Not a lot of new content here recently. The last days, I attended 37c3, the annual hacker convention of the Chaos Computer Club which took place again in Hamburg . So, today, we will have some engineering content rather than the usual physics one.
You have to see the super entertaining talk by two guys who built their own submarine from scratch.
There is a video of their presentation (including English translation) they have a website and there is a documentary about their project.
Money quote: “What distinguishes submarines from other boats is that they can surface again.”