Lost in the forest of science.
The study of science begins for everyone as a small path in the forest of ignorance, but with effort and experience this path becomes our personal path to knowledge and information, opening up many possibilities. Albert Einstein, like everyone else, went to the forest, and he showed that getting out of it is worth the effort, not only for him, but for all of his knowledge for humanity. Science is not for everyone, but several Einsteins exist. Unfortunately, many are lost, confused and disappointed, refusing, before they can say their first Eureka, as the gem of knowledge falls into place. These moments of “Eureka” may worry us to continue on our particular path.
So the first step is to be motivated and want to learn more.
The next important step is to pay attention to the definitions: something important in every field: in sports you need to know the rules of the game: this is the same for science. Knowledge of the definitions eliminates confusion, and their application (problem solving) hardens. Sometimes the scientific method and thinking become a model of life and give an idea of many situations, even outside your specific area of expertise.
There is a structure. For example, biological sciences and medicine are based on biochemistry and pharmacology, which relies on organic chemistry, and organic chemistry depends on physical chemistry. Physical chemistry is based on physics, and mathematics is the logic that binds them all together.
There are many sides along the way, too many to list here: new materials, nanotechnologies are two important and well-known disciplines. Also, different areas overlap in areas of multidisciplinary areas, such as physical chemistry and organic (physico-organic chemistry); organic synthesis and chemical kinetics (organocatalysis), inorganic and organic chemistry (organometallic chemistry): the list goes on and on.
Obviously, no one can become an expert in all these areas. However, a good foundation in the basis of physical science allows at least being able to evaluate the work of others in many areas of scientific activity. You can become a lawyer, a social worker or finance. A good experience in science will help a lawyer to argue his case, say, patent infringement; helps the social worker understand the side effects of drugs that a client can take, and allows the financier to make reasonable decisions about whether to invest in one mining company or another.
On the other hand, you can become a scientist, which leads to a lot of interesting career.
Scientists and engineers
Science can be divided into two broad categories: fundamental science (research) and the application of these ideas (engineering: also called research and development (R & D)). Today there are ten times more engineers than scientists. It takes more effort and more people to accept the core ideas developed by several, and turn them into technologies that we use to improve our quality of life.
Think of the automotive industry. An internal combustion engine based on the Otto cycle was developed by several (who showed that it worked), and then many engineers took this basic idea and over the last hundred years have developed the cars that we have today.
To be a good engineer, you must start with the basics and learn the basics before you can apply them.
Macroscopic and microscopic
A wide division of science occurs in a macroscopic (a large enough sample that we can measure and study), and microscopic (atoms, molecules, and their collections are too small to be observed separately).
There are two large angles of macroscopic science: thermodynamics (the study of heat, work and efficiency) and classical mechanics (Newtonian physics, describing the motion of macroscopic objects).
Microscopic is controlled by quantum mechanics.
Since microscopic particles have a large symmetry, we should mention the field of group theory (a mathematical subject). It helps to visualize molecules and reactions and is of particular relevance in the most basic science, which is physics. You don't have to be a mathematician to use group theory. Mathematics is an instrument of scientists: logic leads us.
The field of statistical mechanics associates macroscopic objects with its microscopic particles.
Chemistry example
Chemistry is the study of building and breaking bonds — chemicals react to various chemicals. A chemical reaction takes place if the conditions are correct: two important conditions are energy and entropy. Both matter and entropy are as tangible as energy. How did this happen?
Engineers began to notice things a couple of centuries ago: like horses that went in a circle and drove a car to start cannons. The horses went at a constant speed (constant energy), but the dim bit produced a lot of heat and not much work (the boring gun was slow), but the sharp bit produced much less heat and became more boring. This is the first law of thermodynamics:
Energy (horsepower) = heat (friction) + work (cannon hole).
It is clear that the energy is not cheap (horses need to buy, feed and care), so it would be better to reduce heat loss and increase the work done. That is, energy efficiency has become an important factor.
