The structure of Ethereum
There is an essential difference between Ethereum and bitcoin. What is the difference? Bitcoin defines a set of currency system, while Ethereum focuses on building a main chain (which can be understood as a road) to allow a large number of blockchain applications to run on this road
from this point of view, Ethereum's application scenarios are more extensive, which is why we say that Ethereum marks a simple monetary system in the era of blockchain
1.0, and a transformation to other instries and application scenarios in the era of blockchain 2.0
however, there is no perfect thing in the world. Although Ethereum has expanded the application scope of blockchain in all walks of life and improved the speed of transaction processing, it also has some disputes and doubts
first, the solution to the lack of scalability of Ethereum: slicing technology and lightning network
the bottom design of Ethereum, the biggest problem is that Ethereum has only one chain and no side chain, which means that all programs have to run on this chain equally, consuming resources and causing system congestion. Just like last year's very popular Ethereum game "encryption cat", when this game was very popular, it once caused Ethereum network paralysis
to improve the processing capacity, Ethereum proposes two ways: shard and lightning network. Let's introce these two technologies respectively
(1) fragmentation technology
vitalik buterin, founder of Ethereum, believes that the reason why mainstream blockchain networks such as bitcoin process transactions very slowly is that every miner has to process every transaction in the whole network, which is actually very inefficient. The idea of fragmentation technology is: a transaction does not need to be processed by all nodes in the whole network, as long as some nodes (miners) in the network are allowed to process it. Therefore, Ethereum network is divided into many pieces. At the same time, each piece can handle different transactions. In this way, the network performance will be greatly improved
however, the slicing technology is also controversial. As we all know, the important idea of blockchain technology is decentralization. Only when the whole network witnesses (processes) the same transaction can it have the highest authority. The Ethereum slicing technology is similar to the group witness, not all nodes witness together. In this way, it will lose the absolute "decentralization" attribute, and can only achieve the purpose of high performance by sacrificing certain characteristics of decentralization
(2) lightning network
lightning network uses the way of transaction under the chain. What does that mean? It means: when the participants of lightning network transfer money to each other, they do not need to confirm the transaction through the main chain of Ethereum, but create a payment channel between the participants and complete it under the chain
however, lightning network is not separated from the main chain. Before establishing a payment channel, you need to use the assets on the main chain as collateral to generate a balance proof, which indicates that you can transfer the corresponding balance. In the case that both parties of the transaction hold the balance certificate, both parties can make unlimited number of transfers under the chain through the payment channel
only when the off chain transaction is completed and the assets need to be transferred back to the chain, the balance change information of the main chain account will be registered on the Ethereum main chain, and no matter how many transactions occur ring this period, there will be no record on the main chain
another real benefit of lightning network is that it can save the cost of miners for you. At present, when we trade on the main chain of Ethereum, we need to consume gas and pay for miners. Once we move the transaction to the lower chain, we can save this part of the cost
Of course, lightning network is not perfect. When using the lightning network, the assets on the main chain should be used as collateral; And this part of assets as collateral can not be used before the user completes the transaction under the chain. This also determines that lightning trading is only suitable for small transactionsthe above is the problem of insufficient scalability of Ethereum, as well as the two main solutions: fragmentation technology and lightning network
Second, there are loopholes in Ethereum's smart contract and the infamous Dao event
Ethereum's smart contract is very powerful, but there are loopholes in any code. The biggest controversy of Ethereum's smart contract lies in the so-called loopholes, that is, security issues. According to relevant research, 34200 (about 3%) of the nearly 1 million smart contracts based on Ethereum contain security vulnerabilities, which will allow hackers to steal eth, freeze assets or delete contracts, such as the infamous Dao incident
(1) what does Dao meanbefore introcing the Dao event, let's first introce what Dao is. Dao is the abbreviation of decentralized
autonomous organization, which can be understood as decentralized autonomous organization. From the perspective of Ethereum, Dao is a kind of contract or a combination of contracts on the blockchain, which is used to replace the government's review and complex intermediate proceres, so as to achieve an efficient and decentralized trust system. Therefore, Dao is not a specific organization, that is to say, there can be many Dao, all kinds of Dao
