APOD: Split the Universe (2017 Apr 01)

Comments and questions about the APOD on the main view screen.
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RJN
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Re: APOD: Split the Universe (2017 Apr 01)

Postby RJN » Sun Apr 02, 2017 1:36 pm

A ​shortcoming​ in this APOD's Schrodinger's cat analogy is that in the famous paradox, the information about the quantum decision that affects the cat is delayed in time from reaching the observer. It is not only about the quantum decision. Therefore, there is a time when the observer does not know the result and so might consider the cat, mathematically at the least, both alive and dead. In this APOD, that would be the time between pressing the button and seeing the resulting cat image. Therefore this APOD is not an exploration of the full Schrondinger's cat paradox, only of the quantum​-​decision part.

A potential fix ("enhancement") might be to build in a time delay between the button press and when the result is revealed. Both potential future images might swirl around for a​ ​second​ or so​ in the inter​i​m, during which each result is possible.

Alternatively, the quantum decision could be made when the person first loads the initial APOD page with the red button, but only revealed when the person clicks the button. But that might remove some of the emphasis from the interesting nature of the quantum decision itself.

​Or -- just dump the cat and use two other potential futures. This also changes the focus away from death. Thoughts anyone?​

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Re: APOD: Split the Universe (2017 Apr 01)

Postby Chris Peterson » Sun Apr 02, 2017 2:19 pm

RJN wrote:​Or -- just dump the cat and use two other potential futures. This also changes the focus away from death. Thoughts anyone?​

The whole concept works because of its reference to Schrödinger's thought problem- one of the most famous concepts in modern physics, and an important bit of scientific history. To alter it from its original form seriously reduces the value of the lesson, given that Schrödinger's Cat is really a part of our popular culture now.

It should not be necessary to sanitize everything with trigger warnings and worries about fragile viewers. This is a hypothetical experiment involving a hypothetical cat!
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Re: APOD: Split the Universe (2017 Apr 01)

Postby neufer » Sun Apr 02, 2017 4:54 pm

RJN wrote:
A ​shortcoming​ in this APOD's Schrodinger's cat analogy is that in the famous paradox, the information about the quantum decision that affects the cat is delayed in time from reaching the observer. It is not only about the quantum decision. Therefore, there is a time when the observer does not know the result and so might consider the cat, mathematically at the least, both alive and dead. In this APOD, that would be the time between pressing the button and seeing the resulting cat image. Therefore this APOD is not an exploration of the full Schrodingers cat paradox, only of the quantum​-​decision part.

What you have already done is quite thought provoking.

To simulate the cat Schrodinger's paradox best, I presume, would be
to start off showing both a live cat and a probability counter set at 1.00000000.

Pressing the button once would hide the cat and start multiplying the probability counter by 0.99997 every millisecond.

Pressing the button twice would stop the probability counter at P
as well as to reveal: 1) a live cat with a probability P or 2) a dead cat with a probability (1-P).

Therefore one would always has full knowledge of the probability P of a live cat
but would presumably only collapse the wavefunction upon the reveal.

Even better.... rather than hiding the cat you could rapidly alternate between the picture of a live cat (with probability P) and a dead cat (with probability P). This flickering would only stop upon the second press of the button. This would really give one the feel of the cat existing in an appropriate meta-state.
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Re: APOD: Split the Universe (2017 Apr 01)

Postby Chris Peterson » Sun Apr 02, 2017 5:36 pm

neufer wrote:Even better.... rather than hiding the cat you could rapidly alternate between the picture of a live cat (with probability P) and a dead cat (with probability P). This flickering would only stop upon the second press of the button. This would really give one the feel of the cat existing in an appropriate meta-state.


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Re: APOD: Split the Universe (2017 Apr 01)

Postby DavidLeodis » Sun Apr 02, 2017 5:54 pm

I profess to not understanding what this APOD is all about but nevertheless I find it very fascinating. I'm glad though that, as far as I can tell, my actions I've not split the Universe....or have I? :wink:

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Re: APOD: Split the Universe (2017 Apr 01)

Postby neufer » Sun Apr 02, 2017 6:52 pm

neufer wrote:
Even better.... rather than hiding the cat you could rapidly alternate between the picture of a live cat (with probability P) and a dead cat (with probability P). This flickering would only stop upon the second press of the button. This would really give one the feel of the cat existing in an appropriate meta-state.

