Have you ever wondered what will happen if you dig a tunnel through the center of the Earth, where will I end up? The answer in "psychiatric hospital" is funny, but not correct. You can calculate right now exactly where you will end up, it's not difficult ... Every point on Earth has coordinates. The ball is conventionally divided into the Southern and Northern hemispheres, according to which latitudes are measured, and the Western and Eastern Hemispheres, according to which longitudes are measured. So, in order to find a point on the Planet opposite to this one, it is necessary to change the sign of the latitude, and subtract the longitude from 180 and also change the sign.
But I hasten to upset everyone ...
... most of the land is projected through the center of the Earth onto the water surface. A very small part of the Earth is projected back into the land. It is shown on the map in black.
There are some interesting coincidences. For example, almost all residents of Argentina and Chile will dig a tunnel to China or Mongolia, and residents of Portugal to New Zealand. In Russia, there is also a small area near Baikal, the tunnel of which will take you to the Falkland Islands
Next logical question: and what will happen if water from the World Ocean starts pouring into this tunnel?
Will it overflow and flood everything around? No, even if we take for simplicity that the temperature in the center of the tunnel will be room temperature, the water will begin to fill in there and fall with acceleration. If the tunnel is wide enough, then according to the principle of communicating vessels, the water levels will become the same when there is the same pressure, in our case R1=R2. Since almost all land lies above the level of the world ocean, a tunnel filled with water will be almost like a well without a bottom. But the tunnel will most likely be too narrow and the water will not even reach the middle. It will be squeezed out by huge pressure.
What happens if you jump into this tunnel?
For the sake of interest, let's assume that the tunnel is solid all the way (an infusible pipe is laid through the molten core), and that you are insensitive to neither temperature nor pressure. Otherwise, everything will end already at a depth of a couple of tens of kilometers :-)
You will accelerate. A little later, the Coriolis force will press you against the wall, and you will slide along it like a hill. Due to friction, you will never reach the other side of the planet. To prevent this from happening, the tunnel must be drilled either from pole to pole, or curvilinearly - you will get an arc, because of which you will not be able to get to the strictly opposite point of the planet in any way.
If the tunnel has the correct curvature, then you will fall into it with normal (at first) acceleration and experience full weightlessness. Meanwhile, the acceleration will gradually weaken, and flying at the point of maximum proximity to the center of the Earth, you will have a speed of about 7 km/sec. If the tunnel runs along the axis of the planet and is straight, then the maximum speed will be exactly equal to the first cosmic for the point from where you started the fall. After passing this point, the acceleration becomes negative and you slow down more and more actively (still experiencing complete weightlessness. Finally, your speed vanishes exactly at the exit of the tunnel. For one second, you can see the Australian landscape, and quickly wave the pen, after which you start falling back, and so you fly back and forth endlessly.
If the tunnel does not run along the axis of the Earth and, therefore, has the shape of an arc, then a second tunnel will be needed for the return flight - with a bend in the other direction. Naturally, this second tunnel will no longer lead you to the point of departure, so for endless flights back and forth you will have to dig up the entire planet with tunnels that may never be able to close back to their beginning. This must be calculated.
Well, if the air still remains in the tunnel, then you can accelerate to a maximum of 200 km / h, and of course, your inertia is not enough to reach the other side of the planet. You will swing several times at a great depth, and you will stop near the center in weightlessness. Finita!
The scientific journal American Journal of Physics (AJP) found it necessary to publish an article by Alexander Klotz, a graduate of McGill University in Montreal, Canada, in which he calculated how many minutes it takes to fly through the Earth through.
This, of course, is about a hypothetical journey through a tunnel-well, which begins, for example, in London, passes through the center of the planet and ends on its other side. If such a tunnel-well actually existed, then its exit would be located on the island of Antipodes, located near New Zealand. This is just opposite London in the perpendicular direction.
If you believe previous calculations made back in the last century, then a person who jumped into a tunnel-well in London would fly out of it on the island of Antipodes in 42 minutes 12 seconds. And according to Klotz, it turned out that the jumper will be at the exit in 38 minutes 11 seconds.
As the graduate explained, previous researchers did not take into account the fact that the density of the Earth changes with depth - they took some average value. In the bowels - especially in the region of the metal core - the planet is much denser. Gravity is stronger there. Accordingly, the acceleration created due to gravitational forces is higher.
Klotz made corrections using data on the density of the subsurface at different depths, obtained recently through seismic sounding. And he determined: the jumper will fly to the center of the Earth faster than previously thought. It will sweep at a speed of 29 thousand kilometers per hour. Then he starts to slow down, approaching the exit. But in the end, it will still get to the island of Antipodes faster - by almost 4 minutes.
Antipodes Island is the largest in the group of Antipodes Islands located near New Zealand. It is there that the traveler will fly, starting from London.
