Comments by "SAL" (@SAL-fs1mr) on "3Blue1Brown" channel.

  1. The majority of Bitcoin mining is done with green renewable energy, so Bitcoin should be the last industry SJW's have a problem with.
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  2. Traditional currencies are easily debased by central banks printing more and more. Bitcoin's fixed supply makes it "harder" than traditional currencies. People just do trades of fiat currencies for bitcoin. If you paid someone dollars for bitcoin, they now have the dollars and you have the bitcoin.
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  3. The first block of bitcoin, known as the genesis block, was published by satoshi with a news paper headline to indicate a transparent method of the start date (Jan 3rd 2009). The coins from this first block we're not spendable. Then block mining proceeded normally after that.
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  4. Not quite, you need to combine the random nonce number with parameters of the previous block and then generate a hash to get x number of leading zeroes. It will therefore be a new puzzle for each new block.
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  5. incorrect, that is not enough money to have control over bitcoin.
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  6. secret keys are not meant to be displayed - instead what is being used is called a "digital signature" - which proves you have the private key without revealing it.
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  7. A miner will choose to build on the chain that already has the most proof of work mining. If they do have the same amount of proof of work, then the miner will choose to build on the block they saw first, because it is likely also the block that got propagated most widely to the rest of the network.
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  8. Emailing random people is definitely a great way to get scammed.
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  9. It simplifies to this: a transaction with a higher fee is more likely to be included in the next mined block whereas transactions with low fees will be sitting in the "mempool" until a miner feels it is worth including into a block, which is fine for people who are in no rush and can wait.
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  10. Both. A message in bitcoin would be either transactions (each transaction consisting of x address paying y amount to z address, along with the unforgeable digital signature) or blocks (bundles of transactions to be added to the blockchain).
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  11. If they transactions are valid, they will be picked up by miners and included in a block on the longest chain.
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  12. All transactions are broadcast to everyone on the network and are kept in the "mempool" until a miner takes them and puts them in a block they mine.
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  13.  @paviad  correct, as more time passes, you can be more confident about it being in the longest valid chain.
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  14. Hyperledger fabric is a completely permissioned system that requires trusting others.
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  15.  @amanpradhan2809  in bitcoin, the consensus mechanism (proof of work) is open to everyone and verifiable by everyone. Hyperledger consensus mechanism is whatever those setting up the new network want it to be - which usually means a small privileged group in control of their hyperledger network. It is not open to everyone.
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  16.  @amanpradhan2809  those are just terms used to describe how the nodes in the closed network group reach consensus. This approach to consensus is rather limited in decentralization because it assumes a relatively high degree of trust among the nodes/servers in the closed network. I don't think hyperledger is a good starting point to understand consensus protocols - Here's why: Think back to when the internet was getting started. There were the OPEN internet protocols that anyone could join. There were also those who thought that the CLOSED/PERMISSIONED inTRAnet approach was going to be more significant. However, we know the inTERnet with open network architecture, was far more impactful on society rather than the small, closed, permissioned inTRAnet approaches. The smart people didn't waste time on intranet until they first understood internet. So if you are interested in learning network consensus, I would recommend starting with understanding the OPEN consensus networks (mainly Bitcoin, and then maybe Ethereum), because they are very likely going to have a much more meaningful global impact rather than the limited, closed, permissioned consensus models such as hyperledger. The book "Mastering Bitcoin" by Andreas Antonolopous is available for free online on GitHub. I would start there.
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  17.  @amanpradhan2809  the first dapp you should try to write is a bitcoin wallet (outlined in the book I already recommended). I would suggest you look into BitcoinJ library to program bitcoin using Java.
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  18. Miners and people running full nodes know which is the real blockchain by seeing if it has followed all the consensus rules and it has the most proof of work mining behind it.
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  19. It's actually working perfectly as outlined.
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  20. No, the majority of Bitcoin mining is done with green renewable energy, not coal. Coal was the major source of Chinese Bitcoin mining, but china banned all Bitcoin mining.
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  21. Some blockchains are centrally managed, so yes those can be shutdown by closing the company or organization running it. But Bitcoin is a decentralized system, so the only way to restrict or stop bitcoin is by shutting the entire internet down forever.
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  22. Duh, it's because the altcoins are NOT better. Speed and fees are already solved with sidechains and lightning network.
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  23. sachinsurya007 if a block doesn't follow the rules of the network, then is is simply ignored. All network nodes are always checking in real time. You can run a node on your laptop to check the work of the miners.
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  24. If you want to do so without trusting any third party, then the answer is yes. Maintaining a fully synced up copy of the entire blockchain is known as running a full node. Your node can tally up the bitcoins of your addresses to show your balance. This is actually the key feature that makes bitcoin unique compared to all other previous forms of money - you can easily do full validation of the entire system yourself without relying on any third party! Unfortunately, most people are lazy and do choose to rely on other services to tell them their balance. Even worse off are people who store their coins with trusted central entities, which make them a big target for hackers.
