Sunday, April 13, 2014

How Bitcoin Works in 5 Minutes

This is a shorter version of my original "How Bitcoin Works Under the Hood" 22 minute video, and it's also geared more towards non-programmers.


Video




If, instead of how it works, you're looking for where to buy Bitcoin, I use coinbase. And for trading, check out bitcoin wealth alliance (both affiliate links).

Introduction

At a very basic level, Bitcoin is just a digital file or ledger that contains names and balances, and people exchange money by changing this file. When Bob sells Carol a lawn mower for 5.2 Bitcoins, Bob’s balance goes up by 5.2, and Carol’s down by 5.2. There’s no gold or government issued money backing these numbers. Bob is only willing to trade his real-life lawn mower for a higher number in this digital file because he has faith that other people will also trust the system.

So who maintains this ledger and makes sure no one cheats? One goal of Bitcoin is to avoid any centralized control, so every participant maintains their own copy of the ledger. One surprising consequence of this is that everyone can see everyone else’s balances, although the real system only uses account numbers and not names, so there’s some level of anonymity.

If everyone maintains their own ledger, how are all the ledgers kept in sync as money is transferred? At a basic level, when you want to send money, you simply tell everyone else by broadcasting a message with your account number, the receiver’s, and the amount. Everyone across the entire world then updates their ledger.

As a quick aside,  I’m describing how Bitcoin works for power users--people who help maintain the system. You can also just use the system to send a receive money, however, without maintaining a ledger.

Account Security

If sending money is as simple as creating a message with some account numbers, what’s to stop a thief, Alice, from spending Bob’s money by using his account number?  Like a pen and paper check, Bitcoin requires a kind of signature to prove that the sender is the real owner of an account, but it’s based on math rather than handwriting.

Sunday, March 16, 2014

How I Moderate Discussions about Controversial Topics in Large Groups

I run a meetup group called Controversial Topic Discussion Club in Atlanta. Complete strangers from college age to retired come together regularly to discuss topics like gun control, abortion, drug legalization, charter schools, religion, and many more. The group size ranges from 8 to 40. Having run over 50 events over 5 years, and watching several others help moderate events, I wanted to share my learnings about moderating discussions to keep them respectful, fair and moving.

Before getting into the details, I want to clarify that the goal of our discussions may be different than the goal of moderating a business meeting, where you might be trying to reach a decision. Our group is more focused on learning rather than reaching any consensus, or changing anyone's mind. We're also more interested in just having a good time rather than detailing out the next health care bill, so I would rather let an interesting conversation meander rather than keep it laser focused.

Preparation


Before each meeting, I prepare a list of sub-topics, questions or interesting facts that I can use to re-start conversations. For example, on our Obamacare event, here are some of my sub-topics and questions: