udacity / blockchain-nanodegree-issues

Issues for Udacity's Blockchain Nanodegree program

blockchain-nanodegree-issues

Issues for Udacity's Blockchain Nanodegree program.

Take this consideration in order to submit a bug

• Try to specify in the title exact problem found.
• Try to copy the classroom link.
• Try to add further descriptions

Archival Note

This repository is deprecated; therefore, we are going to archive it. However, learners will be able to fork it to their personal Github account but cannot submit PRs to this repository. If you have any issues or suggestions to make, feel free to:

• Utilize the https://knowledge.udacity.com/ forum to seek help on content-specific issues.
• Submit a support ticket along with the link to your forked repository if (learners are) blocked for other reasons. Here are the links for the retail consumers and enterprise learners.

blockchain-nanodegree-issues's Issues

Lesson 6.Chapter 13 the blockcypher website does not function

I verified I am on testnet but transactions on the site look old and searching my tx id finds no matches. I think their site is broken.

Lesson 3

(beta) Course 3, Lesson 2, Concept 2

Note was added to the bottom of the Video.

Lesson 9, Video 1: Missing text

Brandy mentions there will be details of public and private blockchains listed below the video, nothing there unfortunately.

lesson5 9. question3 have not correct answer

Lesson 2. Concept 6 Blocks

In the Video minute: 2:46 the instructor says that from the Merkle Root "we can reverse the hash to reconstruct the entire set of transactions from the original block" We should change this part because a hash can never be reversed, we need to change the video or add an explanation note about this.

Knowledge: Nanodegree missing in filter

Knowledge has nanodegree filters but I can't find "blockchain nanodegree" in it (even in create post filter, which should ideally be same)

Jul 11, 2018 5. Blockchain Data Overview

Subtitle Typo Lesson 2, Concept 11

Proof of Work Video in the minute 2:06 "node" -> "nonce"

typo

Second paragraph in Hashing

Coming up, we'll discuss what hashing is, why it's important, and the basics of how it (the?) hashing helps contribute to the structure of the blockchain.

"Proof of work overview" video subtitles: "nodes" instead of "nonce"

At 1:34, "Miners are trying to find the nodes for every new block" ... it should be "find the nonce"

(beta) Course 3, Lesson 1, Concept 2

Note was left at the bottom of the Video

(beta) Course 3, Lesson 1, Concept 3

Note was added to the bottom of the video.

Lessons 8.16 and 8.17: should use the result hash of the signrawtransaction

After signing the raw transaction, the "result hash" should be used in the following commands... Instead, the decoderawtransaction and sendrawtransation commands still use the old hash (the one that is not signed) ...

Lesson 5: "Explore Blockchain JSON data" video subtitles

At 2:15, it should be "vout" instead of "VL"

Lesson 3: "Sign a Transaction Overview" video subtitles

At 0:00, "wallet" instead of "while it"
At 5:34, "mem pool" instead of "memorable"

"Memory Pool Overview" video subtitles: "minors" instead of "miners"

The subtitles have the word "minors" instead of "miners"

Lesson 2: "DBFT overview" video subtitles

At 3:34, I think it should start with "newer mechanisms" instead of "NEO mechanisms"

lesson6 8. screenshot "prune=55"

should be "prune=550"

Blockchain Basics: 10 Consensus

POW: proof of work
DOW: proof of stake
DBFT:????, is this right?I think it's PBFT

Lesson7. 8: incorrect answer for mempool quiz?

getmempoolinfo does not returns the list of transaction IDs ... The correct answer should be the one in the middle of the list, right?

Lesson 5.Chapter 8 - Missing link below the video about Bitcoin developer glossary

In this video https://youtu.be/aNSwRWpd8L0, the instructor said: "If you are curious, you can go to the Bitcoin developer glossary to learn more. We put a link to this down below the video".

However, no link found below the video in Lesson 5.Chapter 8.

Problem Set: Bitcoin Codebase Questions Answers Are Related to Litecoin Source Code

Under the Explore Bitcoins Codebase section. The 3 questions under 'Problem Set: Bitcoin Codebase' the answers refer to the the Litecoin source code rather than the bitcoin source code stated in the question.

Transcript

Is there a way to get transcripts for each video? I try to take notes as I go through the videos, but that's taking an excessive amount of time.

The chat-button covers the titles

The chat button in the left panel covers the titles of the current lesson.

