Everything you need to know physics. Life hacks for those who teach physics: how to learn all the forces? Hubble's law of cosmic expansion

Physics is an exact and fundamental science that studies the general laws of various natural phenomena, as well as the laws of the structure and movement of matter. All laws and concepts of physics form the foundations of the subject of natural science.

Appears in high school separate subject - Physics, whose main goal is to form students' knowledge of the subject, style of thinking and scientific worldview. From the seventh to the ninth grade, schoolchildren study the basic course of physics, thanks to which the idea of \u200b\u200bthe physical picture of the world is formed, basic physical concepts, terms and laws are studied, as well as basic algorithms for solving problems, and research and experimental skills are developed. At the end of the ninth grade, students take GIA in physics... On request in the search engine "physics for free" on the Internet, you can find various video tutorials, reference books, books and articles , to help you prepare yourself .

Experimental and theoretical physics

It is very difficult to determine the line where the theoretical part of the physics course ends and the experimental part begins, since they are very closely interrelated and complement each other. The goal of experimental physics is to conduct various experiments to test hypotheses, laws, and establish new facts. Theoretical physics is focused on explaining various natural phenomena based on physical laws.

Physics subject structure

Structurally, the subject of physics is difficult to divide, since it is closely related to other disciplines. However, all of its sections are based on fundamental theories, laws and principles that describe the essence of physical processes and phenomena.

The main sections of physics:

• mechanics - the science of motion and the forces causing motion;
• molecular physics - study section physical properties bodies in terms of their molecular structure;
• vibrations and waves - a branch of physics that deals with periodic changes in the motion of particles;
• thermal physics - a group of disciplines on the theoretical foundations of power engineering;
• electrodynamics - a section that studies the properties electromagnetic field, electrical and magnetic phenomena, electric current;
• electrostatics - a branch of physics that deals with the electrostatic field, as well as electric charges;
• magnetism - the science of magnetic fields;
• optics studies the properties and nature of light;
• atomic physics - a section of physics about the properties of atoms and molecules;
• quantum physics is a branch of physics that studies quantum mechanical and quantum field systems, the laws of their motion.

How to prepare for the GIA in physics?

It is necessary to repeat and study the material in accordance with the requirements for the GIA in physics. Various reference books, manuals and collections of test items will help with this. It will be useful to physics freeclasses with the analysis of GIA demovariants, which are presented on the site.

Should be interested additional materials and take part in trial testing. During the execution of the test tasks, you get acquainted with the features of the questions. It was noticed that students who took the test classes ended up gaining higher scores. It is necessary to draw up a plan of self-study, indicating the topics that you plan to learn for GIA in physics... You can start with the most difficult and incomprehensible ones. Also, you do not need to try to learn the entire tutorial at once or review all video tutorials. It is important to structure the studied material, draw up plans and tables that will help you better memorize and repeat. It does not hurt to alternate between classes and rest, as well as to be confident in your abilities and not think about failure.

The most common complaint of a student about the difficulty of the subject is: “Why do I need this stupid…. (you can put anything here - physics, mathematics, history, biology), if I'm not going to do it after school ?! ”

Indeed, does the poor child need to cram formulas and deal with the laws of Newton and Faraday? Maybe, well, her, this dirty trick, we'd better do something interesting? Surprisingly, many adults themselves do not understand why they taught physics at school and sincerely do not see the connection between this entertaining science and everyday life. Let's find this connection!

Imagine your typical day. So you got out of bed, stretched and looked in the mirror. And the laws of physics started working right from the start of your day!

The movement, the reflection in the mirror, the gravity that makes you walk on the ground and the water flow into the sink instead of your face, the force it takes to lift the bag or open the door — all this is physics.

Pay attention to the elevator, which quickly and easily takes you to the desired floor, car or other transport, computers, tablets and phones. Without physics, all this would not go anywhere, would not turn on and would not work.

The development of physics can be equated with progress.

First, people understood the laws of optics and invented simple glasses so that those with poor vision could better navigate, read and write. And then microscopes appeared, with the help of which scientists made incredible discoveries in fields such as biology and medicine. And telescopes in which astronomers saw planets, stars and entire galaxies and were able to draw conclusions about the structure of the universe. Each discovery in physics helps humanity to take a new step forward.

Okay, you say. But for all of the above, for all these discoveries and developments, there are physicists. That is, people who deliberately chose this particular science as their main profession. And what about the rest, and even the humanities? What is this knowledge for them, if you can just read the instructions for your phone and this will be enough to use it?

We have already written that, but besides this, we will give several examples from everyday life when basic knowledge of physics can be useful to everyone. Moreover, we will analyze only one section of physics, almost completely created by Isaac Newton - mechanics.

Movement, speed, acceleration.

So, everything in the universe is constantly moving, including our planet and the earth on which we walk. And we go to different places almost every day. This means that we are constantly counting on how quickly we will get to the theater, work, friends, so as not to be late. We solve speed problems in high school as part of a math course, but in reality this is basic physics.

Now imagine you are choosing a car. You have a desire for a fast car, but you need to drive your family, so size matters too. That is, playful and big. And how do you know which one is right? What will you pay attention to? On acceleration, of course! There is such a parameter - constant acceleration, that is, acceleration from 0 to 100 km in a number of seconds. So the shorter the time from 0 to 100, the more cheerful your car will be at the start and cornering. And physics will tell you this!

When you start (and continue) to drive a car, some of the basic physics course will come in handy. For example, you yourself will understand that it is probably not worth it to brake sharply on the highway at a speed of 120 km / h just because you suddenly wanted to admire the beautiful view.

Even if a few more cars are not following you at the same speed, the drivers of which may not have time to react. It's just that when braking, acceleration is negative, so everyone who sits in the car is suddenly thrown forward. Believe me, belts digging into the body and stretched neck muscles are unpleasant. Just keep in mind the concept of acceleration from physics.

Gravity, impulse and other usefulness.

Physics will tell about the law of gravitation... That is, we already know that if you throw an object, it will fall to the ground. What does it mean? The earth attracts us and all things. Moreover, the planet Earth attracts even such a heavy space object as the Moon. Note that the Moon does not fly away along its trajectory and is shown to people every evening. Also, any things that we threw on the floor in our hearts do not hang in the air. Acceleration also acts on thrown objects, because the Earth has a huge gravity force. And also the friction force.

Therefore, knowing about these laws, one can understand what happens if a person jumps with a parachute. Is the area of \u200b\u200bthe parachute related to the slowdown in the fall rate? Maybe you should ask for a larger parachute? How does the impulse work on the skydiver's knees, and why shouldn't one land on straight legs?

How to choose alpine skiing? Are you a great skater or just starting out? Think about friction, check these parameters for your new skis. If you are a beginner who does not know physics, then a mistake in your choice is very likely. Will you have time to stop?

Okay, you're not going to skydive and don't want to know anything about alpine skiing.

Let's get back to everyday life. Here is a nut and a wrench. What part of the wrench must be grasped to apply maximum force to the nut? Those who have studied physics will take the wrench as far away from the nut as possible. To open a heavy door to an old building, you need to press on it from the very edge, away from the hinges. Do I need to talk about the lever and the fulcrum that Galileo lacked so much?

Probably, these examples are still enough to illustrate the daily presence of physics in our life. And that was just mechanics! But there is also optics, which we mentioned at the beginning of the article, and electricity with magnetic fields. And we are modestly silent about the theory of relativity.

Trust me, physics is on basic level is necessary for everyone in order not to look stupid and funny in the most ordinary situations.

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Physics can be called the main science of the study of nature. All the laws of its existence are studied by this branch of knowledge. For all its complexity, finding a way to learn physics easily is not difficult.

The main thing is to competently approach the educational process.

Why study physics?

Once you start studying physics, you don't always understand why it might work. The point is not only that the acquired knowledge may be needed from a professional point of view.

Physics as a science gives a lot:

. the formation of absolute observation;

. the ability to see the connection, its preservation in phenomena. (If you load the cannon and set the fuse on fire, it will shoot);

. correctly directed thinking, sometimes non-standard;

. studying physics helps to learn the world fully and find out what lies behind the most common things;

. good knowledge will be the foundation for a good career abroad.

When studying a discipline, it can be perceived as very difficult and confusing. If you study science as a system, constantly practice and find a good teacher, it will become simple, even interesting.

What are the sections of physics?

“Physics” translated from ancient Greek means “nature”. This science tries to cover in its theoretical calculations and practical conclusions all forms and ways of existence of matter and field. Fundamentals of physics are studied in two different sections: micro- and macrophysics.

Microphysics as the main subject of study is those objects that cannot be seen with the naked eye (molecules, atoms, electrons, other elementary particles).

Macrophysics studies both objects of our usual sizes (for example, the movement of a ball), and of a larger mass (planets).

The structure of macroscopic physics includes mechanics - it studies the motion of bodies and the interaction between them, speed, movement, distance (sometimes classical, relativistic, quantum).

Microscopic includes sections of quantum, nuclear, physics of elements, their properties.

The school physics course is formed in the same order. This is due to the fact that it is much easier for students to perceive what they are familiar with from childhood. Therefore, the study of abstract physical categories of microphysics is more difficult than classical mechanics.

Why is physics difficult to study?

The first acquaintance with the laws of physics takes place at school, starting from the 6th or 7th grade. Initially, there is a smooth transition from natural history to more specific examples from life. Speed, path, body weight are studied.

Learning physics from scratch may not always be effective. There may be several reasons for this:

. absence necessary equipment for a clear demonstration of physical laws. Even the simplest of them are difficult to explain using only the abstract concepts of "contour", "kinetic energy", "potential energy", "atom", "current", "conservation of energy", "gas constant", "wave". Only an abstract presentation in a textbook of a topic will not replace a physical experiment;

. teachers don't always interest children in learning what physics is learning. The educational process is reduced to memorizing definitions, memorizing laws and dry theory;

. complex topics are presented purely within the framework curriculum, only the number of hours that it was allotted. Interesting examples and paradoxes are left out.

It is the "isolation" educational process and the superficiality of studying the discipline from real examples leads to the difficulty of studying physics at school and the preservation of knowledge.

Popular mistakes when preparing for ZNO in physics

While preparing for OLS, many make those mistakes that can be called typical:

. practical tasks and tasks are solved at random, while all the formulas in physics necessary for solving the task have not been learned;

. new formulas and laws are learned by heart, while the most necessary, basic ones are not repeated;

. an instant solution always seems to be correct due to its simplicity;

. while preparing for the ZNO in physics, one can forget that the main language of physics is mathematics. It is necessary to repeat the absolute and relative values, the main theorems (the square of the hypotenuse is equal to the sum of the squares of the legs);

. more difficult topics (quantum physics, theory of relativity, thermodynamics) are left aside;

. before solving a problem in physics, even the thought that it can be combined is not allowed: in order to find the answer, it is necessary to combine several branches of science, remember the units of measurement of quantities;

. training sessions are sporadic and are often scheduled only a few months prior to the EE.

To avoid such errors, it is additionally necessary to solve tasks of a higher level; they will help to form the properties of a quick and correct solution.

So how do you teach physics effectively?

You may need to study physics in many cases: entering a specialized university, passing an exam, writing a test paper, or just for yourself. Where to start studying physics is the main question, and the answer to it is to draw up a study plan for yourself. This is effective in all of the above cases.

This plan includes not only the schedule of classes, but the principle of their assimilation:

. when considering a new topic, it is necessary to write out all the definitions, quantities, formulas, units of measurement;

. analyzing the physical law and its mathematical expression, find out what quantities in it are interconnected;

. while practicing solving new tasks, solve several of the past topics for repetition. Try to come up with tasks yourself;

. do not work at speed - do everything gradually. The volume of material must be dosed;

. solve problems without resorting to intermediate numbers. The final formula should contain only the values \u200b\u200bthat are given in the condition.

How to understand physics and its formulas?

Physics was originally inseparable from nature. The first observations were made thanks to those objects and phenomena that surrounded a person every day. The basic laws of physics were formed on the basis of experience, which gradually accumulated, moving from the contour to the center. Only over time did the experience take shape first into disparate laws, and then into theory.

Understandable physics formed the basis for the more complex hypotheses that led to the modern understanding of the world.

To understand physics as a science and formulas that describe the relationship of phenomena, you just need to go outside or look out the window. All theoretical calculations, heard at the lecture, are at every instant.

The fall of a stone is the transformation of potential energy into kinetic, overcoming the distance to the ground. The tension of the window curtain is the result of the movement of air masses under the influence of different pressures at different points. The gas exhaust of a car is the effect of pressure. But if you insert your fingers into the outlet, this is an electric current.

This subject is not just a typed paragraph in a textbook, or an abstract problem. Nevertheless, the knowledge gained must be projected onto the surrounding world, and recognized in proportion to the available one.

How to solve problems in physics?

Solving problems in physics involves a certain algorithm:

. carefully read the condition of the assignment, find out which sections of physics are involved in it;

. correctly draw up a condition, bring all units of measurement of quantities to the SI system: kilometers - in meters, grams - in kilograms;

. have a list of known formulas on hand. Choose from them those that may be useful;

. use tables of constants (speed of light, density of substances, gas constant, wavelength, volume of 1 mole of ideal gas);

. remember the laws describing the interactions of the proposed quantities (they can be from both the initial sections and from quantum physics);

. using formulas, combine them to find a finite number of answers;

. make calculations and display the unit of measurement of the required value.

If difficulties arise, in an efficient way will present the condition in real life... The usual logic of life will tell you which answer will be absolute and correct, and which options should be discarded.

How to memorize formulas in physics?

On exams and control works the list of required formulas is not allowed. Therefore, it will be useful to use mnemonic rules to memorize relationships and laws - this is how to quickly learn physics.

Formulas are remembered if they are linked into a sound association or scale:

Archimedes' law for liquid:F \u003d pgV: PoZha - Vo!

Ampere's Law F \u003d Bilsina : Ampere beat sine alpha with force.

Potential energy:E \u003d mgh: We are - Shsh!

The movement of a charged particle in a uniform electric field:p \u003d qBR , particle momentum (p ) - impulse of the cobra (q, B, R).

Ideal gas equation:pV \u003d (m / M) RT ... Turn from Madrid to Moscow:pV - pov-, RT - mouth, m / M - from Madrid to Moscow (R - constant, universal coefficient).

Newton's first law:if you don't kick, it won't fly;

Newton's second law (for acceleration):as you kick, it will fly;

Newton's third law: as you kick, you get it.

Physical laws are much easier to remember in the form of rhymes:

Ohm's law for a chain section:

Who doesn't know Ohm's Law?

Everyone knows him, of course.

Repeat the scheme quickly.

U equals RI.

Definition of Leverage:

If any solid body rotates around a fixed support,

Then you should know - it is called a lever.

Preparation for ZNO in physics must be approached with all seriousness:

1. Develop a training plan and follow it clearly.

2. Exercise regularly, about three times a week for one and a half to two hours, without stress.

3. Find a list of recommended topics for preparation for EIT.

4. All formulas and laws, units of measurement (for example, 1 kilometer \u003d 1000 meters) should be written out in a separate notebook.

5. Solve problems on each of the topics and different levels of difficulty, as well as tasks for the combination of various branches of science (for example, energy and motion, heat and electric field, thermodynamics, theory of relativity).

6. A few months before the EIT, go through the examples of previous years, solving them in one sitting.

7. If you have any questions - seek help or advice from a professional teacher.

Good theoretical and practical physics aids are:

. Yavorsky BM, Detlaf AA Physics for high school students and those entering universities. M. Bustard. 2003.

. Savchenko N.E. Problems in physics with analysis of their solutions.Moscow: Education, 2000.

Korshak E.V., O.I. Lyashenko O. I. Physics. K .: Perun, 2011.

