According to science, real-life time travel occurs through time dilation, a property of Einstein's special relativity. Time dilation is the difference in the elapsed time as measured by two clocks. It is either due to a relative velocity between them or to a difference in gravitational potential between their locations. Einstein was the first to realise in the modern era that time is not constant, as previously believed, but instead slows down as you move faster through space. So, time dilation can make it possible for the passengers in a fast-moving vehicle to advance further into the future in a short period of their own time or we can say- time travel. The theory of time travel gained a lot of strength after Einstein. Today's scientists have many beliefs regarding time travel. It is also said that if you are to enter a black hole in space and come back, many years would have passed on earth in that time. Astronauts are the perfect example of the time dilation thing. They spend a lot of time in space stations rotating fast away from earth. According to the theory of relativity, astronauts on the space stations age more slowly due to the spacecraft's high orbital speed. That's time dilation, and it means that when they return to the earth, they are a bit younger than they would have been- as if they have travelled into the past.
In the religious texts and ancient scriptures of our Sanatan, all these things have been accurately described. In the Shrimad Bhagavatam, a similar legend has been told about the time dilation !
In Satyug, there lived a benevolent king named Kakudmi. He had a daughter named Revati. She was endowed with spiritual, virtuous and auspicious qualities. When Revati became of marriageable age, king Kakudmi was worried about her marriage. He did not find any groom suitable for his extraordinary daughter. Unable to find a suitable match for her daughter on the earth, king Kakudmi decided to travel to the Brahmalok (that exists millions of light years away from earth) to get some advice from the Brahmaji. He along with his daughter travelled to the Brahmalok. On arriving at the Brahmalok, they were told to wait as the Brahmaji was listening to a musical performance by the celestial musicians. After the musical performance, Brahmaji met king Kakudmi and asked him for the reason behind his visit. King said, “I am not able to find a suitable match for my daughter. So, I have come here for your guidance and advice.”
Brahmaji smiled and explained to him that time runs differently on different planes of existence. His few minutes in the Brahmalok were equivalent to many yugs on the earth. By the time he stayed there after travelling from the earth, millions of solar years had already passed. He was shocked and surprised to hear that. King Kakudmi asked thou for a solution. Then Brahmaji said to him, “If you start now, by the time you reach earth, you will be in the Dwaparyug. There you can marry your daughter to Balaram, the incarnation of Shesh ( the serpentine demigod (Nag) associated with Vishnuji ). He is the only perfect worthy match for your daughter.”
After gaining guidance from Brahmaji, the king Kakudmi returned to the earth with his daughter Revati. He was amazed to see that the weather, trees, animals, structure of the earth were not the same as before and there had been a huge change in the qualities, size and intelligence of the human beings. The size of all animals, trees, humans had reduced considerably. Humans were also not so strong and tall as before, also their intelligence and spirituality had declined a lot.
King Kakudmi now reached to meet Balramji with Revati without delay and informed him about his dialogue with the Brahmaji in Brahmalok. Revati and Balaramji were certainly a suitable match for each other, but there was a problem. Being from the Satyug, Revati was much taller and bigger in size than Balramji. Balramji found a solution for that, too. He took his divine plough and touched the head and shoulders of princess Revati with the plough. Within a moment, Revati's size reduced to a suitable size for Balaramji. After that, the marriage of Balramji and Revatiji happened.
This legend about the time dilation and in a broader way time travel is a salutation to the knowledge about the science of our ancestors and the Sanatan !
