- What happens in the bitcoin network when two miners solve a block at the same time? Two versions of the blockchain are created
- What is a stale block? A discarded block
- How do stale blocks occur? Two miners solve a block at the same time
- Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? Decreases your chances of your transaction being thrown back to the mempool
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When two miners solve a block at the same time, two different, perfectly valid blocks are created and broadcast to the network.
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A stale block is the result of two blocks being created. Since there can only be one valid block at that position of the blockchain, the block that eventually gets dropped and does not become a part of the blockchain is called the stale block.
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Other nodes on the network will accept different blocks as the “true block” on the chain. The block that eventually becomes accepted on the chain depends on which node first solves the next block on the chain. Whichever node solves the next block “chooses” the correct previous block, as it has created a new block before any other node, which makes it the longest chain within the network, forcing all other nodes to accept it due to the rules of the ecosystem.
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All transactions contained within the stale block are returned to the mempool. It is important to wait for at least 6 block confirmations to make sure that your transactions are not reverted due to a stale block occuring.
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Homework:
- What happens in the bitcoin network when two miners solve a block at the same time?
Answer: You have two competing blocks until one of the blocks is appended to by a new block and the smaller blockchain (based upon proof of work) is dropped per the protocol. - What is a stale block?
Answer: A stale block is a block that was on a blockchain being propagated throughout the network, but then dropped. - How do stale blocks occur?
Answer: Stale blocks occur when a block is dropped from the network. - Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
Answer: Since the blockchain must be propagated throughout a global system there must be enough time for any competing blockchains to be dealt with; 10 minutes – given the speed of the system – is considered adequate enough to deal with this potential issue. i.e. It allows enough time for one blockchain to win out and be fully propagated throughout the global system.
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1.The one with the longest chain will be added to the blockchain. Whilst the other one will be removed.
2. A stale block is a block that has been dropped.
3. Stale blocks occur when there are two miners create a block at the same time. The block that has the longest chain will be the “truth” and the one with the shortest chain will be removed and become a stale/oprhaned block.
4. It is to allow to make sure that the information is propagated and to avoid stale block/orphaned blocks. It is best to wait 6 confirmations to ensure that your transaction is confirmed.
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- Both blocks are added to two different competing branches of the blockchain
- When there are two competing branches in the blockchain, the longer block (the one with the most proof of work / the highest difficulty, lowest nonce) will be accepted and the shorter blockchain will be discarded and becomes a stale or orphaned block. It’s transactions are added to the memepool of unprocessed transactions that reside on the nodes awaiting confirmation
- Stale blocks occur when the you have two perfectly good (verified to have found nonce) blocks added to the blockchain and the shorter blockchain is then rejected from the blockchain or becomes orphaned
- Because the phenomenon of stale blocks makes it difficult to know when a TX is truly confirmed; waiting for six blocks adds surety that your confirmation will not be reversed as a stale block is rejected
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What happens in the bitcoin network when two miners solve a block at the same time?
There are two versions of the blockchain existing in parallel until the next block is mined.
When the next block is mined, the version used to mine that next block will become longer. Which means the block from the other version will be declared orphaned and dropped from the nodes. -
What is a stale block?
A block that won’t become orphaned. -
How do stale blocks occur?
Once a blocked is confirmed six times, it is considered stable. -
Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
To make sure the block does not get dropped.
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- What happens in the bitcoin network when two miners solve a block at the same time? the blockchain will choose the longest most difficult block to become the next part of the chain
- What is a stale block? a stale block is a good block that is rejected by the network and returned to the mempool
- How do stale blocks occur? stale blocks occur when more than one block is trying to be added to the network at the same time. the one that is rejected is the stale block which is a legitimate block but not the longest block.
- Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? 10 minute rule. make sure that a minimum of 6 confirmations [blocks] are added to the network on top of your transaction to ensure that the transaction is indeed accepted by the network.
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1.What happens in the bitcoin network when two miners solve a block at the same time?
When two miners solve a block at the same time it all about time and see
who has the longer chain cause eventually there will just be one winner
2.What is a stale block?
Stale block when it was successfully mined block, but was not
accepted into the chain
3.How do stale blocks occur?
Stale blocks occur when the miner solve a block at the same time
4.Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
To make sure your transaction is final and the block that it belongs to can no longer be dropped
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1-it forks until a miner starts adding blocks to one of the two versions thus making it longer and therefore keeping it as the good version among the two.
2-a stale block or orphan block is a block that is rejected by the network and sent back to the mempool.
3-Stale blocks occur after the fork is resolved by one miner choosing one of the two versions making it the longer one.The shorter version will be dropped and those blocks are called stale blocks
4To make sure that the chain of blocks have been accepted by the network as the true and only version of the blockchain
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- What happens in the bitcoin network when two miners solve a block at the same time?
When this happens, both blocks get added to the blockchain on their node and then propagated out to other nodes. As this is happening, there is basically two versions of the blockchain that is being accepted as the true blockchain, but by separate nodes around the world. As time goes on and new blocks are created and added, whichever version of the blockchain that is the longest (with more blocks) will “win” and will be propagated to the other nodes around the world. The other version of the blockchain will be disregarded and the transactions in the blocks of the disregarded version will be returned to the mempool.
- What is a stale block?
A stale block is a block that was confirmed by certain nodes as a new confirmed block in the blockchain but then was overpowered by the version of a blockchain that was present on other nodes and propagated more widely on the blockchain. Those nodes on the less propagated version are stale because, although they were once confirmed, or even twice confirmed, the nodes decide they are no longer part of the agreed-upon blockchain and all of those transactions inside the stale blocks get returned to the mempool.
