If you are not going to make a secret out of the passage, you can dig in the “Berlin” way: a trench is dug, walls and a roof of the future passage are built in it, after which everything falls asleep. But the neighbors will come to see, everyone wants the same, only bigger, as a result, someone accidentally digs up hell. It is better to dig unnoticed, according to the "Parisian" method: a vertical well is dug, and an adit is led from it sideways.

Where to dig

Sandy soils are ideal. At one time, they made it possible to dig passages under the Berlin Wall, including the famous "Tunnel 29" 140 meters long. Clay is difficult to dig, and there is a higher chance of stumbling into interstratal waters. It is useful to drill wells in advance along the entire trajectory of the course and find out what you will be dealing with.

How to strengthen

If you are digging an adit without reinforcing the walls and ceiling, place a slab with the dates of life on top. When you fill up, relatives will be able to limit themselves to a buffet table. But it is better to strengthen the course every half a meter with a support - a frame of tarred boards. When it is ready, the walls and ceiling must be thoroughly sheathed with boards, or even concreted, as the Palestinians do in the secret tunnels from the Gaza Strip to Israel.

How to equip

To keep the tunnel dry, it must be done under a slope. It is desirable to arrange forced ventilation: a fan at the entrance and pipes with holes along the entire length of the structure. One of the problems of the "tunnel of life" in Sarajevo, through which people got out of the besieged city, was the lack of ventilation. As a result, we had to get oxygen masks.

How not to fall asleep

You can dig an underground passage only in your own land. Otherwise, if it is discovered, it will be covered up, and you will pay for the event. Before starting the process, find out if there are cables, oil pipelines and missile silos in the way. A depth scanner will help with this. And underground gas analyzers for carbon dioxide and methane will not be damaged, otherwise the tunnel will be different - with a flight to bright light and a sense of grace.

How to mask

Newly captured Colombian drug lord Guzmán was leading his underground passages into the sewers, and this helped him for the time being. Crashing into general communications is illegal, but you can apply the principle itself and disguise the exit as a familiar part of the landscape - a board toilet, a beach locker room or a corporate party with Nagiyev.

At the end of December, the 50th anniversary metro station "Exhibition Center" will open in Kyiv. The track section and the station itself were built in record time - less than one year.

Today we will see how the metro is being built, walk through the tunnels, and also see the legendary Zil-130 on railway wheels.

Metro tunnel in front of the Exhibition Center station, Kyiv, Ukraine. This is the lobby of this new station:

There will be rails here soon:

How the tunnel itself is laid. A rotary machine operates in the tunnel, its length is 120 meters, and the main part is the front head, with a diameter of 9 meters. The machine "digs" a tunnel, and all the waste soil is taken to the surface.

The mechanized shield complex must be located at a depth equal to or greater than the size of the shield itself. That is, if the diameter of the shield is 6 meters, then there must be at least 6 meters above it.

The head of the Herrenknecht complex:



View from reverse side. On the left side of the circle, you can see the jacks that rest against the last installed ring and push the shield forward as the soil is developed:

And this is how the tail of the manual complex looks like:

The tunnel consists of rings, each of which consists of seven elements. The round ring is the most optimal design for tunnel construction, far superior to the square shape. Square tunnels are built where the tunnel is built in an open way from above.

The metro is being built around the clock, and 2,500 people work on this line.

Ring elements:

Legendary Zil-130 which I have seen before in pictures. Truck on railroad wheels looks bright! There are 3 such machines, they are used to transport concrete:

The concrete itself is loaded from the surface through special wells:

Probably one of the most trivial questions of an amateur metro builder: “Did you meet something unusual and interesting while laying the tunnel?”

There is nothing unusual here, all that meets on the way are problems and obstacles. There were collisions with reinforced concrete blocks, and then the car broke down. But the metro is being built under residential buildings.

The 50th anniversary Vystavochny Tsentr station was built in just one year, which is an incredible figure given the complexity of the site. In order to be on time, two innovations were introduced - the train exit chamber (the section of the track where the train turns around in the tunnel) was designed and built in front (!), And not after the station.

Departure camera:

Ventilation units:

Concrete pouring of the lower part of the tunnel, where the railway track is then laid:

Surface or underground metro?

The metro must be underground. It does not interfere with existing communications and traffic interchanges, does not create noise for nearby houses. The station itself must be laid at a convenient depth for passengers - 12 meters.

Probably, many have noticed that before and after the metro station goes down. Why is this done? To save electricity! After the station, the train goes down and accelerates, and when approaching the station, it goes up and natural braking occurs. The maximum allowable slope is 4 cm in height per 1 meter of track.

The signal - one strong and fast, and the other slow and weak, as if the heartbeats of a young man and an old man traveled a thousand light years and were heard by the most sensitive "ear" on Earth. The Ear is a five hundred meter radius spherical radio telescope (FAST), which is the largest in the world. The area of ​​the bowl of its antenna is comparable in size to the area of ​​30 football fields. The building is located in one of the valleys of the Guizhou province in southwestern China.

