Jump to content
Conjurer

Boltzmann Brains (split from Spacetime is doomed.)

Recommended Posts

On 6/23/2019 at 3:31 PM, koti said:

Yet we have no idea what time is or what gravity is in its true nature...we have tools that describe virtually everything around us including black holes, first nanoseconds after the BB but we can’t predict where the smoke from my cigarette will go when I light it up and let several seconds pass.

The Boltzmann Equation is based on the probability theory.  Supposedly, it is able to calculate how often the smoke from your cigarette could randomly form into an alien consciousness to form a Boltzmann Brain.

https://en.wikipedia.org/wiki/Boltzmann_equation    

Share this post


Link to post
Share on other sites
11 minutes ago, Conjurer said:

Supposedly, it is able to calculate how often the smoke from your cigarette could randomly form into an alien consciousness to form a Boltzmann Brain.

https://en.wikipedia.org/wiki/Boltzmann_equation    

And yet the page you link to says no such thing. So perhaps you have misunderstood something.

Share this post


Link to post
Share on other sites
1 minute ago, Strange said:

And yet the page you link to says no such thing. So perhaps you have misunderstood something.

What equation is it that is supposed to be able to accomplish that?

Share this post


Link to post
Share on other sites
14 hours ago, Conjurer said:

What equation is it that is supposed to be able to accomplish that?

Whilst I don't see what cigarette smoke has to do with the OP, the rising smoke is an example of flow which becomes turbulent.

You were quite right to observe that our best analysis of the dynamics of a turbulent system is probabilistic, though the probability is much more complicated and much less understood than Boltzman.

Share this post


Link to post
Share on other sites
On 1/5/2020 at 2:33 AM, studiot said:

Whilst I don't see what cigarette smoke has to do with the OP, the rising smoke is an example of flow which becomes turbulent.

You were quite right to observe that our best analysis of the dynamics of a turbulent system is probabilistic, though the probability is much more complicated and much less understood than Boltzman.

In this physics thought experiment, a Boltzmann brain is a fully formed brain, complete with memories of a full human life in our universe, that arises due to extremely rare random fluctuations out of a state of thermodynamic equilibrium. 

https://en.wikipedia.org/wiki/Boltzmann_brain

This page doesn't have any equations on it, but I have heard it is a mathematical process which can be done by some professionals.  It is similar to the process they use to determine what the CMB represents, since it is like a heat map of the universe.

 

The OP stated that cigarette smoke is unpredictable and outside the bounds of science, but scientist have already discovered things like a human consciousness is more likely to exist compared to the current Big Bang model, bringing into question the possibility of a preexisting godlike entity existing before the universe was even created.   

Edited by Conjurer

Share this post


Link to post
Share on other sites
37 minutes ago, Conjurer said:

things like a human consciousness is more likely to exist compared to the current Big Bang model, bringing into question the possibility of a preexisting godlike entity existing before the universe was even created.   

Presumably because if some entity with a human consciousness existed before the universe was created, then that entity might have been responsible for creating the universe? You yourself, would you say that you possess human consciousness? And could you create an entire universe? Or is there any difficulty to do so?

Share this post


Link to post
Share on other sites
3 hours ago, Conjurer said:

In this physics thought experiment, a Boltzmann brain is a fully formed brain, complete with memories of a full human life in our universe, that arises due to extremely rare random fluctuations out of a state of thermodynamic equilibrium. 

https://en.wikipedia.org/wiki/Boltzmann_brain

This page doesn't have any equations on it, but I have heard it is a mathematical process which can be done by some professionals.  It is similar to the process they use to determine what the CMB represents, since it is like a heat map of the universe.

 

The OP stated that cigarette smoke is unpredictable and outside the bounds of science, but scientist have already discovered things like a human consciousness is more likely to exist compared to the current Big Bang model, bringing into question the possibility of a preexisting godlike entity existing before the universe was even created.   

Thank you for the reply.

It is clear that whoever wrote that article you refer to neither understands probability nor predictability and so is leading you up the proverbial path.
The giveaway is that it makes numeric predictions without uttering a single number.
 

