Ethereum Teaching

1. When it comes to money, mining is indispensable. In ethereum network, if you want to get Ethereum, you also need to mine it. When it comes to mining, there must be a consensus mechanism
do you remember what the consensus mechanism of bitcoin is? The consensus mechanism of bitcoin is pow. To put it simply, the more work you do, the higher the amount of computation you pay, the more likely you will be the first to find the correct hash value, and the more likely you will be rewarded with bitcoin
however, there are some defects in the pow of bitcoin, that is, it is too slow to process transactions, and miners need to constantly collide hash values through calculation, which is costly and inefficient. Friends who are interested in blockchain knowledge should see such a saying:
in order to make up for the deficiency of bitcoin, Ethereum has proposed a new consensus mechanism, called POS (this is the abbreviation of English, which means "proof of equity", also translated into "proof of equity")
POS simply means the same as its literal meaning: equity, equity. The more currency you hold, the more equity you have, the higher your equity
Ethereum's POS means that the more money you hold, the longer you hold it, the less difficult it will be to calculate and the easier it will be to mine
in the initial setting of Ethereum, Ethereum hopes to build a relatively stable system by using POW in the early stage, then graally adopt POW + POS, and finally completely transition to POS. So, it's true that the consensus mechanism of Ethereum is POS, but POS is only a plan or goal at the beginning of Ethereum's release. At present, Ethereum has not yet transitioned to POS, and the consensus mechanism adopted by Ethereum is still pow, that is, the pow of bitcoin, but it is slightly different from the pow of bitcoin
the amount of information here is a bit large,
the first information point is that the consensus mechanism currently adopted by Ethereum is also pow, but it is slightly different from the pow of bitcoin. So, what's the difference between the pow of Ethereum and bitcoin: in short, the mining difficulty of Ethereum can be adjusted, but the mining difficulty of bitcoin can't be adjusted. Just like our college entrance examination, because the teaching situation and the number of students in different provinces are not the same, so the college entrance examination is divided into national papers and provincial independent proposition
Ethereum said that I am in favor of the topic by region. Bitcoin said: No, it must be the same volume in the whole country. The difficulty is the same for everyone
the popular explanation is that bitcoin uses computer computing power to do a lot of hash collisions, enumerate various possibilities to find a correct hash value. The Ethereum system has a special formula to calculate the difficulty of each block. If a block is verified faster than the previous block, Ethereum protocol will increase the difficulty of the block. By adjusting the block difficulty, the time needed to verify the block can be adjusted
according to the Ethereum protocol, the dynamic adjustment method of difficulty is to make the time interval of creating new blocks in the whole network 15 seconds, and the network uses 15 seconds to create blockchain. In this way, because the time is too fast, the synchronization of the system is greatly improved, and it is difficult for malicious participants to launch 51% (that is, more than half) of the computing power to modify historical data in such a short time
the second information point is: in the initial setting of Ethereum, we hope to achieve the transition from POW to
POS through phased upgrade
dating back to 2014, at the beginning of Ethereum's launch, the team announced that the launch of the project would be divided into four stages, namely, Froniter, homestead, metropolis and serenity. In the first three stages, the consensus mechanism adopts pow (workload proof mechanism), and in the fourth stage, it switches to POS (equity proof mechanism)
on July 30, 2015, the first phase "frontier" of Ethereum was officially released. This phase is only suitable for developers. Developers can write smart contracts and decentralized application DAPP on Ethereum network, and miners begin to enter Ethereum network to maintain network security and get Ethereum coins. The leading-edge version is similar to the beta version, proving whether the Ethereum network is reliable or not
on March 14, 2016, Ethereum entered the second stage of "homeland". In this stage, Ethereum provides the wallet function, so that ordinary users can easily experience and use Ethereum. There is no obvious technology improvement in other aspects, but it shows that Ethereum network can run smoothly
in September 2017, Ethereum has reached the third stage of "metropolis"“ "Metropolis" is composed of Byzantine and Constantinople. The goal of this stage is to introce the hybrid chain mode of POW and POS, so as to prepare for the smooth transition from POW to POS. This is the latest popular "Ethereum Constantinople upgrade". In the Constantinople upgrade, Ethereum will make some changes to the underlying protocols and algorithms to lay a good foundation for the implementation of POW and
POS
how much reward will Ethereum get for mining? Miners who win the block creation competition will get the following income:
1. Static reward, 5 ethereums
2. The fuel cost in the block, i.e. gas, we talked about in the last issue
3. As a part of the block, it includes the extra reward of "Uncle block". Uncle is uncle of uncle, and each uncle block can get 1 / 32 of the mining reward as a reward, that is, 5 times 1 / 32, which is equal to 0.15625 ethereums. Here, let's briefly explain the concept of "TERT block". The concept of "TERT block" was proposed by Ethereum. Why should we introce the concept of TERT block? This also starts with bitcoin. In the bitcoin protocol, the longest chain is considered absolutely correct. If a block is not part of the longest chain, it is called a "orphan block". An isolated block is a block, which is also legal, but it may be found later, or the network transmission is slower, and it does not become part of the longest chain. In bitcoin, the solitude is meaningless and will be discarded later, and the miners who find the solitude will not receive mining related rewards
however, Ethereum does not think that isolated blocks are worthless, and Ethereum system will give rewards to miners who find isolated blocks. In Ethereum, isolated blocks are called "Uncle blocks", which can contribute to the security of the main chain. Ethereum's ten second block interval is too fast, which will rece the security. By encouraging the use of tertiary blocks, the main chain can obtain more security guarantees (because the isolated block itself is legal). Moreover, paying the tertiary block can also stimulate the miners to actively mine and actively use tertiary blocks. Therefore, Ethereum thinks that it is valuable.

