How big is the universe?

More than 10 billion light-years.

How big is the Milky Way?

100,000 light-years in diameter.

How big is a galaxy?

It's not big, with a radius of about a light year.

But even at a short distance of one light year, at a low flight speed, Feitian flew for nearly three years.

Why can't you go faster and accelerate to the maximum?

The main thing is still for the safety of the ship.

Because outside of Pla, there is an asteroid belt at a distance of forty or fifty million kilometers, and there are many space meteorites, even if its density is relatively sparse, the speed of meteorites is very slow, and the probability of collision is very low, but Feitian still passed through the asteroid belt at a speed of no more than 0.2 times the speed of light in a few minutes.

Further beyond the asteroid belt, a distance of more than a billion kilometers, there is a material belt, called the "Cooper belt", which contains a lot of frozen meteorites and asteroids, which contain more meteorites, but the density is also smaller, and the threat is not very great, so the Flying Sky did not slow down much, and passed through the Cobery belt.

The next long part of the road was relatively safe, but after accelerating the speed to 0.40 times the speed of light, the Flying still did not dare to drive to the maximum speed.

Because close to a light-year away from the central star, there is a belt of matter, called the "Oort Nebula", which is the outermost material that was thrown into the outermost part after the supernova explosion, mainly some hydrogen molecules, and some frozen mass of matter, the density is very low, and it is even difficult to find its distribution under the weak stellar light.

As he travels through the Oort Nebula, Sugaru must be careful not to crash into a mass of matter, even if it's the size of a baseball.

The radar system is turned on at full power, and the weapon officer Gu Fan enters the best shooting position, and once a threatening frozen meteorite appears in front of him, he will immediately destroy it with a high-energy laser!

"Bang!"

"Bang!"

"Bang!"

There was a roar from the outer shell of the spaceship, subtle and crisp.

If you look under a high-magnification microscope, you can see that in the Oort Nebula, some small molecule substances are colliding violently with the force gold of the outer shell of the Feitian spacecraft, and even on the surface of the spacecraft, there are clusters of "sparks", as if an explosion has occurred.

In fact, this is an explosion, 0.4 times the speed of light, even if it collides with a stationary atom, the huge relative speed is equivalent to completing a low-to-medium energy collision in a particle accelerator, and can even blow up the nucleus.

Fortunately, the shell of the Feitian is composed of a kind of force metal, and a layer of high-intensity electric field will be attached to its surface, and after the negatively charged electrons hit this electric field, they will be absorbed, and the positively charged nuclei will be rebounded (photons will also rebound), so as to avoid the bombardment of external nuclei and bring damage to the surface of the spacecraft.

However, this layer of force field can play a good role in protecting the speed of the spacecraft when the speed of the spacecraft is less than 0.5 times the speed of light, and the impact density is small, once the speed of the spacecraft exceeds 0.5 times the speed of light, or is hit by a high-density object, the force of the spacecraft's hull cannot be resisted, and the hull will definitely be damaged.

This is the reason why it is difficult for an object to break through the speed of light under conventional dynamic conditions, the faster the speed, the greater the energy that needs to be given, and the greater the destructive power generated after colliding with extremely trace elements in the thin space of matter.

In addition, there is a ubiquitous "gravitational field" in the universe, in which the faster the moving object is, the greater the mass, and the increased mass will slow down the object's movement, so that it can never break through the speed of light.

The combination of these factors concludes that it is impossible for any object to move faster than light.

This is the "speed of light barrier".

The light-speed barrier cannot be broken, but it does not fully mean that humans cannot achieve faster-than-light flight.

For example, there is a curvature engine that can "glide" forward in distorted space-time, like a person walking downhill, by twisting space, and by changing space, it can achieve faster-than-light flight.

Theoretically speaking, the curvature engine can achieve faster-than-light flight, but how can it be achieved? What is the specific principle? The scientists of the Blue Star Federation have not yet mastered it, and they have not even touched the door...... Science is not imagination, it is not a movie, and every leap forward in science needs to go through a long exploration.

and the accumulation of countless failures.

"The Flying Sky has passed through the Oort Nebula and entered an absolute vacuum. ”

On this day, according to the monitoring data, the spaceship intelligent brain reported.

"It's finally out of the confines of the Brah system!"

Yun Xinghe breathed a sigh of relief, he always had a feeling of being restrained in the stellar sphere of influence, and now that the Flying Sky had flown 1 light year away, the spaceship could accelerate to the fastest speed in an absolute vacuum where there was almost only dim starlight.

"Navigator, has the route been calculated? You have been calculating it for more than two years, have you calculated the best route?" asked Yun Xinghe.

"Forget it!"

The navigator Berekov opened the projection star map, drew a smooth, curved arc in the air with his fingers, and said with a triumphant face: "Follow this route, before reaching the Omar Nebula, we can save 11 days of time, and 0.4 ten-thousandths of fuel, which is the most economical route." ”

"11 days?"

