.

The old man looked up at the sun in the sky, the sun was very good, and the brilliant light shone on the courtyard where the grass hall was full of flowers, and it was about to hang in the middle of the sky.

"Kids, according to the distance between the sun and our position, it's about 150 million kilometers, the speed of light in a vacuum is 300,000 kilometers per second, and it takes about 8 minutes and 20 seconds to get to where we are now, in other words, the sun we see now is just what it looked like it was 8 minutes and 20 seconds ago! But what if it's a star 100,000 light-years away. When we see a star 100,000 light-years away, the beam of starlight that catches our eyes has already traveled 100,000 light-years across the vast universe. In other words, we won't be able to see that star until 100,000 years from now...... The universe is endless, we can't know it all, now, children, let's go on a journey with me for the heart and the eye, okay?"

"Good!" the children said in unison, all of them happy.

"We were on a high-speed trip, jumping at 10x speed every time. Start with 10 to the power of 0, which is 1 meter, and then increase each time to the power of 10. From 10 meters, 100 meters, 1000 meters...... And so on, until the world is endless. Are you ready, kids?"

"Ready, Master. ”

The old man waved his sleeves slightly, grabbed a wisp of green mist in the mountains, put it to his mouth and blew it, only to see an ethereal green cloud lingering around everyone. The old man was the first to step on the rolling green clouds, and the children stepped on the clouds one by one. The clouds are like a spaceship, carrying everyone high into the sky.

"We look at the flower in front of us from a distance of 1 meter, and the petals of the flower, the vivid pink color clearly catches our eyes, and then, we are 10 meters away from the flower, and as we zoom out, we see a flora of flowers, and we continue to zoom out 100 meters, and at this distance, we see the boundary of our courtyard. We stood 1 kilometer in the air, our Lingtai Thatched Cottage was completely in our eyes, the flower was no longer visible, we continued to fly to the air 10 kilometers away from our yard, we can now see the face of the entire Qinggeng Mountain, and the Forgotten Worry River like a silver ribbon flowing into the valley into the distance, but we can no longer see every house in our Lingtai Thatched Cottage. We went to stand 100 kilometers in the air, and from this height, we could see the earth, the mountains and valleys were no longer clear, we could only see the colors of the various areas, the green plains, the yellow-green mountains, and the blue lakes that looked like some strange symbols. ”

The old man stood in the clouds with the children, pointing out the earth below, the clouds and mist were like floating waves, the distant sun spread the golden light on the sea of clouds, and the wind blew the hem of their clothes.

"Now let's go to the station to the 1,000 kilometer point, and let's look at where we started. ”

"Our Lingtai Thatched Cottage can't be seen at all, the whole place is like a dark green patch, surrounded by blue on three sides, it's the ocean. One of the children said.

"Well, let's continue to stand at an altitude of 10,000 kilometers, let's see where we came from. ”

Everyone stood in the sky, there were no clouds around them, it was a dark night, just like standing in a deep black pool, and those distant stars that could be seen were like diamonds set in the curtain of the night. Looking at the place 10,000 kilometers away, there are patches of white clouds drifting on it, which may sometimes cover some areas of the huge blue planet in your eyes, there is a blue sea on the blue star, there are green and yellow-green continents, and there are faintly light brown desert areas on the continent.

They continue to fly 100,000 kilometers beyond the sky. At the moment, the blue planet looks small. The beautiful blue planet resembles a small blue ball in the black sky setting, and a circle of white gas at the edge of the ball reflects the sun's halo, reflecting a bright and dazzling blue, beautiful and charming. Surrounded by distant starlight on the set, the stars were like golden grains of sand scattered on a black curtain, because there were no clouds to obscure the vision, and the stars were always lit up and did not flicker.

"Children, this is the earth we live in, she embraces our other world, that is our home, let's talk about it, is our home beautiful?"

"It's so beautiful!" the children exclaimed.

"We're going to the moon now, which is 380,000 kilometers away from our blue star. "The old man and the children stepped on the light clouds, turned into a blue-white streamer, and flew to the moon.

On the moon, they stood silently on a high cliff protruding from the top of a circular moon mountain, silently staring at the silent blue star in the distant sky. In the silver-blue light and shadow reflected from the blue star, there is the majestic Guanghan Palace located on the far moon surface and the jade pillar of the dragon flying in the square...... , but seeing the distant horizon of the moon, the vast crater, the heavenly river with shining silver waves quietly flowing between the distant stars, and the six stars of the Southern Dipper hidden in the depths of the stars in the black canopy in the distance, as well as the Lingxiao Treasure Hall of the Nantian Heavenly Court looming on its main star Tianfu Star, and the Beigong Heavenly Court located on the main star of the Big Dipper, it seems that the white palace wall that stands thousands of miles is within reach; 。

The sky of the distant divine realm is really dark, mysterious and desolate.

The blue planet hanging obliquely at your fingertips, sprinkled a transparent and pale blue halo on the child's holy and soft face, putting a touch of bleak color on everyone, there is no wind, no clouds, only so lonely and silent .......

Standing on the moon, the universe is pitch black, time is as if it stands still, the sun is brighter than usual, and the earthly earth is much larger than the sun, but there is no beautiful sunrise and sunset, and there is no beautiful scenery of dusk and early morning, the blue star in front of you is very beautiful, but it is also exceptionally bright, and you can clearly see the various continental plates above. Everyone felt that they were so small, and there was a fear in their hearts, a sentimentality of being abandoned by their homeland.

The earth seen from the moon is bright and beautiful, but it is also another inexplicable desolation.

"Children, we are now standing on the moon and looking at the cosmic world at a distance of 1 light year, that is, 9,460 billion kilometers, but this has to be done with the help of the heavenly glasses on the mountain behind our Lingtai Thatched Cottage. ”

The old man said calmly, and casually drew an arc to the crater under his feet, only to see that in the huge crater under their feet, they immediately began to build a huge titanium skeleton network by themselves, and the grid was soon paved with huge triangular silver mirrors. The old man tapped his finger in the void, only to see that in the mid-air in front of them, a miniature three-dimensional small cosmic cloud immediately appeared, and in the cloud, all kinds of cyclone-like substances rotated and splendid, magnificent, and magnificent.