"Theoretical minimum" is a book for those who missed physics lessons at school and institute, but already regret it. Do you want to understand the basics of natural sciences and learn to think and reason the way modern physicists do? In an original and non-standard form, renowned American scientists Leonard Susskind and George Grabowski offer an introductory course in mathematics and physics for inquisitive minds. Unlike other popular science books that try to explain the laws of physics in an accessible way, cleverly evading equations and formulas, the authors teach the reader classic basics natural sciences. The book offers its own original teaching methodology, supplemented by video lectures published on the website theoreticalminimum.com.

What is classical physics?
The term classical physics refers to the kind of physics that existed before the advent of quantum mechanics. Classical physics includes Newton's laws of particle motion, Maxwell-Faraday's theory of the electromagnetic field, and Einstein's general theory of relativity. But this is more than just specific theories of specific phenomena; it is a series of principles and rules - a basic logic that subordinates all phenomena for which quantum uncertainty is insignificant. This vault general rules called classical mechanics.
The task of classical mechanics is to predict the future. The great eighteenth-century physicist Pierre-Simon Laplace expressed this in a famous quote:

"The state of the universe in this moment can be seen as a consequence of her past and as the cause of her future. A thinking creature who, at a certain moment, would know all the driving forces of nature and all the positions of all objects that make up the world, could - if his mind were vast enough to analyze all these data - express in one equation the motion and the most large bodies in the Universe, and the smallest atoms; for such an intellect there would be no uncertainty and the future would open before its gaze in the same way as the past. "

Content
Foreword
Lecture 1 The nature of classical physics
Interlude 1 Spaces, trigonometry and vectors
Lecture 2 Movement
Interlude 2 Integral Calculus
Lecture 3 Dynamics
Interlude 3 Private Differentiation
Lecture 4 Systems of more than one particle
Lecture 5 Energy
Lecture 6 Principle of Least Action
Lecture 7 Symmetries and conservation laws
Lecture 8 Hamiltonian mechanics and time-shift symmetry
Lecture 9 Phase fluid and the Gibbs-Liouville theorem
Lecture 10 Poisson bracket, angular momentum and symmetry
Lecture 11 Electric and magnetic forces
Appendix Central forces and planetary orbits.

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Scientists from planet Earth use a ton of tools to try to describe how nature and the universe in general work. That they come to laws and theories. What is the difference? Scientific law can often be reduced to a mathematical statement such as E \u003d mc²; this statement is based on empirical data and its truth is usually limited to a certain set of conditions. In case E \u003d mc² - the speed of light in vacuum.

Scientific theory often seeks to synthesize a series of facts or observations of specific phenomena. And in general (but not always) there is a clear and testable statement about how nature functions. It is not at all necessary to reduce scientific theory to an equation, but it actually represents something fundamental about the workings of nature.

Laws and theories both depend on basic elements of the scientific method, such as creating hypotheses, performing experiments, finding (or not finding) empirical data, and drawing conclusions. After all, scientists must be able to replicate the results if the experiment is to become the basis for a generally accepted law or theory.

In this article, we'll take a look at ten scientific laws and theories you can brush up on, even if you don't use a scanning electron microscope that often, for example. Let's start with an explosion and end with uncertainty.

If it is worth knowing at least one scientific theory, then let it explain how the universe reached its current state (or did not reach,). Based on research by Edwin Hubble, Georges Lemaitre, and Albert Einstein, the Big Bang theory postulates that the universe began 14 billion years ago with massive expansion. At some point, the universe was confined to one point and encompassed all the matter of the present universe. This movement continues to this day, and the universe itself is constantly expanding.

The Big Bang theory gained widespread scientific support after Arno Penzias and Robert Wilson discovered the cosmic microwave background in 1965. Using radio telescopes, two astronomers discovered cosmic noise, or static, that does not dissipate over time. In collaboration with Princeton researcher Robert Dicke, a couple of scientists have confirmed Dicke's hypothesis that the original Big Bang left behind low-level radiation that can be found throughout the universe.

