If Bitcoin network would have stopped to work, would it be destroyed ?

[Erkallys]

If for any reason, a big electricity cut happens worldwide, would it destroyed Bitcoin ? In an easier way, if everyone would disconnect to the Bitcoin network, would it kill Bitcoin, would it stop to work ?

[DannyHamilton]

If for any reason, a big electricity cut happens worldwide, would it destroyed Bitcoin ?

No, but it would be very difficult to use until the electricity (and internet) functionality returned.  Nearly everyone would stop using it and would wait until the problem was fixed.  Then they would return to using it again.

Of course, in the meantime the world would collapse into chaos.  There would be riots and mobs trying to acquire food and fresh water. Food, water, bullets, and weapons would become the new currency.

In an easier way, if everyone would disconnect to the Bitcoin network, would it kill Bitcoin,

Kill it?  No.  But confirmations would stop happening until some miners and users re-connected.

would it stop to work ?

Confirmations wouldn't happen until there was a way to get transactions from users to miners, and for miners to share completed blocks.  Once a communications method was established, bitcoin could continue to confirm transactions.

[Erkallys]

Okay, I understand, so let's say that solar-panel powered house with two computer connected between them keep running the Bitcoin Core and mining blocks and that the same thing happen in another place, when electricity and then internet will come back, which chain will be described as the right one ? The older ? None of them ?

[DannyHamilton]

Okay, I understand, so let's say that solar-panel powered house with two computer connected between them keep running the Bitcoin Core and mining blocks and that the same thing happen in another place, when electricity and then internet will come back, which chain will be described as the right one ? The older ? None of them ?

The one with the larger proof-of-work. (This generally means the one with more blocks).

Any transactions that are confirmed in both chains (or only in the winning chain) will remain confirmed.  Any transactions that are only confirmed in the "losing" chain will become unconfirmed and will need to be re-confirmed in the new chain.  If any of those transactions that become unconfirmed are invalid in the new chain, then they will cease to exist.

[Erkallys]

Okay, I understand, so let's say that solar-panel powered house with two computer connected between them keep running the Bitcoin Core and mining blocks and that the same thing happen in another place, when electricity and then internet will come back, which chain will be described as the right one ? The older ? None of them ?

The one with the larger proof-of-work. (This generally means the one with more blocks).

Any transactions that are confirmed in both chains (or only in the winning chain) will remain confirmed.  Any transactions that are only confirmed in the "losing" chain will become unconfirmed and will need to be re-confirmed in the new chain.  If any of those transactions that become unconfirmed are invalid in the new chain, then they will cease to exist.

So the "losing chain" will be erased ? This can't lead to a fork ? The two chains can't cohabitate ?

[DannyHamilton]

So the "losing chain" will be erased ? This can't lead to a fork ? The two chains can't cohabitate ?

If all the nodes are running the current consensus protocol, then a permanent fork is impossible.  Nodes will always come to a consensus on one chain and the losing chain will be ignored.

If the nodes on the losing chain WANT a fork, then they can create their own protocol that rejects all blocks from the other chain.  This will cause there to be two currencies both trying to call themselves "bitcoin".  Blocks on one chain won't be valid on the other, and any transactions that use bitcoins that are only confirmed on one chain will be invalid on the other chain.

[Erkallys]

So the "losing chain" will be erased ? This can't lead to a fork ? The two chains can't cohabitate ?

If all the nodes are running the current consensus protocol, then a permanent fork is impossible.  Nodes will always come to a consensus on one chain and the losing chain will be ignored.

If the nodes on the losing chain WANT a fork, then they can create their own protocol that rejects all blocks from the other chain.  This will cause there to be two currencies both trying to call themselves "bitcoin".  Blocks on one chain won't be valid on the other, and any transactions that use bitcoins that are only confirmed on one chain will be invalid on the other chain.

