Madoff is condemned. Good, he is the biggest swindler of all time. However, in this Madoff case the real question is: isn’t our western society a huge Ponzi scheme? Specifically, aren’t our insurances huge Ponzi schemes (Pension, unemployment, health (Medicare), but also finance, car and home insurances)?
The founding principle of an insurance is: one (young, employed, rich and healthy) pay for the others, provided that most people are young, employed, and healthy*. Even for private insurances (cars, home…) the principle is the same, everybody contributes, only a few people need insurance reimbursements. That is, some pay for the others. So what is the link with a Ponzi scheme? “Newcomers pay for the old ones”. Yes, it is the same!

I have been using Twitter only for a couple of months and I love it. Here is why.

The twittosphere is a thinkosphere

A tweet pretends to be an answer to the question “what are you doing?”. But clearly people answer the questions “What are you thinking about?”. For instance they post a link to an article they are reading, they post a link to a blog post they wrote. They tell you what they like or dislike.
At some point people were indeed telling what they were doing. A lot of tweets as fascinating as “I am eating an apple” or “I am going to brush my teeth” were made. But, as you guess, this quickly bored people and so they started elevating the debate, by speaking about technology, politics, news etc.
So Twitter is a set of thoughts. It is a sphere of thoughts, it is a … thinkosphere. I have been (slowly) developing a website called ThinkoSphere for a few years now. So you see why I can only love Twitter. For those who wonder, I’ll come back in a future post on the main similarities and differences between ThinkoSphere and Twitter. Twitter is called a microblogging application. Well, a micropost for a blog is nothing else than a thought. A tweet is a “Quantum of thought”, taking the expression from this very good article: The Future of Social Media: Is a Tweet the New Size of a Thought? by Wired.

When I started the blog post series about autopilots, I did not think flight control systems would become that of a hot subject. And seen the horrible tragedy of Air France flight AF447, I would have preferred it to remain a technical subject for specialist and not something that is in all the media.

It’s time to get the conclusion of this Guidance, Navigation and Control post series.

Conclusion

To sum up:

1. Navigation System (NS): Where are you?
2. Control System (CS): How are you?
3. Guidance System (GS): What are you up to?

And finally, “do not put the cart before the horse”. The cart is the guidance system, the horse is the control system. A good guidance without a good control is totally useless. A good plan is nothing without a good pilot. I’d rather fly in an aircraft with a good Stability and Control System and a poor Guidance System than the opposite. In the first case you might not reach your wanted destination, in the second case you will crash!
We live in an economic world with a lot of guidance and very little control. That is why the finance world totally collapsed, leading us to the current global crisis. More details in a future post…

This post is part of a series about Guidance, Navigation and Control. See the table of contents here.
3 parts are in this post because they are shorter:

• About the human pilot (with fresh news: man in an Unmanned Aerial Vehicle is for “soon”)
• About GNC wordings
• About the various control loops

This post is part of a series about Guidance, Navigation and Control. See the table of contents here.

Paris.rb, local ruby brigad of Ruby France association, is organizing its 12th “Apéro Ruby”.

The 12th Ruby meetup will happen on Wednesday, May 20th, starting at 8pm, at Dune, 18, Claude Vellefaux 75010 Paris, Métro Colonel Fabien or Métro Goncourt (see map or see on Google Maps).

Some good reasons to meet up may be:

• Rails 3 alpha
• RailsConf 09 which finished recently

Contact Cyril Mougel (Shingara) if you wish to do a little talk.

You can bring your laptop with you if you want to hack or debug Ruby code.

I’ll be there, see you there.

Original message from Shingara, in French.

This post is part of a series about Guidance, Navigation and Control. See the table of contents here.

This post is part of a series about Guidance, Navigation and Control. See the table of contents here.

Guidance, Navigation and Control are often together. It makes perfect sense because all three of them depend on control theory and because they are the components of the software part of a Control System. But do you clearly know the differences between Guidance, Navigation and Control? I am going to explain them taking the example of an aircraft. In future posts I will take other examples such as a company, a country government or the go game. This series of posts is a follow up of Control Systems 101.