Research project on the topic "Are there identical snowflakes". Can two snowflakes be exactly the same?

The pioneer of the study of the "theory of snow" was the young farmer Wilson Alison Bentley, nicknamed "Snowflake". From childhood he was attracted unusual shape crystals falling from the sky. In his hometown of Jericho in the northern United States, snowfalls were a regular occurrence, and young Wilson spent a lot of time outside studying snowflakes.

Wislon "Snowflakes" Bentley

Bentley adapted a camera to a microscope given by his mother for his 15th birthday and tried to capture snowflakes. But it took almost five years to improve the technology - only on January 15, 1885 was the first clear picture taken.

Throughout his life, Wilson has photographed 5,000 different snowflakes. He never ceased to admire the beauty of these miniature works of nature. To obtain his masterpieces, Bentley worked in sub-zero temperatures, placing each whole of the snowflakes he found against a black background.

Wilson's work has been praised by both scientists and artists. He was frequently invited to speak at scientific conferences or exhibit photographs in art galleries. Unfortunately, Bentley died at the age of 65 from pneumonia, without proving that identical snowflakes can not be.

The baton of the "theory of snow" was picked up a hundred years later by the researcher of the National Center atmospheric research Nancy Knight. In a paper published in 1988, she proved the opposite - identical snowflakes can and should exist!

Dr. Knight tried to reproduce the process of building snowflakes in the laboratory. To do this, she grew several water crystals, subjecting them to the same processes of supercooling and supersaturation. As a result of the experiments, she managed to get snowflakes absolutely identical to each other.

Further field observations and processing of experimental errors allowed Nancy Knight to assert that the occurrence of identical snowflakes is possible and is determined only by probability theory. After compiling a comparative catalog of celestial crystals, Knight concluded that snowflakes have 100 signs of difference. So way total options appearance is 100! those. almost 10 to the 158th power.

The resulting number is twice the number of atoms in the universe! But this does not mean that coincidences are completely impossible - Dr. Knight concludes in his work.

And now - new research on the "theory of snow". The other day, Professor of Physics at the University of California, Kenneth Libbrecht, published the results of many years of research of his scientific group. “If you see two identical snowflakes, they are still different!” - says the professor.

Libbrecht proved that for every five hundred oxygen atoms with a mass of 16 g/mol, there is one atom with a mass of 18 g/mol in the composition of snow molecules. The structure of the bonds of a molecule with such an atom is such that it implies an innumerable number of options for connections inside crystal lattice. In other words, if two snowflakes really look the same, then their identity still needs to be verified at the microscopic level.

Learning the properties of snow (and snowflakes in particular) is not child's play. Knowledge about the nature of snow and snow clouds is very important in the study of climate change. And some of the unusual and unexplored properties of ice can also find practical applications.

Let's see how this can be arranged.

One water molecule is one oxygen atom and two hydrogen atoms bonded together. When the frozen water molecules bond, each molecule gets four other attached molecules nearby: one at each of the tetrahedral vertices above each individual molecule. This causes the water molecules to fold into a lattice shape: a hexagonal (or hexagonal) crystal lattice. But large "cubes" of ice, as in quartz deposits, are extremely rare. When you look into the smallest scales and configurations, you find that the top and bottom planes of this grid are packed and connected very tightly: you have "flat edges" on two sides. The molecules on the remaining sides are more open, and additional water molecules bind to them more randomly. In particular, hexagonal corners have the weakest bonds, which is why we observe sixfold symmetry in crystal growth.



and the growth of a snowflake, a particular configuration of an ice crystal

New structures then grow in the same symmetrical patterns, building up hexagonal asymmetries after reaching a certain size. In large, complex snow crystals, there are hundreds of easily distinguishable features when viewed under a microscope. Hundreds of features among the roughly 1019 water molecules that make up a typical snowflake, according to Charles Knight of the National Center for Atmospheric Research. For each of these functions, there are millions of possible places where new branches can form. How many such new features can a snowflake form and still not become another of many?

Every year around the world, approximately 10 15 (quadrillion) cubic meters of snow fall on the ground, and each cubic meter contains on the order of several billion (10 9) individual snowflakes. Since the Earth has existed for about 4.5 billion years, 10 34 snowflakes have fallen on the planet throughout history. And do you know how many, statistically speaking, separate, unique, symmetrical branching features a snowflake could have and expect a twin at a certain point in the history of the Earth? Only five. Whereas real, large, natural snowflakes usually have hundreds of them.



Even at the level of one millimeter in a snowflake, you can see imperfections that are difficult to duplicate.

