Timed Quizzes websites like Sporcle have really taken off! There are just under 3,500 quizzes now on my original How Many Xs Can You Name In Y Minutes? post.

Unfortunately, due to both the growing popularity of these quizzes and growing personal commitments, it has become too difficult to manually update the list.

Don't worry though! I'm not going to leave Timed Quiz fans out in the dark! I've created an alternative automatic feed, which can now be found at:
http://feedstitch.com/1983/how-many-xs-can-you-name-in-y-minutes

You can subscribe its feed by entering the following address in your feed reader:
http://feedstitch.com/1983/how-many-xs-can-you-name-in-y-minutes.rss

The How Many Xs Can You Name In Y Minutes? widget has already been updated with the new feed, and my Timed Quizzes Dashboard Widget now links to this entry as its most recent entry.

I hope this doesn't cause too much confusion, so you can continue to enjoy your favorite sources of Timed Quizzes!

Yes, we're going to travel back in time, and re-visit some older feats to update them!

Our first stop back is also our farthest on our journey. In my Old Paths, New Directions post, I described my Psuedo-Phone Book Memorization feat. It used the props and instructions from a trick that, shortly after I posted that, went out of print.

However, I'm thrilled to announce that the missing trick, Meir Yedid's Predict-Perfect is now available again! For those of you who have Mind Blasters, the approach is similar to Stephen Jones' 1812 trick. However, Predict-Perfect comes complete with the props, as well as all the needed information spelled out.

Our next stop is a personal favorite of mine: the Day of the Week For Any Date Feat. I've been using iPhone version of Mental Case to keep the needed key numbers in my head, but there's really no way to set that program up to quiz you on random days while on the go.

There's also no iPhone app to quiz you on random days, either. However, I found one app that unintentionally works great for quizzing you on random days! It's a calendar app called This Day (iTunes link). If you hold your thumb across the days listed in the middle of the app, and shake the iPhone (or click on the Shake button), you'll get a random date (from 1600-3000) with the day of the week hidden. Determine the date as quickly as you can, and then lift your thumb to see if you're correct.

Back in March of 2006, I discussed non-transitive dice, and their amazing mathematical properties. Just last month, Scam School featured a non-transitive dice episode where you can see them in action:



Just to save you some Google-time, you can find non-transitive dice available in either a numbered version or a more traditional spotted version at Grand Illusions' Toy Shop. A great explanation of the dice, along with some great links, can be found in Ed Pegg's Tournament Dice article.

Funnily enough, instead of spending time either making your own non-transitive dice (as described in the above video) or buying them, you can do a non-transitive bet with regular coins, as described here, with a more complete explanation here.

Speaking of Scam School, they've also made this last update possible. I took a trick of Robert E. Neale's, called Election Game, and gave it a memory-demonstration presentation called Remembering The Election. Unfortunately, the resources I listed weren't easy to find, so there was little understanding of the feat.

Fortunately, Robert E. Neale recently gave permission to Scam School to teach his Rock-Paper-Scissors version of this same feat!



The principle, as well as the inspirational force, behind Remembering The Election is exactly the same as that of the Rock-Paper-Scissors trick above.

To make it clearer, imagine starting with the trick in the above video, and making the following changes:

1) We're going to move the trick from the bar to a stage.

2) The small props could be difficult to see on stage, so we're replacing the sugar packets ("Red", "Whitey" and "Bluto"), with audience volunteers.

3) Instead of having Rock, you have a card with the following qualities and descriptions on it:

Intelligence: Smart

Appearance: Plain

Personality: Average

(This card is remembered with the mnemonic SPA for "Smart/Plain/Average")

4) Instead of having Paper, you have a card with the following qualities and descriptions on it:

Intelligence: Dumb

Appearance: Average

Personality: Exciting

(This card is remembered with the mnemonic DAE for "Dumb/Average/Exciting")

5) Instead of having Scissors, you have a card with the following qualities and descriptions on it:

Intelligence: Average

Appearance: Handsome

Personality: Dull

(This card is remembered with the mnemonic AHeaD, with the small vowels ignored, for "Average/Handsome/Dull")

From here on out, everything is pretty much the same as in the Rock-Paper-Scissors effect, with the exceptions mentioned in the original article, and the fact it's being presented as a memory feat instead of mind reading.

