Your understanding of the way blocks are assigned is incorrect. There is no guarantee (initially) that all nodes will unilaterally agree on the same next block to be added to the chain. Dispute situations are relatively common, and stem from multiple miners solving the next block close enough to simultaneously in order for some nodes to receive one candidate for the next block from one of the miners, and other nodes to receive a different suggestion.
The longest chain solution solves this dilemma by reverting the entire chain to the suggested block + any further blocks added, once one of the disputing chains has been mined at a faster rate than the other and so becomes longer.
So there are “collisions”, however the system inherently deals with these situations algorithmically.
How effective this system is.. well in 9 years there hasn’t been an instance of system failure, because of this potential threat, or any other. The mathematical security built into blockchain as a whole is far superior to any previous digital currency conceptions, which all had issues with one or more of these potential threats which they could not solve. Blockchain is a highly complete solution, not just to trustless decentralised value transfer, but to many other applications which are only really possible because of a few key securing features, such as the longest chain concept, digital signing etc
so why everybody uses blockchain. Isn't it possible to use paxos + proof of work + verification of the work ? Efficiency would be much better. Why blockchain is so massively used, it is the worst algorithm I have seen. – Nulik – 2017-09-27T08:46:28.977
ups, found an answer to the comment above: https://www.quora.com/Why-would-you-use-blockchain-over-a-distributed-consensus-protocol-like-Paxos-or-Raft
– Nulik – 2017-09-27T08:53:10.747Two main factors are scalability and presence byzantine faults. Much effort has been put into making Paxos and its many variants scale, but the truth is it could never scale to the size of a blockchain based consensus, not in the Internet, at least. As for byzantine failures, the Paxos versions that supports it scale even less. – Nulik – 2017-09-27T08:53:36.727
>>> Why blockchain is so massively used <<< People do strange things. Blockchain is not "used" today. Everything bitcoin-related is pyramid-scheme bubbles – amaclin – 2017-09-27T09:07:04.043
while it has speculative money in the price it is not a pyramid-scheme because some useful work is done. The problem of course is with the true value of this work, but don't worry, markets are rational and will correct themselves, and they usually do it with a lag. – Nulik – 2017-09-27T09:15:12.367
It can not be "useful work" for $10 per transaction because we have much more effective ways to do such work. Okay, show me the "useful work" :) – amaclin – 2017-09-27T09:21:11.457
you mean a
distributed ledger without the problem of double spending and centralization? I would like to see this technology. AFAIK there is no such thing. That's why everyone uses blockchain. Because otherwise you have to have centralized authority, which is nobody wants. You are seeing $10 in transaction but you are forgetting 3% inflation every year and the cost of bank rescue which increases country's debt. Such things would be 0 with cryptocurrencies. – Nulik – 2017-09-27T10:35:50.380For example, if you earn 100K per year, you are wasting $3,000 money because of inflation. If you divide this by 365 you will get 8.91 per day, without even using banking services. Include the debt and you will be shocked. So. ... $10 per transaction is not expensive. – Nulik – 2017-09-27T10:35:54.770
with multiple inputs and multiple outputs you can write a single transaction to pay for all your bills once in a month. – Nulik – 2017-09-27T10:37:25.707
also, where did you get that number $10 per transaction, it is very strange that this is the real cost, too expensive. how can you spend $10 on one transaction – Nulik – 2017-09-27T10:39:46.303
>>> where did you get that number $10 per transaction <<< Take the hashrate here: https://bitcoinwisdom.com/bitcoin/difficulty ~7000000000 GH/s, calculate how many asics are working, take the sum of electricity spent per day and divide by the number of daily transactions
– amaclin – 2017-09-27T11:31:47.340@amaclin: If you believe Bitcoin is a pyramid scheme, why are you active on bitcoin.se? – Meni Rosenfeld – 2017-09-30T21:45:39.780
@MeniRosenfeld because I'm not a coward like Satoshi Nakamoto – amaclin – 2017-10-02T04:34:13.003