Who else will add on this hypothetical topic?
By the way, about the first photo, read here , and here The original article is on the website InfoGlaz.rf Link to the article from which this copy is made -
The fun part of theoretical physics (and according to some, the best part of it) is that you can ask a stupid question and calculate the answer (sometimes stupid too). For example, what happens if you drill a hole through the center of the Earth and jump through it? "Who can do such a stupid thing?" - you ask. Obviously no one. Such an act will kill you very subtly and split you millions of times. But. Let's assume that some daredevil decided on this for the sake of science? What could happen, theoretically?
First, let's state the obvious: you can't drill a hole through the center of the earth. To say that we do not have enough technical capabilities to carry out this significant action would be a very, very big exaggeration. But, of course, we can drill holes in the Earth in principle. How deep have we gone?
To date, the deepest hole on the planet is the Kola Superdeep Well. Its drilling began in the 1970s and ended about 20 years later, when the drillers reached a depth of 12,262 meters. This is approximately 12 kilometers. But this is not even a hair compared to the diameter of the Earth. Why did we stop? As you get closer to the center of the Earth, everything heats up noticeably. This is because the Earth's core is made up of liquid metal and heated to 5400 degrees Celsius. And already at a depth of 12 kilometers, the drillers encountered a temperature of 170 degrees Celsius.
I think you know that at this temperature you will not live long.
But if you can somehow manage to dive even deeper, at a depth of 48 kilometers you will find magma. At this point, you will be incinerated.
And even assuming you've managed to overcome this embarrassing inconvenience, if you've developed some sort of tube that allows you to safely pass through searing magma, the air itself will kill you. More specifically, air pressure. In the same way that you feel pressure when diving deep into water, you feel pressure when there is a lot of air above you (so the thick atmosphere of Venus will flatten you into a cake). On our own planet, you need to dive to a depth of 50 kilometers before the pressure in the pipe becomes as high as at the bottom of the ocean.
Therefore, if your goal is not self-destruction, you should not stay at such depths.
But even if you managed to make a pipe that allowed you to penetrate the magma, solve air issues and the suit made your life easier, problems remain. For example, the rotation of the planet. Halfway to the center of the Earth, you will be moving sideways about 2,400 kilometers per hour faster than the walls of your tube. This is not very good for your health. You can hit the wall of the pipe, well, die, it turns out.
Well, if we also solved this question (and several others that we didn’t even mention), if we were able to jump over the Earth, your momentum will allow you to move on the other side of the core. How long it will be going on?
- This is the answer to all questions, as far as we know. 42 minutes.
But the fun doesn't end there. Due to the powerful gravity of the Earth and your powerful momentum, once you are on the other side, you will start falling towards the Earth again. And do it all over again. You will oscillate back and forth along a sinusoid, like a yo-yo.
The task of the Chikyu project is to drill through the earth's crust. So far, no one has been able to do this. The project of Japanese scientists has already been compared with a flight to the moon.
Near the Japanese islands, they are going to carry out an experiment that has already been compared with a flight to the moon. The experiment, however, involves traveling over more modest distances - a little more than a dozen kilometers, with all the living participants in the project remaining in their places, and the equipment will do the "dirty" work. One way or another, a group of specialists is going to go deeper than anyone else into the earth's crust: they will drill the deepest well at the bottom of the ocean. Geologists, biologists and geophysicists are equally interested in the well. Unlike astronauts, who are able to look at the future landing site through a telescope, here scientists are forced to act mostly blindly. At their disposal are data on the passage of seismic waves through the Earth and rather modest results of previous attempts. And they show that "underground" forecasts, unlike "heavenly" ones, rarely turn out to be correct.
The deepest (so far) well was dug on the Kola Peninsula by Soviet naturalists. Work began in 1970. At that moment, the earth's crust was still imagined as a "simple" two-layer structure - first granites, then basalt. Below, according to calculations, was the boundary of liquid and solid - the "surface of Mohorovichich", or "Moho". Even lower is the mantle, that is, the molten layer, which accounts for most of the planet's mass. Having advanced over 12 kilometers in 22 years, they stopped digging - not least because expectations were not met. The Boers were never able to reach the mantle, and temperature measurements showed that it would not be possible at all to achieve this with the available means. The equipment repeatedly broke down, which caused many more holes to be made in the earth's crust than planned.
As it will be
Japanese explorers took a different path - underwater. Under the continents, the mantle boundary is located deeper than 30 kilometers, and at the bottom of the ocean, the earth's crust is much thinner. These considerations underpinned the very first ultra-deep well project, conceived in 1957 and known as the Mohole (Mohorovicic hole). Then, however, only 5 small holes were made at the bottom off the coast of Mexico. Despite the promising plan, no one has achieved supernatural heights (more precisely, depths) in its implementation: the longest well now goes only 2111 meters below the bottom. It was drilled by the American ship JOIDES Resolution, converted from an oil producing vessel, in the eastern Pacific Ocean. Until recently, it was the only tool for solving such problems. The "balance of power" was changed by the Chikyu built in Japan.