China's 500m FAST Telescope

While the telescope was being debugged and the trial mode of operation was in progress, after its commissioning in 2016, FAST discovered dozens of possible pulsed sources of radio emission - pulsars, six of which were confirmed when studying telescopes from other countries. Chinese scientists managed to fix the sound from the first two discovered pulsars. The sounds that we managed to get are called "heartbeats" in the depths of the universe.

With the help of the telescope, it is planned to study and detect pulsars, neutral hydrogen, interstellar molecules, as well as possible signs extraterrestrial life. The search for extraterrestrial life is another of the goals of the FAST telescope, but so far scientists have not embarked on this task.

However, one of the pulsars that FAST detected, on this moment not decoded. The first signal was received back in 1967 and was mistaken for a signal from aliens.

What is a pulsar?

A pulsar is a rotating neutron star with high magnetic properties which emits two electromagnetic beams. Such rays can only be detected when they are directed towards the Earth, just as the light of a beacon can be seen by the one to whom it is strictly directed.

Pulsars are also called neutron stars. A neutron star is the collapsing core of a huge star. Of all famous stars the neutron star is the smallest and densest. It is so dense that one teaspoon of its mass can weigh as much as a mountain 3000 meters high weighs.

Due to the super-strong gravity and electromagnetic fields, the pulsar is considered as a natural laboratory with extreme physical conditions. Pulsars can help scientists study gravitational waves. FAST will help increase the chances of detecting low-frequency gravitational waves.

Pulsars have very precise pulse intervals ranging from milliseconds to a few seconds, which is why they are considered the most accurate astronomical clocks in the universe. Scientists believe that someday pulsars could be used as cosmic "beacons" for navigation during interplanetary or interstellar travel.

The first two pulsars were recorded by the FAST telescope on the night of August 22 and the night of August 25. But experts do not remember the detection scenario in exact detail, because FAST had already detected a dozen pulsar-like objects before, thanks to its high sensitivity. "Honestly, we can detect a lot of pulsar-like objects every night."

When the first pulsar was found half a century ago, China was plunged into turmoil and poverty. As a result, the "celestial" did not take part in any of the approximately 2,700 discoveries made in this area.

But today, China is building a fairly wealthy society and has the opportunity to explore the mysterious celestial bodies and try to find answers to questions such as "How was the universe created?", "Where did we come from?", "Are we alone in the universe?".

To take a leading position in world astronomy, Chinese scientists need advanced research tools. The launch of the FAST radio telescope, the largest structure in the history of Chinese space exploration, cost the country $182 million. The project took about 20 years to complete, and highly qualified Chinese scientists and engineers were also involved.

Now the world's scientists are welcoming China to the pulsar club. Chinese experts predict that once FAST is fully operational in 2019, they will be able to discover more than a hundred pulsars a year. The telescope is expected to double the number of pulsars we currently know. It is also planned to detect 50 to 80 pulsars in M31 - the closest to milky way galaxy. This is the only telescope in the world capable of realizing this task.

This year is a turning point for the Chinese space community: on June 15, in order to detect pulsars and black holes, a Chinese telescope was launched to work with a hard x-rays Hard X-ray, which is orbital station. With the launch of the FAST telescope, China managed to be in the future: “The era of continuous study of pulsars, thanks to the Chinese telescope, has just begun, and we hope that FAST will become an important tool for the science of all mankind,” says the astronomical community.

A multi-beam receiver will be installed on the telescope to increase its functionality by several times. This means that it will be possible to collect data on pulsars, conduct spectral analysis, and quickly scan bursts of radio emission. With this technique, scientists will be able to detect more than 1,000 pulsars, more than 100,000 galaxies, and a dozen fast bursts of radio emission.
“We will rely on the latest equipment and advanced study methods to continually make new discoveries. It's dawn new era. For a person to explore something new is the same everyday need as food or sleep. Exploring the unknown will inspire creativity in humanity, make us achieve unprecedented achievements, and inspire our imagination to find new ways, which is, in fact, priceless,” say Chinese scientists.

On Sunday, September 25, 2016, in the presence of hundreds of astronomers, enthusiasts and just spectators, the official launch ceremony of the new radio telescope Five-hundred-meter Aperture Spherical Telescope (FAST) took place in a karst valley in Guizhou province in southwest China.

FAST radio telescope

This radio telescope, which is the largest radio telescope to date, will be used to study processes that reveal the mysteries of the origin of the universe, to search for artificial radio signals of extraterrestrial origin, and much more.

The first work under the FAST project began in 2011, 17 years after the project was submitted to the Chinese government by a group of astronomers. The telescope is located high in the mountains in Guizhou province in southwest China, the diameter of the telescope is 500 meters, and the perimeter of the structure is 1.6 kilometers. The cost of building this huge structure, consisting of 11-meter 4450 reflector segments and an area equal to 30 football fields, amounted to about $ 180 million (1.2 billion yuan).

