Louis Bloomfield's book How Everything Works. The laws of physics in our life”, prepared for publication by the Corpus publishing house with the double support of the Polytechnic Museum and “ book projects Dmitry Zimin. Let's talk about why it is worth reading - especially if physics seems to you to be something boring and incomprehensible.
Getting up in the morning from a spring mattress, turning on the electric kettle, warming our hands on a cup of coffee and doing dozens of other everyday things, we rarely think about how exactly all this is happening. Perhaps, in someone's memory, Ohm's law or the gimlet's rule sticks out like a lone fragment (well, if you remember at all that "gimlet" is a screw, not a surname).
It is far from always clear at what moments of life we encounter current strength and angular momentum.
Of course, there are scientists, technicians and geeks. We are even ready to believe that there are people who simply taught physics very well at school (our respect to them). It will not be difficult for them to tell how exactly an incandescent lamp or a solar battery works and explain, looking at a spinning bicycle wheel, where is the static friction and where is the sliding friction. However, let's be honest, most people have very vague ideas about all this.
This makes it seem like natural objects and mechanisms behave in one way or another due to some magical powers. Everyday understanding of causes and effects can protect against some mistakes (for example, do not put food wrapped in foil in the microwave), but a deeper understanding of physical and chemical processes allows you to better understand what's what and argue your decisions.
Louis Bloomfield is a professor at the University of Virginia and a researcher in atomic physics, condensed matter physics, and optics.
Even in his youth, he chose experiments as the main method of studying the world, drawing inspiration from everyday things for doing science. In an effort to make knowledge available to many people rather than a handful of specialists, Bloomfield is teaching, appears on television and writes popular science works.
The main task of the book “How it all works. The laws of physics in our life” - to refute the idea of physics as a boring and out of touch science, and make it clear that it describes real phenomena that can be seen, touched and felt.
It has always been a mystery to me why physics is traditionally taught as an abstract science - after all, it studies the material world and the laws that govern it. I am convinced of the opposite: if physics is deprived of countless examples from the living, real world, it will have neither a basis nor a form - like a milkshake without a glass.
Louis Bloomfield
We are talking about the movement of bodies, mechanical devices, heat and much more. Instead of starting with a theory, the author goes from the things around us, formulating laws and principles with their help. Starting points are carousels, roller coasters, plumbing, warm clothes, audio players, lasers and LEDs, telescopes and microscopes...
Here are some examples from the book in which the author explains the mechanics of simple things.
Why do skaters move fast?
Skates are a convenient way to talk about the principles of movement. Even Galileo Galilei formulated that bodies tend to move uniformly and rectilinearly in the absence of external forces, whether it be air resistance or surface friction. Skates are able to almost completely eliminate friction, so you glide across the ice with ease. An object at rest tends to stay in place, while an object in motion tends to move on. This is what is called inertia.
How scissors cut
By moving the rings of the scissors, you produce moments of force, under the action of which the blades close and cut the paper. The paper tends to push the blades apart due to the moments of forces that “spread” the blades. If you apply a sufficiently large force, the "shifting" moments of forces will prevail over the "bringing" ones. As a result, the scissor blades will acquire angular acceleration, will begin to turn, close and cut the sheet of paper.
What's going on in the skewers
If one end of a metal rod is heated, the atoms in that part of the rod will vibrate more intensely than at the cold end, and the metal will begin to conduct heat from the hot end to the cold end. Some of this heat is transferred due to the interaction of neighboring atoms, but most of it will be transferred by mobile electrons, which carry thermal energy over long distances from one atom to another.
How nails are hammered
All the downward momentum you impart to the hammer by swinging is transferred to the nail during the brief blow. Since the momentum transfer time is short, a very large force must be applied from the side of the hammer in order for its momentum to pass to the nail. This impact force drives the nail into the board.
Why are balloons heated?
It takes fewer particles to fill a balloon with hot air than it does to fill it with cold air. This is because, on average, a particle of hot air moves faster, collides more often, and takes up more space than a particle of cold air. Therefore, a balloon filled with hot air weighs less than the same balloon filled with cold air. If the weight of the ball is small enough, the resultant force is directed upward and the ball rises.