And only at the most mundane level can you mistakenly see two identical snowflakes. And if you're willing to go down to the molecular level, things get much worse. Oxygen usually has 8 protons and 8 neutrons, while hydrogen has 1 proton and 0 neutrons. But 1 out of 500 oxygen atoms has 10 neutrons, 1 out of 5000 hydrogen atoms has 1 neutron, not 0. Even if you form perfect hexagonal snow crystals, and you counted 10 34 snow crystals in the entire history of planet Earth, it will be enough to go down to size several thousand molecules (less than the length visible light) to find a unique structure the planet has never seen before.



But if you ignore the atomic and molecular differences and abandon the "natural", you have a chance. Snowflake researcher Kenneth Libbrecht of the California Institute of Technology has developed a technique to create artificial "identical twins" of snowflakes and photograph them using a special microscope called the SnowMaster 9000.

By growing them side by side in the lab, he showed that it was possible to create two snowflakes that were indistinguishable.



Two nearly identical snowflakes grown in a Caltech lab

Almost. They will be indistinguishable to a person who looks with his own eyes through a microscope, but they will not be identical in truth. Like identical twins, they will have many differences: they will have different places bundles of molecules, different branching properties, and the larger they are, the stronger these differences. That's why these snowflakes are very small and why the microscope is powerful: they are more similar when they are less complex.



Two nearly identical snowflakes grown in a Caltech lab

Nevertheless, many snowflakes are similar to each other. But if you are looking for truly identical snowflakes on a structural, molecular or atomic level, nature will never give you this. Such a number of possibilities is great not only for the history of the Earth, but also for the history of the Universe. If you want to know how many planets you need to get two identical snowflakes in 13.8 billion years of the history of the universe, the answer is on the order of 10 1000000000000000000000000. Given that there are only 1080 atoms in the observable universe, this is highly unlikely. So yes, snowflakes are indeed unique. And that's putting it mildly.

The pioneer of the study of the "theory of snow" was the young farmer Wilson Alison Bentley, nicknamed "Snowflake". From childhood, he was attracted by the unusual shape of crystals falling from the sky. In his hometown of Jericho in the northern United States, snowfalls were a regular occurrence, and young Wilson spent a lot of time outside studying snowflakes.

Wislon "Snowflakes" Bentley

Bentley adapted a camera to a microscope given by his mother for his 15th birthday and tried to capture snowflakes. But it took almost five years to improve the technology - only on January 15, 1885 was the first clear picture taken.

Throughout his life, Wilson has photographed 5,000 different snowflakes. He never ceased to admire the beauty of these miniature works of nature. To obtain his masterpieces, Bentley worked in sub-zero temperatures, placing each whole of the snowflakes he found against a black background.

Wilson's work has been praised by both scientists and artists. He was often invited to speak at scientific conferences or exhibit photographs in art galleries. Unfortunately, Bentley died at the age of 65 from pneumonia, without proving that there are no identical snowflakes.

The baton of the "theory of snow" was picked up a hundred years later by Nancy Knight, a researcher at the National Center for Atmospheric Research. In a paper published in 1988, she proved the opposite - identical snowflakes can and should exist!

Dr. Knight tried to reproduce the process of building snowflakes in the laboratory. To do this, she grew several water crystals, subjecting them to the same processes of supercooling and supersaturation. As a result of the experiments, she managed to get snowflakes absolutely identical to each other.

Further field observations and processing of experimental errors allowed Nancy Knight to assert that the occurrence of identical snowflakes is possible and is determined only by probability theory. After compiling a comparative catalog of celestial crystals, Knight concluded that snowflakes have 100 signs of difference. Thus, the total number of appearance options is 100! those. almost 10 to the 158th power.

The resulting number is twice the number of atoms in the universe! But this does not mean that coincidences are completely impossible - Dr. Knight concludes in his work.

And now - new research on the "theory of snow". The other day, Professor of Physics at the University of California, Kenneth Libbrecht, published the results of many years of research by his scientific group. “If you see two identical snowflakes, they are still different!” - says the professor.

Libbrecht proved that for every five hundred oxygen atoms with a mass of 16 g/mol, there is one atom with a mass of 18 g/mol in the composition of snow molecules. The structure of the bonds of a molecule with such an atom is such that it implies an innumerable number of options for compounds within the crystal lattice. In other words, if two snowflakes really look the same, then their identity still needs to be verified at the microscopic level.

Learning the properties of snow (and snowflakes in particular) is not child's play. Knowledge about the nature of snow and snow clouds is very important in the study of climate change. And some of the unusual and unexplored properties of ice can also find practical applications.