(2) the infamous Dao event
however, when we talk about Dao now, we basically refer to the Dao event, that is, the infamous hacker attack event we just mentioned. As we know, the English word "the" refers to "the Dao event". The Dao event
refers to "the Dao event", because we just said that Dao is not a specific organization, there can be many Dao, all kinds of Dao
in 2016, slock.it, a German company focusing on "smart locks", launched the Dao project on Ethereum in order to realize decentralized physical exchange (such as apartments and ships). Since April 30, 2016, the financing window has been open for 28 days
unexpectedly, this Dao project is very popular. It raised more than US $100 million in just half a month. By the end of the whole financing period, it raised a total of US $150 million. Therefore, it has become the largest crowdfunding project in history. However, it didn't last long. In June, hackers took advantage of the loopholes in the smart contract to successfully transfer more than 3.6 million Ethernet coins and put them into a Dao sub organization, which has the same structure as the Dao. At that time, the price of Ethernet currency fell directly from more than $20 to less than $13
this event shows that there are loopholes in smart contracts, and once the loopholes are exploited by hackers, the consequences will be very serious. This is why many people criticize Ethereum and say that its smart contract is not smart
to solve this problem, many foreign companies begin to provide code audit services in order to solve the vulnerability problem of smart contract. From a technical point of view, some teams are currently testing smart contracts. Most of these teams are led by professors from Harvard, Stanford and Yale, and some of them have obtained investment from leading institutions
in addition to the problems of insufficient expansibility and loopholes in smart contracts, the controversy over Ethereum lies in the POS consensus mechanism it pursues, that is, the proof of equity mechanism. Under the proof of equity mechanism, if anyone holds more money and holds it for a longer time, he will get more "rights" (interests) and have the opportunity to get bookkeeping power, Bookkeeping can also be rewarded. In this way, it is easy to create the oligarchic advantage of "the stronger the stronger"
Another problem is the chaos of ICO. ICO is a common way to raise funds for blockchain projects, which we can understand as pre-sale. The outbreak of ICO projects on Ethereum has caused illegal activities such as fund allocation and money fraud under the banner of ICO, which has caused security risks to social and financial stabilityeach version of Ethernet has a maximum cable length limit (that is, the length without amplification). Signals within this range can propagate normally, and signals beyond this range cannot propagate
in order to allow the construction of a larger network, repeaters can be used to connect multiple cables. Repeater is a physical layer device, which can receive, amplify and retransmit signals in two directions
extended data
several common Ethernet interface types
1. SC optical fiber interface
SC optical fiber interface has been applied in the era of 100base TX Ethernet, so it was called 100base FX at that time (F is the abbreviation of optical fiber). However, at that time, because the performance was not more prominent than twisted pair, but the cost was higher, so it was not popularized. Now the instry vigorously promotes gigabit network, and SC optical fiber interface is re valued
2. RJ-45 interface
this kind of interface is the most common network equipment interface, commonly known as "crystal head", and the professional term is RJ-45 connector, which belongs to the type of twisted pair Ethernet interface. RJ-45 plug can only be inserted along the fixed direction, and a plastic spring piece is set to be stuck with RJ-45 slot to prevent it from falling off
3. FDDI interface
FDDI has the highest transmission rate among the mature LAN technologies. It has the characteristics of timed token protocol, supports a variety of topologies, and its transmission medium is optical fiber. Fiber distributed data interface (FDDI) is a set of protocols developed by American National Organization for Standardization (ANSI) to transmit digital signals on optical cables
reference source: Network Ethernet interface
there is no central server in Ethereum. Instead, there are many equal nodes connected by P2P protocol, which store all the data in many nodes. When a user initiates a transaction, the transaction will be broadcast out through P2P protocol. The miner node verifies, packages and further broadcasts the transaction to the whole network. After confirmation in the blockchain, the operation is considered to be unchangeable
in the articles on blockchain on the Internet, the two words distributed and decentralized are mentioned, sometimes slightly different, sometimes mixed. The author thinks that if we want to distinguish accurately, the distributed system emphasizes that multiple components work together by sending messages, and the decentralized system emphasizes that there is no central node to control the operation of the whole system. Therefore, we think that Ethereum is both decentralized and distributed, or running a decentralized program on a distributed platform.