Sugaru, who was in the pilot's seat, pouted, shook his head, and said: "Brother Berekov, our voyage is 186 years, and you helped save more than ten days?"

"Tenths of a ten-thousandth of a dozen of fuel, the afterburner rod in my hand will be used up after pushing it forward for a few minutes, what savings?"

Sugaru's face was full of disdain.

"Fly your ship, don't talk nonsense!"

Yun Xinghe glared at him, turned his head to Berekov and said, "Ignore him, introduce the best route into the intelligent piloting system, the spaceship will start accelerating immediately." ”

"Yes, Captain!"

After Berekov introduced the route into the piloting system, Yun Xinghe issued an order: "The chief engineer pays attention to the working state of the engine, and the helmsman begins to accelerate!"

"Yes!"

"Yes!"

After the output power of the material reactor increased, Sugaru looked excited, and with a force on his hand, the afterburner rod was pressed down by him.

A powerful push back sensation came from the back.

"The spacecraft is accelerating, and the current acceleration is 1G, 1.5G, 2G...... 7G, 8G, has reached the maximum. ”

"The current spacecraft speed is 0.4000012 times the speed of light, 0.4000014 times the speed of light......"

"Oh~Accelerate!Accelerate!" Seeing that the speed of the spacecraft was increasing on the speedometer, Sugaru shouted, very excited.

However, the acceleration of 8G is equivalent to the weight of eight people pressing on themselves, and everyone feels a little uncomfortable, and the male team members may be fine, but for the female team members who are slightly weaker, they are all holding on.

"Mai Trin, Ai Jia, Qiaoqiao, this acceleration will last for 100 hours, will you all stick to it?"

"Hold on. Xianglan Mikoto said softly.

"What is this level, the old lady has played more exciting. Aika Uehara looked relaxed, to this extent, as a repair officer and a female man, she can really bear it.

"Brother, I can do it. Yun Qiaoqiao's face was a little pale, she was the weakest among the three female team members, even if she passed strict training before getting on the spacecraft, but it was indeed a challenge for her to bear the 8G load for a long time.

"The chief engineer and helmsman reduced the acceleration of the spacecraft to 6G for 50 hours, accelerating in three parts. In order to take care of the female team members on the ship, Yun Xinghe adjusted the acceleration strategy.

"Yes!"

After a while, everyone's burden was reduced a little and they were a lot more comfortable.

……

A month later.

The Flying Spacecraft reached its maximum speed of 0.55 times the speed of light.

The three main engines were shut down, and the two low-power engines were started every ten hours to keep the spacecraft roaming at a constant speed.

Before entering the dormant chamber to sleep, Yun Xinghe and all the crew members planned to record a video and send it to the relatives on the planet Blah to report that they were safe.

In the star field of exactly 0.5 light moon away, there is a large quantum communication relay base station, through which the recorded video can be transmitted to the Bola star within 2 seconds, and because of the close distance, there is not much limit on the amount of information, as long as it does not exceed 1G.

So taking advantage of this last opportunity to express their thoughts about their relatives without restraint, the ten crew members on the Feitian, each of whom spoke for more than half an hour in front of the camera, made various grimaces, took selfies, interacted with teammates, and finally used a high bitrate format to compress the video, and the amount of information was only 0.8G.

Before sending the message, because the time to mark the video was to be marked, and the time on the spacecraft at this time was September 11, 1531, 9:48:32, Yun Xinghe subconsciously entered this time, and the first mate Lan Xiulong walked over, suddenly shook his head and said, "No, this time is not right." ”

"What's wrong?"

Yun Xinghe raised his head and asked suspiciously.

"The speed of the Flying is now 0.55 times the speed of light, according to the time dilation formula, our time should be expanded by 1.156 times, that is, we spent one day inside the Flying Sky, and 1.156 days have passed outside, we entered this speed about a month ago, and the outside world should have passed 34.68 days, and they may have been September 15, 6. ”

"I almost forgot about it. ”

Yun Xinghe patted his head and immediately modified the video recording time.

In fact, the clocks in the Feitian will be adjusted every once in a while, especially the hometown time, in the past three years, they have adjusted dozens of times, and now, the time difference between the two clocks has exceeded 100 days.

According to the theory of relativity, the faster the moving object, the slower the flow of time, if the speed of the spacecraft can reach 0.999C, time will expand by 22.36 times, and the closer to the speed of light, the more time will be dilated.

This is a very normal physical phenomenon, especially for astronauts who are active in space, time slows down, their aging speed will be a little slower than outside, and those who want to go will feel like they will arrive earlier than expected.

But for fellow relatives, the faster you run, the faster they will age and the faster they will leave you.

In this regard, time is unfair, as if it is playing a joke on you and playing tricks on your perception of common sense.

But that's the law of physics, and that's ...... It's the law of time and space.