Do you have any new touches for something you've discovered on this site? I'd love to hear about them in the comments!

Memorization scares many people, often because it was one of the hardest tasks for them in school. My first effort in making memorization easy for people who come here was the Memory Basics page, where links to free online memory courses can be found.

I've also included video memory lessons in my Free Online Memory Course Videos post.

Here's the newest free online video memory course I've discovered, produced by eduFire. It's called How To Remember Anything (in 6 parts), and is an excellent introduction to all the possibilities for improving your memory. It also includes an introduction to memorizing lists of things.



If you're just learning memory techniques, this is a great place to start. From here, any of the videos from my Free Online Memory Course Videos post are excellent choices for further study.

On March 5, Disney will release Tim Burton's Alice In Wonderland. As wild as the original Lewis Carroll books were, he just didn't make up the craziest stuff which crossed his mind.

There's a surprising amount of hidden jokes and even math hidden in the original works.

To start, enjoy the trailer of the upcoming movie:


Although the movie is titled Alice in Wonderland, it's actually about Alice returning to Wonderland after her previous adventures.

To get more enjoyment out of the movie, you should definitely read the original works, Alice's Adventures in Wonderland and Through the Looking-Glass, and What Alice Found There.

What about the math I mentioned that is hidden among all the nonsense and wild stories?

For the first example, in Chapter 2, Alice recites her multiplication tables: “Let me see: four times five is twelve, and four times six is thirteen, and four times seven is–oh dear! I shall never get to twenty at that rate!” This doesn't seem to make any sense! However, Alice is actually correct on all counts, if you take other number systems and bases into account. Not only do Alice's equations work out perfectly in other bases, they begin to fall apart eventually, and will never get to 20!

Why would Lewis Carroll sneak math into these stories? It turns out that the books themselves may have been a way to introduce mathematical concepts that were new at the time, such as imaginary numbers, to a younger generation.

If the mathematical aspects of Lewis Carroll's works intrigue you, Grey Matters' favorite author, Martin Gardner, has written two works I highly recommend: The Universe in a Handkerchief and The Annotated Alice: The Definitive Edition. The former focuses on all of Lewis Carroll's works relating to mathematics, and the latter focuses on his two Alice works, allowing the reader to get a deeper understanding of the meanings.

I've posted several times before on game theory, but I keep finding more and more interesting game theory works on the web.

My favorite game theory resource, Mind Your Decisions, teaches how to find cheap gas using game theory. When you have perfect information about gas rates, it's a simple matter of running the numbers through the right equations. However, the Mind Your Decisions article teaches a surprising way to find a good price without knowing the prices of all the local gas stations!

The gas approach was brought up by William Spaniel, whose excellent lectures on game theory are available on YouTube. Subscribe to JimBobJenkins' channel to get new ones as they become available. With the exception of the Terramorphic Expanse video (see video note), which was purposely posted out of order, the videos should be watched in the order they were posted.

Benjamin Polak's free Yale game theory course, which I mentioned last November, is still a good (and free!) course, as well.

Getting back to the Mind Your Decisions post about gas and cars, Bruce Bueno de Mesquita has used his game theory expertise to develop a car-buying approach that gives the advantage to you, instead of the car dealer. TED fans will recognize Bruce from his analysis of Iran's future.

For something called game theory, we sure haven't talked much about games as most people think of them, have we?

On very popular game is the popular Deal Or No Deal game show. Unlike many game shows, this one boils down to almost pure mathematics, and can be played as such. Game theory is well-suited to analyzing your best moves at any point in the game, as discussed in this chapter of Introduction to Game Theory. In Deal or No Deal: A Statistical Deal, an effective strategy is even developed and explained.

Once you read that strategy, you might wish you could try it out yourself. If your browser still supports Flash, you can play the official NBC online game. If you're on an iPhone or iPod Touch, you can play the free web app version in your browser, or buy the official native app.

