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Puzzles, situation puzzles and recreational mathematics.

situation puzzles and recreational mathematics. Neuron juice

Neuron juice.

The important thing is not to stop questioning. (Albert Einstein.)


 July 2015.

The number of visits to Neuron Juice from mobile devices has overtaken the visits from PC, so I will begin to change the desktop view in order to adapt it to those devices, although some pages will remain the same due to the huge number of HTML pages.


January 2012

        After some years without updating the site, I have spent my free time over last Christmas changing the format of Situation puzzles. Riddles, optical illusions and impossible objects can now be visited in a new page with a new design.

        Riddles, optical illusions and impossible objects

        This section in Neuron Juice is updated to follow the tendency of Web 2.0. What before was written here (few stuff, I know), will now be written in the blog of Neuron Juice.

        Situation puzzles blog.


October 2007 (II)

        Two new sections have been added to Neuron Juice. The first one is devoted to number pi, Although at first sight it seems to have nothing to do with recreational mathematics, over the history of maths many people has 'had fun' looking for more and more decimals, and nowadays they are still been looked for.

        The other section of this new update is devoted to prime numbers, more or less due to the same reason as Pi although in this case nowadays looking for new prime numbers has began a business rather than a pastime because of their use in encryption systems.


October 2007

        The design change in Neuron Juice has successfully come to an end. More than 100 HTML pages have been modified one by one, correcting all the code in order to get this icon to show correctly:

Valid XHTML 1.0 Transitional

        The whole site is codified in XHTML 1.0 Strict, the latest standard of the World Wide Web Consortium. The exception is the section of simulators —being programmed in Java, which doesn't allow the strict standard, they have been left in XHTML Transitional, validated too.

        There is another exception, which is yet to be solved, is the homepage. Although it is completely operational and has no display problems, it doesn't meet the standard. That is the price I have to pay to include the Google search engine.


September 2007

        Neuron Juice was born in 1999 with the objective of organizing and sharing the riddles and situation puzzles I had in my mind or in my small collection. Later on, this site began to grow: first, I included the game simulators that had something to do with cleverness or at least would make you think; then, other things that attracted my attention, kaleidocycles, mathematical magic, small printable puzzles to assemble objects, etc. Finally, with the last update, I added impossible images or figures, optical illusions and palindromes. aims to be an alive site. Even though it is not frequently updated, I will add everything I run into that attracts my attention and is related to the content of Neuron Juice, the recreational mathematics.

        After not changing the design of for 8 years, now has come the day to make a big change, especially due to the changes in html standard. Neuron Juice had (and still has) many code mistakes which I would love to eliminate even if they don't cause display problems. The first version was written in HTML with taking into account any code validation, the important point was for it to be shown. Now this will slowly change into XHTML Strict and validated by



June 1999

        As you might have already realized, the content of Neuron Juice is composed by situation puzzles, riddles or pastimes. Although I have been into these games for years, my collection had just 10 of them until I met 'El Ocho Tumbado', the best site in Spanish I have visited about this subject so far. As well, the 'Orden en el Caos' distribution list (the club of the puzzles) has been helpful for me to know more about these fascinating and educational pastimes.

        The HTML code has been edited using just Windows Notepad, and the HTML manual by Webmaestro has been very helpful.

        On May 30, 1999 these pages were sent for the first time to the server so they were placed at the disposal of all their possible readers. Since then, the content has been increased and the desktop view has been changed as my little knowledge in HTML has broadened. I'm sure there must be mistakes —I trust you will forgive me and tell me so I can solve them.

        I hope you enjoy your visit to these pages.