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The hydrogen bomb "two changes" is enough to destroy the world

Le 2 mars 2018, 03:24 dans Humeurs 0

The hydrogen bomb "two changes" is enough to destroy the world.

Initiating nuclear fusion after fission.

Last time mentioned scientist Albert Einstein (AlbertEinstein) and szilard (LeoSzilard) in 1939 wrote a letter to President Roosevelt, at that time contributed to the macondo plan (ManhattanProject), and

then started our entanglements with nuclear weapons in the history of a new chapter. On the positive side, the atomic bombs dropped on Japan quickly ended the second world war, but since then humans have

had the power to destroy the world in a very short time.

Even the "nuclear winter" radiation from the heat is still difficult.

After the second world war, the whole world quickly entered the cold war era. In order not to fall behind, both sides are committed to developing new and more powerful nuclear weapons. Last time, the

atomicbomb used nuclearfission to release a lot of energy in a short period of time. Nuclearfusion is more powerful than fission, so it was used shortly after the end of the second world war to make

another generation of the more powerful hydrogenbomb.

The sun can glow because of nuclear fusion, so its power is predictable. As the name suggests, in fusion, lighter nuclei (such as hydrogen and its isotope) other "gather together into heavier nuclei, and

of" see "the quality is the same as nuclear fission, according to the equations of Einstein's E = MC2 converted to energy.

It is difficult to make an atomic bomb.

Nuclear fusion has a technical difficulty: nuclei are positively charged, so they repel each other. It takes a lot of pressure or heat to get them together, and fusion can happen. It's not a problem at the

center of the sun, because it's really hot. How can we do that on the earth's surface?

The hydrogen bomb, one of the design is to cause fission explosion (like detonated a bomb) first, then by the resulting temperature and pressure will hydrogen nuclei "forced" together, induce fusion. So

it's very difficult to make hydrogen bombs, so you have to have the technology to make the bomb.

The power of nuclear weapons is powerful, but the worry is that it is not just in the vicinity of the explosion that will be affected. Many scientists, including CarlSagan, a prominent American astronomer

and science writer, have pointed out the possibility of "nuclearwinter".

The powerful explosion of a nuclear weapon is enough to bring dust to the clouds; And once used, it can easily trigger multiple fires and create a lot of smoke.

The dust can stay above the clouds for a long time, blocking the sun from reaching the ground, causing the global ground to remain cold for long periods of time and entering a nuclear - induced winter. So

if nuclear war broke out, even if we happen to be not in the area of nuclear explosion, can avoid the high temperature and radiation released by the nuclear explosion, all mankind will need to be thinking

about how to through the "nuclear winter".

summary

Over the past 200 years, human technology has developed particularly rapidly, and we have mastered the power to destroy the world. I hope you will remember to use these forces prudently, and do not make

rash decisions. Dr. Zhang wenyan.

Author: bachelor of civil and structural engineering, university of Hong Kong. After a brief internship in civil engineering, he decided to follow his interest in science and obtained a bachelor's degree

and a PhD in philosophy from the university of Toronto in Canada. He is currently a lecturer at the university of Hong Kong, who teaches basic science and general courses, and participates in science

popularization and knowledge exchange activities from time to time.

It's Wednesday.

The original address: http://paper.wenweipo.com/2018/01/24/ED1801240012.htm

 

put down the depression grammar and taste the literary emotion

Le 5 avril 2017, 10:42 dans Humeurs 0

[the teacher] put down the depression grammar and taste the literary emotion.

One of the courses I teach is an introduction to western literature. In the first class, I always ask my classmates to describe their impression of "literature" with one or two adjectives. I almost

certainly hear the words "difficult" and "interesting".The new polyu e admission portal is a one-stop platform aimed at handling applications of university degree courses. With PolyU e Admission, the application process is refined into three simple steps.

There is a deep meaning in the fairy tale.

Many students think that the English section only has grammar and sentence structure, which makes them feel very depressed and lose interest in learning. Literature will add interest to the learning

process: when reading stories, we will share the joys and sorrows of the characters, and reflect on our own encounters or larger life issues.

Unfortunately, some students equate reading with reading comprehension exercises and ignoring the pleasure of reading. Some people have avoided the book since childhood, forming a vicious circle: do not

read, so the language foundation is not good; The language foundation is not good, so reading is difficult, not want to read.Shenzhen Transpring Enterprise Ltd. is one of the leading Oil Vaping Pen and vaporizer (A3 Vape Cartridge etc) manufacturer and supplier in China. Over the years, we have been serving many customers from USA, ...

The only way to break the cycle is to start reading. However, reading is not necessarily a profound masterpiece, but it can be a small story that makes us feel intimate, such as Hans Christian Andersen's

fairy tales.

Some people ask: isn't that for children to read? Original content is not so simple, such as the mermaid princess (TheLittleMermaid), everyone is affected by the Disney animation, thought it was the

princess prince love story, but a more poignant novel original ending: mermaid princess die for love, flying above, uniting the immortal soul.

Like "TheLittleMatchGirl," it doesn't end with a girl dying in the snow. After she dies, she meets her grandmother and arrives in heaven. The original story teaches people in a broken and poor world,

believing in hope and salvation.

In addition, I have once seen the short story of ShelSilverstein with the students of TheGivingTree.

Although they do not perform well in the diploma test, they are weak, but they can enjoy the plot. It talked about a boy and a tree, and when he was growing up, he cut down the tree to build a house in

order to pursue a rich life, until it had only a short cut and a short cut. When he was old, he found himself still lonely, and returned to the tree, and the old tree spared him.

The story is short and profound and explores the spirit of greed and sacrifice in human nature.

There is no shortcut to learning Chinese.

The students who do not normally study in this class, when writing their reflections on the story, discuss the plot from time to time, and the learning atmosphere is better than that of practicing grammar.

When English grammar exercises become boring and repetitive, students may contact the above stories to inject interest and emotion into the study. There is no shortcut to learning Chinese, only to

accumulate reading experience, learn from other people's beautiful words, imitate, and increase their own vocabulary.

Literature makes all the students who are willing to learn English have a sense of thinking and feeling in the process. Therefore, it should not be reserved for the best students in English. A lecturer at

the college of humanities and language.

The newspaper reports on Wednesday.

The original address: http://paper.wenweipo.com/2018/01/24/ED1801240010.htm