- How do stale blocks occur?
Stale blocks occur when blocks are created at the exact same times by different miners. After this occurs, there is a period of time in which both blocks are considered the actual new block of the blockchain as seen by their node. The nodes around the world propagate their version of the blockchain and as this happens the longer chain will be the one that is accepted by the nodes, rendering the other blocks of the recently formed version of the chain “stale” and their transactions go back to the mempool.
- Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
Given that a “confirmed” transaction could actually turn out to be a part of a stale block, its agreed that waiting for six confirmations, ie that the transaction is in a block that is six blocks back in the chain from the most newly minted block. A block holding a transaction that far back in the blockchain has essentially zero chance of being a stale block. Six confirmations would take approximately 60 minutes, and 60 minutes is more than enough time for nodes to talk to each other and resolve different versions of the blockchain that are being propagated by nodes.
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1. What happens in the bitcoin network when two miners solve a block at the same time?
The blockchain will accept the 2 blocks and split into 2 possible routes of propagation temporarily.
2. What is a stale block?
Stale block is a block that is dropped off from the blockchain.
The transactions and data in the stale block will be returned to the mempool, waiting to be added to the blockchain by miners.
3. How do stale blocks occur?
The blockchain has to discard this stale block to favour the longer blockchain length after it was created. Otherwise, the blockchain will have splits and it cannot achieve certain properties of blockchain being a consensus public ledger. There will be non-uniformity of information in the blockchain if this occurs.
4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
This is to prevent the occurrence of the block turning into a stale block. If it happens all the transactions in the stale block will be returned to the mempool and become unconfirmed transactions (again).
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The chain forks and whichever chain is longest is the one that is accepted and the other chain is dropped.
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A stale block is a block that was dropped from the chain because there is another chain that is longer.
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A stale block occurs when two miners mine different blocks at the same time and both are valid and added to the chain, it creates a fork in the chain. Whichever chain ends up being longer is the one that gets excepted and the other block is then considered a stale block.
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It is important to wait for at least six blocks to be confirmed to insure you do not add your block to a stale block.
But if blocks are being added it means they might be appended to the stale block 
why is this important from the perspective of the user that is trying to send or receive a tx?
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I believe the user that is trying to send or receive a transaction will have that transaction put back into the mempool causing it to take longer to process. Which would be a bummer. Let me know if I am way off!
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1. When 2 miners solve a block at the same time eventually one chain will develop to be longer and will become the version of truth while the other block or blocks will be discarded.
2. A stale block is the version of the block chain which is discarded after there has been 2 miners solve a block at the same time.
3. Stale blocks occur when 2 versions of the truth are created by 2 miners solving blocks at the same time and the stale blocks are discarded back to the mempool.
4. It is important to wait for more than one block to be confirmed when sending and receiving a transaction to ensure that the block containing that transaction has been accepted to the network as the longest chain (and therefore not a stale block).
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You are correct! 
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- both blocks if valid might get appended to the blockchain and both start propagating through the network. Then after block time has passed another miner will come and append another block to one of the two blocks… in the end one of the two chain appendices (the shorter one) will be dropped according to the “longest chain rule” and the transactions in it will return to the mempool.
2 & 3. it’s a block that’s been dropped. There might be various reasons like collisions, network updates/forks.
- Because due to the possibility of having that the transaction is in a stale block and therefore the possibility of it being dropped. So it’s best practice to wait for 6 block confirmation.
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What happens in the bitcoin network when two miners solve a block at the same time?
Two separate valid blocks are temporarily created (in a fork) until the next blocks, the next blocks are added to either one of the new chains and creates the longer chain of the 2 options, the block that isn’t added to becomes stale (orphaned) and the utxo’s within it are sent back the mempool
What is a stale block?
Is the block that is created in unison with another block at the same time but no longer considered a part of the chain
How do stale blocks occur?
2 blocks are mined at the same time and put on the blockchain as valid, but only one can be part of the longest chain, so one block is rendered stale while the other is verified on the blockchain as a part of the longest chain
Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
To ensure your transactions have been confirmed/verified on chain and not been included in a stale block. If your txn is added to a stale block the transaction will be reverted back to the mempool
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What happens in the bitcoin network when two miners solve a block at the same time?
Answer: When two miners solve a block at the same time, then the block that is built on first and creates the longest chain will win. The other block will be negated and the transactions within it are then returned to the mempool. -
What is a stale block?
Answer: A stale or orphaned block is a block that is dropped by the network because it was mined at the same time as another and was not built on quickly enough, therefore not creating the longest chain. -
How do stale blocks occur?
Answer: Stale blocks occur because sometimes miners will mine a block at the same time with the same version of truth causing both blocks to link to the blockchain. When this occurs, the blocks are propagated by the nearest nodes in the network. Once there is a block that is appended to one of the blocks that were mined at the same time, then that chain succeeds and the other block that was not mined on fast enough will become a stale block. -
Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
Answer: It is important to wait for more than one (six is ideal) block to be confirmed when sending or receiving a transaction because it ensures enough time for the transaction to travel through the computer network and that it won’t be dropped from the blockchain.
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1.- When 2 blocks create a block at the exactly same time, both blocks will be added to the blockchain but just one of them will remain in there (the one with the longest chain)
2. Block that has been discarded (transaction put back to the mempool) because there was another block that was created at the same time and has a longer chain.
3.- Because 2 blocks where created at the same time, so some nodes have 2 different version of the chain and just one version (the longest) can survive
4.- To ensure that will not be a stale block
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