2. We can buy etheric currency on many exchanges. We can only make money when etheric currency rises sharply. In fact, in the realm Kingdom, we can also trade ether coins. We can make profits when we buy up or down the price of ether coins, and we can trade it for only $5, so we won't take too much trading risk.

3. Do you want to learn blockchain development technology or just want to know what blockchain is? If it is the former, you can look at the code of other blockchain projects and learn about it first. If it is the latter, we can pay attention to some good blockchain we media. Blockchain is an emerging instry. There is no ready-made training course. It depends on self exploration and understanding.

4.

Eth is the Federal Institute of technology of Zurich, located in Zurich, Switzerland. It is a world-renowned top research university. For many years, it has ranked first in European universities and enjoys the reputation of "the first university in Europe". It ranks sixth in the world in the comprehensive ranking of QS World Universities in 2020

The Federal Institute of technology in Zurich was founded by the Swiss Federation in 1854 and began to teach as a technical college in 1855. Initially, it consisted of six faculties of architecture, civil engineering, mechanical engineering, chemistry and forestry, as well as an organization integrating mathematics, natural sciences, literature, social sciences and politics

the Federal Institute of technology of Zurich ranked 9th in the world in the 2016 QS World University comprehensive ranking; In 2017, QS ranked the eighth in the world; Ranked 10th in the world in the comprehensive ranking of QS World Universities in 2018; Ranked 7th in the world in the comprehensive ranking of QS World Universities in 2019; In 2020, QS ranked the sixth in the world

< H2 > extended materials

the development status of eth

the Swiss Federal Institute of technology was established by the Swiss Federal Government in 1855 for the needs of national instrialization, which is a Federal University. It is not only for its own development, but also for the whole country, Europe and even the world to engage in scientific research. At the beginning, the university only had civil engineering, forest science, mechanical engineering and chemistry, and then added humanities, sociology and political science

the school has 26000 teachers and students from more than 100 countries in 16 departments, and its teaching and research fields include architecture, engineering, mathematics, natural science, social science and management science. For eth, the number of students enrolled and tuition fees are not considered at all. With the support of the federal government, the college receives as much as 9.2 billion Swiss francs a year for ecation, which does not include the use of property management and new teaching facilities

the college has also received up to 3 billion Swiss francs from third-party funding and its own technology transformation. All these funds are used for school running and scientific research, or most of them are directly used for more than 20000 students and 500 professors (full-time equivalent personnel of more than 9000 person years)