Of course I meant:

Rather than hiding the cat you could rapidly alternate between
    the picture of a live cat [with probability P]
    and a dead cat [with probability (1-P)].
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Re: APOD: Split the Universe (2017 Apr 01)

Postby neufer » Sun Apr 02, 2017 6:55 pm

DavidLeodis wrote:
I profess to not understanding what this APOD is all about but nevertheless I find it very fascinating. I'm glad though that, as far as I can tell, my actions I've not split the Universe....or have I? :wink:

Well...of course if we substitute a sentient tiger, or a sentient human (, or a sentient flea) does the experiment change :?:
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Re: APOD: Split the Universe (2017 Apr 01)

Postby Chris Peterson » Sun Apr 02, 2017 7:02 pm

neufer wrote:
DavidLeodis wrote:
I profess to not understanding what this APOD is all about but nevertheless I find it very fascinating. I'm glad though that, as far as I can tell, my actions I've not split the Universe....or have I? :wink:

Well...of course if we substitute a sentient tiger, or a sentient human (, or a sentient flea) does the experiment change :?:

Not from the standpoint of a viewer outside the box.
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Re: APOD: Split the Universe (2017 Apr 01)

Postby neufer » Sun Apr 02, 2017 7:29 pm

Chris Peterson wrote:
neufer wrote:
DavidLeodis wrote:
I profess to not understanding what this APOD is all about but nevertheless I find it very fascinating. I'm glad though that, as far as I can tell, my actions I've not split the Universe....or have I? :wink:

Well...of course if we substitute a sentient tiger, or a sentient human (, or a sentient flea) does the experiment change :?:

Not from the standpoint of a viewer outside the box.

I agree with you...but probably for very different reasons
(; i.e., these experiments demonstrate a deep flaw in quantum mechanics, IMO).
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Re: APOD: Split the Universe (2017 Apr 01)

Postby Ann » Mon Apr 03, 2017 7:37 am

Adam at left, Neil at right.
There is another way of "splitting the universe", as demonstrated by identical twins Adam and Neil Pearson of Croydon, South London. They were born with the same genetic defect, type 1 neurofibromatosis, but in one brother's case, cell divisions in his face when he was in his mother's womb somehow coincided with an active phase of the disease, and he has now grown a very severe facial disfigurement. In the other brother, his genetic condition, identical to the one of his brother, never caused any serious tumors.

It seems to me that these two identical twin brothers have indeed "split the universe".

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Epigenetics

Postby neufer » Mon Apr 03, 2017 12:14 pm

https://en.wikipedia.org/wiki/Epigenetics wrote:
<<Epigenetics are stable heritable traits (or "phenotypes") that cannot be explained by changes in DNA sequence. The Greek prefix epi- (Greek: επί- over, outside of, around) in epigenetics implies features that are "on top of" or "in addition to" the traditional genetic basis for inheritance. Epigenetics often refers to changes in a chromosome that affect gene activity and expression, but can also be used to describe any heritable phenotypic change that doesn't derive from a modification of the genome, such as prions. Such effects on cellular and physiological phenotypic traits may result from external or environmental factors, or be part of normal developmental program. The standard definition of epigenetic requires these alterations to be heritable, either in the progeny of cells or of organisms.>>
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Re: APOD: Split the Universe (2017 Apr 01)

Postby RJN » Mon Apr 03, 2017 1:57 pm

Thanks everyone. Good discussion and ideas!

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Re: APOD: Split the Universe (2017 Apr 01)

Postby rstevenson » Mon Apr 03, 2017 3:30 pm

I was going to comment, but the 'me' that was almost ready to start typing disappeared and I'm now sitting here wondering what it was 'me' was going to type. Oh well, no doubt the universe is unfold... .

