Live Wilderness Adventure

Chapter 398: Digging a Hole

With the hustle and bustle of the outside world, thousands of miles away, it is impossible for Bi Fang, who is on top of the world, to know.

In the confined and narrow space, he is holding the snow wall to measure the size of the space, and at the same time teaching the audience some questions about how to save themselves after encountering an avalanche.

"The release process of an avalanche usually goes through three stages: First, under certain snow conditions, external factors cause some snow layers to shear, break, and dislocate, causing small scars to appear on the fragile snow."

"Then, this small scar will 'infect' the surrounding snow layer, and the scar gradually expands, displacing the surrounding snow layer."

"In the end, the snow on the hillside continued to collapse like dominoes, forming a scar on the calm hillside. The scar eventually fell off, and the avalanche also poured down. This kind of avalanche can be avoided by observing in advance."

"Of course, there are also unexpected types, such as slab avalanches, which are characterized by linear cracks in the snow block in the area where the avalanche originated. It looks like a whole slab of snow has avalanche. The crack propagation is sometimes several Hundreds of meters long. Even with the thinness of the board, the total volume of these moving snow volumes can be staggering."

[Then what kind of avalanche did Lao Fang encounter? 】

"Although I can't see the barrage now, I know you will definitely ask me what kind of avalanche I encountered this time, but in fact, I don't know. It's four o'clock in the morning and it's too dark. I can't see it carefully. If so, you should be able to see, "

Bi Fang shook his head, he always felt that this avalanche might not be accidental, otherwise why would he be so unlucky this time?

"If the avalanche is already in sight, take a deep breath, hold your breath, and if there are trees, rocks or solid objects around you, hold on tight, because the impact of the avalanche is very strong, try not to be swept away by the snow flow."

"In case the avalanche happens to happen at your feet, try to jump up and run up across the fault line. However, generally avalanches happen very fast, and there is no time to react like this. If you are unfortunately caught in a snow current, you must do it upstream In the swimming position, the limbs swim upwards, and the maximum is on the surface of the snow flow, and the shallower the burial, the greater the chance of survival."

"When you are buried by an avalanche of snow and cannot break free, you must reduce your activities and slow down your breathing to save energy. Some emergency breathing devices can help victims persist for tens of minutes."

"Of course, you can also try to save yourself, by shaking your body to expand the surrounding space little by little, freeing up your hands to swim up like swimming, b but without certain skills and judgment ability, I don't recommend doing this, because widening the space The process is very exhausting, which means that the oxygen consumption will increase, and the risk of suffocation will increase. Normal people cannot judge how deep they are buried, and the deeper they are, the greater the danger."

[By the way, although the space has become bigger now, is it okay for Fang Shen to keep talking? Will it increase oxygen consumption? 】

[Yeah, although everyone else uses oxygen cylinders, this amount of space won't last long, right? 】

"After the avalanche, we are lucky to be in a situation like ours. If you encounter this situation, there is no need to go out at all. It is no problem to stay here for a day. As for the oxygen problem, there is no need to worry at all. As long as How long can a person breathe in a cubic meter of air?"

Bi Fang stretched out one palm, and under the illumination of headlights, the audience could clearly see the five fingers.

Although Bi Fang had to pretend not to see the barrage, he could answer questions with more context to ensure audience interaction.

Five fingers, that's... five minutes?

The audience thought about it, and probably guessed a time, five minutes per cubic meter, which is almost the same number.

"It's five hours."

puff!

five hours?

Are you kidding me?

[Five hours, are you crazy? 】

[Is this the turtle breath technique? 】

[I have read a novel written by an author named Shellant Ant, and I heard that the turtle's breathing technique is because the turtle's water can exchange gas through the organs near the g gate, and I don't know if it is true or not]

[If the person who said this was not Fang Shen, it would be absolutely impossible for me]

In any case, it is unbelievable that one cubic meter of air can last for five hours.

