Introduction

The title question – Science, where to begin? – can be answered in several ways. This text offers only one of many ways of knowing the scientific world and the incredible richness and beauty of how it is possible to understand reality through science. Therefore, it is not intended to be a definitive guide.

The term ‘Science’, using an ostensive definition [1], indicates, here, areas of knowledge such as physics, chemistry, biology, geology, astronomy, etc., areas in which Nature (experiment and observation) [2, 34] always has the last word. In another time, under the topics of Philosophy of Science and Metaphysics, I will approach the nuances and difficulties involved in the concept of science.

Goal

The purpose of this text is to answer the question of the title, offering an introductory perspective to science. Introduce elements that help to recognize when in fact a statement, argument or theory is presented from a scientific perspective. In a way, to present an approach inspired by the work carried out by the professors that participated of GREF, that is, an initiation to scientific understanding as simple as possible, without entering into technical or formalist details [3].

Context

In general, the development of a scientific approach involves the understanding of two contexts or aspects that, together, underlie scientific investigation, methodological (how to do science) and the object of study (what is investigated by science) [4]. Both aspects have particular characteristics in each field of scientific investigation, however, it is possible to establish a common basis for all scientific areas in relation to both aspects.

In this text, the focus will be the “basic” understanding of the objects of study that are fundamental to all scientific knowledge, matter and energy [5, 6, 7, 8, 9, 20]. At another time, also under the Philosophy of Science and Metaphysics topics, a discussion about materialist monism can to elucidate the reasons for this delimitation of the investigated objects. In this way, I will leave for an upcoming text an explanation about the scientific method.

Without further ado, let’s go to the presentation of the stars of this text, matter and energy.

Matter

Notion

Matter is everything that occupies space, has mass and can be perceived, directly or indirectly, by the human senses, which can assume the solid, liquid and gaseous states [6, 9, 10, 11].

Aspects 

Body | Ciência, por onde começar?
Body

The matter analyzed under the aspect of quantity, limited amount of matter [8, 9, 10].

Substance | Ciência, por onde começar?

Substance

Matter analyzed under the aspect of quality, “… with total abstraction of form, dimension and mass …” [9, 10].

Object | Ciência, por onde começar?

Object

Limited portion of a body, the matter worked by and with certain use for the human being [9, 10].

Types of substances 

Pure Substance | Ciência, por onde começar?

Pure substance 

When matter has a characteristic chemical composition and a defined set of properties, whose melting and boiling occur at a constant temperature, given a pressure and density characteristic at a certain temperature and pressure [6, 9, 10].

Mixture | Ciência, por onde começar?

Mixture

Two or more grouped substances, exhibit variation in the melting and boiling temperature and different density of the pure substances that compose it, that is, its composition and properties are variable [6, 9, 10, 11].

General Properties

The general properties are those common to all kinds of matter. For example: mass, extension, impenetrability, elasticity, compressibility, divisibility, indestructibility, discontinuity and inertia [9, 10, 12, 30]. 

Compressibility | Ciência, por onde começar?

Compressibility 

The ability of matter to have its volume reduced, decreasing the void space between its particles when subjected to pressure [9, 11, 12].

Elasticity | Ciência, por onde começar?

Elasticity 

After compression, the matter is capable of resuming its volume in whole or in part [9, 11, 12].

Descontinuity | Ciência, por onde começar?

Discontinuity 

At the microscopic level, matter has empty spaces between its particles [6, 12, 13].

Divisibility | Ciência, por onde começar?

Divisibility 

The matter can be divided into smaller portions [9, 10, 11, 12].

Volume | Ciência, por onde começar?

Extension or volume 

The ability to occupy a place in the space, also indicates, as physical quantity, the amount of matter present in a body [6, 9, 10, 11, 12, 30].

Indestructibility | Ciência, por onde começar?

Indestructibility 

The matter is not susceptible to complete destruction, matter can neither be created nor destroyed, only transformed [9, 10, 12].

Impenetrability | Ciência, por onde começar?

