Homework on Stale Blocks

Blockchain and Bitcoin 101
#181 
**1. What happens in the bitcoin network when two miners solve a block at the same time?**

When you have two miners solving a block at the same time that results one of those blocks will end up as a stale block. That stale block will be rejected from the chains network and the Tx list will go back to Mempool till the miner solve the puzzle again.

**2. What is a stale block?**

A stale block is the result of when two miners mined the same time a block and the network rejects one of them because the next miner choose the others block hash data to include in his block data so he will connect with it. when that happens the block that doesnt get first a next block gets rejected from the chain and its TX list goes back to Mempool.

**3. How do stale blocks occur?**

A stale block occurs when its chain stops to get more blocks and gets dropped.

**4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?**

So you know if the transaction will not be in a stale block and have your transaction send back to Mempool cause the block got rejected from the chain

#182
  1. We have a fork in the blockchain but in the end the longest chain will win because he has more proof of work.
  2. A stale block has a valid nonce, hash but in competition he will have less proof of work so he won’t be integrated in the chain.
  3. When 2 blocks are mined at the same time in chain appears a temporary fork. After this the block which will have more linked blocks will become the valid chain and the blocks who lost the competition are declared stalled or orphaned.
  4. Because the block to which is appended the mempool might be invalidated and the transactions rescheduled.
#183

There is a difference between a stale or orphan block!
https://en.bitcoin.it/wiki/Orphan_Block

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#184
  1. The block propagating the longest chain is appended. This chain incentiveses the miners and the other block is made stale or orphaned with people mining on the longest chain.
  2. This is a block that wasn’t appended on to the chain.
  3. They are produced at the same time with blocks that are appended to the chain.
  4. This will help avoid double spend.
#185

  1. What happens in the bitcoin network when two miners solve a block at the same time?
    then two chains will be created and both will exist until later when the next block is found and the longest chain is continued

  2. What is a stale block?
    it’s a block that was part of a forked chain created when two miners found a block at the same time

  3. How do stale blocks occur?
    they occur when the blockchain is forked due to two miners finding a block at the same time and

  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
    because it is possible that the transaction was mined in a stale block so there’s a possibility of the transaction to go back to the mempool

#186

What happens in the bitcoin network when two miners solve a block at the same time?
The chain forks temporarily
What is a stale block?
The block that gets droped from the blockchain because another block that was produced at the same time was part of a longer chain.
How do stale blocks occur?
When 2 valid blocks are mined at the same time, but is droped because the blockchain continues on another block that gets longer.
Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
Because the tx can be part of a staleblock that is droped from the chain.

#187

  1. When two miners solve a block at the same time the chain splits momentarily, then the network decides which will be included based on the difficulty level of the block and the length of the chain, longest chain wins and the other block is dropped. The discarded block transactions are brought back to the mempool.

  2. A stale block is a discarded block as a result of two blocks produced at the same time, two versions of the truth so to speak, the stale block’s transactions are brought back to the mempool.

  3. Stale blocks occur when two blocks are produced at the same time and the chain forks.

The chain will choose one block over the other. The rejected block is the stale block.

  1. It is important to wait for more than one block to be confirmed when sending or receiving a transaction because the transaction’s block can still be rejected,which, in turn, will make the transaction not valid. The longer one waits the less chances the block will be discarded.
#188

yes, it all depends on wich of those 2 competing blocks the next block will be mined. (wich forms a longer chain)
According to some video of Andreas Antonopolis, this happens approximately once a week.

#189

1shortest gone be droped!
2. Is the shorthes block been made by other miner at the samtime.
3… Mini g hppening 24/7 all around a world, inf. To work on is same!
4… To be sure it been taken from more nodes

#190

How can a “parent” be unknown…??

Thank you btw

#191 
1.The block propagates to the nodes closest to each miner. The blockchain forks until the next block(s) are created.  Eventually, the blockchain goes with the longest chain.  All of the transactions of the dropped block will be returned to the mempool.

2. Stale blocks contain valid data, but they are not accepted into the blockchain.  All of the transactions are returned to the mempool.

3.  When two blocks are created at the same time, then the blockchain forks.  Then new blocks are added.  The longer chain will be accepted.  The shorter chain consists of stale blocks.

4. If you wait for 6 confirmations, then you can be assured that your transaction was accepted.  If you don’t wait, the block could be dropped and become a stale block.
#192
  1. What happens in the bitcoin network when two miners solve a block at the same time?
  • the blocks A and B (which both are valid) are propagated to nodes which are confirming them.
  • when the node has received both A and B to confirm, it chooses the one representing highest PoW and drops the other.
  • the transactions of the dropped block is put back into the mempool.
  1. What is a stale block?
  • A block that is valid but it was mined with the same ancestor as another block. It got dropped/made stale by nodes because it represented the end of a chain with lower PoW spend.
  1. How do stale blocks occur?
  • A block that is valid but it was mined with the same ancestor as another block. The node dropped/made stale by putting the transactions back into the mempool.
  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
  • the transaction sent/received might be included in a stale block
  • the transaction is put back into the mempool so UTXOs are not yet updated.
  • waiting for 6 confirmations (praxis) usually ensures the transaction is in a block that will not be made stale.
#193

  1. What happens in the bitcoin network when two miners solve a block at the same time? - there is a split in the chain and the next block that is appended is kept as it is the longest chain.