Hubble's law of cosmic expansion

Let's hold Edwin Hubble for a second. While the Great Depression was raging in the 1920s, Hubble performed groundbreaking astronomical research. He not only proved that there were other galaxies besides the Milky Way, but he also found that these galaxies were sweeping away from our own, and this movement he called recession.

In order to quantify the speed of this galactic motion, Hubble proposed the law of cosmic expansion, aka Hubble's law. The equation looks like this: speed \u003d H0 x distance. Velocity is the speed at which galaxies are moving away; H0 is the Hubble constant, or parameter that indicates the rate of expansion of the universe; distance is the distance of one galaxy to the one with which the comparison is made.

The Hubble constant was calculated at different meanings for quite a long time, but at present it has frozen at a point of 70 km / s per megaparsec. It's not that important for us. Importantly, the law is a convenient way to measure the speed of a galaxy relative to our own. And more importantly, the law established that the Universe consists of many galaxies, the movement of which can be traced back to the Big Bang.

Kepler's laws of planetary motion

For centuries, scientists have battled with each other and with religious leaders over the orbits of the planets, especially whether they revolve around the sun. In the 16th century, Copernicus put forward his controversial concept of the heliocentric Solar systemin which the planets revolve around the sun, not the earth. However, it was only with Johannes Kepler, who relied on the work of Tycho Brahe and other astronomers, that a clear scientific basis for the motion of the planets emerged.

Kepler's three laws of planetary motion, formed at the beginning of the 17th century, describe the motion of planets around the Sun. The first law, sometimes called the law of orbits, states that the planets revolve around the sun in an elliptical orbit. The second law, the law of areas, says that the line connecting the planet to the sun forms equal areas at regular intervals. In other words, if you measure the area created by a line drawn from the Earth from the Sun and track the movement of the Earth for 30 days, the area will be the same regardless of the Earth's position in relation to the origin.

The third law, the law of periods, allows you to establish a clear relationship between the orbital period of a planet and the distance to the Sun. Thanks to this law, we know that a planet that is relatively close to the Sun, like Venus, has a much shorter orbital period than distant planets like Neptune.

The universal law of gravitation

Today this may be the order of things, but more than 300 years ago Sir Isaac Newton proposed a revolutionary idea: any two objects, regardless of their mass, exert gravitational attraction on each other. This law is represented by the equation that many schoolchildren face in the senior classes of physics and mathematics.

F \u003d G × [(m1m2) / r²]

F is gravitational force between two objects, measured in newtons. M1 and M2 are the masses of two objects, while r is the distance between them. G is the gravitational constant, currently calculated as 6.67384 (80) · 10 −11 or N · m² · kg −2.

The advantage of the universal law of gravitation is that it allows you to calculate the gravitational attraction between any two objects. This ability is extremely useful when scientists, for example, launch a satellite into orbit or determine the course of the moon.

Newton's laws

While we're on the subject of one of the greatest scientists who ever lived on Earth, let's talk about other famous Newton's laws. His three laws of motion form an essential part of modern physics. And like many other laws of physics, they are elegant in their simplicity.

The first of the three laws states that an object in motion remains in motion unless an external force acts on it. For a ball that is rolling on the floor, the external force can be friction between the ball and the floor, or a boy who hits the ball in a different direction.

The second law establishes a relationship between the mass of an object (m) and its acceleration (a) in the form of the equation F \u003d m x a. F is the force measured in newtons. It is also a vector, that is, it has a directional component. Due to the acceleration, the ball rolling on the floor has a special vector in the direction of its movement, and this is taken into account when calculating the force.

The third law is quite meaningful and should be familiar to you: for every action there is an equal reaction. That is, for every force applied to an object on the surface, the object is repelled with the same force.

The laws of thermodynamics

The British physicist and writer C.P. Snow once said that the non-scientist who did not know the second law of thermodynamics was like the scientist who had never read Shakespeare. Snow's now famous statement emphasized the importance of thermodynamics and the need even for people far from science to know it.

Thermodynamics is the science of how energy works in a system, be it the engine or the core of the Earth. It can be boiled down to several basic laws, which Snow outlined as follows:

• You cannot win.
• You will not avoid losses.
• You cannot quit the game.

