Unfortunately, the reality is not science fiction. Humans don't have the common technologies in novels, such as space folding, wormhole crossing and superluminal driving.

The existing technology makes interstellar very time-consuming and labor-intensive, and it is impossible to go to new galaxies.

But Philip Rubin, a physics professor at the University of California, Santa Barbara, and Joel Rothman, a biologist, gave different answers.

They recently published a paper in the academic journal Journal of Astronautics, arguing that interstellar space is not only possible, but also quite easy.

However, the method that the two professors came up with was not to send human astronauts, but the water bear worm, the "strongest creature" on earth.

They are going to shoot water bear worms at the nearest planet with lasers. ...

Why do you want to travel through galaxies in this strange way?

This has to start with the disadvantages of traditional space technology.

For decades, scientists have been using chemical fuels to launch rockets.

Compared with other tools, this speed is fast, but in the vast universe, the chemical propeller is too slow.

As of this year, less than five spacecraft have crossed the top of the solar wind layer. It is where the solar wind meets the interstellar medium and cannot be blown. It is considered as the boundary of the solar system.

Traditionally, it takes decades to reach the top of the solar wind layer.

The first spacecraft to leave the solar system was Voyager 1, which was launched on September 5, 1977. Due to several gravitational accelerations, it flies faster than other spacecraft.

But even it, after 35 years, finally passed through the top of the solar wind layer and entered the interstellar medium on August 25, 20 12.

The same is true of other spacecraft, which travel at a speed of over 35,000 miles per hour and take 40 years to get there.

At this rate, it will take 80,000 years to reach the nearest star, proxima centauri under Alpha Centauri!

(Incidentally, Alpha Centauri is the hometown of the three-body in the science fiction novel Three-body).

It's hard to say whether human beings still exist or not after such a long time. This method is definitely not feasible.

Therefore, Professor Lubin of the University of California began to think about how to use other non-chemical methods to promote the high-speed operation of spacecraft.

"Under the existing physical and engineering technology, only antimatter and photon propulsion can be used." He wrote in his paper, "Because antimatter lacks realizable equipment, only photons are left to drive it."

What we are talking about here is photon propulsion, that is, launching a laser to send a spacecraft into space.

Lu Bin and his team turned their attention to robotics and photonics.

In 20 15, with the support of NASA and private foundations, they designed a small spacecraft with solar sails, which can reach the speed of light of 20% to 30% after being launched on the earth or the moon with a laser array.

At a speed of about 65438+ 10 billion miles per hour, these spacecraft will only take about 20 years to reach proxima centauri!

"This is unprecedented, pushing macro objects at a speed close to the speed of light." Lu Bin told the media.

In order to approach the speed of light, the mass of the spacecraft must be as small as possible, so the spacecraft made by Lubang is only a few grams.

This is a palm-sized CD, which looks like a DVD. It is filled with all kinds of precision instruments, which can sense, collect and transmit all kinds of data to the earth along the way.

These spacecraft belong to NASA's Starlight Program. With the continuous expansion of this project, Lu Bin said that in the future, a laser launch spacecraft with greater mass and slower speed will be developed, enabling humans to complete the mission to Mars within one month.

Why use laser to launch? We figured it out.

But what about the water bear worm?

The reason is actually very simple. When the spaceship arrived in Dakban, Lu realized that it could accommodate creatures.

In that case, why not take this precious opportunity to study the effects of interstellar travel on living things?

Few animals want to put a living thing into a narrow spacecraft and let it survive in the space environment for a long time.

Water bear worm is one of them. It can perfectly cope with space travel, and it seems to be born for this.

Water bear worms, also known as slow-moving animals, are extremely small, only 50 microns to 1.4 mm, mainly living in fresh water and wet soil.

This animal has super endurance to extreme environment, and can survive from -200 degrees to 149 degrees. They can be found from the snow-capped mountains at an altitude of 6000 meters to the deep sea of 4000 meters.

Water bear worms can survive in a vacuum, can withstand radiation hundreds of times higher than the lethal dose of human beings, and can also survive under the seabed pressure of 6 times that of human beings.

Lack of oxygen and water will not kill the water bear worm, it will automatically dehydrate the body and curl up with eight legs into a suspended animation.