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Re: APOD: Split the Universe (2017 Apr 01)

Postby Case » Mon Apr 03, 2017 4:16 pm

While trying to see how this is done, before seeing RJN’s post (thanks for the backstory!), I thought I would examine a few things about the script:
1/ There is a difference between precision and accuracy. Any form of time keeping has a finite resolution (accuracy), regardless for the number of digits in the notation (precision). Beyond that accuracy, more precision is without meaning, and thus could introduce a systematic component to calculations, without knowing it. However, this is well beyond milliseconds for modern pcs, and seems no issue here.
2/ JavaScript requests that the browser asks the time from the OS. Numbers gets tossed around between layers of programs, and get converted. However, JS can request the time thousands of times within one millisecond and get the same number each time, followed by t+1, t+2, t+3, etc. Again, no issue here.
3/ JavaScript is executed on top of other applications and processes. That means it has to wait its turn to be able to do anything. This would reduce its moments for which it is able to get the timestamp. In theory, this could influence the measured timestamp, and restrict the available outcomes. This could influence the intended randomness and uncertainty. In practice, my comp does between 1345 (with heavy background task (video encoding)) and 3667 (without heavy background task (everything else idle)) routine loops within one millisecond (as registered within that loop) in a certain browser. This seems to indicate that there is little need for concern that an operation is delayed until the next millisecond.
4/ The date and time gets converted to milliseconds (since 1970/01/01). This numbers gets a bitwise AND operator function with 32-bit "2" (n=n & 2;). The result of which is 0 or 2, alternating in pairs (0,0,2,2,0,0,2,2,…) for sequential numbers. Thus the decision precision is 0.002 second, not 0.001 second precision mentioned from the retrieved number. Still a small number, but the odds have doubled.

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Re: APOD: Split the Universe (2017 Apr 01)

Postby Fred the Cat » Mon Apr 03, 2017 4:25 pm

Chris Peterson wrote:
Fred the Cat wrote:At least choosing a cat makes you curious to look. If he chose a snake no one would want to look. :ohno:

A "Schrödinger's snake" wouldn't portray any thought with which we'd want conduct experiments. :no:

Great, another person irrationally afraid of snakes. Next you're going to tell us you have a problem with spiders, I guess?


Fears, like other emotions, aren't always rational but they do motivate us to make conscious decisions. Our thoughts seem to be split between subconscious and conscious components. Until we fully understand the nature of that split we can only guess at its origin. I might tend to wish we have roots deeper than our physical, comprehensionable world where others would hang their "cats" on a different belief. Perhaps each of us is driven by our own subconscious like a drone is flown by its pilot. Until we know the truth of the aspect of physics that leads of the Schrödinger's cat paradox we are left to our own conscious thoughts and imaginations. :?
Feynman's Felicity "Only ascertain as a cat box survivor"

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Re: APOD: Split the Universe (2017 Apr 01)

Postby BDanielMayfield » Mon Apr 03, 2017 4:46 pm

APOD Robot wrote:Yet others believe that the universe is classically deterministic, so that by pressing the button you did not really split the universe, but just carried out an action predestined since time began.


Is this real, or part of the April fools gag?

I have a scientific aversion to the doctrine of Predestination, and a religious aversion to the theory of classical determinism. (This is not meant as a joke. I know that religion is very off topic here, but the roots of this debate were religious.)

Scientifically, is classical determinism still taken seriously?

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Re: APOD: Split the Universe (2017 Apr 01)

Postby neufer » Mon Apr 03, 2017 5:00 pm

BDanielMayfield wrote:
APOD Robot wrote:
Yet others believe that the universe is classically deterministic, so that by pressing the button you did not really split the universe, but just carried out an action predestined since time began.

Is this real, or part of the April fools gag?

Scientifically, is classical determinism still taken seriously?

Quantum & Chaos combined to kill the cat of classical determinism.
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Re: APOD: Split the Universe (2017 Apr 01)

Postby RJN » Mon Apr 03, 2017 5:16 pm


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Re: APOD: Split the Universe (2017 Apr 01)

Postby Chris Peterson » Mon Apr 03, 2017 5:31 pm

BDanielMayfield wrote:
APOD Robot wrote:Yet others believe that the universe is classically deterministic, so that by pressing the button you did not really split the universe, but just carried out an action predestined since time began.


Is this real, or part of the April fools gag?

I have a scientific aversion to the doctrine of Predestination, and a religious aversion to the theory of classical determinism. (This is not meant as a joke. I know that religion is very off topic here, but the roots of this debate were religious.)

Scientifically, is classical determinism still taken seriously?

Depends on what you mean by "classical". It is a valid scientific viewpoint that the Universe is a static structure in four dimensions, which means, essentially, that the future is already part of it. In that sense, there is a kind of determinism in place. It is irrelevant to most issues, however, as from the vantage point of "now" we have no way to predict that future. So in that sense, it isn't deterministic.