After reading the answers of other respondents, I really want to laugh. It's not terrible to pretend that I don't understand. What's terrible is to answer blindly. There's something wrong with this question. The burst of 5.7 billion yuan has nothing to do with a drop of 10 cents. It can even be said that its disappearance is e to the sharp rise. So where is the decline? If bitcoin really falls, it will not be 5.7 billion capital washed away, it will be tens of billions, hundreds of billions of capital evaporated, those who talk about trends and development, please study the capital and stock market well, and by the way, please search for the meaning of the word "burst", no culture is too terrible
in addition, I would like to make a digression. Recently, a hot topic is fund. In 2021, the annual meeting is more or less a national fund. In 2020, the fund manager is still a good active fund. Even if the position is not changed, the annual yield will reach at least 40%, but this does not mean that this year is still OK, It's not that everyone can make money playing with funds. it's similar to the nature of stocks. Index funds, stock funds and even active funds are risky. I think many people say that they should get on the bus quickly. They are really worried about your funds of course, 2021 may be a bull market. It is estimated that the whole network has spread, many people are rubbing their hands to make a lot of money, but I can't do much. I just advise you not to go with the flow too much, don't be greedy, and don't think you are. That's all. Good luck
I wish you a smooth customs clearance and look forward to your contact
in the 19th century, scientists graally found that light is a kind of wave, and most of the waves in life need propagation media (for example, the transmission of sound waves needs air, and the transmission of water waves needs water, etc.). Influenced by traditional mechanics, they assumed that there was a kind of matter called ether everywhere in the universe, and it was this kind of matter that played a role of medium in the transmission of light
according to Maxwell's equations, the propagation of electromagnetic wave needs an "absolute" reference frame. Only in this reference frame can the speed of light have the value C = &# 92 predicted by Maxwell's equations; frac{1}{\ sqrt{\ varepsilon_ 0\ mu_ 0}} Among them, 92; varepsilon_ 0 is the vacuum dielectric constant, μ 0 is the vacuum permeability. This "absolute frame of reference" is ether. The speed of light measured in other reference frames should be the vector sum of the speed of light in this "absolute" reference frame and the speed of this "absolute" reference frame relative to the observer
according to the conjecture at that time, ether filled the whole universe, and electromagnetic waves could propagate in it. When the earth revolves around the sun, it has a velocity V relative to the ether. Therefore, if the speed of light is measured on the earth, the values measured in different directions should be different, with the maximum of C + V and the minimum of C-V (at this time, it is assumed that the ether is stationary relative to the solar reference system). But even if the ether is not stationary relative to the solar reference system, the values measured in different directions should be different. However, from 1881 to 1884, Albert Michelson and Edward Morley concted the famous Michelson Morley experiment to measure the relative speed of the earth and ether, and measured the speed of light in different directions. However, the experimental results show that there is no such speed difference. In fact, this proves the principle of invariance of light speed, that is, the speed of light in real space has the same value in any reference frame, which has nothing to do with the relative speed of reference frame. In fact, ether does not exist. Later, many experiments supported the above conclusion
the theory of ether was once deeply rooted in people's minds for a period of time, and profoundly influenced the thinking of physicists. Lorentz, a famous physicist, has deced the Lorentz transformation formula which accords with the condition of electromagnetism covariance, but he can't abandon the viewpoint of ether. Einstein boldly abandoned the theory of ether and thought that the constant speed of light was the basic principle. Based on this, he established the special theory of relativity. Although later facts proved that there was no ether, the ether hypothesis still left traces in our lives, such as Ethernet.
ethno, ethnopsychology; Race, people, nation
this is what I can come up with