Yes smoke is unpredictable but not outside the bounds of science.

Do you understand the difference between the exact predictability of Boltzman which results nevertheless in a probability and the unpredictability of turbulence which is also treated probabilistically and exactly why this difference occurs?
In a word it is due to the existence or not of 'states'.

Any by the way you keep asking for equations. There is much more to Mathematics and Science than equations.

 

Edited by studiot

Share this post


Link to post
Share on other sites
4 hours ago, studiot said:

Thank you for the reply.

It is clear that whoever wrote that article you refer to neither understands probability nor predictability and so is leading you up the proverbial path.
The giveaway is that it makes numeric predictions without uttering a single number.

I heard about it from Sean Carroll.  He may have something about it on https://www.preposterousuniverse.com/blog/

He actually does work on it, and it is part of the reason why he is trying to provide proofs that the mathematics of it is wrong.  I guess from him being an atheist.

4 hours ago, studiot said:

Any by the way you keep asking for equations. There is much more to Mathematics and Science than equations.

That was because someone was asking me about it actually being the equations that determine that, but I didn't mean to imply that it was to begin with.  I asked, because I was curious if they actually knew.  There doesn't seem to be much about it on the internet.  I assumed they knew them, since they knew that wasn't it.  You should never assume anything; I guess.

4 hours ago, studiot said:

Do you understand the difference between the exact predictability of Boltzman which results nevertheless in a probability and the unpredictability of turbulence which is also treated probabilistically and exactly why this difference occurs?
In a word it is due to the existence or not of 'states'.

I didn't think they actually have to know the exact state of every particle starting out, and that is how it worked.  I thought that it worked by finding the most likely state from potentially any starting state of every particle.  It seems like you would disavow that any of his work actually accomplishes anything, because none if it based on knowing an exact predetermined state.  There were ways around having to know that information, to determine what happens.  

Share this post


Link to post
Share on other sites
6 hours ago, Conjurer said:

I didn't think they actually have to know the exact state of every particle starting out, and that is how it worked.  I thought that it worked by finding the most likely state from potentially any starting state of every particle.  It seems like you would disavow that any of his work actually accomplishes anything, because none if it based on knowing an exact predetermined state.  There were ways around having to know that information, to determine what happens.  

You misunderstand me.

Where did I say you have to know the state of every (or indeed any) particle ?

My point is far more fundamental than that.

Share this post


Link to post
Share on other sites
7 hours ago, Conjurer said:

I heard about it from Sean Carroll.  He may have something about it on https://www.preposterousuniverse.com/blog/

!

Moderator Note

If you're going to link to a source, actually link to the source, i.e. an article that discusses the support for your idea. IOW, we need a title and page numbers, not just the section of the library where you can find the book. 

 

note: discussion has been split from https://www.scienceforums.net/topic/119374-spacetime-is-doomed/

 

 

 

 

 

Share this post


Link to post
Share on other sites
On 1/14/2020 at 6:22 AM, swansont said:
!

Moderator Note

If you're going to link to a source, actually link to the source, i.e. an article that discusses the support for your idea. IOW, we need a title and page numbers, not just the section of the library where you can find the book. 

 

note: discussion has been split from https://www.scienceforums.net/topic/119374-spacetime-is-doomed/

 

 

 

 

 

He wrote about it in the book, The Particle at the End of the Universe.  You would have to use an index if you wish to look it up, because I no longer have the book with me.

He published some papers about it, but I forgot how you get in to searching for scientific papers.  You could search for Boltzmann Brains and Sean Carroll, and it will probably come up with his paper in how he was trying to disprove that Boltzmann Brains are formulated correctly.  The reason why he did it in his book, was because people were trying to use it to discover the mind of God.  

On 1/14/2020 at 4:47 AM, studiot said:

You misunderstand me.

Where did I say you have to know the state of every (or indeed any) particle ?

My point is far more fundamental than that.

I said that, because I don't believe your argument on fundamentals was conducive to the fundamentals of the theory.  Then you would be arguing the legitimacy of the theory at that point. 