Why does the shuttlecock always fly the same way
A badminton shuttlecock always flies head first because the resultant pressure force is applied at its center of pressure, some distance from its center of mass. If suddenly the plumage is accidentally in front of the head, air resistance will create a moment of force relative to the center of mass and return everything to its place.
What makes water hard
Hard water is considered to be water in which the content of positively charged calcium and magnesium ions exceeds 120 mg per liter. Ions of these and some other metals bind negative ions of soap and create insoluble foam, deposited as a dirty coating on the sink, shower head, bathtub, in the washing machine and on clothes. Having started washing with soap in hard water, be prepared for unpleasant surprises.
Take a course with the author
You can learn from Louis Bloomfield online in the How Things Work course: here he starts cars, goes to the playground to talk about swings, makes experiments and talks about everything in the world.
Even if this is not enough for you, and you want to see the professor with your own eyes, there is also such an opportunity: Louis Bloomfield will be in Moscow from December 3 to 8.
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Slides captions:
physics in our life
Nature always lives according to its own laws. We study them in an effort to understand, And it is very important to know and understand the basics, in order to apply this knowledge in life. And man - a phenomenon of nature itself - Always strived for her, she is his soul. Energy is everywhere, the energy of freedom And how good nature is!
The joy of seeing and understanding is the most beautiful gift of nature. The task of physics: To make the UNKNOWN KNOWN, to turn ignorance into KNOWLEDGE. A. Einstein
Where does the wind come from? Why is it raining? What is a thunderstorm? Studying physics will help you explain natural phenomena answer many questions,
Why did the sun go down and it's still light? Why is the moon different in the sky?
Northern Lights Have you seen such beauty? It floats, changes, plays. And pulls to a witching height. He flaps his wings and flies into the abyss. What strength and what delight! What colors, my heart stops! It flies by, see the dragon there? Look, now the organ is playing. The radiance of the north, you are like a Deity! You are not subject to the mind or the body! Oh my God! Great and easy! Such a miracle here in the far north!
What is a rainbow?
What is fire? What is electrification?
PHYSICS AND SPACE What is a meteorite? What is a satellite?
What is the speed of the rocket? What are asteroids?
Is it possible to live on other planets? Mercury SATURN
What Atmosphere pressure? How is our planet?
What is sound? How are our eyes arranged? Why do they fall into the snow?
How does a light bulb work? How does an electric motor work? How does a piston pump work? How does a refrigerator work?
Physicists Archimedes Blaise Pascal Albert Einstein Galileo Galilei Isaac Newton Rene Descartes M. V. Lomonosov 2 3 1 4 5 6 2. 7
Water vapor doesn't stay in the air all the time. Part of it turns back into water. This is called condensation and happens when the air cools down. Where does the water go when it dries up? You can answer some physical questions right now Water from the air You can make water appear yourself Put a glass of water in the refrigerator for an hour to cool it down. When you take it out, you will see drops of water begin to appear on the walls of the glass. A cold glass cools the air around it, and water vapor from the air, condensing, forms water droplets on the walls of the glass. For the same reason, you see water droplets running down the inside of a misted window pane on cold days.
Water appears to be harmless. And it happens that the water explodes like gunpowder. Yes, that's rubbish. Water is twenty times more dangerous than gunpowder if you don't know how to handle it. There was a case when water blew up an entire five-story house and killed twenty-three people. It was in America about forty years ago. How could this happen? The fact is that this house was a factory. On the lower floor, a huge cauldron was stuck into a large stove. There was as much water in it as in a large pond. When the stove was heated, the water in the boiler boiled, and the steam went through the pipe to the steam engine. Once the engineer gaped and did not pump water in time. There is very little water left in the boiler. But the stove continued to heat up. From this, the walls of the boiler became hot. The driver did not think about it - he took it and put water into the red-hot cauldron. Do you know what happens when you pour water on hot iron? She immediately turns into steam. The same thing happened here. All the water turned into steam, too much steam accumulated in the boiler, the boiler could not stand it and burst. It happened even worse: in Germany, twenty-two boilers once exploded at once. All the houses around were destroyed. The fragments of the boilers were lying at a distance of half a kilometer from the explosion site. What a terrible thing water vapor is! Can water blow up a house?
