Am 10.01.2017 um 20:17 schrieb Kevin Wampler:
> Ha! Love the post title.
> 
> Hmmm, I am by no means anything of an expert on this, but some of the
> points in that video seem either wrong or poorly described.
> 
> The main issue I think is that randomness or entropy are not properties
> of a single chunk of data or matter, but apply only to probability
> distributions of data/matter.  If you don't have a probability
> distribution, the appropriate concept is complexity (or
> compressibility), which is related but not the same.  The video tries so
> hard to confuse these concepts it almost appears intentional.

Is it truly confusion, or could it actually be insight?

> I think this confusion is behind some strange claims in the video.  For
> instance:
> 
>     claim: If information is constant, then since information is
> entropy, entropy must be constant, which we know is false from the
> second law of thermodynamics.
> 
> Contrary to the video's claims, as far as I'm aware the information in
> the universe is actually believed to be constant, despite the second law
> of thermodynamics.  This is ok, since the second law of thermodynamics
> is really about probability distributions of those states the universe
> might have given our limited observations, but the information content
> is about the state of the entire universe (independent of our
> observations).  So they're really two different things and there's no
> conflict.

Remember that quantum theory does away with the idea that there even
/is/ such a thing as "the" state of the universe.

Also, from a quick glance on Wikipedia, it seems that there isn't really
a clear consensus - let alone irrefutable proof - whether the amount of
information in the universe is constant not.

And I have a hunch that even if the use of technical terms isn't as
precise as a scientist could wish for, these guys may be onto something.


> All in all, interesting and fun, but I'd caution against trusting it
> much (unless I'm totally wrong here myself, which is certainly possible).

According to Heisenberg, shouldn't that be "uncertainly possible"? ;)

Post a reply to this message

clipka <ano### [at] anonymousorg> wrote:
> Just a random video I found on YouTube.
>
> https://youtu.be/sMb00lz-IfE

Deep.  Really deep.

Except that I have a deep quarrel with them over the nature of free will.

Post a reply to this message

On 1/11/2017 2:13 AM, Cousin Ricky wrote:
> clipka <ano### [at] anonymousorg> wrote:
>> Just a random video I found on YouTube.
>>
>> https://youtu.be/sMb00lz-IfE
>
> Deep.  Really deep.
>
> Except that I have a deep quarrel with them over the nature of free will.
>
>

The only thing to do is behave as if you have it,

-- 

Regards
     Stephen

Post a reply to this message

So I wrote a bunch of stuff in response (included below in case you're 
interested).  But in retrospect I think that my issue is that there are 
multiple definitions of "information" at play here, and the video 
switches between them.  Here's some possible ways to define "information":

1) Information is a measure of the number of underlying degrees of 
freedom in a physical system.

2) Information is a measure of the minimal compressed size of a complete 
description of a physical system.

3) Information is a measure of the size of the smallest *physically 
feasible*  compressed representation of the complete description of a 
physical system.

4) Information is a measure of the degree of one's (possibly incomplete) 
knowledge about the complete state of a physical system.

5) Information is the amount of one's ignorance as to the complete state 
of a physical system.

For what it's worth, definition (1) is the one I'm used to (see here 
https://en.wikipedia.org/wiki/Physical_information#Classical_versus_quantum_information),

although the video doesn't seem to be using it at all.

Anyway, here's where specifically I think the video gets into trouble. 
As near as I can tell they make an argument which switches which 
definition of information it's using:

1. information is the same thing as entropy
	- true only for definition (5)
2. the entropy of the universe is always increasing
3. therefore the information of the universe is always increasing
	- since it relies on point 1, also true only for definition (5)
4. determinsitic physics cannot increase information
	- true for definition (2), false for (3), (4) and (5)
5. therefore non-determinism (like QM) must be responsiable for the 
increase in information
	- since there is no definition on information true for both points 3 
and 4, this is an unfounded conclusion
	
Hopefully that's more clear in conveying my confusion with the video's 
claims?  If you have another way of interpreting the video's argument 
that makes more sense I'd be interested to hear it.