Share this post


Link to post
Share on other sites
6 minutes ago, Conjurer said:

 

I said that, because I don't believe your argument on fundamentals was conducive to the fundamentals of the theory.  Then you would be arguing the legitimacy of the theory at that point. 

I sorry I have no idea what you mean.

My point was put as a simple question which you have not even attempted to answer.

 

On 1/13/2020 at 11:15 PM, studiot said:

Do you understand the difference between the exact predictability of Boltzman which results nevertheless in a probability and the unpredictability of turbulence which is also treated probabilistically and exactly why this difference occurs?

 

Share this post


Link to post
Share on other sites
4 minutes ago, studiot said:

I sorry I have no idea what you mean.

My point was put as a simple question which you have not even attempted to answer.

 

 

I believe it considers an average state to begin with, and it determines where it will be with a high probability according to that.

The Boltzmann equation can be used to determine how physical quantities change, such as heat energy and momentum, when a fluid is in transport. One may also derive other properties characteristic to fluids such as viscosity, thermal conductivity, and electrical conductivity (by treating the charge carriers in a material as a gas).[2] See also convection–diffusion equation.

https://en.wikipedia.org/wiki/Boltzmann_equation

The equation arises not by analyzing the individual positions and momenta of each particle in the fluid but rather by considering a probability distribution for the position and momentum of a typical particle—that is, the probability that the particle occupies a given very small region of space (mathematically the volume element {\displaystyle \mathrm {d} ^{3}{\bf {r}}}{\displaystyle \mathrm {d} ^{3}{\bf {r}}}) centered at the position {\displaystyle {\bf {r}}}{\displaystyle {\bf {r}}}, and has momentum nearly equal to a given momentum vector {\displaystyle {\bf {p}}}{\displaystyle {\bf {p}}} (thus occupying a very small region of momentum space {\displaystyle \mathrm {d} ^{3}{\bf {p}}}{\displaystyle \mathrm {d} ^{3}{\bf {p}}}), at an instant of time.

Share this post


Link to post
Share on other sites

What considers an average state?

Share this post


Link to post
Share on other sites

https://en.wikipedia.org/wiki/Boltzmann_equation

Just now, studiot said:

What considers an average state?

The equation arises not by analyzing the individual positions and momenta of each particle in the fluid but rather by considering a probability distribution for the position and momentum of a typical particle—that is, the probability that the particle occupies a given very small region of space 

Share this post


Link to post
Share on other sites
Just now, studiot said:

That is not an answer.

Are you stating that Boltzman considers a state or states or are you referring to turbulence ?

It has more to do with thermodynamics or temperature, but temperature can cause turbulence.

The Boltzmann equation can be used to determine how physical quantities change, such as heat energy and momentum,

Share this post


Link to post
Share on other sites

Gosh wriggle, wriggle wriggle.

Why is that ?

Why not a straightforwrd yes or no to a straightforward question?

Here is my straightforward answer.

Boltzmann does indeed refer to states.

That is how he derives the probability.

BUT

There are no states defined in a turbulent system.

 

Because the Boltzmann equation describes the distribution of some state variable of interest over the totality of states available to any system this distribution can be used as an exact calculation of probabilities of any given state.

But state variables are only defined for defined states, which are of course equilibrium states. (So yes this comes from Thermodynamics)
 

But the equation offers no information about that state variable when the system is not in a defined state or how it passes through any region to get from one defined state to another.

 

On the other hand since there are no equations that can exactly predict variables in a turbulent system because it is not in equilibrium, we are left with empirical measurements.
Some of these are probabilities, since the results vary over a range, and some are pretty tight, for example the fanning friction factor in a pipe.

 

That is the difference.

Boltzmann is the result of theoretical calculation.

Turbulence is the result of empirical measurement and observation.

Of course once we have measured empirically we can compare with known distributions and say

Well hey there, it looks a bit like Boltzmann, if considered locally.
So for want of something better perhaps we can use Boltzmann as a model for small enough spaces.

