Winston Churchill liked his chocolate and he liked it rich and dark. At least that is what Hitler must have been convinced of as he decided to lure the British prime minister not with cigars but with dark chocolate. Churchill barely escaped his death by chocolate and went on to win the Nobel Prize in literature.

Coincidence?

Well, kind of. David Wineland and Serge Haroche have not endangered any living beings. That is to say: probably not in their physics experiments. 

Yet, although they stayed at a safe distance from bringing life form into quantum superposition, both physicists have thoroughly explored the schizophrenic world of the quantum, and opened the door to the direct observation and manipulation of quantum superpositions. By cleverly exploiting the fundamental interaction between light and matter, the two quantum optics experts have managed to pull off a range of experiments in which Schrödinger's cat states lead to bizarre results.

The deeper we look into the universe, the deeper we look back in time. When in the night sky you see planets like Jupiter and Saturn, you look about an hour back in time. Look at the stars, and you are looking back in time anywhere from years to several centuries. Bring a binocular to a dark site and you will be able to see galaxies millions of years back in time. Get a decent telescope to the same site and you look even further back.

In the previous blog post we discussed entropy. I provided you with a less well-known perspective on entropy and demonstrated that this generic perspective is fully compatible with the more traditional (and more narrow) thermodynamics view on entropy.

I promised you a toy model to elucidate the information-theoretical entropy that was introduced. You have been waiting patiently, and you get your new toy today. But before we start playing, let's test your patience for a few more minutes, and first expand upon the results obtained in the previous blog post.

Trivializing The Second law

Entropy. A subject that comes back again and again and again and again and again in this blog. And so does the question in my inbox: "what exactly is entropy?" On the internet you can find a plethora of answers to this question. The quality of the answers ranges from 'plain nonsense' to 'almost right'.