Also, there's a nice and readable discussion of the relationship between 
information and entropy here: 
https://en.wikipedia.org/wiki/Physical_information#Physical_information_and_entropy 
In fairness, it does closely match some parts of what the video is 
trying to go for, but it has the advantage that it keeps the same 
definition of "information" and doesn't end up with strange (and AFAIK 
false) conclusions about QM being necessary for the second law of 
thermodynamics to exist.

I dunno, maybe I'm just being unnecessarily grumpy about nit-picking 
this.  Information *is* a really cool and current topic in theoretical 
physics, and the video does give semi-correct introductions to some of 
the relevant ideas in an entertaining way.  I just wish it was more 
concerned with being accurate.


(old stuff I typed out follows)


On 1/10/2017 1:15 PM, clipka wrote:>
 > Is it truly confusion, or could it actually be insight?
 >

I think it's confusion.  Or, at least, even if the authors know their 
stuff I think the video is very confusing.

This is not to say that it's complete bunk!  There are very deep 
connections between physics, entropy, and information, and AFAIK some 
prominent physicists expect it to be an up-and-coming area of study in 
the future of theoretical physics.  So it's not that the video doesn't 
look into some real and interesting topics, it's just that I think 
someone watching it would be likely to be misled in some important details.

For instance: From the video I think someone would probably get the 
impression that information and entropy are exactly the same thing, but 
I think it's actually better to think of them as opposites.  That is, 
one very useful way to think of entropy is as a measure of the 
uncertainty/ignorance of the underlying state of a physical system, 
which is to say a measure of your *lack* of information about the 
system.  Which is sort of the opposite of what it seems the video is 
trying to say.  (note: after hastily typing this I realized that there 
were multiple definitions of information at play, so probably ignore 
this paragraph)

Maybe it's just an issue with me being confused by an otherwise 
straightforward video, but certainly *I* have trouble making sense of 
what it's saying in a way which isn't subtly false.

 >
 > Remember that quantum theory does away with the idea that there even
 > /is/ such a thing as "the" state of the universe.
 >

Hmm what do you mean?  I was under the impression that quantum mechanics 
describes the state of the universe perfectly well with a giant quantum 
wave function?  Not the notion of "state" that we're used to from 
classical physics, but I was assuming that this would still count as a 
"state".

 >
 > Also, from a quick glance on Wikipedia, it seems that there isn't really
 > a clear consensus - let alone irrefutable proof - whether the amount of
 > information in the universe is constant not.
 >

Certainly if you just take straight quantum mechanics then information 
is conserved.  My impression is that while there's not universal 
agreement for cases outside of standard QM, the situations where 
information might not be conserved are generally considered to be 
problems which can hopefully be fixed with further analysis.  Hence the 
hand wringing over the black hole information paradox.

But yeah, I probably over stated the amount of certainty in information 
conservation.  Nevertheless, I'm not aware of any seriously considered 
physical theory which allows information to increase like the video 
claims (taking "information" to mean the number of bits/qbits required 
to completely specify the state of the universe).  If you are aware of 
such a theory I'd be super interested to hear about it.

 >
 > According to Heisenberg, shouldn't that be "uncertainly possible"? ;)
 >

lol

Post a reply to this message

On 1/12/2017 1:49 AM, Kevin Wampler wrote:
> So I wrote a bunch of stuff in response (included below in case you're
> interested).  But in retrospect I think that my issue is that there are
> multiple definitions of "information" at play here, and the video
> switches between them.  Here's some possible ways to define "information":
>

[Snip]

>
> I dunno, maybe I'm just being unnecessarily grumpy about nit-picking
> this.  Information *is* a really cool and current topic in theoretical
> physics, and the video does give semi-correct introductions to some of
> the relevant ideas in an entertaining way.  I just wish it was more
> concerned with being accurate.
>
>

I don't know how you could be bothered analysing it. It reeked of 
misdirection and false assumptions, as you show. And their presentation 
is too polished for what it is.