 

 

Edited by studiot

Share this post


Link to post
Share on other sites
5 hours ago, studiot said:

But the equation offers no information about that state variable when the system is not in a defined state or how it passes through any region to get from one defined state to another.

It considers all possible positions and momenta in a phase space, which is where all possible states are represented.  Then it gives a probability density function, where it gives the likely hood that it could represent a sample.

I really see no difference in saying that this theory actually makes no predictions and quantum mechanics makes no real predictions.  In quantum mechanics, you cannot know the exact speed and position of a particle, ever.  Then it uses probability to determine the most likely state the particle will be in.  Why argue that the Boltzmann equation makes no real predictions when you could say the same thing about quantum mechanics?  Then quantum mechanics is the most well proven theory in all of science...

 the "diff" term represents the diffusion of particles, and "coll" is the collision term – accounting for the forces acting between particles in collisions

Share this post


Link to post
Share on other sites
11 hours ago, Conjurer said:

He wrote about it in the book, The Particle at the End of the Universe.  You would have to use an index if you wish to look it up, because I no longer have the book with me.

He published some papers about it, but I forgot how you get in to searching for scientific papers.  You could search for Boltzmann Brains and Sean Carroll, and it will probably come up with his paper in how he was trying to disprove that Boltzmann Brains are formulated correctly.  The reason why he did it in his book, was because people were trying to use it to discover the mind of God.  

!

Moderator Note

(emphasis added)

No, that's not what others should do, it's what you need to do. You must do a better job of supporting claims. Otherwise it's soapboxing, which is against the rules.

 

Share this post


Link to post
Share on other sites
5 hours ago, swansont said:
!

Moderator Note

(emphasis added)

No, that's not what others should do, it's what you need to do. You must do a better job of supporting claims. Otherwise it's soapboxing, which is against the rules.

 

You will have to tell me how I can get into searching for the research paper, because I lost my link to it.  Didn't Cornell University have a site that could do that?

Share this post


Link to post
Share on other sites
11 hours ago, Conjurer said:

Why argue that the Boltzmann equation makes no real predictions when you could say the same thing about quantum mechanics?

Perhaps you should re-read what I actually said.

But before you do or search for advanced research papers, I suggest you find out what is meant by  a 'state' and a 'state variable'.

Boltzman's state variables were not position or momentum.

They were energy and temperature.

And his results are deterministic, as stemming directly from deterministic equations.

 

Try looking here for some mathematics.

http://hyperphysics.phy-astr.gsu.edu/hbase/Kinetic/maxspe.html

 

 

Edited by studiot

Share this post


Link to post
Share on other sites
1 minute ago, Conjurer said:

I think you are getting it confused with the Boltzmann entropy formula, or variations on it he worked on with Maxwell.  I think they are two separate beast.

https://en.wikipedia.org/wiki/Boltzmann's_entropy_formula

From my link

Quote

Mathematically, the Boltzmann distribution can be written in the form

mspe.gif

 

This couldn't be clearer.

I have referred to the Boltzman Distribution many times in this thread.

 

Share this post


Link to post
Share on other sites
41 minutes ago, studiot said:

This couldn't be clearer.

I have referred to the Boltzman Distribution many times in this thread.

 

Okay, that is nothing like the equations I was referring to on the Boltzmann equation page of the wiki.  This was independent work he did himself, and you are referring to the Maxwell-Boltzmann distribution.

https://en.wikipedia.org/wiki/Boltzmann_equation

Then a link at the top of that page takes you to a different page.

https://en.wikipedia.org/wiki/Maxwell–Boltzmann_distribution

It appears that they are two different things.  They have different equations with different descriptions and mathematics on them.

Boltzmann worked with people like Maxwell and Einstein, and his work with them was generally accepted.  Although, his independent work was not widely accepted, since they had no way to verify it.  It didn't help him when he came up with the idea of Boltzmann Brains, because it seemed so far fetched that the general public made fun of him about it.  It was around the same time they had the radio scare of an alien invasion.  It is the reason why they made a lot of the hoop-la in science fiction about invaders from the fifth dimension.  But, his work is currently being used and analyzed in higher end theoretical physics. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.