The ship with a displacement of 57,000 tons and a length of 210 meters is a third larger than its predecessor. Chikyu has a helicopter landing pad for 30 people and its own "railway" to bring equipment up to the 121-meter tower. It is she who will carry out the main work - to drill the ocean floor. During this process, the ship must remain "locked" to the borehole axis, so it is instructed to check its position with the help of several GPS satellites. In addition to drills, the ship will be connected to the ocean floor by 4 kilometers of thick pipes - a system that has not been used before. It is assumed that with this equipment on board, he will have time to make a seven-kilometer hole in the ocean floor in about six months to a year.
All this time, the ship with 150 crew members will spend 60 kilometers from the coast of Japan, and auxiliary ships will deliver materials, water and food there. However, the main difficulties are not connected with this at all. The closer the drill comes to the Mohorovichic surface, the more the instruments will heat up. Temperatures of several hundred degrees Celsius are enough to destroy electronics. In addition, at a depth of thousands of meters, the pressure reaches thousands of atmospheres. Therefore, they decided to fill the pipes from the inside with "artificial mud": due to circulation, it will cool the drills and sensors, maintain the "balance of forces", and at the same time - wash out the rock fragments.
Why is it needed
From the point of view of geologists, the main goal of the experiment is to extract the substance of the mantle and deliver it to the surface. In addition to volcanoes, which (in the form of lava) bring it out of the depths, there have not yet been any other devices for its extraction. (It is important to note that magma, that is, future volcanic lava, in general, does not coincide in composition with the substance of the mantle - it may consist of crust minerals melted under the action of high temperatures.) Some have reasonably compared this with the "Apollo lunar project" - although it would be more correct to recall the delivery of the first lunar minerals to earth by the Soviet apparatus Luna-16.
Of course, scientists are also interested in many things that can be encountered along the way to the mantle. In particular, they do not rule out that they will stumble upon an oil or gas field, although this is spoken of rather as a prospect that is dangerous for the drilling procedure. However, commentators agree that in resource-dependent Japan, oil is unlikely to be perceived as an unpleasant surprise. However, the study also has other practical goals. The "bottleneck" of the earth's crust 600 kilometers from Tokyo, where the ship will be sent, lies on the border of two tectonic plates - the Philippine and Eurasian. This means that it is there that earthquakes occur - and according to seismologists, every fifth of the strong earthquakes occurs in the vicinity of Japan. Modern theories explain most of the cataclysms by mechanical stresses accumulated at the edges of the plates, the "removal" of which causes the plates to move. However, it is practically impossible to measure voltages remotely, and now they want to observe them up close.
Another circumstance brings the underground mission closer to space ones: biologists intend to find life under the ocean floor. It used to be thought that microorganisms inhabited a thin layer of underwater soil, but in previous wells it was possible to detect bacteria at a depth of more than a kilometer. All of them, due to exotic living conditions - excessive temperature and pressure, are classified as extremophiles. It is known that proteins isolated from the first such organisms could be "grafted" into plants to make them more resistant. Scientists, however, are not only interested in applications. The depth at which the last living creature will be found will automatically be considered the lower boundary of the biosphere - and with the shift of the boundary, estimates of the amount of biomatter on the planet should also change.
Like attempts to explore outer space, ultra-deep exploration does not leave indifferent people who are traditionally far from science. A number of religious websites call this the intent to "dig up hell". So, referring to the Soviet scientist Atstsakov (probably, when translating into English, the surname was distorted), who "participated in the creation of a well in Siberia" (meaning the Kola well), they report "shouts and groans" recorded by microphones at a depth.
"Excavations of hell" Japanese ship will begin in September 2007. In early December, he collected the first samples and demonstrated that he was efficient. It is impossible to say with certainty whether the "full-size" experiment will be successful and how long it will last. However, this method of "getting to the bottom of the matter" has already proved its worth.
As Lenta.Ru reported, the first stage of the largest deep drilling project in the earth's crust has been successfully completed, the Japan Agency for Marine and Terrestrial Research and Technology (JAMSTEC) said in a press release.
The task of the Chikyu experiment is to drill through the earth's crust (until now no one has been able to do this), drilling a six-seven-kilometer well.
Japanese scientists decided to drill into the sea floor: despite the additional complexity of underwater drilling, this generally simplifies the task: the earth's crust at the bottom of the ocean is much thinner. The main instrument of the project is the Chikyu vessel, which is connected to the bottom by a system of drilling tools and pipes. The project pursues several goals at once: to extract the substance of the mantle and deliver it to the surface, to explore mineral deposits, to measure the stress on the border of tectonic plates near Japan, which often leads to earthquakes, to clarify the lower boundary of the biosphere.
From September 21 to November 15, the bottom of the Nankai depression was drilled (at depths of two to four kilometers). A total of 12 wells were drilled in six areas. The work was hampered by the strong Kuroshio current (speed up to four knots) and the peculiarities of the drilling region: severe deformation of the structures at the junctions of the plates. The lower part of one of the drilling rigs suddenly broke off, resulting in the loss of the drill bit and measuring equipment.
The scientists used the logging-while-drilling method, taking the necessary measurements directly during the advance of the bit in the hole, so valuable geological data has already been obtained. Despite the difficulties, the first phase of the project was completed successfully. On November 16, the second began immediately.
Consider the fall from the point of view of physics. Let us neglect air resistance (and its existence) and friction against the walls of the tunnel. We will assume that the density of the Earth is homogeneous, although in reality this, of course, is not so)
We found out that your fall will be similar to the movement in a harmonic pendulum and calculated the time it would take you to fly by the Earth. Of course, then you have to do it again and again. Although, due to the resistance of the air and walls and the heterogeneity of the Earth, someday your fall will stop, and you will get stuck at the center of the Earth.
Now about what you will see and feel. Let's assume that during this short trip you will not die from temperature, pressure or g-forces and will be able to follow the changes in the environment. The picture strongly depends on the point at which you started to fall. You were probably on the Continent. In this case, at first you fly about 30 km of the earth's crust. Here it should be pointed out that, in principle, all our knowledge about the structure of the Earth and its deep conditions is hypothetical and based on geophysical data, such as changes in the speed of waves passing through various layers. So. The thickness of the continental crust will depend on tectonic conditions. It will be the largest in the mountains (up to 70-75 km), the smallest - in the territories subjected to tension, on the oceanic margins and in the depressions of the seas. First of all, you will fly through a layer consisting of sediments and sedimentary rocks, if present. Then comes a layer of gneisses and other metamorphic rocks. Intruded granites are visible in them. Under this layer there will be highly metamorphosed basalts that have turned into amphibolites and granulites. All this time, pressure and temperature will steadily increase. Here we can recall such a thing as a geothermal gradient, which shows how much the temperature rises with depth. It strongly depends on tectonic conditions and will be maximum under the mountains.
If for some reason you started your fall from an oceanic island or ocean, then you will first pass through the sedimentary layers, then through the basalt pillow lavas and the dikes leading to them. They are underlain by gabbro intrusions. Finally, you come to the mantle. The thickness of the oceanic crust will be seven kilometers. In general, the picture you see can be very unusual and depends on the tectonic region in which you drilled a hole.
The division between the mantle and the crust is the Moho boundary. The mantle consists of peridotites containing olivine (Mg,Fe)2SiO4 and pyroxene (Mg,Fe)2Si2O6. When immersed, they will turn into more stable polymorphic modifications. This will be noticeable at depths of about 410 and 660 km. Moving down from the Moho boundary through a rather hard mantle, you will reach a layer that appears more viscous and fluid. The fact is that the material of this layer, the asthenosphere, is subjected to partial melting. Approximately 1-5% of the substance melts (the amount strongly depends on tectonic conditions). The high pressure created by the overlying layers prevents it from completely melting. The resulting melt envelops the grains of minerals and ensures the fluidity of the substance. Hearths of basic and ultrabasic magma rising up can also be formed here. All those relatively hard and elastic layers above the asthenosphere are the lithosphere. Divided into plates resembling watermelon peels, it glides across the asthenosphere and makes vertical movements, floating on the surface of this viscous layer. Below the asthenosphere and at a boundary of 410 km, a more viscous mesosphere stands out. At this mark, olivine passes into a modification with a spinel structure.
The lower mantle begins at a depth of 660 km. It is probably composed of minerals with the perovskite structure (Mg,Fe)SiO3 and magnesiowustite. In the lower mantle, minerals contain huge reserves of water. The whole mantle that you passed through was solid, because along with high temperatures, it was also subjected to high pressures. Convective currents in the mantle are too slow to be noticed.
Finally, you reach the Gutenberg boundary separating the core and lower mantle. You are separated from the surface by 2900 km. This border is covered by a cemetery of mountains of submerged and partially melted lithospheric plates.
From 2900 to 5120 km you dive through the liquid outer core, which consists of an iron-nickel alloy with impurities of sulfur, hydrogen and some other elements. There is an intense mixing of matter that creates the Earth's magnetic field, but because of the low speed, you are unlikely to see it. A solid inner core extends to a depth of 6370 km, a product of gradual cooling and solidification of the outer core. It has a similar composition and is composed of iron, sulfur and nickel.