Devices How are they arranged? How to use? What is being measured?
MYSTERIES The bear roared over all the mountains, all the seas. What it is? 1. SONG 2. THUNDER 3. SHOROCH How big watermelons are, How small apples are. They cannot speak, but they can determine the weight. Passes through the nose to the chest And the reverse keeps the path. He is invisible, and yet we cannot live without him.
Will tell everything, though without language, When it will be clear, and when - clouds. Thunderstorm outside, heavy rain. Which phenomenon will we record first: will we hear thunder or see lightning?
I keep hot, I keep cold, I will replace the oven and refrigerator for you on the campaign. Snow and ice sparkle there, Winter itself lives there. An iron whale under water, Day and night, the whale does not sleep Day and night under water Protects your peace.
What needs to be done so that one of the sheets falls before the other? Answer. One of the solutions: crumple one sheet, the volume will decrease, the body will fall faster.
Physical Instruments
physical phenomena lightning friction inertia motion rainbow molecule
STRIVE TO UNDERSTAND SCIENCE EVERYTHING DEEPER, TO KNOW THE ETERNAL THIRST languish. ONLY THE FIRST KNOWLEDGE WILL SHIN THE LIGHT FOR YOU, YOU KNOW: THERE IS NO LIMIT FOR KNOWLEDGE. Ferdowsi (Persian and Tajik poet, 940-1030)
Ecology of life: Armed with this knowledge, you will definitely not fall into the trap of myths, do not buy a charlatan device and will be able to confidently answer children's questions in the spirit of “Why is the sky blue?”.
Louis Bloomfield's book How Everything Works. The laws of physics in our life. Let's talk about why it is worth reading - especially if physics seems to you to be something boring and incomprehensible.
Getting up in the morning from a spring mattress, turning on the electric kettle, warming our hands on a cup of coffee and doing dozens of other everyday things, we rarely think about how exactly all this happens. Perhaps, in someone's memory, Ohm's law or the gimlet's rule sticks out like a lone fragment (well, if you remember at all that "gimlet" is a screw, not a surname).
It is far from always clear at what moments of life we encounter current strength and angular momentum.
Of course, there are scientists, technicians and geeks. We are even ready to believe that there are people who just taught physics very well at school (our respect to them). It will not be difficult for them to tell how exactly an incandescent lamp or a solar battery works and explain, looking at a spinning bicycle wheel, where is the static friction and where is the sliding friction. However, let's be honest, most people have very vague ideas about all this.
Source: pinterest
Because of this, it seems as if natural objects and mechanisms behave in one way or another due to some magical forces. Everyday understanding of causes and effects can protect against some mistakes (for example, do not put food wrapped in foil in the microwave), but a deeper understanding of physical and chemical processes allows you to better understand what's what and argue your decisions.
Louis Bloomfield is a professor at the University of Virginia and a researcher in atomic physics, condensed matter physics, and optics.
Even in his youth, he chose experiments as the main method of studying the world, drawing inspiration from everyday things for doing science. Seeking to make knowledge available to many people rather than a handful of specialists, Bloomfield teaches, appears on television, and writes non-fiction.
The main task of the book “How it all works. The laws of physics in our life” - to refute the idea of physics as a boring and out of touch science, and make it clear that it describes real phenomena that can be seen, touched and felt.
It has always been a mystery to me why physics is traditionally taught as an abstract science - after all, it studies the material world and the laws that govern it. I am convinced of the opposite: if physics is deprived of countless examples from the living, real world, it will have neither a basis nor a form - like a milkshake without a glass.