In the 19th century, thermodynamics developed further, due to the need to increase the efficiency of the steam engine, leading to an industrial revolution. The first steam engines were about 3% efficient, and therefore certain improvements were needed. For example, adding a second cylinder improved, but could they do more? Can the dream of 100% efficiency come true, that is. Perpetual motion?
This led Sadi Carnot in 1830 to define the cycle for the steam engine, from which entropy was discovered, and the Second Law of Thermodynamics was formulated - perpetual motion was shown to be impossible. The Otto cycle was developed for an internal combustion engine about forty years later.
Although alchemy is an old topic, it was only after the First and Second laws of thermodynamics were developed that chemistry really took off. Many were involved in its development. There are several famous names among Sadi Carnot - James Maxwell, Rudolph Clausius, James Joel, Willard Gibbs and Ludwig Boltzmann.
The ideas they developed are well suited to chemistry. When bonds are broken, energy must be added to the system; and when bonds are formed, energy is released into the environment. Some chemical reactions produce more randomness (higher entropy), and sometimes a higher order (lower entropy), when atoms are rearranged to form products. Energy (heat and work) and entropy (randomness) play an important role in the spontaneity of a chemical reaction.
Here is an example. Trinitrotoluene (TNT) may explode (fast chemical reaction). From the chemical formula, it has three nitrogen bonds. Most chemical explosives contain nitrogen. A collision of one mole of TNT yields 3,400 kJ mole-1 energy,
C2H5N3O6 (s) + 21/4 O2 (g) 7 CO2 (g) + 5/2 H2O (g) + 3/2 N2 (g) † H = -3,400 kJmol-1
Compare this, however, with the energy of burning sugar in the form of sucrose (slow chemical reaction)
C12H22O11 (s) + 12 O2 (g) à12 CO2 (g) + 11 H2O (l) À † H = -5,644 kJ mol-1
Sucrose produces a lot more energy per mole than TNT! So why doesn't sucrose also explode? Sucrose slowly burns relative to TNT with a corresponding slow release of carbon dioxide. TNT burns so fast that a lot of energy is released in a short time. In addition, solid TNT takes up a small volume, but the final volume is 11 moles of gas (about 250 liters at STP). The destruction is caused not so much by heat as by the rapid expansion of the gases produced. Using the first law, the energy released by one mole (3400 kJ) heats up to some extent, but much of the work is done for the environment as the gas expands and this can cause damage.
This means entropy. Please note: the right side of TNT combustion is only 21/4 = 5.25 mol of gas, and the RHS has 11 moles of gas. This means that the RHS has more unrest than the LHS. Obviously, the rapid expansion of the explosive combustion of TNT can lead to destruction (this will remove Humpty-Boltait from its wall) and cause more confusion, and therefore the entropy increases. For this reaction, both energy and entropy are favorable. This is not always the case, especially biological processes, where the main driving force is entropy, not energy.
Thermodynamics tells us which chemical reactions will continue and which will not. Chemical kinetics tells us how quickly these reactions occur, and how much energy is needed to initiate the reaction. TNT is not very sensitive to shock because it has a high activation energy. On the other hand, nitroglycerin (NG), another chemical explosive (with a large number of nitrogen bonds), explodes with a small blow and cannot be transported in liquid form at room temperature. It has a low activation energy. Alfred Nobel solved the problem of nitroglycerin by inventing dynamite: reducing susceptibility to impact, soaking NG in sawdust, paper, or some absorbent material. The patent was so successful that it left us the legacy of the Nobel Prize.
Today, equilibrium thermodynamics is a closed field, and no new fundamental research is being conducted. This is a beautiful, complete and compact theory that provides a connection between macroscopic quantities that we can measure: energy, heat capacity, compression ratios and many others, with wide application.
Thermodynamics is essential knowledge for all chemists. However, thermodynamics cannot explain why these relationships exist. This is given by another elegant theory called statistical mechanics.
Physical chemistry covers it all.
There is a lot more to say, but this is a summary. In fact, many say that thermodynamics is not a good name, because it describes the properties of equilibrium, and not dynamic. A better name would be a thermostat, but no one calls it.