As always, I hope you find these links fun, useful, and perhaps even educational.

Yes, it's time for February's snippets!

• So, you've mastered the Day For Any Date feat and 40 30s 4 15? Now, you take them both to the next level simultaneously with the 41 Puzzle Mint Calendar! This is basically a 41-piece version of the classic 15 puzzle, prepared as a calendar, and using extra icons that can be used to denote special days.

• I've certainly mentioned plenty of iPhone and iPod Touch flashcard programs to help your memory. However, now there's a memory-helping program of a different sort. It's called Memgellan (iTunes Link), and instead of quizzing you on Flashcards, it helps you develop mental journeys for the Journey and Loci memory systems. You can create and review journeys in this app, which helps you use them as mnemonic hooks later on. Take a look at this video to get a better idea of exactly what it does:



• Do you enjoy Sudoku, but get frustrated when you can't solve the puzzle you're working? Let Excel solve it for you! If you think Sudoku problems are too difficult for a spreadsheet program to solve, then you're in for a surprise. The Microsoft Excel team themselves show you how to do just this in their article Building a Basic, Understandable Sudoku Solver Using Excel Iterative Calculation (Part 1, Part 2). You may or may not be able to adapt this technique to other spreadsheets, since it largely depends on iterative calculations.

• This entry could only be last, because part of it will seem like snippets-within-snippets! Check out Clifford A. Pickover's site. If his name doesn't ring a bell, the best place to start is his About section, of course. However, you should explore the site as a whole. Regular Grey Matters readers will definitely enjoy the Alien Tiles Puzzle and the Reality Carnival. I'm currently reading his Math Book (yep, that's the real name!), which seems to teach me something new everytime I open it!

Have you found anything you'd like to share with Grey Matters readers? Let's hear about them in the comments!

Yep, I'm posting a day late. Why? On Feb. 8th, 1910, the Boy Scouts of America was first incorporated. They're 100 years old today!

I was a Boy Scout myself, and have many fond memories of those years. One of the things scouting is definitely responsible for was helping instill a love of the art of magic.

Sure, TV specials featuring magicians helped quite a bit, but I really didn't get into it until I learned from Bill Severn's magic column (click any issue to see its magic column) in Boys' Life magazine. It was there that I truly learned the difference between how an audience perceives magic and what is actually happening.

During my Cub Scout years, I went for my magic merit badge (yes, there really is one), and I performed a trick where someone stacked 3 dice, and I could instantly give the total of all the hidden sides. Admittedly, I've been a math and magic geek for a long time now. Given the basic idea of the routine, can you figure out how it was done?

Funnily enough, just a few short years after my time in scouting, Bill Severn wrote up a trio of dice tricks that probably would've made my routine even better.

It's kind of fun looking back in Boys' Life at other interests I've developed since my scouting days. Originally, I don't think I noticed many of the memory articles, but they sure are interesting to read now.

Happy 100th Birthday, Boy Scouts of America!

BetterExplained, as regular Grey Matters readers will know, not only teaches math, but teaches it in such a way that you get that "A-ha!" experience while learning about it. Such math resources are both valuable and rare.

Another such great resource debuted just recently in the New York Times. They've added a new columnist, Steven Strogatz (pictured at the intro to this article), to discuss mathematical matters.

His first column is titled From Fish To Infinity, starts at the perfect place: the beginning. The attitude in this piece is that if we're going to deal with math, let's start by understanding what numbers are and why we use them.

While this could be a very technical discussion, Mr. Strogatz illustrates it so simply, that the main point is illustrated with a skit from Sesame Street. I often talk about difficult mathematical concepts, so it's quite nice to have someone explain things simply, clearly, and from a shared starting point.

If you're curious about what kind of discussions you can expect from his column in the future, he already has already several online videos available. I especially enjoyed his TED Talk on how things in nature tend to sync up:



Whether you enjoy mathematics, or just want to learn about them clearly and understandably, my top 3 recommendations for doing so are now these (in alphabetical order): Beauty and Mathematics DVDs, BetterExplained blog, and Steven Strogatz' NYTimes column.