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Scientific laws can often be reduced to mathematical expressions, such as the great E=mc2. This type of formula is a specific expression based on a large amount of experimental data, and generally only holds when certain specific conditions exist. However, these laws or theories are difficult for ordinary people to understand. This article allows us to easily embark on the best shortcut to basic science just like looking at "a hundred thousand whys".
The contents of the 10 articles will be in the form of inverted statements that are easy to understand and conform to the law of development. Starting from the stage of the Big Bang, understanding planets, describing gravity, and then starting the evolution of life, finally dive into quantum physics, and go for a while. The most dizzying thing in the world.
10. A stepping stone to theories: The Big Bang Theory
Standard interpretation: The Big Bang is a cosmological model that describes the initial conditions of the birth of the universe and its subsequent evolution. It has received the most extensive and accurate support from scientific research and observation today.
The current big bang view generally refers to: the universe evolved from an primordial state with extremely high density and extremely high temperature before a finite time in the past (according to the best observation results obtained in 2010, these initial states It existed about 13.3 billion to 13.9 billion years ago), and has reached its present state after continuous expansion.
When anyone wants to try to touch the esoteric scientific theories, then it is right to start from the universe, and the Big Bang theory that explains how the universe has developed to this day is the best choice.
The basic structure of this theory is based on the research of Edwin Hubble, Georges Lemaitre, Albert Einstein, and many others. To put it plainly, the theory assumes that the universe started at almost 14 billion A heavyweight explosion a year ago. The universe at that time was confined to a singularity and contained all the matter in the universe. The original movement of the universe: maintaining outward expansion, is still going on today.
The big bang theory can get such widespread support, inseparable from the credit of Arnold Penzias and Robert Wilson. They set up a horn-shaped antenna that received a kind of noise signal that could not be eliminated, that is, the electromagnetic radiation of the universe, that is, the cosmic microwave background radiation. It was the first big bang that made the entire universe now full of this detectable weak radiation, corresponding to a temperature of about 3K.
9. Calculate the age of the universe: Hubble's law
Standard interpretation: The redshift of light from distant galaxies is proportional to their distance. This law was first formulated in 1929 by Hubble and Milton Schumerson after nearly ten years of observations. Vf=Hc×D (distance rate=Hubble constant×distance relative to the earth), which is often used today Cited as an important piece of evidence in support of the Big Bang and became the basis of the theory of universe expansion.
This involves the person mentioned earlier, Edwin Hubble. This man’s contribution to cosmology is worth looking back at his deeds: in the 1920s when the Great Depression faltered and the Great Depression faltered, Hubble performed ground-breaking astronomical research.
He not only proved that there are other galaxies besides the Milky Way, but also discovered that those galaxies are moving away from the Milky Way, and the speed of the distance in his formula is the speed at which the galaxy retreats. The Hubble constant refers to the parameter of the expansion rate of the universe, and the distance from the earth is the main body of these galaxies.
However, it is said that Hubble himself, respected as the founder of galaxy astronomy, dislikes the term "galaxy" very much and insists on calling it "galactic nebula".
As time goes by, the stars shift and the value of Hubble's constant also changes, but it doesn't matter much. What is important is that it is this law that helps quantify the motion of the galaxies in the universe and calculate the distance of distant galaxies.
The concept of "the universe is composed of many galaxies" and the discovery of the motion of these galaxies can be traced back to the Big Bang. They all make Hubble's law as famous as the astronomical telescope named after this man.
8. Changing the whole astronomy: Kepler's three laws
Standard interpretation: the law of planetary motion, the three simple laws of planetary movement discovered by Kepler.
The first law: each planet orbits the sun along its own elliptical orbit, and the sun is in a focal point of the ellipse;
The second law: In the same time, the area swept by the line between the sun and the moving planet is the same;
The third law: The square of the orbit of each planet around the sun is proportional to the cube of the semi-major axis of their elliptical orbit.
Around the planet's orbit, especially whether they are centered on the sun, scientists have fought for centuries with religious leaders and their colleagues.