  2. What is a stale block? - a stale block is the block that does not get appended to first and is dropped transactions are returned to the mempool.

  3. How do stale blocks occur? - they occur when more than one version of a block is solved at the same and is dropped if it is not the next block to be appended to.
    Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? - It is important to wait for multiple confirmations to ensure it is included in the longest chain and not in a block that is dropped.

#194
  1. both miner blocks are accepted until one block’s chain becomes longer
  2. a stale block is a block that was validly added to the chain but later rejected as a block of a shorter chain.
  3. when multiple miners solve the puzzle near the same time.
  4. to make sure the transaction block doesn’t get orphaned.
#195

The block that becomes the longest in ten minutes wins.
The blocks that were shorter are considered stale and return to the mempool
Stale blocks are blocks that were solved at the same time as other blocks and forked off but didn’t grow longer faster within ten minutes.
Waiting for six confirmations helps figure out which blocks have to be returned to the mempool as stale.

#196
  1. both blocks will be active on the network att the same time untill next block is created so that tha longsta chain win and become a part of the entire network
    2.stale block or orphanblock are the blocks that never got in the blockchain
    3.orphan block comes to be when two miners find the same nonce in the current block and the network is unsure on whit one to mine fuhter
    4.6 blocks is the regular confermation block amount to be sure that someone else cant invalidate your block
#197
  1. What happens in the bitcoin network when two miners solve a block at the same time?

There will be a temporary fork, after which the chain that is supported by the most computing power and therefore is the longest will be added to the blockchain. The blocks of the other chain will become orphan blocks. The transactions of the orphan blocks are no longer part of the blockchain and will be returned to the mempool.

  1. What is a stale block?

An orphan or stale block is a block that is not included in the blockchain and whose transactions are returned to the mempool.

  1. How do stale blocks occur?

They occur when two miners mine a valid block approximately at the same time.

  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

The longer it’s been since a block has been made, the higher the chance that this block won’t become a stale block, 6 confirmations is recommended.

#198
  1. The chain splits into two valid ends.
  2. A block that was dropped from the Blockchain due to an occurrence of a fork.
  3. They occur when two miners mine a valid block approximately at the same time.
  4. In case of the occurrence of two chains, once one chain is accepted as the main chain, the transactions of the loosing chain are returned back to the mempool.
#199

1- Their blocks are confirmed and added to the blockchain and start getting propagated to the network. This leads to having 2 different blockchains coexisting during a certain period of time until of one them is dropped by the network.

2- It is a valid block which was initially accepted and added to the blockchain and later rejected due to the existance of another competiting block which also got accepted and reused on another blockchain which became the accepted one by the network based on the PoW rule (the blockchain with most PoW is kept and the others are dropped).

3- It can happen that 2 miners add valid blocks to the blockchain at the same time. In this case 2 blockchain co-exist at the same time until one of them is dropped by the network which leads to stale block.

4- Because you can’t be certain that the block in which your transaction has been added won’t be stale. In which case your transaction will be sent back to the mempool and wait to be mined again.

#200

check this:
https://bitcoin.stackexchange.com/questions/5859/what-are-orphaned-and-stale-blocks
There are several definitions with overlapping meanings.

The first is perhaps best called extinct blocks. These are blocks that were produced by building on an block that is no longer the active tip of the chain. Some nodes may have considered it to be the best block at some point, but they switched to another chain which does not contain the relevant block anymore. They are valid, verified, and their ancestry up to the genesis block is fully known - they’re just not currently ‘active’. They are sometimes called stale blocks (typically in the context of mining software realizing it built on old data) or orphan blocks. The latter name originates from the fact that payouts from extinct blocks are denoted as “orphaned” in the reference client (referring to the fact that their coinbase transactions are now orphaned).

However, there also exist real orphan blocks, with orphan in its original meaning of “having no parent”. These are blocks received by a node that does not have its entire ancestry (yet) and thus cannot be validated. Nodes keep such blocks in memory, while asking their peers to fill in the gap of their history. The client does not show these, so when people talk about orphan blocks, they are most likely referring to extinct blocks. Note that since Bitcoin Core v0.10, there are no such orphan blocks anymore, due to a significant change in the download mechanism.

Terminology is confusing here :slight_smile:

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