Lesson 7, Video 14: Text missing

'Feel free to read through the text below the video'

--Unfortunately no text

Lesson 5: "Interview: How to Get Involved" video subtitles

At 0:56, it should be "block sizes" instead of "Buck sites"

Probably documentation missing?

Lesson 9, in the Introductory video the instructor said that is going to be more detail about cryptography down bellow the video, but there is nothing there, is missing any link to documentation?

Incorrect answer for Lesson 7, Chap 6 "What is the merkle root for block 1000?"

The correct Merkle Root is none of the available options.

Since I cannot upload an image of my console, here's a link to a third-party site showing the merkle root for Block 1000:

https://blockexplorer.com/block/00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09

knowledge bar lightbulb missing

In lesson 1 part 7 (nanodegree resources) the lesson states that "You should be able to access Knowledge anytime by clicking on the lightbulb on the left hand side of the classroom." I am not able to find the lightbulb, and another user in the classroom chat mentioned that they could not see it either.

Lesson 1 part 4: Sierra Leone election

In Lesson 1, part 4 Influence of BlockChain, there's an incorrect reference to Sierra Leone having hosted world's first blockchain powered election. They did demonstrate a use-case for this, but never actually used it in the election. More on this - https://techcrunch.com/2018/03/19/sierra-leone-government-denies-the-role-of-blockchain-in-its-recent-election/

Lesson5 9. question1 pszTimestamp answer is wrong

Lesson 2: "Proof of Stake Overview" video subtitles

At 3:16, it should be "create blocks" instead of "create box"

Lesson 7-10 the quiz incorrectly requires "hex"

"hex" is listed as an output from the function, not an argument. Either it should not be required or it should be another argument such as "hexstring"

Lesson 2: "Problems with Proof of Work" video subtitles

At 1:07, it should be "rigs" instead of "rays"

Lesson 7, Video 4 BIP link incorrect

The link to BIPs mentioned in video 4 (Blockchain Commands) is placed underneath the previous video (Debug Console).

Lesson 6: "Bitcoin Core - Overview" video subtitles

At 1:45, it sounds like "full node" instead of "4-node"

Broken Link- blockexplorer.com

https://classroom.udacity.com/nanodegrees/nd1309/parts/c27351e7-b0ea-480c-bde9-a936817e4fe4/modules/0af5bc78-b446-4b60-b9cd-8659536cd59f/lessons/808abc06-4959-499c-9c31-54be1838096f/concepts/2638b316-58fb-48b3-b2a9-5730bfae8c14

Lesson 5: Blockchain Data Overview
8. Explore Blockchain Data

blockexplorer.com gives 404.

Thank you!

Jul 12, 2018 Lesson 9

(beta) Course 3, Lesson 1, Concept 3

Note was wrote bellow the video

Lesson 3, Concept 8 - Restoring Blockchain Identity

BitcoinElectrum.com is linked vice versa on Importing and Sweeping your private key external link

Course 2, Concept 7. Blockchain

Lesson 3: "Blockchain Transaction Lifecycle" video subtitles

At 0:32, "spans" instead of "spends"
At 1:09, "signs his" instead of "scientists"
At 1:30. "block gains" instead of "bargains"

Lesson 3: "Non-Deterministic Wallets" video subtitles

At 1:47, "determined" instead of "chairman"

One resource link does not work in Lesson 2 / 5 Hashing

Under "Resources"

The link of "Bitcoin Hash Wiki" is incorrect:
ttps://en.bitcoin.it/wiki/Hash
(the "h" is missing from the beginning).

Explore Bitcoin's Codebase Quiz

Lesson 3: "Blockchain Identity Overview" video subtitles

At 3:15, "it shouldn't" instead of "it should"
At 4:14, "our private key" instead of "or private key"

Lesson 6.Chapter 12 sending/receiving wallet identical

If you follow the instructions both wallets are copies of the original wallet.dat. As a result you see the same balance in both and you immediately "receive" the coins in the sending wallet. To do it properly, you have to set the wallet filename in the config but not copy the wallet.dat file. Instead, let the client create the wallet for you for each of them, which it does automatically when you start the gui.

Can you please use UTC time zone

Hi
When putting times on events etc can you also use the UTC timezone. This makes it much easier for those of us not in the USA

Hashing Demo audio

The audio for Hashing Demo video comes only from the left ear. I think something went wrong when the team rendered the video.