Louis Bloomfield
We are talking about the movement of bodies, mechanical devices, heat and much more. Instead of starting with a theory, the author goes from the things around us, formulating laws and principles with their help. Starting points are carousels, roller coasters, plumbing, warm clothes, audio players, lasers and LEDs, telescopes and microscopes...
Here are some examples from the book in which the author explains the mechanics of simple things.
Why do skaters move fast?
Skates are a convenient way to talk about the principles of movement. Even Galileo Galilei formulated that bodies tend to move uniformly and rectilinearly in the absence of external forces, whether it be air resistance or surface friction. Skates are able to almost completely eliminate friction, so you glide across the ice with ease. An object at rest tends to stay in place, while an object in motion tends to move on. This is what is called inertia.
How scissors cut
By moving the rings of the scissors, you produce moments of force, under the action of which the blades close and cut the paper. The paper tends to push the blades apart due to the moments of forces that “spread” the blades. If you apply a sufficiently large force, the "shifting" moments of forces will prevail over the "bringing" ones. As a result, the scissor blades will acquire angular acceleration, begin to turn, close and cut the sheet of paper.
Source: PexelsWhat's going on in the skewers
If one end of a metal rod is heated, the atoms in that part of the rod will vibrate more intensely than at the cold end, and the metal will begin to conduct heat from the hot end to the cold end. Some of this heat is transferred due to the interaction of neighboring atoms, but most of it will be transferred by mobile electrons, which carry thermal energy over long distances from one atom to another.
How nails are hammered
All the downward momentum you impart to the hammer by swinging is transferred to the nail during the brief blow. Since the momentum transfer time is short, a very large force must be applied from the side of the hammer in order for its momentum to pass to the nail. This impact force drives the nail into the board.
Why are balloons heated?
It takes fewer particles to fill a balloon with hot air than it does to fill it with cold air. This is because, on average, a particle of hot air moves faster, collides more often, and takes up more space than a particle of cold air. Therefore, a balloon filled with hot air weighs less than the same balloon filled with cold air. If the weight of the ball is small enough, the resultant force is directed upward and the ball rises.
Why does the shuttlecock fly always the same about
A badminton shuttlecock always flies head first because the resultant pressure force is applied at its center of pressure, some distance from its center of mass. If suddenly the plumage is accidentally in front of the head, air resistance will create a moment of force relative to the center of mass and return everything to its place.
What makes water hard
Hard water is considered to be water in which the content of positively charged calcium and magnesium ions exceeds 120 mg per liter. Ions of these and some other metals bind negative ions of soap and create insoluble foam, deposited as a dirty coating on the sink, shower head, bathtub, in the washing machine and on clothes. Having started washing with soap in hard water, be prepared for unpleasant surprises. published
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Daniel Kahneman: Thinking and Thinking - what's the difference
No sphere human activity not without the exact sciences. And no matter how complex human relationships are, they also come down to these laws. invites you to remember the laws of physics that a person encounters and experiences every day of his life.
The simplest but most important law is The law of conservation and transformation of energy.
The energy of any closed system remains constant for all processes occurring in the system. And we are in such a closed system and we are. Those. how much we give, so much we get. If we want to get something, we must give the same amount before that. And nothing else!
And we, of course, want to get a big salary, but not go to work. Sometimes an illusion is created that "fools are lucky" and happiness falls on many people's heads. Read any fairy tale. Heroes constantly have to overcome huge difficulties! Then swim in the cold water, then in boiling water.
Men attract the attention of women with courtship. Women, in turn, take care of these men and children. And so on. So, if you want to get something, take the trouble to give first.
The force of action is equal to the force of reaction.
This law of physics reflects the previous one, in principle. If a person has committed a negative act - conscious or not - and then received a response, i.e. opposition. Sometimes cause and effect are separated in time, and you can not immediately understand where the wind is blowing from. We must, most importantly, remember that nothing just happens.
The Law of the Lever.
Archimedes exclaimed: Give me a foothold and I will move the Earth!". Any weight can be carried if you choose the right lever. You should always estimate how long the lever will be needed in order to achieve this or that goal and draw a conclusion for yourself, set priorities: do you need to spend so much effort to create the right lever and move this weight, or is it easier to leave it alone and do other activities.