Even so, ETH continues to say that it is short of money in its annual reports in recent two years, and the reason is very simple. In order to compete with other institutions (universities), our independence is the most important, so we need a long-term sustainable financial support

last year, we expanded the enrollment of 4% of the students. At present, the number of students is 156% of that ten years ago, the number of professors has increased by 23%, and the number of scientific research personnel has increased by 53%. However, the government's scientific research funding has only increased by 42%, and the available area for ecation has only increased by 7%. We are facing great challenges

However, it is not surprising in Switzerland. Due to its unique ecation system, all resources in Switzerland are concentrated in 10 universities and 2 federal polytechnics. In other words, there are only 12 universities at the level of higher ecation, and the country is not short of money, so the current situation is formed

5. There must be some people who accept it. There are a lot of 0.5eth. Fire money and coin can be traded, first into usdt, then into legal money

6.

To apply for eth in Switzerland, the specific requirements for GPA, TOEFL and IELTS are as follows:

IELTS 7-8, TOEFL 110-120, GPA above 3.0

The full name of eth is the Federal Institute of technology of Zurich, which ranks 9th in the world in the 2016 QS World University comprehensive ranking; In 2017, QS ranked the eighth in the world; Ranked 10th in the world in the comprehensive ranking of QS World Universities in 2018; In the comprehensive ranking of QS World Universities in 2019, it ranks 7th in the world

Eth is also famous for its high elimination rate and low admission rate, which is less than 10%

extended materials:

the relevant requirements of the Federal Institute of technology in Zurich:

1. The main teaching language of the undergraate courses of the Federal Institute of technology in Zurich is German (but the teaching language of indivial courses is English or French). Most of the master's courses are taught in English. In addition, some of the courses are bilingual teaching, while a few are mainly taught in German

2. The main library of the Federal Institute of technology in Zurich has a collection of over 6.9 million books, newspapers, maps and other materials, which is the largest library in Switzerland and the Swiss science and Technology Information Center [5]. The main library is responsible for maintaining the Swiss network of libraries and information centers (nebis), through which readers can borrow materials from more than 80 universities or research institutions in Switzerland

3. According to the world's four major rankings (USNEWS world university rankings, times world university rankings, QS World University Rankings, soft science world university academic rankings), the Federal Institute of technology of Zurich is the world's top 20, ranking first in the European continent for many years, and enjoys the same high reputation as MIT all over the world

7. You can sign up for the courses offered by the water quantum community, and recommend the following three or two kinds of advanced training courses: 7-day cultivation advanced course, which can explain and practice the in-depth application of blockchain, participate in the creation and operation of blockchain projects, and provide entrepreneurial project support. The 14 day advanced training course for blockchain engineers of fintech Academy of Sciences is mainly for the development of skilled and practical talents. The courses are set in Taipei and Malaysia, and are trained by the technology experts of fintech Academy of Sciences.

8.

In practical work, we often encounter the operation of restarting the network card in Linux system. There are three methods as follows:

1, service network restart

< UL >

you can use CRT tools to connect to the Linux command line interface; You can also enter the operating system interface, and then select the terminal input:

< / UL >

3, ifconfig eth0 up can be used to start the network card

Ifconfig eth0 down can be used to disable the NIC

9. Eth is the abbreviation of Zurich Federal Institute of technology, also known as Swiss Federal Institute of technology. As one of the world's top research universities, it has been ranked the first in European universities for many years. It is known as the "No.1 University in Europe". It is famous for its extremely low admission rate and extremely high teaching elimination rate. Among the alumni of Zurich Polytechnic, there are 32 Nobel Prize winners including Einstein, 4 fields prize winners and 1 Turing prize winner. The university is a member of the International Research University Alliance and the global university institute alliance
Polytechnic Zurich ranks sixth in the 2020qs World University, 13th in the 2020 Thames Higher Ecation World University, 19th in the 2019 soft science world university academic rankings, and 25th in the 2020u.s. news world university rankings. According to the latest news on June 10, 2020, Zurich Polytechnic is still ranked sixth in the QS World University Rankings in 2021.