I got the impression I was watching two conmen.



-- 

Regards
     Stephen

Post a reply to this message

Am 12.01.2017 um 02:49 schrieb Kevin Wampler:

> Hopefully that's more clear in conveying my confusion with the video's
> claims?  If you have another way of interpreting the video's argument
> that makes more sense I'd be interested to hear it.

I won't argue about whether they might have gotten some stuff wrong.
They're not professional physicists, so I guess it's almost inevitable
that they did.

For me the question is not whether every conclusion in this video's
train of thoughts is correct and irrefutible, but whether it leads to an
interesting perspective on information and entropy that warrants to be
pondered further.

Human ingenuity has always been fueled by lucky mistakes.

>> Remember that quantum theory does away with the idea that there even
>> /is/ such a thing as "the" state of the universe.
> 
> Hmm what do you mean?  I was under the impression that quantum mechanics
> describes the state of the universe perfectly well with a giant quantum
> wave function?  Not the notion of "state" that we're used to from
> classical physics, but I was assuming that this would still count as a
> "state".

According to the Kopenhagen interpretation, the wave function does not
describe a particular state. It describes the /probability/ of a certain
state.

There is no spoon. Not until you have a close look at it, at any rate.

You /can/ look at the spoon so closely that you force it to coalesce
into a state -- but then you spoil any chance of predicting /anything/
about the spoon's future. In other words, it will evaporate. Instantly.
(Or not. Because even evaporation won't be guaranteed then.)

If the universe ever /has/ a particular state, "it will instantly
disappear and be replaced by something even more bizarre and
inexplicable", as an ingenious mind once put it.

Post a reply to this message

On 1/12/2017 12:10 PM, clipka wrote:
> Am 12.01.2017 um 02:49 schrieb Kevin Wampler:
>
>>> Remember that quantum theory does away with the idea that there even
>>> /is/ such a thing as "the" state of the universe.
>>
>> Hmm what do you mean?  I was under the impression that quantum mechanics
>> describes the state of the universe perfectly well with a giant quantum
>> wave function?  Not the notion of "state" that we're used to from
>> classical physics, but I was assuming that this would still count as a
>> "state".
>
> According to the Kopenhagen interpretation, the wave function does not
> describe a particular state. It describes the /probability/ of a certain
> state.
>
> There is no spoon. Not until you have a close look at it, at any rate.
>
> You /can/ look at the spoon so closely that you force it to coalesce
> into a state -- but then you spoil any chance of predicting /anything/
> about the spoon's future. In other words, it will evaporate. Instantly.
> (Or not. Because even evaporation won't be guaranteed then.)
>
> If the universe ever /has/ a particular state, "it will instantly
> disappear and be replaced by something even more bizarre and
> inexplicable", as an ingenious mind once put it.
>


How does one follow on from the other?


-- 

Regards
     Stephen

Post a reply to this message

Am 12.01.2017 um 13:49 schrieb Stephen:
> On 1/12/2017 12:10 PM, clipka wrote:
>> Am 12.01.2017 um 02:49 schrieb Kevin Wampler:
>>
>>>> Remember that quantum theory does away with the idea that there even
>>>> /is/ such a thing as "the" state of the universe.
>>>
>>> Hmm what do you mean?  I was under the impression that quantum mechanics
>>> describes the state of the universe perfectly well with a giant quantum
>>> wave function?  Not the notion of "state" that we're used to from
>>> classical physics, but I was assuming that this would still count as a
>>> "state".
>>
>> According to the Kopenhagen interpretation, the wave function does not
>> describe a particular state. It describes the /probability/ of a certain
>> state.
>>
>> There is no spoon. Not until you have a close look at it, at any rate.
>>
>> You /can/ look at the spoon so closely that you force it to coalesce
>> into a state -- but then you spoil any chance of predicting /anything/
>> about the spoon's future. In other words, it will evaporate. Instantly.
>> (Or not. Because even evaporation won't be guaranteed then.)
>>
>> If the universe ever /has/ a particular state, "it will instantly
>> disappear and be replaced by something even more bizarre and
>> inexplicable", as an ingenious mind once put it.
>>
> 
> 
> How does one follow on from the other?