In the 16th century, Copernicus put forward the heliocentric theory that caused great controversy at the time. He believed that the planets orbit the sun instead of the earth. Since then, Tycho Brahe and others have also discussed. But it was Johannes Kepler who really established a clear scientific basis for planetary kinematics.
The three laws of planetary motion proposed by Kepler in the early 17th century describe how planets move around the sun.
The first law is also known as the ellipse law; the second law is also known as the law of area. In other words, to explain this law, if you track and measure the area formed by the connection between the earth and the sun as the earth moves for 30 days , You will find that no matter where the earth is in the orbit, and no matter when the calculation is started, the result is the same. As for the third law, also called the law of harmony, it allows us to establish a clear relationship between the planetary orbital period and the distance from the sun.
For example, planets like Venus that are very close to the sun have a much shorter orbital period than Neptune. It was these three laws that completely destroyed Ptolemy's complex universe system.
7. The cornerstone of most theories: the law of universal gravitation
Standard interpretation: Newton's universal law of universal gravitation is expressed as that any two mass points are attracted to each other by the force in the direction of the connecting center line.
The magnitude of this gravitational force is proportional to their mass product, inversely proportional to the square of their distance, and has nothing to do with the chemical nature or physical state of the two objects and the intermediary matter. This theory can be expressed by a formula that has been written into today's high school physics textbook: F=G×[(m1m2)/r2]
Although people take it for granted today, when Isaac Newton put forward the theory of universal gravitation more than 300 years ago, it was undoubtedly the most revolutionary event at that time.
The theory put forward by Newton can be simply expressed as: any two objects, regardless of their respective masses, will exert force on each other, and the greater the mass, the greater the gravitational force generated by the object. In the formula, F refers to the gravitational force between two objects, using "Newton" as the unit of measurement; m1 and m2 represent the mass of the two objects respectively; r is the distance between the two; G is the gravitational constant.
This is a fairly accurate law under many practical conditions, but since the development of physics, people have known the imperfections of Newton's description of gravity.
However, this law is still one of the most practical concepts in all sciences so far. It is simple, easy to learn, and covers a wide range, so that there were few people interested in it during the first period of general relativity. More meaningfully, the law of universal gravitation gives tiny humans the ability to calculate the gravitational forces between huge planets, and is especially useful in launching orbiting satellites and mapping lunar exploration routes.
6. Physical science has a basic theorem: Newton's law of motion
Standard interpretation: Newton's first law is the law of inertia; Newton's second law establishes the relationship between mass and acceleration; Newton's third law is the law of acting force and reaction force.
Still Newton. Whenever we talk about one of the most outstanding scientists in human history, we cannot help but start with his three most famous laws of mechanics. Because these simple and elegant laws laid the foundation of modern physics.
To simply understand the meaning of the three laws, the first of them let us know that the reason why a rolling ball can move on the floor must be driven by external forces. This external force may be friction with the floor, or a kick from a child.
The second law is expressed by the formula F=ma, which also means a vector with directionality. When the ball rolled across the floor, due to acceleration, it obtained a vector pointing in the rolling direction. It can calculate the force on the ball.
The third law is quite succinct and most well-known. Its meaning is nothing more than that if you poke the surface of any object with your finger, they will respond with the same force.
5. The foundation of thermodynamics is basically complete: the three laws of thermodynamics
Standard interpretation: The first law of thermodynamics, heat can be transformed into work, and work can also be transformed into heat, which is the law of energy conservation and transformation; the second law has several expressions, one of which is that it is impossible to transfer heat from a low-temperature object To high-temperature objects without causing other changes; the third law, when the thermodynamic temperature is zero (ie T=0 K), the entropy value of all perfect crystals is equal to zero.
British physicist and novelist Charles Percy Snow once made a very famous statement: "A scientist who does not understand the second law of thermodynamics is like a scientist who has never read Shakespeare." Snow's words meant. Criticizing the isolation and split of the "two cultures" between science and humanities, but inadvertently "popularizing" the second law of thermodynamics in the literati circle.