Impenetrability 

Two or more bodies can not simultaneously occupy the same place in space [9, 10, 11, 12, 25].

Inertia | Ciência, por onde começar?

Inertia

The natural tendency of matter to maintain its state of movement or rest, resistance that matter offers to the change of motion [8, 11, 12, 16, 25, 30].

Mass | Ciência, por onde começar?

Mass 

The quantity of matter in a body, property that can be determined from the inertial property of matter [6, 8, 9, 10, 11, 12, 15, 16, 19, 30].

Specific properties 

The properties that allow to establish the different types of matter, to differentiate one from the other or identify each individually, they are correlated to the type of substance that composes matter. They can be classified into organoleptic, physical and chemical properties [9, 10, 14].

Organoleptic properties | Ciência, por onde começar?

Organoleptic properties 

Those perceived by the sense organs: sound, odor, taste, texture, physical state, color, brightness, etc. [9, 10, 14].

Physical properties | Ciência, por onde começar?

Physical properties 

The properties of matter that manifest without changing the composition of the observed substance. For example: melting point, boiling point, absolute density, magnetic property, malleability, ductility, hardness, tenacity, solubility, thermal conductivity, electrical conductivity, etc. [9, 10, 11, 14].

Thermal Conductivity | Ciência, por onde começar?
Thermal Conductivity 

The capacity that matter has to conduct heat (thermal energy) [10, 17, 28].

Electrical conductivity | Ciência, por onde começar?
Electrical conductivity 

The capacity that matter has to conduct electric current [6, 11, 18, 28].

Density | Ciência, por onde começar?
Density 

The amount of matter contained in a given unit of volume, expresses the relation (ratio) between the mass and volume of a body under certain temperature and pressure conditions [6, 9, 10, 14, 28].

Ductility | Ciência, por onde começar?
Ductility 

The property that, mainly, metals have to be transformed into wires [9, 10].

Hardness | Ciência, por onde começar?
Hardness 

The property related to the ability of a material to offer resistance to be scratched by other substance or to scratch other substance [9, 10, 11, 14].

Malleability | Ciência, por onde começar?
Malleability 

The capacity that the matter has to undergo deformations when laminated or hammered [9, 10, 14].

Magnetic property | Ciência, por onde começar?
Magnetic property 

The name given to the ability of some substances to attract pieces of iron and nickel [9, 10, 11].

Boiling point | Ciência, por onde começar?
Boiling point 

The ability to pass from the liquid state of the matter to the gaseous, when subjected to heating and always in relation to a certain pressure [6, 9, 10, 11, 14].

Fusion point | Ciência, por onde começar?
Fusion point 

The property that matter has to pass from the solid state to the liquid, under certain pressure [9, 10, 11, 14].

Solubility | Ciência, por onde começar?
Solubility 

The ability of a given substance (solute) to be dissolved by another substance (solvent) [10, 11, 20].

Tenacity | Ciência, por onde começar?
Tenacity

The property of the matter resist fracture during mechanical shock with another matter [9, 10, 14].

Chemical properties | Ciência, por onde começar?

Chemical properties

The properties of matter that require chemical transformations (reactions) to be observed, properties that define the types of possible transformations to be made in matter [9, 10, 11, 14].

Functional properties 

The characteristics that allow to group different types of matter in relation to similar chemical properties (chemical function). Mentioning only the inorganic ones, the main ones are: acids, bases, salts and oxides [6, 10, 14].

Acids | Ciência, por onde começar?

Acids 

In general, substances that have a sour taste [6, 10, 14].

Bases | Ciência, por onde começar?

Bases 

In general, substances that present astringent taste, which “ties” in the mouth [6, 14].

Salts | Ciência, por onde começar?

Salts 

In general, substances that taste salty and are formed through the reaction between a base and an acid [6, 10, 14].

Oxides | Ciência, por onde começar?

Oxides

In general, substances of binary composition formed by oxygen and any other element [6, 10, 14].