The gimlet rule.
The rule is that points to the direction magnetic field. This rule answers the eternal question: who is to blame? And he points out that we ourselves are to blame for everything that happens to us. No matter how insulting it is, no matter how difficult it is, no matter how unfair it may seem at first glance, we must always be aware that we ourselves were the cause from the very beginning.
law of the nail.
When a person wants to hammer in a nail, he does not knock somewhere near the nail, he knocks exactly on the head of the nail. But the nails themselves do not climb into the walls. You must always choose the right hammer so as not to break the nail with a sledgehammer. And when scoring, you need to calculate the blow so that the hat does not bend. Keep it simple, take care of each other. Learn to think about your neighbor.
And finally, the law of entropy.
Entropy is a measure of the disorder of a system. In other words, the more chaos in the system, the greater the entropy. A more precise formulation: in spontaneous processes occurring in systems, entropy always increases. As a rule, all spontaneous processes are irreversible. They lead to real changes in the system, and it is impossible to return it to its original state without expending energy. At the same time, it is impossible to repeat exactly (100%) its initial state.
To better understand what kind of order and disorder we are talking about, let's set up an experiment. Pour black and white pellets into a glass jar. Let's put in the blacks first, then the whites. The pellets will be arranged in two layers: black on the bottom, white on top - everything is in order. Then shake the jar several times. The pellets will mix evenly. And no matter how much we then shake this jar, we are unlikely to be able to achieve that the pellets are again arranged in two layers. Here it is, entropy in action!
The state when the pellets were arranged in two layers is considered ordered. The state when the pellets are evenly mixed is considered disordered. It takes almost a miracle to return to an ordered state! Or repeated painstaking work with pellets. And it takes almost no effort to wreak havoc in a bank.
Car wheel. When it is inflated, it has an excess of free energy. The wheel can move, which means it works. This is the order. What if you puncture a wheel? The pressure in it will drop, the free energy will "leave" in environment(dissipates), and such a wheel will no longer be able to work. This is chaos. To return the system to its original state, i.e. put things in order, you need to do a lot of work: glue the camera, mount the wheel, pump it up, etc., after which it is again necessary thing that can be beneficial.
Heat is transferred from a hot body to a cold one, and not vice versa. The reverse process is theoretically possible, but practically no one will undertake to do this, since enormous efforts, special installations and equipment will be required.
Also in society. People are getting old. Houses are crumbling. Rocks sink into the sea. The galaxies are scattered. Any reality surrounding us spontaneously tends to disorder.
However, people often talk about disorder as freedom: No, we do not want order! Give us such freedom that everyone can do what they want!» But when everyone does what they want, this is not freedom - this is chaos. In our time, many praise disorder, promote anarchy - in a word, everything that destroys and divides. But freedom is not in chaos, freedom is precisely in order.
Organizing his life, a person creates a reserve of free energy, which he then uses to implement his plans: work, study, recreation, creativity, sports, etc. In other words, it opposes entropy. Otherwise, how could we have accumulated so many material values over the past 250 years?!
Entropy is a measure of disorder, a measure of the irreversible dissipation of energy. The more entropy, the more disorder. A house where no one lives is falling into disrepair. Iron rusts over time, the car gets old. Relationships that no one cares about will break down. So is everything else in our life, absolutely everything!
The natural state of nature is not equilibrium, but an increase in entropy. This law works inexorably in the life of one person. He does not need to do anything to increase his entropy, this happens spontaneously, according to the law of nature. In order to reduce entropy (disorder), you need to make a lot of effort. This is a kind of slap in the face to stupidly positive people (under a lying stone and water does not flow), of which there are quite a lot!
Maintaining success requires constant effort. If we do not develop, then we degrade. And to keep what we had before, we must do more today than we did yesterday. Things can be kept in order and even improved: if the paint on a house has faded, it can be repainted, and even more beautiful than before.
