Earth created in two periods: Quran 41:9 "Say, "Do you indeed disbelieve in He who created the earth in two days and attribute to Him equals?..."
Universe in six periods:
Your Lord is Allah, Who created the heavens and the earth in six days and then settled Himself firmly on the Throne... (Qur'an, 7:54)
With this we know, that the age of the Earth = 2/6 * age of the universe
Simplified it says, the age of the Earth is one third of the age of the universe.
Let's confirm it now! 13.7 billion * (1/3) = 4.5 billion years! Yes it's correct!
But why in a ratio? Let's see the explanation:
According to the Theory of General Relativity, "time has no independent existence apart from the order of events by which we measure it."
Basically, time is a perception, and not a fact.
EXAMPLES:
How old am I? 16 years old
Now it is just my perception that I'm 16 years old. The years are calculated from how many times the Earth revolved the Sun. Every time measuring device has some sort of pendulum or ticking. It is only relative to the perceiver.
Our body has no natural system to calculate time. Lincoln Barnett: "Just as there is no such thing as colour without an eye to discern it, so an instant or an hour or a day is nothing without an event to mark it."
Example 2: Dreams
Our dreams seem to last hours or days, when in reality only a few seconds pass between each dream!
Einstein says: "the speed of time changes depending on the speed of the object and its distance from the centre of gravity. As speed increases, time is shortened, compressed; and slows down as if coming to the point of "stopping".
For example, if you're locked in a room with a window where you can clearly see the sun set and rise, you can use this to calculate how many days you've been in the room for. When your kidnapper asks you how long you've been in the room for, you'd think 5 days because the sun set 5 times, but the kidnapper says it was actually 3 days. The window was just projected by a simulation machine and the Sun was moving quicker. Think, is there any other way you could measure the time without ticking equipment?
In the Qur'an!!
On that Day He will call you, and you will answer (His Call) with (words of) His Praise and Obedience, and you will think that you have stayed (in this world) but a little while! (Surat al-Isra, 52)
And on the Day when He shall gather them together, (it will seem to them) as if they had not tarried (on earth) longer than an hour of a day: they will recognise each other. (Surah Yunus, 45)
He will say: "What number of years did you stay on earth?" They will say: "We stayed a day or part of a day: but ask those who keep account." He will say: "You, stayed for only a little while – if you had only known!" (Surat al-Mumenoon, 112-114)
Yet they ask you to hasten on the Punishment! But Allah will not fail in His Promise. Truly, a day in the sight of your Lord is like a thousand years of your reckoning. (Surat al-Hajj, 47)
The angels and the spirit ascend to him in a day the measure of which is like fifty thousand years. (Surat al-Maarij, 4)
Then We drew (a veil) over their ears, for a number of years, in the Cave, (so that they could not hear). Then We wakened them up so that We might know which of the two parties would best calculate the time that they had tarried. (Surat al-Kahf, 11-12)
Such (being their state), we roused them (from sleep), so that they might question each other. Said one of them, "How long have you stayed (here)?" They said, "We have stayed (perhaps) a day, or part of a day." (At length) they (all) said, "Allah (alone) knows best how long you have stayed here.... (Surat al-Kahf, 19)
Or (take) the instance of one who passing by a hamlet, all in ruins and quite desolate, said: "Oh! how shall Allah (ever) bring it to life, now that it is dead?" Therefore, Allah caused him to die for a hundred years, then brought him back to life. Allah asked: "How long did you tarry (thus)?" He said: (Perhaps) a day or part of a day." He said: "No, you have tarried thus a hundred years; but look at your food and your drink; they show no signs of age; and look at your donkey: And so that We may make you a sign to the people, look further at the bones, how We bring them together and clothe them with flesh." When this was shown clearly to him, he said: "I know that Allah has power over all things." (Surat al-Baqara, 259)
