There are so many problems with eggs. Expect a series of videos on egg mechanics in October. Please watch out for them. In answer to this question, will the high pressure of 10,000 meters of water crush the thin eggshell? Let the data speak for itself.
1. Environmental Parameters of 10,000 Meter Deep Water
On Earth, the average ocean depth is 3,700 meters, and few oceans can reach a depth of 10,000 meters. meters. The deepest is the famous Yana Trench, in Mali. The recent measurement record is 11,040.41 meters.
In an environment with a depth of 10,000 meters, not only sunlight cannot reach the bottom, but also due to the 'existence. of water pressure, the pressure changes very big. According to the formula for calculating water pressure in fluid mechanics, it can be concluded that water pressure at awater depth of 10,000 meters is about 100 MPa. This type of water pressure is definitely unbearable for the human body, but some metal entities can withstand it. In fact, 100 MPa is insignificant for ordinary metals.
2. Mechanical Model of Eggs
Eggshells are not metallic and their carrying capacity is certainly much lower than that of metals. So, can it withstand 100 MPa hydrostatic pressure? I found some information. Some people from Jiangsu University have done research on eggs. They did a static test and got the curve below. Therefore, the maximum force of the egg is less than 50n1. But this student is obviously not engaged in mechanics, and he has not drawn the key stress-strain curve (only the force unit is N and the stress unit is Pa).
According to the description of the experiment in his article, he simplyment pressed the egg with the indenter and then recorded the force. In the egg's belly, as shown below. The area of the yellow circle is a, so the ultimate compressive stress of the egg can be calculated to be 1.14 MPa. We assume that the radius of the egg abdomen is 2 cm and the thickness is 0.35 mm. estimate because it is close to the pressure head, which is damaged. The dangerous part is that there is egg liquid inside the egg. Therefore, taking a coefficient of 1.5, the ultimate compressive stress of the eggshell is approximately 0.76 MPa.
3. Discussion Results
Generally, the internal pressure and external pressure of the eggshell are balanced, that is, there is an internal pressure of 1 atmosphere. The external pressure is 100 MPa and the load form is as follows.
The results are as follows: the maximum stress is 393 MPa, far exceeding the ultimate stress of'egg. This stress value even exceeds the bearing capacity of ordinary metal.
4. Disadvantages of the model
The above calculation model has an obvious flaw: the tightness of the eggshell. In the calculations above, it is assumed that the egg shell is sealed and that sea water will not erode into the egg shell. This will cause a huge pressure difference between the inside and the outside, which will crush the egg. How to seal a real egg? The structure of the eggshell is a biological structure. From a microscopic point of view, there are a lot of voids. Due to breathability requirements, it is obviously not possible to seal biological structures.
So when an egg is at a depth of 10,000 meters, water enters the egg, so the pressure difference between the inside and the outside will be much smaller. If the time is long enough, the internal and external pressurera exactly the same as 100 MPa.same. At present, the ultimate stress of eggshell cannot be characterized by the macroscopic value of 1 MPa. At present, the principal stress of eggshell is 100 MPa. It is not known whether this pressure exceeds the microscopic capabilities of the eggshell. 5. Summary
Eggs will be crushed under 100 MPa water pressure when the water is less than 10,000 meters deep. But if the egg falls to the ground very slowly, sea water will seep inside the egg. Whether the egg is crushed at this time must be analyzed from the point of view of the binding energy of the shell molecules.
1. Reasons for the blue color of the ocean
Sunlight is made up of seven types of visible light: red, orange, yellow, green, and cyan. , blue and purple. These seven types of light have different wavelengths, and seawater located at different depths absorbhas light beams of different wavelengths.
After red, orange, yellow and other light beams with longer wavelengths are emitted into sea water, they are gradually absorbed, while blue and cyan light beams with shorter wavelengths are emitted into and encounter seawater. molecules or other tiny particles, floating bodies suspended in the ocean, scatter and reflect in all directions .
In particular, seawater absorbs less blue light and reflects it more. The deeper you go, the more blue light is refracted toward the water surface. Therefore, the sea water we see in the ocean is blue. color.
2. Minerals in the ocean
Dilute manganese nodules, oil, seafloor hydrothermal mineral deposits, nickel, copper, cobalt and salt.
3. Animals myrins
Lighting zone: (from the water surface to 200 meters underwater) where a large number of planktonic creatures, algae and coral reefs live, except for fish and marine mammals. . , there are also a large number of marine invertebrates, such as jellyfish, cephalopods, etc., as well as marine reptiles, seabirds, etc.
Low light zone: (200 meters 1000 meters underwater) Most organisms have large eyes and light-emitting organs, and some animals hide in dimly lit areas during the day and move into shallow water to forage for food at night.
Deep water zone: (below 1000 meters underwater), the sun's rays never shine here, it is dark all year round, and there is little submerged food. Few animals can survive in the deep sea.
Detailed information:
Classification of marine animals:
1, divided by lifestyle
Marine animals mainly include three types ecological: marine zooplankton, swimming marine animals and benthic marine animals.
2. Classification system
There are dozens of categories of marine animals, which can be divided into three broad categories: marine invertebrates, marine protozoa, and marine vertebrates.
Marine invertebrates represent the vast majority of marine animals and include the most diverse categories. The main ones are protozoa, sponges, coelenterates, platyhelminths, nematozoa and brachiates, echinoderms and hemichordates, etc.
Marine protochordates are animals living in the ocean between vertebrates and invertebrates, including urochordates and cephalochordates.
Marine vertebrates, including fish, reptiles, birds andmammals that depend on the ocean.
Reference documents:
Baidu-Ocean Encyclopedia
Baidu Encyclopedia-Marine Animals