Phenomena 

In relation to matter, any chemical or physical transformation. In a broader sense, any fact or occurrence of scientific interest that can be described and explained scientifically [8, 9, 10, 11].

Physical phenomena | Ciência, por onde começar?

Physical phenomena 

Facts or events that do not require the transformation of matter to be studied, a phenomenon that occurs without changing the fundamental structure of matter [9, 10, 11].

Chemical phenomena | Ciência, por onde começar?

Chemical phenomena

Facts or events that require the transformation of matter to be studied, a phenomenon that occurs with the alteration of the fundamental structure of matter [9, 10, 11].

Energy

Proposing an understanding of energy is a bit more challenging, because it is difficult to speak of a well-established consensus on the subject [8, 21]. I propose to think of it, initially, from what energy is not.

Energy does not exists as something concrete, like a rock, for example. From this perspective, energy is understood as an abstract concept that allows us to rationalize certain phenomena we observe in reality [11, 22, 23].

Notion

Energy can be understood as a property attributed to the state of bodies or systems, which expresses their capacity to undergo transformations (changes of state) or to bring about changes in interacting with others; something that transforms and is transmitted, presents itself in different forms, has a systemic and relative character and, fixed a system, is conserved. Abstract quantity that is usually associated with the capacity to perform work by a physical system, body or substance [6, 8, 9, 10, 11, 19, 21-24, 28].

Systemic and Relative Character

As energy can only be measured as a result of its transformation or transference, it must always be considered in a context. For example, we discuss the “potential energy of the rock-earth system” and not the “potential energy of the rock”; we discuss the “kinetic energy of a body in relation to a reference” and not only the “kinetic energy of a body” [3, 6, 23].

State of bodies or systems

Characterization that allows to establish the conditions in which a body or system is found. For example, if a body is in motion or not, states (solid, liquid or gaseous) of matter, etc. [10, 11, 22].

Work

It is associated with the conversion of energy to some useful purpose, relative to the variation produced in a body by the application of a force [8, 10, 11, 19, 22, 23].

Conservation

Energy can not be created or destroyed, only transformed. In processes of converting one form of energy into another, the total amount of energy at the end of the process is equal to the initial energy quantity [3, 8, 10, 11, 19, 21-25, 30].

Forms

There are different types, or forms of energy, there are proposals that suggest from two to four basic forms of energy (((kinetic energy and potential), rest energy), field energy). In this way, other forms of energy can be understood as manifestations of these basic forms [9, 10, 11, 19, 23, 24].

Kinetic energy | Ciência, por onde começar?

Kinetic energy

Energy associated to the movement of a body or system [3, 8, 9, 10, 11, 19, 23, 24, 28, 30].

Potential energy | Ciência, por onde começar?

Potential energy

Energy associated to the position of a body or system [3, 8, 9, 10, 11, 19, 23, 24, 28, 30].

Rest energy | Ciência, por onde começar?

Rest energy

Energy associated to the mass of a body at rest, or the internal energy of a particle or system of particles at rest [11, 18, 23, 24, 26, 27, 32, 33].

Field energy | Ciência, por onde começar?

Field energy

Energy associated with fields (regions under the influence of some force) gravitational and electromagnetic [8, 11, 23, 26, 29, 31, 32].

Final considerations

I would like to reinforce the introductory character of the presented concepts. Therefore, it is possible to move on to more precise levels and objectives of understanding, certainly I will bring new contributions in this direction.

On the question of “defining“, conceptually or empirically, what can be scientifically studied, briefly, it is related to an important principle in science, the need to submit our reasoning about reality to experimental verification. That is, scientific hypotheses must be true or false [1, 4]. This is only possible if the object of study allows its claims to go through the criterion of falsifiability.

Finally, I express my hope that this text will help to broaden the horizon of understanding the reality through science.

P.S.: The general and specific properties of matter are a conceptual resource that allows to understand the matter in a gradual way. This approach reflects, in a general way, the philosophy of work that permeates all Science, that is, to understand the object of study in an incremental way.

Images by: Sofia Iervolino.

References

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