I wanted to put in here a few notes about today's APOD. Possibly nobody cares, but here is some of the backstory about today's APOD. Sorry for the long post.
First, I have always been interested in things like the Schrodinger's cat (SC) paradox but never saw a way previously to include SC specifically into APOD. Several years ago I recorded a lecture on SC freely available here:
http://asterisk.apod.com/viewtopic.php?f=39&t=21138 .
A second milestone was by chance becoming aware of an iPhone app called "Universe Splitter" here:
https://itunes.apple.com/us/app/univers ... 33299?mt=8 . Now I have an Android, not an iPhone, and it does not seem that this app is available for Android. I have therefore never run this app, but found it's concept, as described, intriguing. It seemed to me, though, that the app description did not connect directly to Schrodinger's cat, and seemed to give only one interpretation of what happened when you pressed the "Split Universe" button. I considered linking to this app but the app costs money and so I did not want it to appear like APOD is advertising it.
Next, I looked to see if any quantum random decisions could be generated more generally over the web. The closest I found were pages that would return random numbers based on a laboratory quantum process. Here is an example:
https://qrng.anu.edu.au/ . It did not seem that this process was easily accessible by general HTML through a standard web page.
Therefore, for some time, I did not think it presently possible to create and APOD like today's. Then I was re-reading a paper I admire for other purposes: "Origin of probabilities and their application to the multiverse" by Albrecht and Phillips here:
http://adsabs.harvard.edu/abs/2014PhRvD..90l3514A . Much of this paper I find fascinating including the section where they find that flipping a coin can have a significantly quantum random component (Section 4). In that section it says: "The signal triggering the flip travels along human neurons which have an intrinsic temporal uncertainty of ... 0.001 seconds." This uncertainty, they guess, may be dominated by quantum noise.
The result is that a human brain guessing a time interval longer than this is essentially a classical process which a human could do with greater than 50% accuracy. So for example, if a computer was counting by seconds and you were tasked to click when the number showing was an even number (not odd), then you could do this with high accuracy. However, if the computer was counting by 0.001 second intervals and you were tasked to click when the number in the 0.001's place was even, you could NOT do this will high accuracy. Because your brain and neurons and its connection to your arm and finger is not only not fast enough, but there is a built in undefeatable quantum-random process that is operating. (See also this paper:
http://www.nature.com/nrn/journal/v9/n4 ... n2258.html titled "Noise in the Nervous System" by Faisal, Selen & Wolpert)
So it occurred to me that computer processors work on time scales much faster than this. But could a browser read the computer clock to 0.001 second accuracy? There seemed to be no HTML commands for this, but after some searching I found that Javascript could -- it could actually read out the operating system clock with 0.001 second accuracy.
Now I have little experience with Javascript, but I started playing around and after a few days I had it! I could get a browser to display the 0.001 time and even effectively tell me if this was even or odd! (Strange little triumphs like this can make me ecstatic.)
I then played more with Javascript and eventually got a browser to display a different image depending on the 0.001 clock readout when the user clicked. If all of this is correct, the clicking of hyperlinks which is usually classical could be made to have a significant quantum random component. This would be the first case like this of which I was aware! Hyperlinks are supposed to be classical and deterministic.
But when could I run this on APOD? Well this was in early March and sure enough April Fools days was coming around. Just enough time, it seemed.
I went through several image possibilities but settled on the famous astronaut with the sign -- it was surreal and public domain and humorous and had not appeared on APOD before.
I originally had the astronaut holding one of two signs -- "This Universe" or "That Universe". But then I decided that was too abstract -- it was better to use the known relation to Schrodinger's cat. Everyone's heard of Schrodinger's cat. I found suitable thumbnail images (no real dead cat of course) and coded and tested it during March. Jerry noted it. I edited the text several times making final edits as late as yesterday.
Postscript. After midnight when the APOD appeared, I showed a person I know hoping to get a "Cool!" response. But this APOD made that person sad. The dead cartoon cat made them remember a recently deceased real cat of which they were fond. Apparently the thought of a dead cat -- and possibly killing a cat -- even a virtual cat -- weighs heavily on people's minds. Oops. And so maybe the tie-in to Schrodinger was less appealing than I thought.