So from what I understood, if nodes on the losing chain don't create their own protocol, they won't fork ? But if there is the same number of nodes in each of the two chains (I'm still taking the exemple of the electricty collapse and the two homes network that cohabitate), which one will win ? And will each chain create blocks at the same time ?

[DannyHamilton]

So from what I understood, if nodes on the losing chain don't create their own protocol, they won't fork?

Correct.  The fork that occurs during the outage will resolve itself once it becomes possible for the blocks to be shared between the two networks.

But if there is the same number of nodes in each of the two chains (I'm still taking the exemple of the electricty collapse and the two homes network that cohabitate), which one will win?

The number of nodes doesn't matter.  The longer chain (the one with a larger proof-of-work) will win.

And will each chain create blocks at the same time ?

Block solving is a random process.  There is no way to know exactly how long it will take.  Therefore, while it is possible that they might solve blocks at the same time, it is unlikely.

When the networks are finally connected to each other, if both chains are the same size, then each "home" will work on it's own chain until it solves a block.  Then it's chain will be the longest and it will "win".  If, after being connected, both "homes" just happen to solve a block at almost the exact same moment, then both chains will grow by one block and they will continue to remain forked until the next block is solved.

This process will continue until one of the "homes" solves a block first and has the longest chain.  Then it will win.

Note:

All of this is very hypothetical and not very realistic.  Something like what you are describing would certainly never occur.

However, if it did then the current proof-of-work difficulty is VERY VERY HIGH.  If all nodes could no longer communicate, then mining pools could no longer exist (until the communication was re-established).  Anyone with hash power could solo mine their own blocks, or they could just shut down their mining.  The person that has control of the largest amount of hash power, and continues mining, would have the best chance of finding a block while the entire network was down.

With such a high difficulty, it would require a person to either have a LOT of hash power, or to be VERY lucky to find a block.  If someone had control of 168.7 TeraHash per second of hash power (that's 22 of the fastest hashing ASIC currently available), they'd solve (on average) about one block per year.

[Erkallys]

If there is no competition at all shouldn't be the difficulty ridiculously low ? If there is only one guy that mine, even with a smartphone CPU shouldn't he be able to solve any block ?

And yes, I know it is very unlikely to happen, but sometimes really rare cases theory can help use understand eventual problem that could occur soon.

[smith coins]

Can bitcoin network working in big LAN networks so miners can confirm the transactions?
But with my logic if there is no network there is no confirmation and there is no use of bitcoin at that time.

[The Sceptical Chymist]

Okay, I understand, so let's say that solar-panel powered house with two computer connected between them keep running the Bitcoin Core and mining blocks and that the same thing happen in another place, when electricity and then internet will come back, which chain will be described as the right one ? The older ? None of them ?

The one with the larger proof-of-work. (This generally means the one with more blocks).

Any transactions that are confirmed in both chains (or only in the winning chain) will remain confirmed.  Any transactions that are only confirmed in the "losing" chain will become unconfirmed and will need to be re-confirmed in the new chain.  If any of those transactions that become unconfirmed are invalid in the new chain, then they will cease to exist.

Interesting, this answers one of many questions I have about bitcoin.  I love the concept but my background is not in computers. 

[DannyHamilton]

If there is no competition at all shouldn't be the difficulty ridiculously low ? If there is only one guy that mine, even with a smartphone CPU shouldn't he be able to solve any block ?

Difficulty is adjusted every 2016 blocks, so you would have to wait for at least 2016 blocks solved at the lower hash rate (which would take a very long time) before difficulty adjusted back to a rate where the individual could solve a block every 10 minutes.

If someone has enough hash power to solve 1 block per month all by themselves at the current difficulty, it would take at least 168 years (and probably longer) until the difficulty dropped low enough for them to solve a block every 10 minutes.

Note that if that much hash power actually somehow disappeared from the existing network and it was confidently believed that it would not return, there would almost certainly be a lot of people that would demand a protocol change to force an easier difficulty.  As long as nearly everyone upgraded to the new protocol, the difficulty could be forced to the easier value.