A lot of this comes down to definitions and semantics more than it does physics.
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Re: APOD: Split the Universe (2017 Apr 01)

Postby DavidLeodis » Mon Apr 03, 2017 5:35 pm

Perhaps it was pre-determined that this APOD would be issued :).

I had thought it was my free will that made me stop trying to understand the 'sciences' behind the fascinating discussion, but perhaps not! :)

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Re: APOD: Split the Universe (2017 Apr 01)

Postby Chris Peterson » Mon Apr 03, 2017 5:37 pm

DavidLeodis wrote:Perhaps it was pre-determined that this APOD would be issued :).

I had thought it was my free will that made me stop trying to understand the 'sciences' behind the fascinating discussion, but perhaps not! :)

The problem with any discussions of "free will" is that nobody has ever successfully defined what that even means. So all philosophical discussions around the topic are essentially empty.
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Re: APOD: Split the Universe (2017 Apr 01)

Postby DavidLeodis » Mon Apr 03, 2017 5:44 pm

Chris Peterson wrote:
DavidLeodis wrote:Perhaps it was pre-determined that this APOD would be issued :).

I had thought it was my free will that made me stop trying to understand the 'sciences' behind the fascinating discussion, but perhaps not! :)

The problem with any discussions of "free will" is that nobody has ever successfully defined what that even means. So all philosophical discussions around the topic are essentially empty.


Wow that was a rapid response Chris :). I'm unsure though if you think I was being serious, which I was not as my post was meant to be light-hearted.

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Re: APOD: Split the Universe (2017 Apr 01)

Postby Chris Peterson » Mon Apr 03, 2017 6:04 pm

DavidLeodis wrote:
Chris Peterson wrote:
DavidLeodis wrote:Perhaps it was pre-determined that this APOD would be issued :).

I had thought it was my free will that made me stop trying to understand the 'sciences' behind the fascinating discussion, but perhaps not! :)

The problem with any discussions of "free will" is that nobody has ever successfully defined what that even means. So all philosophical discussions around the topic are essentially empty.


Wow that was a rapid response Chris :). I'm unsure though if you think I was being serious, which I was not as my post was meant to be light-hearted.

Not too serious, no.
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Re: APOD: Split the Universe (2017 Apr 01)

Postby RJN » Mon Apr 03, 2017 6:32 pm

Case wrote:4/ The date and time gets converted to milliseconds (since 1970/01/01). This numbers gets a bitwise AND operator function with 32-bit "2" (n=n & 2;). The result of which is 0 or 2, alternating in pairs (0,0,2,2,0,0,2,2,…) for sequential numbers. Thus the decision precision is 0.002 second, not 0.001 second precision mentioned from the retrieved number. Still a small number, but the odds have doubled.


Thanks, Case, for deconstructing the algorithm I was using. Before I used the mod function, I practiced by printing out the long integer of milliseconds since 1970. If I recall correctly, these integers would always be different. And "even" half the time. Wouldn't that mean 0.001 second precision? If not, I don't understand -- where did I go wrong?

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Re: APOD: Split the Universe (2017 Apr 01)

Postby Case » Mon Apr 03, 2017 7:19 pm

RJN wrote:Thanks, Case, for deconstructing the algorithm I was using. Before I used the mod function, I practiced by printing out the long integer of milliseconds since 1970. If I recall correctly, these integers would always be different. And "even" half the time. Wouldn't that mean 0.001 second precision? If not, I don't understand -- where did I go wrong?

Here’s a series of test numbers for the millisecond timestamp and the result of the function, as used for the split:
1491246442956 - (n & 2 = 0) - live
1491246442957 - (n & 2 = 0) - live
1491246442958 - (n & 2 = 2) - dead
1491246442959 - (n & 2 = 2) - dead
1491246442960 - (n & 2 = 0) - live
1491246442961 - (n & 2 = 0) - live
1491246442962 - (n & 2 = 2) - dead
1491246442963 - (n & 2 = 2) - dead
As millisecond numbers ending in 56 and ending in 57 both have the same result, I would think the precision is at 0.002 second, because of the double size of the interval.

Edit: For even/odd one could use the function (n & 1) instead of (n & 2).


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