MOBU "Ruem secondary school"

"Can snowflakes be the same"

(project)

Completed by: Pugacheva Alina,

2nd grade student

Head: Zakharova A.M.,

primary school teacher

Ruem settlement, 2013

I love watching falling snowflakes. I was wondering if all snowflakes are the same? I decided to ask the guys in my class what they think about this.

To answer this question, I will have to look through additional scientific and educational literature, look for additional material in the Internet.

Many probably know that it is impossible to meet a pair of identical snowflakes in nature, but they can be very similar to each other. This phenomenon is the centuries-old mystery that the process of computer simulation has helped to reveal today.

For the first time, the German astronomer and mathematician Johannes Kepler tried to get closer to the solution, writing in one of his treatises that all snowflakes have six faces and one axis of symmetry. The great scientist associated such a structure with the nature of the arrangement of the particles. his assumptions formed the basis of the science of crystallography.

Another philosopher and mathematician, the Frenchman René Descartes, in 1635 began to study and describe snowflakes, observing them with the naked eye. The scientist described their structure as similar to roses, lilies and mechanical gears with six teeth. Descartes was also the first to see and describe a snowflake with 12 rays. Until now, it is believed that the twelve-pointed snowflake is a rarity, it is not known for certain under what conditions its formation occurs.

In 1665, the English naturalist Robert Hooke studied snowflakes under a microscope. he left to science a large number of sketches. And the first photographs were taken by American farmer Wiles Bentley. This man from childhood was fond of the structure of snowflakes, and when he had the opportunity, he devoted himself to photographing them. To get the first shots, he spent two years. Designed by Bentley, the camera is a hybrid of a camera and a microscope. It is interesting that at first these pictures were not considered authentic, but a few years later they were recognized and successfully used as illustrations for various scientific articles. In 1931, Bentley published the book Snow Crystals, which contained over 2,500 photographs.

But the Japanese approached the study of the issue most scrupulously. Ukihiro Nakaya, a professor at the University of Hokkaido, began growing artificial snowflakes in 1932, which allowed him to create the first classification of snow crystals. as well as to determine the dependence of the shape and size of these formations on the temperature and humidity of the surrounding air. He created a classification containing 41 individual types. In the city of Kaga, which is located in the west of the island of Honshu, there is a "Museum of Snow and Ice", bearing the name of a scientist. there is a machine for the production of artificial snowflakes. Many years later, in 1996, 80 types were described by meteorologists Magano and Xu Li.

Thus, having studied the scientific and educational literature on this issue, searching the Internet, after watching the falling snowflakes, I came to the conclusion that There are no identical snowflakes, each snowflake is beautiful in its own way.

Snowflakes

Winter is covered in snow

From morning until dark.

Snowflakes curl, spin

At our window.

As if the stars are sparks

scattered around.

The silver ones are rushing

They look into the house.

Then they will ask for a room,

They run away again

Behind the glass they rush

They call to the street.

S. Baruzdin

Used sources:

1. Are snowflakes the same, or what is hidden in frozen water? - Access mode:http://shkolazhizni.ru/archive/0/n-33171/
2. Poems about snow and snowflakes. - Access mode:http://www.razumniki.ru/stihi_ro_sneg_i_sneginki.html

Familiar to every schoolchild, the statement that there are no two identical snowflakes has been repeatedly questioned. But the unique studies of the Californian technological university were able to put an end to this truly New Year's issue.

Snow forms when microscopic water droplets in clouds are attracted to dust particles and freeze.

The ice crystals that appear in this case, which at first do not exceed 0.1 mm in diameter, fall down and grow as a result of condensation of moisture from the air on them. In this case, six-pointed crystalline forms are formed.

Due to the structure of water molecules, only 60° and 120° angles are possible between the rays of the crystal. The main water crystal has a shape in the plane regular hexagon. New crystals are then deposited on the tops of such a hexagon, new ones are deposited on them, and thus various forms of snowflake stars are obtained.

Professor of physics at the University of California Kenneth Libbrecht published the results of many years of research by his scientific group. “If you see two identical snowflakes, they are still different!” says the professor.

Libbrecht proved that for every five hundred oxygen atoms with a mass of 16 g/mol, there is one atom with a mass of 18 g/mol in the composition of snow molecules.

The structure of the bonds of a molecule with such an atom is such that it implies an innumerable number of options for compounds within the crystal lattice.

In other words, if two snowflakes really look the same, then their identity still needs to be verified at the microscopic level.

Learning the properties of snow (and snowflakes in particular) is not child's play. Knowledge about the nature of snow and snow clouds is very important in the study of climate change.