From the day human beings were born, we have seen the vast world of the earth. In the eyes of the ancients, the earth was vast and could never be finished. The ancients basically relied on their feet to walk, and the most advanced means of transportation was nothing more than a horse-drawn carriage.
Most of the ancients believed that the earth is an endless world, and it is impossible to complete it by relying on human resources. However, with the continuous development of human civilization, when we entered the age of science and technology, we realized that the world of the earth is not boundless, but a sphere, and human beings live on the surface of this sphere.
Standing outside the earth, we can easily see that the earth has a size. The circumference of the earth is about 40,076 kilometers from the equator. Although this distance is relatively large, it can still be completed at the speed of human walking. If there are no obstacles along the way, at our walking speed of 5 kilometers per hour, it takes about 8015 hours to walk along the equator, which is about a year or so.
Of course, the above situation is only in our ideal state. In fact, the surface of the earth is full of risks and obstacles of various terrains such as the ocean. It is impossible for us to walk along the equator to complete a circle. When we see this data, we understand that the earth is actually not big and can travel the world in human footsteps. Otherwise, Homo sapiens, the ancestor of modern humans tens of thousands of years ago, would not have come to Asia from Africa.
On the earth, in order to better measure distance, we have meters, kilometers and other distance units. These distance units have played an important role in the development of mankind on the earth. But these distance units, when humans walked out of the earth, the moment they saw the vast universe, its limitations were manifested.
We can measure distances on the earth in meters and kilometers, but facing the vast universe, these distance units are too small. If the distance between celestial bodies in the universe is measured and recorded in meters and rows, such as the distance between stars, then a distance is a huge number. A thick stack of paper may only be able to record the distance between two stars, and the distance between galaxies is even more distant, making it impossible for us to record in units of distance from the earth.
At this time, scientists proposed a new distance unit: light years. Light-year refers to the distance traveled by light in a year. It is used to measure the distance between distant celestial bodies in the universe. It is a unit of distance unique to the universe. So what is the distance in one light-year?
We all know that the speed of light is about 300,000 kilometers per second, and the time of a year is about 31556925.9747 seconds, so the distance traveled by light in a year is 9.46 trillion kilometers. So human beings rely on walking, and it will not take long to walk the earth, so how long will it take to walk a light-year?
We can make a simple calculation. As we said earlier, the speed of human walking is about 5 kilometers per hour, and one hour is 3,600 seconds. We walk non-stop, we can walk 120 kilometers in a day, 3,600 kilometers a month, then 43,200 kilometers a year. It takes 219 million years for a person to travel a light-year.
The number of 219 million years makes many people feel incredible. You must know that in the age of life on earth, dinosaurs were just born 219 million years ago. At that time, the earth was not divided into six major plates, but it was still a whole Pangea continent. At the speed of human walking, it takes more than 200 million years for us to complete a light-year. Obviously, we can’t finish it at all. The life span of human beings is only about a hundred years, and human beings are only a few million years old.
And light-years are just the most basic unit of distance in the universe, equivalent to meters in the age of the earth. One light-year is very far away to us, but one light-year is nothing in the universe. The star system closest to the solar system is 4.2 light-years away. In the entire solar system, the diameter of the Oort cloud can reach more than one light-year.
It is because we have seen the vastness of the universe that many people are worried about the future of mankind. We must know that the fastest detector for human beings is the Parker Solar Probe, which has a speed of 95 kilometers per second. This speed is incredible on the earth, but this speed is still pediatric in front of the speed of light, even the speed of the tortoise. Not on.
So is the speed of light fast in the universe? Of course not. In fact, the speed of light can only be regarded as a tortoise speed in the universe. To know that the diameter of the Milky Way is more than 100,000 light-years, it takes at least 100,000 light-years to travel through the Milky Way at the speed of light. And the Milky Way is just dust in the universe, and above it there is an even more expansive Virgo Supercluster, which has a range of hundreds of millions of light-years.
At present, the observable universe is 93 billion light-years away. This range is not the entire universe. It may be just the tip of the iceberg of the entire universe. If the vast space of the universe, even if we achieve the speed of light, we can only move within a limited range of the Milky Way at best, and cannot reach other large galaxies, such as the neighboring Andromeda Galaxy, which is millions of light-years away from the Milky Way.
It can be seen that the speed of light is nothing at all in the universe, and human beings are too small in front of the universe. If we want to truly explore the mysteries of the universe and become the overlord of the universe, then we need the ability to travel across the universe. And this ability requires a speed mode beyond our cognition, we can also call it space jump.
It is impossible for the traditional speed model to explore the entire universe. Whether it is the speed of light or the ordinary speed of light, the scope of the universe we can explore is also very limited. Only with the ability to break through space and realize the legendary space jump can we hope to quickly travel to every corner of the universe.
Of course, human beings need to face many problems to achieve such a goal, and it takes a very long time. The first impression of the universe currently observed by mankind is that it is very lonely. According to the age of the universe at 13.8 billion years, there should be a large number of intelligent civilizations. If some of these civilizations develop early, they may already have the ability to jump in space, but until now, we have not found any advanced civilization to come to the earth.
Such a result makes many scientists feel terrified. The lonely universe indicates that the Great Filter Law may be real. The universe civilization will go through filters one after another during the development process. The higher the level of civilization, the greater the danger it faces. Many ancient civilizations of wisdom may disappear into the long river of the universe because of the existence of the big filter.
If this is the case, then human beings may or may not finally reach the end of science, and will not have the ability to travel throughout the universe. Even so, human beings cannot be pessimistic. Only by working hard to develop technology step by step can we continue to grow stronger and discover the truth behind the universe.