The metabolism of water bear worm in suspended animation is very little, only 0.0 1% in normal state, and there seems to be no sign of life.

But after a few decades, even with a little water, they can instantly revive and continue their previous lives.

Because of the characteristics of this "invincible Xiao Qiang", Lu Bin decided to make it the first passenger in interstellar travel, and let the universe see how powerful the insect-level animals on the earth are.

Along with them are Caenorhabditis elegans, an old passenger who travels in space. Caenorhabditis elegans has often been the experimental object on the International Space Station and spacecraft, and once survived the disintegration accident of the space shuttle Columbia.

Although the resistance is not as strong as that of the water bear worm, it can also enter the suspended animation state through dehydration and freezing.

After being frozen for decades, the larvae can immediately revive, quickly develop into adults and give birth to hundreds of offspring two days later.

In the environment of food shortage or overcrowding, larvae will enter the stage of alternative development and can survive for months without eating.

Because the genome of Caenorhabditis elegans has been thoroughly studied, Professor Rothman, who is in charge of biology, is modifying its genes in order to enhance its resistance to space radiation.

After the completion, water bear worms and Caenorhabditis elegans will be loaded on the spacecraft, with thousands of them in each disc, and they will automatically enter the frozen suspended animation state.

These creatures will always fly in suspended animation, and when the spacecraft reaches a specific position, the built-in chip will heat up and wake them up.

After that, other instruments will detect the influence of interstellar travel on them and send the results to Earth.

"When spacecraft fly away from the earth at near the speed of light, we can test their memory ability of trained actions." Rothman said, "We can check their metabolism, physiological function, neurological function, reproduction and aging."

"Most experiments done in the laboratory can be carried out on chips in space."

Since 20 15, researchers at the university of California, Santa Barbara have been preparing to go to other stars, but so far, they still don't know when the spacecraft can leave, which may take several years.

But netizens have panicked. They are worried that water bear worms will invade aliens in minutes and the universe will be polluted.

"This is the origin of embryology. No, life did not come from the impact of space meteorites, but happened to fall on an unsuspecting planet.

That's not true.

The real origin of embryology is a group of boring space monkeys shooting water bears everywhere with super gorgeous laser cannons.

I wrote the script myself. "

(note: embryology is a theory of the origin of life, which holds that life on earth comes from a meteorite carrying microorganisms)

"Well, launch billions of sleeping water bear worms into space and launch them wildly in all directions. After a billion years, we humans will rely on the water bear worm brothers to colonize all the planets. "

"In a thousand years, alien civilizations will attack us and accuse us of sending water bear insect commandos to sneak up on them."

"Damn, maybe this is the purpose of our human existence, sending water bear worms to as many planets as possible and sowing as many seeds of life as possible. In this way, there are always some lives that can survive. "

Lu Bin said that they had considered ethical issues and thought that the project would not pollute other planets.

"Some people talk about spreading life, called embryology. That is, life spread to the earth through comets, or another civilization deliberately spread life to the earth. If you really spread life like this, it will really cause big problems. "

"But so far, there is no danger of external pollution. Because any detector close to other planets will burn in their atmosphere or be destroyed in a surface impact. "

"At the same time, our spacecraft is flying in one direction, so there is no danger of bringing alien microbes to the earth."

In 20 19, the Israeli lunar probe loaded with water bear insects crashed on the moon, which caused considerable panic at that time, fearing that water bear insects would rule the moon.

A group of scientists experimented with water bear worms on the earth and killed them with shells of 90 1 m per second, which proved that they could not survive the crash.

Flying to proxima centauri, 4.2 light years away, the chances of water bear insects surviving are even smaller, and all kinds of things may be encountered along the way, and machines will kill insects and die.

but ...

if ...

What if life really spread?

Lubang and others don't want to stop because of this possibility, although stopping is indeed the safest way.

"I think it is our human destiny to keep exploring." Rothman said, "We explore in smaller and smaller dimensions and find subatomic particles. We are also exploring in larger and larger dimensions.

This constant exploration is the core of our species. "

"The desire to explore is innate. I don't think it should, and in fact it will not be suppressed. "

Well, human scientific and technological progress is always carried out in various adventures, and this time is no exception.

It's just that if something really goes wrong, we don't know what will happen in distant space ...