It will surpass the largest telescope currently in Puerto Rico, which is 300 meters in diameter.

“This will be an extremely good telescope for studying some areas of astronomy, especially for studying pulsars and the placement of galaxies in the universe. The new telescope will make a significant contribution to understanding the structure and history of the universe,” said Donald Campbell, professor of astronomy at Cornell University (USA).

The construction of the radio telescope was completed back in July, by which time its main systems had already gone through a multi-stage testing program.

"Thanks to the antenna large sizes and greater overall system flexibility, the FAST telescope will be able to cover twice as much area of ​​the sky as the equivalent telescope at the Arecibo Observatory. At the same time, the sensitivity of the new telescope will be three to five times higher, depending on the range of received radio signals,” says Li Di, head of work from the Chinese Academy of Sciences.

According to Lister Stavely-Smith, an astronomer at the University of Western Australia, the high sensitivity and resolution of the FAST telescope will enable comprehensive exploration of thousands of galaxies far beyond the Milky Way.

China Central Television previously reported that FAST will be connected to one of the fastest computers in the world, Sky Eye 1, to perform astronomical calculations to search for life on other planets and study dark matter. With the help of FAST, astronomers intend to observe space objects remote from Earth at a distance of up to 11 billion light years.

The world's largest radio telescope FAST

Earlier, the Chinese authorities relocated 9 thousand people who lived within a radius of five kilometers from the radio telescope.

600 houses were built for them in two new settlements, which are located about ten kilometers from their former place residence. The authorities spent about $269 million on the construction of new housing.

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The FAST radio telescope is a spherical radio telescope with a five-hundred-meter aperture, which is a literal translation from English phrases: "Five hundred meter Aperture Spherical Telescope", abbreviated as "FAST". The unofficial Chinese name for the telescope located in Guizhou Province is Heavenly Eye (天眼). In addition to promising scientific research, the science project should demonstrate China's ambitions in space exploration.

The construction of this telescope was completed in July 2016, and took five years and 180 million dollars. Since the completion of construction, the FAST Observatory has received honorary title a radio telescope with a filled aperture of the largest diameter, namely 500 meters. Thus, FAST bypassed another giant radio telescope, which for 53 years remained the largest, with an aperture diameter of 304.8 meters.

Speaking about the largest radio telescopes with an unfilled aperture, this niche is still occupied by the Russian RATAN-600 (576 m).

Design

The design of the FAST telescope is in many ways similar to the Arecibo observatory. Its aperture consists of 4,450 triangular perforated aluminum plates with a side of 11 meters. These plates are arranged in the form of a geodesic dome on suspended steel cables forming a grid. All aperture is in natural natural depression- karst funnel. It is noteworthy that the depression itself was formed in the mountains, at an altitude of about 1 km above sea level, which also positively affects the quality of observations carried out by FAST in the future.

Unlike the static aperture of the Arecibo observatory, each panel of the FAST radio telescope is able to change its position using hydraulic actuators that drive a grid of cables.

Above the dish-shaped reflector is a movable cabin, which moves with the help of cable robots. The receiving antennas located in the center of the "dish" are also movable, as they are installed on a movable platform (Hugh - Stewart).

Characteristics

According to information received from Chinese media, the FAST telescope has twice the sensitivity of the Arecibo radio telescope, as well as more than five times high speed exploration of the sky.

The frequency range that the radio telescope covers is from 70 MHz - 3 GHz. The FAST radio telescope can be focused in a direction that, together with the zenith, forms an angle of at least 40°.

Although FAST is called a spherical radio telescope with a 500-meter aperture, it is clearly not spherical, and its effective reflector diameter (radius of curvature) is 300 meters. And while Arecibo can make full use of its 305-meter aperture by making observations at the zenith, objects are often observed obliquely, where the effective aperture is only 221 meters. Since the reflector of the FAST radio telescope is much deeper than that of Arecibo, this expands the field of view for observing.

Yet despite the higher performance of FAST, the Arecibo observatory remains the leader in some types of research. For example, the study of the earth's ionosphere, the study inner planets solar system, as well as making accurate measurements of the orbits of asteroids in the vicinity of the Earth. Such studies are available to the Arecibo observatory due to the presence of transmitters and other special equipment that is not available on the FAST radio telescope. In addition, the latter is located 7.5° north of the Arecibo observatory. With such a closer location of the observatory to the equator, several more cosmic bodies fall into its field of view than in the FAST field of view.

Significance for science and the public

The scientific community intends to use the FAST radio telescope to search for, capture radio emission from, and also to detect artificial extraterrestrial signals.

For the first couple of years, this telescope is available only to Chinese scientists and specialists, after which it will be open to the international scientific community.

Despite the fact that in order to prevent radio interference within a radius of five kilometers, the authorities resettled more than 9 thousand residents with subsequent compensation payments, various tourist sites were built near the observatory, which will allow interested persons to attend excursions to the largest radio telescope in the world. For example, the Arecibo observatory is visited annually by about 200 scientists and 90 thousand tourists from all over the world.