In your example, there is no good way to communicate with everyone else (since the network is "down") so there is no way to be confident that everyone else is adopting your new easier difficulty.  If you mine at an easier difficulty and others don't update their software to use the same, then they will all reject your blocks as invalid.  All your mining effort will have gone to waste and you would have accomplished nothing but burning a lot of electricity.

[btcdevil]

this thread and the conversation has helped a lot for all the users of bitcoin network about the doubt of if their is any natual calamity of internet or electricity.

yours replys are very informative. thanks for all the information and doubts clearing

[DannyHamilton]

this thread and the conversation has helped a lot for all the users of bitcoin network about the doubt of if their is any natual calamity of internet or electricity.

This thread has helped the OP and a few people that bothered to take the time to read it.  That is all.

If discussions like this actually helped "all the users", then this thread wouldn't even exist.

These same questions have been asked MANY times in the past and have been answered hundreds of times (probably a few dozen times by me).

The same questions will be asked by someone new in a few weeks.

Most new users don't understand how bitcoin works and don't want to bother taking the time to read the whitepaper, the wiki, or using Google to search and learn the technical details on their own.  Instead they make incorrect assumptions or ask hypothetical questions.  They all tend to make the same assumptions, and ask the same questions.

[Erkallys]

this thread and the conversation has helped a lot for all the users of bitcoin network about the doubt of if their is any natual calamity of internet or electricity.

This thread has helped the OP and a few people that bothered to take the time to read it.  That is all.

If discussions like this actually helped "all the users", then this thread wouldn't even exist.

These same questions have been asked MANY times in the past and have been answered hundreds of times (probably a few dozen times by me).

The same questions will be asked by someone new in a few weeks.

Most new users don't understand how bitcoin works and don't want to bother taking the time to read the whitepaper, the wiki, or using Google to search and learn the technical details on their own.  Instead they make incorrect assumptions or ask hypothetical questions.  They all tend to make the same assumptions, and ask the same questions.

So there should have a sticky about this. I find that the whitepaper doesn't obviously reply to this question. Also common terms are better than sigmas and math equations.

[Velkro]

If for any reason, a big electricity cut happens worldwide, would it destroyed Bitcoin ? In an easier way, if everyone would disconnect to the Bitcoin network, would it kill Bitcoin, would it stop to work ?

I would not worry about bitcoin then but whole world, normal markets would crash also, everything would crash actually, hospitals (power generators don't work long) etc.

[Erkallys]

If for any reason, a big electricity cut happens worldwide, would it destroyed Bitcoin ? In an easier way, if everyone would disconnect to the Bitcoin network, would it kill Bitcoin, would it stop to work ?

I would not worry about bitcoin then but whole world, normal markets would crash also, everything would crash actually, hospitals (power generators don't work long) etc.

If there electricity cut lasts only a few hours, the world won't collapse. There will maybe have a bit of anarchy, but since people won't have news from outside, they won't know this would have happened worldwide, so damages will be none or really low. I thought Bitcoin will collapse if there is an interruption in the network, but now I'm confident .

[DannyHamilton]

- snip -
So there should have a sticky about this.

If the forum created a sticky for every basic question that anyone asks, then there'd be so many posts pinned to the top of the forum that it wouldn't help you find what you are looking for.

I find that the whitepaper doesn't obviously reply to this question. Also common terms are better than sigmas and math equations.

I see what you mean.  All these sigmas and math equations in this quote from Section 5 of the whitepaper make it very difficult to understand that the longest chain wins:

Nodes always consider the longest chain to be the correct one and will keep working on extending it. If two nodes broadcast different versions of the next block simultaneously, some nodes may receive one or the other first. In that case, they work on the first one they received, but save the other branch in case it becomes longer. The tie will be broken when the next proof-of-work is found and one branch becomes longer; the nodes that were working on the other branch will then switch to the longer one.