In fact, Snow’s argument does emphasize and appeal to all humanists to understand its importance.
Thermodynamics is the science of studying the movement of energy in a system. The system here can be either an engine or a hot earth core. Snow used his ingenuity to streamline it into the following basic rules: you can't win, you can't achieve balance of payments, you can't quit the game.
How to understand these statements? First look at the so-called "you can't win".
Snow means that since matter and energy are in a conservation relationship, in the process of energy conversion, we cannot achieve the equivalent conversion from one energy form to another without losing part of the energy. Just like if the engine is to do work, it must provide heat.
Even in a perfectly closed space, part of the heat will inevitably escape to the outside world.
This leads to the second law "You can't achieve balance of payments." Given the infinite increase in entropy, we cannot return or maintain the same energy state. Because entropy always flows from a place with a high concentration to an area with a low concentration. The existence of entropy is also the reason why perpetual motion machines cannot appear.
Finally, there is the third law "games that cannot be quit". This involves absolute zero, that is, the lowest temperature that can be reached in theory, and generally refers to zero Kelvin (minus 273.15 degrees Celsius or minus 459.67 degrees Fahrenheit).
The third law states that when the system reaches absolute zero, the molecules will stop all movement, that is, without kinetic energy, the entropy can reach the theoretical minimum. But in the real world, even in the depths of the universe, it is impossible to reach absolute zero. You can only approach the so-called end infinitely.
4. The Great Wisdom of 200 BC: Archimedes' Law
Standard interpretation: Archimedes' law in physics, the principle of Archimedes buoyancy, means that the resultant force of an object immersed in a static fluid is equal to the gravity of the fluid expelled by the object. This resultant force is called buoyancy . The mathematical expression is: F float = G row
Regarding how Archimedes discovered the principle of buoyancy, a major breakthrough in physics, there is a legend: When Archimedes took a bath, he saw that the water in the bathtub would rise as his body was immersed. Inspire and start thinking.
And when he finally determined that he had discovered the theory of buoyancy, the greatest philosopher of ancient Greece excitedly shouted "Found it! Found it!" while rushing naked in the streets of Syracuse.
The ancient discoveries of ancient Greek scholar Archimedes have been widely used in various fields of human social production. According to the principle of buoyancy, the force exerted on an object partially or entirely submerged in liquid is equal to the weight of the liquid discharged from the internal volume of the object.
This is of key significance for calculating the density of objects and then for the design and construction of submarines and ocean-going ships.
3. Our own discussion: evolution and natural selection
Standard interpretation: Evolution, that is, evolution, in biology refers to the change of genetic traits in a population between generations.
Natural selection, also known as natural selection, refers to the fact that the genetic characteristics of organisms have a certain advantage or a certain disadvantage in the competition for survival, and then produce differences in survivability, and lead to differences in reproductive ability, so that these characteristics are preserved or eliminated .
Now that we have established a number of basic conceptual systems on how the universe came from nothing and how physics plays a role in daily life, the next step can start to focus on the question of our own form, that is, how we became where we are today. Fan looks like.
We know that genes will be copied to the next generation, but genetic mutations will change their situation. This changed new situation may be passed on to the population as species migrate.
So according to most scientists today, all earth creatures once had a common ancestor. Later, with the development of time, some began to evolve into specific species with distinctive characteristics. Over time, biodiversity has gradually increased and expanded in all organic organisms.
In the most basic sense, mutation mechanisms such as gene mutations have been occurring in the course of biological evolution. The changes in these details at each stage will be preserved through the inheritance of generations.
Correspondingly, biological populations have developed different characteristics, and these characteristics can often help organisms to flourish and survive. For example, brown-skinned frogs are obviously more suitable to survive in muddy swamp areas in camouflage than their counterparts of other colors. This is the so-called natural selection.
Of course, for evolution and natural selection theory, we can also apply it to a wider range of biology. However, Darwin's proposal in the 19th century that "the rich diversity of life on earth comes from natural selection in evolution" is undoubtedly still the most basic and pioneering.
