Update 10/13/09: corrected for ice cream flavor and location, thus merging two related universes.

There is a story about Richard Feynman that while he was at Princeton MIT he had a hard time with dessert. Apparently they always served either chocolate or vanilla ice cream and Feynman would agonize over which he wanted that night. Then one day he decided that he was wasting his time making this decision and so he would solve this by only choosing vanilla chocolate and from that point on in life that is what he did. He no longer wasted time choosing, and, apparently, ate a lot of vanilla chocolate ice cream. Of course there is an equally valid and equally elegant solution to this problem which is in fact the exact opposite of Feynman's deterministic solution: choose randomly! Chocolate or vanilla? Choose randomly. Stop at the stop sign or not? Choose randomly (okay maybe not!) Of course there is the question of exactly how you choose randomly. For some, dice may suffice, but isn't there a better way than carrying around a bag of dice which makes you look like your heading out for a night of RPGing?

Well today I'm happy to report to you that there is a solution to this problem: use your iPhone! As many of you know, when I'm stuck on a plane I like to write iPhone apps (thus leading to my app for accesing the arXiv: arXiview.) So on a few of these flights recently I kludged together a new iPhone app: MakeRandom. This app gives you access to custom random lists, dice, random numbers, and random words. To get the randomness you just set up the list you want to randomly select from and shake! Exciting, no? But today I got an email about an even more exciting use of randomness in the iPhone: Universe SplitterÂ©:



Scientists say that every quantum event plays out simultaneously in every possible way, with each possibility becoming real in a separate universe. You can now harness this powerful and mysterious effect right from your iPhone or iPod Touch! How? Whenever you're faced with a choice -- for example, whether to accept a job offer or to turn it down -- just type both of these actions into Universe SplitterÂ©, and press the button. Universe SplitterÂ© will immediately contact a laboratory in Geneva, Switzerland, and connect to a Quantis brand quantum device, which releases single photons into a partially-silvered mirror. Each photon will simultaneously bounce off the mirror and pass through it -- but in separate universes. Within seconds, Universe SplitterÂ© will receive the experiment's result and tell you which of the two universes you're in, and therefore which action to take. Think of it -- two entire universes, complete with every last planet and galaxy, and in one, a version of you who took the new job, and in the other, a version of you who didn't!

Classic! Watch as this quantum physicist who wrote an app for randomness slaps himself on the forehead for not thinking of this. Check out Universe Splitter's website for a great quote by Garrett Lisi.

Universe SplitterÂ© is available from the iTunes store for $1.99 here

MakeRandom is also available from the iTunes store for $0.99here.

Below the fold: screenshots and a philosophical discussion of the difference between the applications.

First up lets look at some of the screen shots of the apps, a.k.a. apporn. UnivereSplitterÂ© has an awesome looking steampunk interface:

I particularly like the idea of using the application to eat and chose your cake. Forks in roads will never be the same.

Next up is MakeRandom whose highlight from a apporn point of view is the cool spinning wheels:

Okay now on to the philosophy! So Universe SplitterÂ© connects to a device which generates random numbers from a "quantum" experiment. MakeRandom on the other hand, chooses a random seed based upon the time and then uses a pseudo-random number generator. I will now claim, because it is fun, that there is no difference from the many-worlds point of view between these applications...for one use of the iPhone app!

What are you talking about Quantum Pontiff, of course there is a huge difference between a device which uses a beam splitter and one using a pseudo-random number generator. But let's think a little bit more about that pseduo-random number generator. It gets its seed, essentially, from the time of day. Given the seed we can determine its entire sequence of future numbers. So no one will argue that given the seed MakeRandom produces random numbers. But I will argue that the seed step is indeed random. But Pontiff, you say, of course the time of day is something which I can, by observing you, figure out and then it won't be random. But dear reader, last time I checked, time is a physical property of our universe, clocks are themselves physical objects which measure this property (indeed you may know that "time" is not a good observable in quantum theory, but my argument is not based on "time" being an observable, but on a clock as measuring some physical property of the clock.) And because time is physical, we must have arrived at that random seed by some measurement of a physical property of the universe, and because the world is quantum, we must branch into universes depending on what that actual outcome was.

Yes, yes, I hear you saying: but Pontiff the clock is a fully classical device. But I'm a many-worlder. Classical is not in my vocabulary (and if it is, mostly I say it when talking about decoherence and confusing the measurement problem with the emergence of classicality problem.) I will not allow a universe in which there is anything more than quantum physics at work, and therefore every measurement must split the universe and MakeRandom on setting its seed is, then, no different from the Universe SplitterÂ© (besides the later being so much cooler than the former, of course.)

Please ignore the fact that my argument can be applied universally to every process ever run on every iPhone and every computer, to every biological system moving around its environment, to Kayne's interruption, and to the grades my students received in their class. Being a many-worlder is a costly endeavor, what with all those universes you've orphaned and left decoherent, never to rejoin your own personal universe. The iPhone apps described above, however, are emmenantly affordable.