People should try to "pacify" the arbitrary destructive behavior that prevails in modern world everywhere, to try to reduce the state of chaos, which we also dispersed to grandiose limits. And this is a physical law, and not just a chatter about depression and negative thinking. Everything either develops or degrades.
A living organism is born, develops and dies, and no one has ever observed that after death it revives, becomes younger and returns to the seed or womb. When they say that the past never returns, then, of course, they mean, first of all, these vital phenomena. The development of organisms sets the positive direction of the arrow of time, and the change from one state of the system to another always occurs in the same direction for all processes without exception.
Valerian Chupin
Source of information: Tchaikovsky.News
Comments (3)
Wealth modern society grows, and will grow to an ever greater extent, primarily by universal labor. Industrial capital was the first historical form of social production, when universal labor began to be intensively exploited. And first, the one that he got for free. Science, as Marx observed, cost nothing to capital. Indeed, not a single capitalist paid a reward to either Archimedes, or Cardano, or Galileo, or Huygens, or Newton for the practical use of their ideas. But it is precisely industrial capital that, on a mass scale, begins to exploit mechanical technology, and thus the general labor embodied in it. Marx K, Engels F. Soch., vol. 25, part 1, p. 116.
Scientists from planet Earth use a ton of tools to try to describe how nature and the universe as a whole work. That they come to laws and theories. What is the difference? A scientific law can often be reduced to a mathematical statement, like E = mc²; this statement is based on empirical data and its truth, as a rule, is limited to a certain set of conditions. In the case of E = mc² - the speed of light in vacuum.
A scientific theory often seeks to synthesize a set of facts or observations of specific phenomena. And in general (but not always) there is a clear and verifiable statement about how nature functions. It is not at all necessary to reduce scientific theory to the equation, but it actually represents something fundamental about the workings of nature.
Both laws and theories depend on the basic elements of the scientific method, such as making hypotheses, doing experiments, finding (or not finding) empirical evidence, and drawing conclusions. After all, scientists must be able to replicate results if the experiment is to become the basis for a generally accepted law or theory.
In this article, we will look at ten scientific laws and theories that you can brush up on even if you don't use the scanning electron microscope. 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 it). Based on studies by Edwin Hubble, Georges Lemaitre, and Albert Einstein, the Big Bang theory postulates that the universe began 14 billion years ago with a massive expansion. At some point, the universe was enclosed in one point and encompassed all the matter of the current universe. This movement continues to this day, and the universe itself is constantly expanding.
The Big Bang theory gained widespread support in scientific circles after Arno Penzias and Robert Wilson discovered the cosmic microwave background in 1965. Using radio telescopes, two astronomers have detected cosmic noise, or static, that does not dissipate over time. In collaboration with Princeton researcher Robert Dicke, the pair of scientists confirmed Dicke's hypothesis that the original Big Bang left behind low-level radiation that can be found throughout the universe.
Hubble's Cosmic Expansion Law
Let's hold Edwin Hubble for a second. While the Great Depression was raging in the 1920s, Hubble was performing groundbreaking astronomical research. He not only proved that there were other galaxies besides Milky Way, but also discovered that these galaxies are rushing away from our own, a movement he called a 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 = H0 x distance. Velocity is the speed of the recession of galaxies; H0 is the Hubble constant, or a parameter that indicates the expansion rate of the universe; distance is the distance of one galaxy to the one with which the comparison is made.
The Hubble constant has been calculated at different values for quite some time, but it is currently stuck at 70 km/s per megaparsec. For us it is not so important. The important thing is that 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 to the Big Bang.
Kepler's laws of planetary motion
For centuries, scientists have battled each other and 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 system where the planets revolve around the sun instead of the earth. However, only with Johannes Kepler, who relied on the work of Tycho Brahe and other astronomers, did a clear scientific basis for the motion of the planets.
Kepler's three laws of planetary motion, developed in the early 17th century, describe the movement 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 drawn line from the Earth to the Sun and track the movement of the Earth for 30 days, the area will be the same regardless of the position of the Earth relative to the origin.