2. Forever changed the way of understanding the universe: general relativity
Standard interpretation: Gravity is described here as a geometric property (curvature) of space-time, and this space-time curvature is directly related to the matter and radiation energy and momentum tensor in space-time, and the contact method is Einstein The gravitational field equation (a second-order nonlinear partial differential equation system).
For anyone who has never studied or researched it, the standard interpretation of general relativity has not looked the same. Because it used at least 4 sets of words that are not understood by people when explaining the entry.
Its connotation and extension are so extensive that it seems that it cannot be described in non-thesis form. Here, let us take a look at what is being discussed by the highest level of general relativity, which is called the highest level of modern gravitation theory research. As a more general theory than Newton's universal gravitation, mass is still an important attribute that determines gravity, but it is no longer the only source of gravity.
In Einstein's case, gravity is no longer a force described by Newton. It can even be said that the original concept of gravity is gone.
Because Einstein regarded it as the curvature of space-time around the object, the previously mentioned "motion of an object under the action of gravity" was attributed to the free movement of the object along a short-range line in a curved space-time.
If the concept of "curved space-time" is made clearer, one can imagine the astronauts in a space shuttle flying around the earth. For them, they are flying in space in a straight line, but in fact the space-time around the space shuttle, It has been bent by the gravity of the earth, which makes the space shuttle an object that can fly forward and revolve around the earth.
According to John Wheeler, the chief expert in American relativity research, the geometric properties of this so-called space-time can be summarized as follows: space-time tells how matter moves, and matter tells how space-time bends. Therefore, it can show how the cosmic starlight bends under the influence of large celestial bodies, and lays a theoretical foundation for the study of black holes.
1. Does God roll the dice? : Heisenberg Uncertainty Principle
Standard interpretation: German physicist Heisenberg proposed in 1927 to show that the uncertainty in quantum mechanics means that in a quantum mechanical system, the position of a particle and its momentum (the mass of the particle multiplied by the speed) cannot be Also ok.
"Measurement! In classical theory, this is not a problem to be considered." "The History of Quantum Physics" said.
That's because in classical physics, you, me, or anyone as an observer has no influence on the objective object waiting to be measured, or the influence is so small that it is negligible. At that time, even if we don't understand the principle, it doesn't prevent the principle from staying there, waiting for us to learn more slowly.
But now we are about to step into the magic pond of the quantum world. Here, as an observer, we will cause a certain disturbance to the experimental phenomenon. Therefore, if you measure the momentum of an electron, the value obtained is only relative to your observer. In the microcosm, we should use "probability" to talk about it, the so-called God rolls the dice.
Warner Heisenberg made a breakthrough discovery in this. People can't get the accurate information of the two variables of the particle at the same time, even with sophisticated instruments.
Specifically, you may know the position of the electron accurately, but you cannot know its momentum at the same time, or vice versa. And similar uncertainties also exist between energy and time, angular momentum and angle and many other physical quantities.
Maybe you didn't understand the weirdness of this matter. As mentioned before, since the quantity in the quantum world is relative, as long as it exists, it should be able to be measured. Since it cannot be measured anyway, it ceases to exist. Therefore, it is meaningless to talk about this physical quantity when you are not sure of the means to measure it. The momentum of an electron is only meaningful when you measure it.
This is more of a philosophical topic. The "Heisenberg Uncertainty Principle" is not so much discovered in an experiment as it is discussed by Heisenberg, his teacher Bohr and others.
By Bohr, he discovered that electrons have the dual properties of both particles and waves (the pillars of quantum physics, wave-particle duality). When we measure the position of electrons, we treat them as particles with variable wavelengths; and when we want to measure momentum When we treat it as a wave, we know the magnitude of the wavelength but lose its place.
Even if you are incredibly confused now, it is still no big deal. Bohr's famous saying is: "If anyone is not confused by quantum theory, then he must not understand quantum theory." Feynman also said similar words. So we have nothing to be depressed, Einstein is in the same situation as us.
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