After a long period of evolution and exploration, physics has found that the speed of time is not immutable, in the three-dimensional space we live in, objects are always in constant motion, there is no absolutely stationary thing, even if an object is stationary relative to the earth under its feet, but it is moving relative to the boat that is moving in the river.

Time, on the other hand, is always perpendicular to all the directions of motion of objects in space, and time and space are a whole, called "space-time", and the speed of the passage of time and the combined speed of the object's motion speed show the constant speed of light. That is, if the object is absolutely stationary, then the speed of time is equal to the speed of light.

And the faster the object moves, the slower time passes, just as the time of a person flying at high speed in an airplane will always pass a few seconds slower than the time of a person walking slowly on the ground.

If a mass object moves at the speed of light (which is basically impossible), then time stops passing, that is, the object moving at the speed of light does not grow old, does not disappear in history, it becomes eternal.

Is there a place in the world where time stands still?

Yes, this place is called a "black hole".

Physicist Schwarzschild calculated that if the radius of the Sun were reduced to 3,000 meters, the Sun would become a black hole and no light would emit anything. If the Earth were compressed to a radius of only nine millimeters, the Earth could also become a black hole. Any object that has mass, compressed within the Schwarzschild radius, becomes a black hole, which is also figuratively called the "event horizon", because the human line of sight is at this radius as the critical point. Once this radius is crossed, it is "all black".

The enormous gravitational pull in the black hole cannot escape even at the speed of light, and time stops flowing in it, or in other words, time no longer exists, (a situation that humans cannot imagine).

……

The "black hole" is shaped like a funnel, and the bottom of the two "black hole" funnel is combined with each other to form a "wormhole", and the central point of the connection of the two "black holes" is called the "space-time node".

There is a certain type of researcher who believes that our world is made of the void, and that all things in time are composed of some kind of non-attribute energy, which can change and build our world, people, animals, metals, trees, ...... Because someone is looking at things, things have specific shapes and properties, but are these real? Is what is in front of you really there?

Regardless of such awkward philosophical questions, the current situation is that there is a "river" of energy in the void, with no beginning and no end, and there is a view that most people support, that is, time is flowing, which is the "river" in front of us, and the front of the river may be the future scene.

If so, is time travel possible?

The results of this observation caused a super earthquake to occur throughout the scientific community. It may herald the dawn of a new era, whether it will be a blessing or a curse, it is unknown.

……

Luo Yu was lying on the bed, falling into a dream at this time.

The river is still familiar, black and white, Luo Yu stands on top of a flat boat, the surrounding wide and boundless river surface is not alarmed, although it is in a dream, his consciousness seems to be very awake, there is an independent consciousness, and he can distinguish the difference between reality and dreams.

He was already surprised, and when he raised his head, there was a deep starry sky in the sky, the white fog in front of him was full of white fog, and he couldn't see anything clearly, and the back was lifeless, and he couldn't see through it.

Suddenly, at this moment, the red crystalline energy body in the core of the ability trembled, and in the blink of an eye, it came out of the body, and it appeared suspended in front of the wooden boat, and Luo Yu was startled.

This crystal was obtained from a creature in another dimension, how could such a change occur at this time?

The next situation made Luo Yu stunned, the appearance of the crystal seemed to touch a certain nerve of the wooden boat, the whole body of the boat was covered with a misty halo, and the strange words that were originally faintly on the soles of the feet gradually condensed and glowed at this moment.

In an instant, a clear stream of consciousness information was transmitted to Luo Yu's mind, not only the information of words, but also many feelings, hearing, touch, and even smell, as well as various perceptions of this information, as if from the original memory.

Luo Yu closed his eyes and carefully comprehended this information, the expression on his face changed, as if he had lost and regained, and as if he was lost, and his emotions naturally flowed out that even he couldn't control himself.

This is a memory of how to use the red crystalline energy body.

Luo Yu stepped forward and grabbed the red crystalline energy body with his hand, walked to the edge of the wooden boat, picked up a little "river water" with his hand, poured it on the crystal, the crystal shone slightly, he bit his finger, a drop of blood fell on it, and then used his fingertips to paint a strange symbol on the crystal.

After doing this, he took the crystal and pressed his hand to the middle of the spine behind his back.

"That's it," he muttered to himself.

One, two, three......

About a minute later.

"Brush", a fiery red wing stretched out from behind, the length of the wing is about ten meters, and the wings of the arrogant and violent fire dragon that day are the same, covering the sky and the sun, breathtaking.

Luo Yu suddenly had an urge to flutter his wings and fly to the sky.

The wings are extended, and the feathers are bright red as blood, like the most beautiful treasures in the world, shining with the brilliance of flames.

Luo Yu bent his knees, jumped forward, and his body soared into the air.

"Boom!" Just after jumping to a height of about five meters, his whole body seemed to have smashed into some invisible barrier above, and the center of gravity of his whole body was unstable and fell down.

……

"Oops......" he touched his head as if something had just hit him, and he grinned in pain.

With his hazy eyes open, his vision gradually cleared, and he looked at the window, and the moonlight poured through the gap on the desk, on the floor and on the edge of the bed, gilding the room with a silver glow, beautiful and dreamy.

Just like the dream just now.

Suddenly he touched the position behind him, and suddenly his expression froze.

In the moonlight, in an ordinary dormitory room, a young man spread his flaming wings on his back, filling most of the room.

"It's terrifying!"

……