeless cause. The cause is the cause of its own existence. It requires no air (external impulse) to exist. It exists on svadha, self impulse.
The fourth line corresponds to the Vedic concept of a single cause: There was only that one, no other. That one exists on its own, and the existence of cause cannot be said to be an existence since there is time.
तम।आअसीत्तमसा गूह्ळमग्रॆ प्रकॆतं सलिलं सर्वमा।इदम् ।
तुच्छॆनाभ्वपिहितं यदासीत्तपसस्तन्महिना जायतैकम् ॥३॥
At first there was only darkness wrapped in darkness.
All this was only unillumined water.
That One which came to be, enclosed in nothing,
arose at last, born of the power of heat.
This line talks about the absence of light, and space. The darkness existed refers to darkness due to the absence of light. The darkness that covers it refers to the mysticism that remains in a dark void spaceless timeless entity. In the absolute void that existed before time was that, which caused one entity to be formed from heat (or energy, tapas). Present physics theories of Big Bang also says the energy causes the one quark to form the whole universe.
कामस्तदग्रॆ समवर्तताधि मनसॊ रॆत: प्रथमं यदासीत् ।
सतॊबन्धुमसति निरविन्दन्हृदि प्रतीष्या कवयॊ मनीषा ॥४॥
In the beginning desire descended on it
that was the primal seed, born of the mind.
The sages who have searched their hearts with wisdom
know that which is kin to that which is not.
According to modern science, creation of the universe is a spontaneous process from nothing, by separation of positive and negative energies. The zero-energy process is said to be “spontaneous”. This “spontaneity” is what is termed “desire” in the verse. The “seed” may stand for a quark too. The seed is referred to poetically as the “mind” of the universe. It is that which acts. The third line tells that sages know what is connected to “the not existing” to the timeless cause seems as non-existing. This paradox, however, has been solved by sages, searching their hearts for wisdom.
तिरश्चीनॊ विततॊ रश्मीरॆषामध: स्विदासी ३ दुपरिस्विदासीत् ।
रॆतॊधा।आसन्महिमान् ।आसन्त्स्वधा ।आवस्तात् प्रयति: परस्तात् ॥५॥
And they have stretched their cord across the void (or Rays),
and know what was above, and what below.
Seminal powers made fertile mighty forces.
Below was strength, and over it was impulse.
The word “Rashmi” can mean both void and rays. The sages went transverse through the quest of creation, and they knew that powers of seed made forces, self-power was below all, an effort was the above of all. Through self-power, the God (One) creates the seed, the seed creates through effort. (Seed can also be Hiranyagarbha, a Cosmic Egg)
कॊ ।आद्धा वॆद क।इह प्रवॊचत् कुत ।आअजाता कुत ।इयं विसृष्टि: ।
अर्वाग्दॆवा ।आस्य विसर्जनॆनाथाकॊ वॆद यत ।आबभूव ॥६॥
But, after all, who knows, and who can say
Whence it all came, and how creation happened?
The gods and the seekers are later than creation,
So who knows truly whence it has arisen?
The Veda repeats the questions of atheists and ignorant people and shows that the who is the only One who can tell regarding all this, and that is timeless. The verse also uses a word Arvak that means both before and after. The third line can thus mean simultaneously “Since God are after the creation” or “Gods are before creation”. The first meaning of the third line makes the third and fourth lines a question put by the atheists. The second meaning of the same word says the answer: “God is before the creation”, so that who is the only one that knows truly whence all this has come to be.
इयं विसृष्टिर्यत ।आबभूव यदि वा दधॆ यदि वा न ।
यॊ ।आस्याध्यक्ष: परमॆ व्यॊमन्त्सॊ आंग वॆद यदि वा न वॆद ॥७॥
Whence all creation had its origin,
Maybe he holds the reins, or maybe he doesn’t,
He, who surveys it all from highest heaven,
Maybe he knows it all, or maybe even he doesn’t.
All creation has its origin, without a cause there is no creation. Veda says the “Cause” may or may not even know the “Cause of the creation”. The cause is omnipotent through zero-knowledge. A common intellect of ours cannot figure out the “cause” of the creation of the universe. But, Vedic Sages (Rishis) knew it all and transferred the knowledge by composing beautiful literary works like Vedas.