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  25. Yes, you seem to have a good understanding of how it works. I like to think of each block in the blockchain as a "page in the ledger". In general, the order isn't important within a specific block. Sometimes however a specific set of connected transactions all happen quickly before a block is mined. It is possible that A sent to B, and B sent to C, and C sent to D before a block is mined, at which point all 3 transactions will be mined together and will be listed in order within the same block (the transactions will reference each other within that one block). Each block contains a hash of the previous block. New transactions need to reference past transaction outputs (from previous blocks) that were unspent until now.
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  26. Perhaps, but then all bitcoin would need is a simple upgrade to a quantum resistant algorithm, problem solved!
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  27. All the other 'better' algorithms out there are much less secure.
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  28. A miner has to show they have a valid proof of work (energy expenditure) before they can get a reward from the network.
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  29. Starting with the zeroes is what the network accepts, it means heavy computational work was done to find the block that has the transaction. Anyone can easily spit out a random hash that starts with any random sequence of 1s and 0s, but finding a hash with 60 leading zeroes is very computationally expensive.
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  30. With shorter block times, there is a much higher chance of competing blocks being mined simultaneously, but since only one block will win at any given height, it leads to wasted mining. This also creates more short-term uncertainty about transactions being confirmed because competing blocks could easily have different transactions in them.
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  31. jk jk the difficulty for mining is dynamic, based on how much mining power is currently mining.
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  32. We know them. Look up how cryptographic hash functions work. Bitcoin uses SHA256.
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  33.  @sagethephoenix7494  these are one-way asymmetric mathematical functions. so any input can be quickly verified to see if it produced the correct output, but you can't use an output to figure out the input.
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  34. Each new block is going to have a hash of the previous block.
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  35.  @toasty9757  right, so doing that check shows that the altered first block needs to be regarded as invalid with the blockchain. The network is going to always follow the chain with the most cumulative proof of work mining that adheres to the protocol rules.
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  36.  Dirk Knight  that's not really accurate. You do your own validation on your own computer to make sure you are not accepting invalid blocks.
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  37. The initial blocks didn't have any transactions. Even today, miners can choose to not have any transactions in any blocks (but they will forfeit the fees from the transactions by doing so, so it doesn't really happen much at all). There was no initial bitcoin, all bitcoins had to be mined.
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  38. 1 confirm means that the payment has been included in the latest block. Any number of confirmations thereafter means more blocks have been added since.
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  39. A person mining uses computer hardware, electricity, and mining software, to do the proof of work hash function as outlined in the video here.
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  40. To scale Bitcoin to handle tens of thousands of transactions every second, people are talking about "second layer protocols" which would include things like the Lightning Network and sidechains. With these type of solutions, each regular blockchain transaction could be used as a way to power the second layer to boost throughput a thousand fold. You are correct about miners putting the transactions they choose. All the transactions that are not yet included in a block sit in a data structure called the "mempool", That is where they sit and wait for a miner to include them in a block.
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  41. "Alice and Bob" is the go to example that has been used in computer science for many decades. Kind of like how in algebra is is usually "find X".
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  42. But isn't that how all money work? We all have to believe it's valuable.
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  43. The blocks are braodcast on a peer to peer network - basically, the block is sent to all network nodes the miner is connected to and all those nodes send the block to all nodes they are connected to, etc. Etc.
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  44. The private key is used to create a digital signature that proves it belongs to a specific public key without revealing itself! It is crazy mathematical stuff, but it works! Look up how public key cryptography works.
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  45. You are correct that the ledger only stores the public key (or the public address rather), but the main point you might be missing is that each public key is derived from a specific private key! So when a transaction is signed with a private key, it is possible to check the digital signature against the public key without needing to see the private key!
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  46. When Alice signs her transaction - she creates a DIGITAL SIGNATURE that can be verified for accuracy by comparing it to the corresponding PUBLIC KEY, thus, the private key never needs to be revealed! I would urge you to look up a video about how public key cryptography works :)
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  47. Yes, a unique digital signature is created for each transaction. Public keys are derived from their corresponding private keys. Basically, you generate a random string as your private key, and from that key, you create a public key/address (and this is what you give to people so that they can send you bitcoin). It is always the sender of coins that creates a digital signature indicating how much of their bitcoin tied to their public address gets transferred to the receiver's address.
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  48. Maybe in 20 years they'll be good enough to do that. But at that point, bitcoin would have just upgraded to a quantum resistant algorithm.
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  49. Correct, it isn't exactly efficient, but it is what is necessary to achieve a decentralized payment network. But if widely adopted, then the efficiency will come in the form of making banks obsolete for payments.
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  50.  @paulgibby6932  do you also go around telling people that putting up Christmas lights is a waste of time and energy? Maybe someone might tell you that watching YouTube is a waste of time and energy. Ultimately, it's up to each person to decide what they determine to be wasteful or useful with their time and the energy they paid for.
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