"I know some of you can't do it. In fact, you can do a simple addition and subtraction. I'll give you the first question." Bi Fang smiled, then pondered for a while, and spoke after a while.

"It is known that in the normal air of one atmospheric pressure, an ordinary adult male will inhale about 0.5 cubic meters of air per hour, the concentration of oxygen is 21%, and breathe 0.5 cubic meters of air per hour while lying still. At the same time, 5% of oxygen is consumed, and the exhaled gas contains about 16% of oxygen and 4% of carbon dioxide. But when the oxygen concentration drops to 6%, and the carbon dioxide concentration reaches 8%, the heart will stop beating in a few minutes. There is a man trapped with only one cubic meter of air, how long can this man wait until rescued?"

It's outrageous!

[I've graduated from fucking university, can't I get rid of math problems? 】

[Algebraist! 】

[It turns out that mathematics can not only be used to buy vegetables, it is really useful, woo woo woo. 】

【Forget it, forget it】

【Forget it】

"Air has two functions for human breathing. One is to provide sufficient oxygen for inhalation. The inhalation is about half a cubic meter per hour. On the other hand, air is also responsible for the diffusion of carbon dioxide exhaled by people. It takes about 30 cubic meters per hour, which is the standard for a healthy life."

"There have been incidents of sudden death while running while wearing a mask. The root cause is that the carbon dioxide in the exhaled air did not have time to diffuse and was sucked back in."

"I don't know if anyone has calculated the result now, but I can tell you now that the answer is about 5.2 hours. Of course, this is a rough estimate, and the actual situation is different. Because the oxygen content in the air after breathing for a short period of time Low, people will increase the breathing depth and even yawn, coupled with the tight breathing rate in a small closed space, 5.2 hours is the ideal state, basically ordinary people are prone to belching in three hours."

Bi Fang raised his head and looked around, fully showing the confined space.

"There are at least ten cubic meters here. There is no need to worry about the oxygen problem. It is fine to talk, but we still have to go out as soon as possible, because the stability here is doubtful and it is likely to collapse. We can't stay here forever. . Randomly digging holes may affect the stable structure of the entire space, so we go out from the hole we dug from time to time.”

Bi Fang looked at the entrance of the cave where he and Dan Zeng came in, and began to take out the snow in the cave, and at the same time kicked Yao Jun who had collapsed on the ground.

"What are you doing in a daze, get up and work, do you still want to eat?"

Yao Jun froze for a moment: "Eat? Is it batter again? I'm about to throw up."

"It's a pity that I didn't bring many energy bars, so you can't even eat batter here, you can only eat energy gels."

"yue!"

Thinking of the energy gel that tasted like snot, Yao Jun almost retched, and could only reluctantly get up from the ground.

"Damn, I'm really working hard."

It is known that the volume fraction of CO2 contained in the air to cause death or shock is 10%.

For easy calculation, the volume fraction is used here, which is different from the concentration in the text. These are two things.

Therefore, when the CO2 in the air reaches 10%X1000L=100L, it will cause death or shock.

The volume fraction of CO2 in air is 0.03%.

The original CO2 in the air is about 0.03%X1000L= 0.3L.

So as long as you exhale CO2 100L-0.3L=99.7L, you will die

The volume of air that a person exhales each time is about 0.5L.

Take about 16 breaths per minute.

The volume of exhaled air per minute is about 16X0.5L=8L.

The volume fraction of CO2 in the exhaled gas is about 4%, and the CO2 contained in the exhaled gas per minute is about 4%X8L=0.32L.

There is no need to worry about oxygen. The volume fraction of oxygen in the exhaled air is 16%, which cannot be completely inhaled. 16% of the volume of oxygen is still discharged into the air with each breath. Usually, only the concentration of carbon dioxide can be calculated.

Therefore, when a person breathes about 99.7÷0.32=311.5625min≈5.19h, he will die.

Scientific rigor, Resby.