First of all my respectful greetings to all the academic and scientific community of Hive.blog, and as we know both areas are essential for our exponential development in all senses.

Introduction

Our existence is undoubtedly at all times under the influence of any type of phenomenon that develops around us, therefore, this time we will relate generally with one of them as it is the atmospheric pressure, and it acts permanently on any living species on our planet, whether they are both on the earth's surface and submerged in media such as water, among others.

When we talk about atmospheric pressure we are relating to that essential mixture of gases in which we are all immersed, that is, air, where, in this mixture we find the vital element for our existence such as oxygen (O), in addition to other recognized elements such as nitrogen, and in a very small percentage gases such as argon (Ar) and carbon dioxide (CO2).

Perhaps any person on our planet could have the idea that the air around us does not exert any action towards us or any other living species, particle or object next to us, that is why in this opportunity we will try to demonstrate this action with some small but significant examples, where you can witness what we have called atmospheric pressure.

It is important to express that the air besides providing us with oxygen, has served as transport for the propagation of essential phenomena such as sound and light, although the latter (light) also has the ability to propagate in a vacuum, therefore, my dear readers, the material medium air represents our atmosphere, and thus envelops the Earth and everything on it in which we all are.

Therefore, the air that surrounds us is under the gravitational effects of the Earth, and in this way, it will exert a constant pressure on us unless we elaborate other conditions in an artificial way, where we can move away or isolate ourselves from the atmospheric pressure, otherwise we will always be under its effects, and this will be visualized later.

The main objective of this article is to show the effects of air or atmospheric pressure on everything around us, that is why it is important to always keep in mind the conceptualization of pressure, and it is represented by the relationship between the amount of force applied on a certain area, and acting perpendicular to the area of application, so we denote it as P = F / A, and with this expression we can know the effects of the pressure exerted by any material medium such as air or any other body or object in our environment.

So my dear readers in relation to the above formula of pressure we can say that it will be directly proportional to the amount of force exerted at a certain time, and also linked this action with the area in which the force is applied, so that the action of the pressure is inversely proportional to the area of application, ie, if a certain amount of force applied we keep constant, but increase the area, then the value of the pressure would decrease.

In this theoretical and general way we have been able to analyze the physical magnitude of pressure, and as we know at any time of our lives we can make use of this phenomenon both ourselves, with any part of our body, and the pressure exerted by the material medium, where we usually spend most of our existence as is the air.

In general terms, we can say that there are several units that allow us to measure or quantify the magnitude of pressure, and this, both in the international system (SI) such as N/m2, Pascals (Pa), atmospheres (atm), bar, millimeter of mercury (mmhg), as well as others in the English system (lb/ft2) pounds per square foot or square inch (lb/in2) or Psia, however, our goal in this opportunity is to visualize the action or presence of atmospheric pressure in our daily environment.

That is why I will perform a small, but significant practical experience in order to show the effect of the action of atmospheric pressure around us, and check with it, that although we can not see or feel the weight or pressure. However, it is present in every instant where we are.

Atmospheric pressure

As we have already expressed in our introduction, this pressure is represented by the homogeneous mixture of gases that constitutes the air, and that the same allows us to breathe thanks to its oxygen content, although the air in addition to possessing the above mentioned characteristic, it maintains the balance of any object or body on the crust of the Earth, and this will be witnessed at the time of our practice, and also any of you could do it easily at home, remembering that science is in any corner of our existence.

In spite of the powerful action of atmospheric pressure, perhaps some inhabitants of this planet might doubt this action or effect, since they might think that air does not weigh, and therefore, it would not have any force to exert pressure both towards our body and towards everything around us.

Therefore, if someone were to think in this way we could remind him that each one of us carries on our shoulders or heads a certain amount of mass representative of a column of air, therefore, we could express that we constantly carry a certain part of the atmosphere on our shoulders, and which represents a certain weight of the atmosphere distributed over a unit of surface in relation to our body.

To continue deepening in the above mentioned as important data we can say that it has been indicated that the atmospheric pressure exerted by the column of air above mentioned on our body, has the same pressure that can exert a column of water (H2O) of 10 meters high, as well as a column of mercury of 760 mm, the above mentioned in controlled conditions, the above mentioned can be seen in a general way in the following figure 1.

_{Figure 1. Atmospheric pressure over our body in relation to a column of water and mercury}

As you could notice in the previous figure 1, it was related to several types of media which exert the same pressure on our bodies, varying the length or height of the column of each material medium.

Therefore, my dear readers, once shared some general characteristics of the magnitude of the pressure, and above all, of that exerted by the atmosphere, it is important to carry out our practical experience, which only we must have a heat source (burner or stove), container where we place ice water, hollow cylindrical aluminum can, water at room temperature, and thus can visualize the remarkable and constant effect of atmospheric pressure in any place where we are, so then I share with you the following images.

In the previous images, in a very simple way and with elements easily found in our homes, we were able to witness some of the many effects of atmospheric pressure, since it is exerted by the air in which we are immersed, and therefore, with great influence in our lives.

This time we saw how the walls of the aluminum container collapsed when the water vapor that had replaced the air inside the container cooled back to a liquid state, and therefore, the inside of the container was unprotected causing the air from the outside to collapse the walls.

Conclusion

Innumerable phenomena are developed around us and the same of vital importance for humanity, and that is why man has taken great interest in knowing about each of them, such is the case of atmospheric pressure, since it often we do not realize its action, by the fact that we can believe that the air has no weight, and therefore, any force to exert some kind of pressure.

In this opportunity they were able to observe how the air that surrounds us exerts great pressure on every body or object on the earth's crust, where, of course, we are included in this action, and we also demonstrated this with a simple but remarkable practical experience as you could see in the images above.

There are many examples that we can find around us, which is why, in future installments we will be relating to other types of visible effect of the action of atmospheric pressure, and also as it will always be part of our existence.

Until another opportunity my dear readers of Hive, especially to the members of the great community of #stemsocial, for which I highly recommend to be part of this beautiful project, because it highlights the excellent work of the academy, and also, the great work of the entire scientific-technological field.

Note: All images are my own and were captured with the camera of the Samsung Galaxy J2 Pro cell phone, the animated gif was made with the PhotoScape application.

Bibliographic references consulted and recommended

[1]Atmospheric pressure.

[2]Física, presión.