Kopenhagen interpretation plus Heisenberg's uncertainty principle.

According to the Kopenhagen interpretation, particles don't assume any
particular state or location until they are measured.

According to the uncertainty principle, the more precisely you measure a
particle's /current/ state or location, the more likely it will /change/
its state or location.

Post a reply to this message

On 1/12/2017 1:51 PM, clipka wrote:
> Am 12.01.2017 um 13:49 schrieb Stephen:
>> On 1/12/2017 12:10 PM, clipka wrote:

>>>
>>> You /can/ look at the spoon so closely that you force it to coalesce
>>> into a state -- but then you spoil any chance of predicting /anything/
>>> about the spoon's future. In other words, it will evaporate. Instantly.
>>> (Or not. Because even evaporation won't be guaranteed then.)
>>>
>>> If the universe ever /has/ a particular state, "it will instantly
>>> disappear and be replaced by something even more bizarre and
>>> inexplicable", as an ingenious mind once put it.
>>>
>>
>>
>> How does one follow on from the other?
>
> Kopenhagen interpretation plus Heisenberg's uncertainty principle.
>
> According to the Kopenhagen interpretation, particles don't assume any
> particular state or location until they are measured.
>
> According to the uncertainty principle, the more precisely you measure a
> particle's /current/ state or location, the more likely it will /change/
> its state or location.
>

But the state is resolved. Why should it be un-resolved?
-- 

Regards
     Stephen

Post a reply to this message

On 1/12/2017 4:10 AM, clipka wrote:
>
> For me the question is not whether every conclusion in this video's
> train of thoughts is correct and irrefutible, but whether it leads to an
> interesting perspective on information and entropy that warrants to be
> pondered further.
>

Indeed I think it does... although maybe it's partially lost on me since 
I was lucky enough to first learn about entropy in 
semi-information-theoretic terms anyway.  Anyway, if you have the time 
there's a lecture I like by someone who actually *is* a top theoretical 
physicist related to these concepts and how they relate to black hole 
holography.  Maybe this is a good example of where you can get by 
pondering this stuff further (in addition to being substantially more 
precise about things): https://www.youtube.com/watch?v=2DIl3Hfh9tY

Another interesting related trend I've seen in physics is to start 
looking at the relationship between fundamental physical properties and 
computational complexity.  I know very little about this but it seems 
like a super neat connection between physics and information science.

>
> According to the Kopenhagen interpretation, the wave function does not
> describe a particular state. It describes the /probability/ of a certain
> state.
>

Oh man, the Copenhagen interpenetration is such a can of worms.  I 
actually like to think of it as actually not saying much of anything 
about the nature of reality, just as a way to tell you what you'll get 
as the result of a measurement of a quantum system.  Sort of the "shut 
up and calculate" interpretation of quantum physics.

But taking it as a serious model of reality, I have to admit that I've 
never understood precisely what sort of ontology or lack thereof is 
actually being proposed by this interpretation.  So it's hard for me to 
say much about it.

Nevertheless, I'll try anyway.  Even under the Copenhagen 
interpretation, you can resurrect a notion of state by simply looking at 
the amount of information needed to distinguish one wave function from 
another, and calling a physical instance of this information a "state". 
  It might have some strange more-epistemological-than-ontological 
status, but you can largely evade this to a large degree by focusing 
solely on the "state" as being just that which changes the probabilities 
of what you'll see as the result of an observation.

I think (but I have not done the math) if you do use this notion of 
state, then the information theoretic properties of it will match what I 
mentioned earlier where information can be destroyed but not created.

Anyhoo, you may not call that a "state", but I'm pretty comfortable 
doing so, in which case it's just a disagreement of whether a certain 
English word is appropriate to describe a particular concept, and the 
math is the same either way.

Post a reply to this message