What are Uncles in Ethereum ?

Recently I started learning blockchain and related technologies. There is SO MUCH to learn. I started with blockchain basics (and it inevitably uses bitcoin as an example) If you are new to blockchain (not ZERO knowledge) I recommend you checkout the blockchain demo It is one thing to say you can not modify “old” blocks, but visualizing it really makes the difference. (It is important to understand it for the topic under discussion)

Prize Linked Savings Account

Prize Linked Savings

Recently I heard an episode on Freakonomics podcast called “No-lose Lottery”. You can listen to the episode here

Apparently, this is a rebroadcast. Original episode was in 2010.

But those details aside, this post is to quickly summarize the concept of “Prize Linked Savings Account”

What is mix.lock file

In past, I have seen several processes create .lock files, to usually write pid of the process. e.g. Emacs desktop package creates .emacs.desktop.lock file to save the PID of the emacs instance that created this file. Eventually, it will use this to ensure that no other instance overwrites it, and also gives a warning as such. There have been other instances we well. So when I started working on elixir, I always ignored mix.

Change the default Screen shot location for macOS

By default, macOS saves all screenshots to the ~/Desktop. If you'd like screen shots to be saved somewhere else, you have to configure it manually from the terminal. For instance, if you'd like your screenshots to be saved in the ~/screenshots directory, then enter the following commands: 1 2 3 $ mkdir ~/screenshots $ defaults write com.apple.screencapture location ~/screenshots $ killall SystemUIServer source

SMTPAuthenticationError : 534

One of the website suddenly stopped sending emails from the “Contact Us” form My fellow engineer tried to debug the problem, but could not. so I stepped in. The first thing I tried was to verify that the username/password was correct, by logging into the gmail account via the browser. It was. So then I considered changing to TLS from SSL, but before I did that on production setup, I decided to do all the trials locally.