(And could you live there inside?)
Jules Verne was good - he lived in the days of gullible readers. For someone to figure out his fantasies and then say - can't this be? There was no such thing. Therefore, no one interfered with his expedition to the center of the Earth, and everyone safely got to the surface, having experienced, of course, a lot of adventures - to the delight of many readers.
Initial prerequisites
But to believe in such a thing in our time?
Imagine believe. The Earth, it turns out, is hollow inside and due to its rotation and the resulting centrifugal force on the inner surface of the Earth, you can walk as calmly as on the outside.
And if so, then knowledgeable (dedicated!) People have been living there for a long time. There, of course, went to the survivors of the disaster, the wise inhabitants of ancient Atlantis, as well as selected representatives of the 3rd Reich, who periodically go out on reconnaissance on absolutely invulnerable UFOs.
Promotional video:
In short, there is no limit to fantasies. One young man noticed that the satellites drawing a map of the Earth near the pole left a black spot. Why? Because it is there that the entrance to the inner cavity of the Earth is located, and we, mere mortals, should not know about it.
The fact that the military is hiding something from us, I willingly believe, but will they in this case leave an attention-getting black spot on the map?
This young man even knows the thickness of the solid layer of the Earth - exactly 1000 km - and so that those living inside there do not sit in the dark, it turns out that there is a small Sun (luminary?) Just in the center of the Earth. True, he did not say how and due to what it is there in the hollow center of the Earth, but perhaps he at least does not know this. And then even somehow it becomes creepy from their complete ignorance.
Did the young man calculate everything that he told us?
We were all sitting with our ears hanging and watching the video. Not everyone has money to travel to the Pole, and trams do not go there yet. It is not so easy for a mere mortal to check for a cavity. And almost every family has paper and pencil. And the military has not yet turned off the universal directory called the Internet. Let's do some calculations ourselves, sitting on the sofa.
Let's cling to the hole at the pole first. There is no centrifugal force, this greatly simplifies the initial situation. So, let's imagine a well through the Earth to a cavity with a depth (length?) Of a thousand kilometers. The radius of the well does not matter, take at least a meter, at least a thousand. How will air pressure change with depth in it?
I don't know where, but Wikipedia knows a formula for changing air pressure from height:
P = P o e -Mgh / RT
where P o - pressure Pa at sea level [Pa]; M is the molar mass of dry air 0.029 [kg / mol]; g - acceleration of gravity 9.81 [m / s ²]; R is the universal gas constant 8.31 [J / mol K]; T- absolute air temperature [K], T = t + 273, where t- temperature in ° C; h- height [m].
At low altitudes, every 12 m ascent, the atmospheric pressure is reduced by 1 mm Hg. At high altitudes, this pattern is violated [1].
We will not make accurate calculations, therefore we will use only the knowledge of the last two sentences, from which it follows: the pressure changes by 1 mm Hg. Art. for every 12 m ascent or descent. From this it will turn out, since 760 mm Hg x 12 m = 9120 m, which at an altitude of 9120 m there will no longer be air. This, as we know, is not so, somewhere one third of the air remains, but for our estimation it will do, since we will go not up, but down. When moving down, the formula P = P o e-Mgh / RT is no longer suitable, since as we move inside the Earth, the gravitational acceleration g will decrease and upon reaching the cavity it will even become equal to zero (if the cavity is empty). But at first, as it moves inside the Earth, the pressure of the air column will grow at the same speed - by 1 mm Hg. Art. every 12 m. In other words, at a depth of 9120 m, the pressure will be no less than 2 atmospheres. Let's say even more inaccurately - at a depth of 10 km, the pressure will increase by one more atmosphere and will be equal to 2 atmospheres.
But at a pressure of 2 atmospheres, the air density will be twice as large. Consequently, over the next 10 km, the pressure will increase not by one atmosphere, but by two and will be equal to 4 atmospheres at a depth of 20 km.
But at a pressure of 4 atmospheres, the air density will be 4 times greater. Consequently, over the next 10 km, the pressure will increase not by 2 atmospheres, but by 4 and will be equal to 8 atmospheres at a depth of 30 km. Etc.
We get a series of 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 atmospheres, respectively, for depths of 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 km.
I'm already getting scared to count on.
Can you imagine what terrible pressures we will get for the next hundred kilometers? And even deeper? But in any case, our rough calculations are no longer good enough there, because no one knows the properties of air at such huge pressures.
But let's say this: at a depth of 1000 km, the air pressure will most likely be at least 1000 atmospheres.
Can anyone live there?
People dive to a depth of 100 meters, the pressure there is 10 atmospheres, and nothing, do not complain. Maybe 1000 atmospheres can be safely sustained? Well I do not know.
Moving on to "higher" mathematics - counting on the fingers
Okay, let's move on. If we do not take into account the rotation of the Earth, then the air pressure inside the cavity, according to our very rough calculations, will be no less than 1000 atmospheres. In this case, the air density will already be comparable to the density of water. From the point of view of gravity, the cavity clearly cannot be considered "empty". The gravity inside the cavity will clearly not be zero. The air pressure will grow and rise to the very geometric center of the Earth. The density of the air will also increase. But I will not evaluate it any more.
Here I am more interested in the value of the gravitational acceleration g at the boundary of the cavity. I think that its average ceiling value will be at least 0.5 of its value on the surface of the Earth. It will probably be higher than on the moon. Even if I was mistaken 10 times, and I was not so wrong, this value still suits me.
Why should I?
Our dreamers assured that due to the rotation of the Earth, one can safely walk along the inner surface of the cavity. The centrifugal force will push us against it no worse than the usual gravity. Yes?! Let's look at the Internet. "At the equator of S., t. Is about 0.5% less than at the pole." (https://dic.academic.ru/dic.nsf/enc_physics/2738/ POWER). Due to centrifugal force on the Earth's surface, approximately only 0.005 of gravity develops! And inside the cavity, this value will be even less.
Thus, with an air pressure in the cavity of the order of 1000 atmospheres, the centrifugal force acting on a person or on any loose body will obviously not be able to balance the gravity that arises in the cavity due to the gravity of the air mass. Everything that is loose and denser than air will fall towards the geometric center of the Earth.
In other words, the existence of such a cavity is impossible. The earth cannot be hollow.
Can a cavity exist if there is no hole at the poles or where else? Of course not. The air will seep over time through the smallest pores between stones or even in the stones themselves.
But I'll give you another killer argument. Not about the cavity, but about the possibility of living beings on it. This is the ultra-deep well data:
"At the 7 km mark, the bottomhole temperature was 120 ° C, at 12 km it reached 230 ° C." (https://www.vokrugsveta.ru/vs/article/417/).
I, of course, do not know what the temperature will be at a depth of 100 km, let alone 1000 km, but I am afraid that our dreamers need to find another base for UFOs and for the surviving representatives of the 3rd Reich. It's a pity. It would be nice to look at the Atlanteans.
Johann Kern, [email protected]