The third law, the law of periods, allows you to establish a clear relationship between the orbital period of the 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.
Universal law of gravity
This may be par for the course today, but more than 300 years ago, Sir Isaac Newton proposed a revolutionary idea: any two objects, regardless of their mass, exert a gravitational attraction on each other. This law is represented by an equation that many schoolchildren encounter in the senior grades of physics and mathematics.
F = G × [(m1m2)/r²]
F is gravitational force between two objects, measured in newtons. M1 and M2 are the masses of the 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 gravity 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 ever to live on Earth, let's talk about Newton's other famous 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 it is acted upon by an external force. For a ball rolling on the floor, the external force could be friction between the ball and the floor, or a boy hitting the ball in the other 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 = m x a. F is a force measured in newtons. It is also a vector, meaning it has a directional component. Due to the acceleration, the ball that rolls 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 and opposite reaction. That is, for every force applied to an object on the surface, the object is repelled with the same force.
Laws of thermodynamics
The British physicist and writer C.P. Snow once said that an unscientist who did not know the second law of thermodynamics was like a 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, whether it be an engine or the Earth's core. It can be reduced to a few basic laws, which Snow outlined as follows:
- You cannot win.
- You will not avoid losses.
- You cannot exit the game.
Let's look into this a bit. What Snow meant by saying you can't win is that since matter and energy are conserved, you can't gain one without losing the other (that is, E=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 escape into the open world, leading to the second law.
The second law - losses are inevitable - means that due to 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 - refers 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 real world it is impossible to reach absolute zero - only very close to it.
Strength of Archimedes
After the ancient Greek Archimedes discovered his principle of buoyancy, he allegedly shouted "Eureka!" (Found!) and ran naked through Syracuse. So says the legend. The discovery was so important. Legend also says that Archimedes discovered the principle when he noticed that the water in the bathtub rises when a body is immersed in it.
According to Archimedes' principle of buoyancy, the force acting on a submerged or partially submerged object is equal to the mass of fluid that the object displaces. This principle has essential in density calculations, as well as in 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 lives, let's turn our attention to the human form and find out how we got to this point. According to most scientists, all life on Earth has common ancestor. But in order to form such a huge difference 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 survival traits, like brown frogs that camouflage themselves in swamps, were naturally selected for survival. This is where the term natural selection comes from.
You can multiply these two theories by many, many times, and actually Darwin did this in the 19th century. Evolution and natural selection explain the enormous diversity of life on Earth.
General theory of relativity
Albert Einstein was and still is major discovery that forever changed our view of the universe. Einstein's main breakthrough was the statement that space and time are not absolute, and gravity is not just a force applied to an object or mass. Rather, gravity has to do with the fact that mass warps space and time itself (spacetime).
To make sense of this, imagine that you are driving across the Earth in a straight line in an easterly direction, say from northern hemisphere. After a while, if someone wants to accurately determine your location, you will be much south and east of your original position. This is because the earth is curved. To drive straight east, you need to take into account the shape of the Earth and drive at an angle slightly north. Compare a round ball and a sheet of paper.
Space is pretty much the same. For example, it will be obvious to the passengers of a rocket flying around the Earth that they are flying in a straight line in space. But in reality, the space-time around them is curving under the force of Earth's gravity, causing them to both 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 Mercury's orbit, showed how starlight bends, and laid theoretical basis for black holes.
Heisenberg uncertainty principle
Einstein's expansion of relativity told us more about how the universe works and helped lay the groundwork for quantum physics, which led to a completely unexpected embarrassment of theoretical science. In 1927, the realization that all the laws of the universe are flexible in a certain context led to the startling discovery of the German scientist Werner Heisenberg.
In postulating his uncertainty principle, Heisenberg realized that it is impossible to know at the same time as high level exactly two properties of the 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 the electron has the qualities of both a particle and a wave. The concept became known as wave-particle duality and formed the basis 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 the momentum, we consider the electron as a wave, which means we can know the amplitude of its length, but not the position.