I can also see how all these sigmas and math equations in this quote from the wiki make it very difficult to understand:

If there is even a "trickle" of a connection between two sides of a segmented network, things should still work perfectly. When block chains are combined, all of the non-generation transactions in the shorter chain are re-added to the transaction pool -- they'll start over at 0/unconfirmed, but they'll still be valid.

And after clicking the top result from Google when searching for "bitcoin isolated network" I can see how all these sigmas and math equations also make it difficult to understand:

When bitcoin client downloads two conflicting blockchains, in other words when fork happened, it chooses the longer blockchain as valid, and the shorter becomes invalid and called "orphan blocks". "Length" is calculated as total combined difficulty of that chain, not number of blocks.

As a bonus for the confusion, this Google search result has this very complicated explanation about how blocks might be slow until the difficulty adjusts:

Difficulty gets adjusted every 2016 blocks, so there is a bit of a lag between network hash rate change and the adjustment, and it is possible for a blocks to take longer to mine before it gets adjusted back to 1 block per 10 minutes. So lets say . . . 1% of total network hash rate, therefore, after separation, it will take roughly 1000 minutes to mine a block before it reaches the next checkpoint and sets the difficulty correctly

[RodeoX]

I think the question is "would it kill the internet"?
Assuming the electricity came back on, then I think the internet and bitcoin would bounce back quickly. However it may hurt adoption to see a real loss of service for any length of time. 

[Erkallys]

- snip -
So there should have a sticky about this.

If the forum created a sticky for every basic question that anyone asks, then there'd be so many posts pinned to the top of the forum that it wouldn't help you find what you are looking for.

I find that the whitepaper doesn't obviously reply to this question. Also common terms are better than sigmas and math equations.

I see what you mean.  All these sigmas and math equations in this quote from Section 5 of the whitepaper make it very difficult to understand that the longest chain wins:

Nodes always consider the longest chain to be the correct one and will keep working on extending it. If two nodes broadcast different versions of the next block simultaneously, some nodes may receive one or the other first. In that case, they work on the first one they received, but save the other branch in case it becomes longer. The tie will be broken when the next proof-of-work is found and one branch becomes longer; the nodes that were working on the other branch will then switch to the longer one.

I can also see how all these sigmas and math equations in this quote from the wiki make it very difficult to understand:

If there is even a "trickle" of a connection between two sides of a segmented network, things should still work perfectly. When block chains are combined, all of the non-generation transactions in the shorter chain are re-added to the transaction pool -- they'll start over at 0/unconfirmed, but they'll still be valid.

And after clicking the top result from Google when searching for "bitcoin isolated network" I can see how all these sigmas and math equations also make it difficult to understand:

When bitcoin client downloads two conflicting blockchains, in other words when fork happened, it chooses the longer blockchain as valid, and the shorter becomes invalid and called "orphan blocks". "Length" is calculated as total combined difficulty of that chain, not number of blocks.

As a bonus for the confusion, this Google search result has this very complicated explanation about how blocks might be slow until the difficulty adjusts:

Difficulty gets adjusted every 2016 blocks, so there is a bit of a lag between network hash rate change and the adjustment, and it is possible for a blocks to take longer to mine before it gets adjusted back to 1 block per 10 minutes. So lets say . . . 1% of total network hash rate, therefore, after separation, it will take roughly 1000 minutes to mine a block before it reaches the next checkpoint and sets the difficulty correctly

You already know the solution to the problem, so that's sure you know which questions you can ask to Google. I'm sorry, it seems I've looked to the whitepaper too quickly, and I didn't see it. Maybe a sticky that would stock all the questions would be a good idea, but that's just a suggestion.

I think the question is "would it kill the internet"?
Assuming the electricity came back on, then I think the internet and bitcoin would bounce back quickly. However it may hurt adoption to see a real loss of service for any length of time.  

If banks take too much time to get back to normal status, it may help some people to rejoin Bitcoin.