Let's figure it out a bit. By saying that you cannot win, Snow meant that since matter and energy are conserved, you cannot gain one without losing the other (ie E \u003d mc²). It also means that you need to supply heat to run the engine, but in the absence of a perfectly closed system, some heat will inevitably go into the open world, which will lead to the second law.

The second law - losses are inevitable - means that due to the increasing entropy, you cannot return to the previous energy state. Energy concentrated in one place will always tend to places of lower concentration.

Finally, the third law - you can't get out of the game - applies to the lowest theoretically possible temperature - minus 273.15 degrees Celsius. When the system reaches absolute zero, the movement of molecules stops, which means that the entropy will reach its lowest value and there will not even be kinetic energy. But in the real world, it's impossible to reach absolute zero - just get very close to it.

Archimedes' strength

After the ancient Greek Archimedes discovered his principle of buoyancy, he allegedly shouted "Eureka!" (Found it!) And ran naked across Syracuse. So the legend says. The discovery was so important. Also, legend says that Archimedes discovered the principle when he noticed that the water in the bathroom rises when the body is immersed in it.

According to the buoyancy principle of Archimedes, the force acting on a submerged or partially submerged object is equal to the mass of the liquid that the object displaces. This principle has critical importance in density calculations, as well as the design of submarines and other ocean-going vessels.

Evolution and natural selection

Now that we have established some of the basic concepts of how the universe began and how physical laws affect our daily life, let's pay attention to human form and find out how we got there. According to most scientists, all life on Earth has a common ancestor. But in order for such a huge difference to form between all living organisms, some of them had to turn into a separate species.

In a general sense, this differentiation has occurred in the process of evolution. Populations of organisms and their traits have gone through mechanisms such as mutations. Those with more favorable traits for survival, such as brown frogs that camouflage themselves well in the swamp, were naturally chosen for survival. This is where the term natural selection comes from.

You can multiply these two theories for many, many times, and in fact Darwin did it in the 19th century. Evolution and natural selection explain the vast variety of life on Earth.

General theory of relativity

Albert Einstein was and remains the most important discovery that forever changed the way we view the universe. Einstein's major breakthrough was his claim that space and time are not absolute, and gravity is not just a force applied to an object or mass. Rather, gravity is related to the fact that mass bends space and time itself (space-time).

To make sense of this, imagine that you are driving across the earth in a straight line eastward, say from the northern hemisphere. After a while, if someone wants to accurately determine your location, you will be much south and east of your starting position. This is because the Earth is curved. To drive straight east, you need to consider the shape of the earth and drive at an angle slightly north. Compare a round ball and a piece of paper.

Space is pretty much the same thing. For example, for the passengers of a rocket flying around the Earth, it will be obvious that they are flying in a straight line in space. But in reality, the spacetime around them bends under the influence of the Earth's gravity, causing them to simultaneously move forward and stay in Earth's orbit.

Einstein's theory had a huge impact on the future of astrophysics and cosmology. She explained a small and unexpected anomaly in the orbit of Mercury, showed how the light of the stars bends and laid theoretical basis for black holes.

Heisenberg uncertainty principle

An extension of Einstein's theory of relativity told us more about how the universe works and helped lay the foundation for quantum physics, which led to a completely unexpected embarrassment in theoretical science. In 1927, the realization that all the laws of the universe in a given context are flexible led to the startling discovery of the German scientist Werner Heisenberg.

Postulating his uncertainty principle, Heisenberg realized that it is impossible to simultaneously know with a high level of accuracy the two properties of a particle. You can know the position of an electron with a high degree of accuracy, but not its momentum, and vice versa.

Later, Niels Bohr made a discovery that helped explain the Heisenberg principle. Bohr found that an electron has the qualities of both a particle and a wave. The concept became known as wave-particle duality and became the foundation of quantum physics. Therefore, when we measure the position of an electron, we define it as a particle at a certain point in space with an indefinite wavelength. When we measure momentum, we consider the electron as a wave, which means we can know the amplitude of its length, but not the position.