How to explain the benefits of string theory to my grandmother

[chrisina]

Rewebster, if I may disagree : let's take two examples of what may be considered as "good" and fundamentally new theories : General Relativity and Quantum mechanics.
GR was written in 1915, and it immediately could explain what was then a mystery at the time, the anomalous perihelion precession of Mercury. It only took 4 years for Eddington to come up with a series of experiments / observations on stars near the eclipsed sun that confirmed GR. I could add the failure to explain Michelson / Morley's experiments (1897) which by far preceeded the advent of GR...
Let's look at the history of quantum mechanics, you will see again a recurring theme : the failure of understang current experimental results gave rise to "new Physics" :
1900 : failure to understand the reason for the pattern of black body radiation (1862): Planck introduces quantization of energy
1905 : failure to understand the photoelectric effect (1839) : Einstein, based on Planck's quantum hypothesis introduces the new theory of light
1913 : failure to understand the Rydberg formula (1888) : Bohr introduces his new model of the atom based on the 2 previous ideas

etc...

As you can see, science progressed fundamentally because of it's failure to understand experimental results which had already been carried.

I believe we have now a BEAUTIFUL case of the same : our failure to understand the cosmological constant problem.

If the only way we can explain it is to resort to the anthropic landscape of string theory, me will miss on an opportunity to discover fundamentally new things.
Because let's not forget that the main motivation to do theoretical physics, is not to have "fun" (although of course I am not excluding it...), but the conviction that it is the most profound way for mankind to improve its ability to exploit the resources of nature.

 

[Anonym]

Let's look at the history of quantum mechanics, you will see again a recurring theme : the failure of understang current experimental results gave rise to "new Physics" :
1900 : failure to understand the reason for the pattern of black body radiation (1862): Planck introduces quantization of energy
1905 : failure to understand the photoelectric effect (1839) : Einstein, based on Planck's quantum hypothesis introduces the new theory of light
1913 : failure to understand the Rydberg formula (1888) : Bohr introduces his new model of the atom based on the 2 previous ideas

etc...

Could you complete a list down to end of 20 century?

Regards, Dany.

 

[rewebster]

Rewebster, if I may disagree : let's take two examples of what may be considered as "good" and fundamentally new theories : General Relativity and Quantum mechanics.
GR was written in 1915, and it immediately could explain what was then a mystery at the time, the anomalous perihelion precession of Mercury. It only took 4 years for Eddington to come up with a series of experiments / observations on stars near the eclipsed sun that confirmed GR. I could add the failure to explain Michelson / Morley's experiments (1897) which by far preceded the advent of GR...
Let's look at the history of quantum mechanics, you will see again a recurring theme : the failure to understand current experimental results gave rise to "new Physics" :
1900 : failure to understand the reason for the pattern of black body radiation (1862): Planck introduces quantization of energy
1905 : failure to understand the photoelectric effect (1839) : Einstein, based on Planck's quantum hypothesis introduces the new theory of light
1913 : failure to understand the Rydberg formula (1888) : Bohr introduces his new model of the atom based on the 2 previous ideas

etc...

As you can see, science progressed fundamentally because of it's failure to understand experimental results which had already been carried.

I believe we have now a BEAUTIFUL case of the same : our failure to understand the cosmological constant problem.

If the only way we can explain it is to resort to the anthropic landscape of string theory, me will miss on an opportunity to discover fundamentally new things.
Because let's not forget that the main motivation to do theoretical physics, is not to have "fun" (although of course I am not excluding it...), but the conviction that it is the most profound way for mankind to improve its ability to exploit the resources of nature.

my, my, MY...


I wasn't expecting such an intensive reply from your grandmother...



...but she seems to be agreeing with me rather than disagreeing with me as to the amount of time it takes sometimes to get a result from a hypothesis/theory/initial observation to 'some kind' of a example/result to help the 'unknown' initial query along.



...and I can guess that you haven't read some of my other answers (in other threads), then, about the 'unknowns'/fundamentals; as I try to promote the 'search' and not to accept them as 'givens' and to try to understand more of the 'reasons' of what the 'fundamental' classical processes are.

 

[chrisina]

... the point I was making (not my grandmother), is that experimental confirmations came relatively quickly after the first "good" hypothesis were made. And this despite the very revolutionary character of these hypothesis.

Try to think of someone living in the early 1900s and you get two "crackpots" like Planck and Einstein who come up with their crazy theories. How long did it take before the first experimental confiirmations came ? A few years. How long before general scientific consensus that they had found something really interesting, a bit longer.

I watched the debate between Smolin and Damour online, and this issue of the criticality of speed in the experimental confirmation came up.

This is precisely the main objection to String theory, people have been working on it for more than 25 years, and still no light of any experimental confirmation... This never happened in the past.

 

[rewebster]

How long of a 'time' period was it between Newton's 'ideas' and Einstein's 'ideas'?

Atoms were 'purposed' in Greek times---how long did it take to substantiate THAT claim?


----------------------------
--and then there were a lot of astronomical observations back in medieval times...
------------------------------

... the point I was making (not my grandmother), is that experimental confirmations came relatively quickly after the first "good" hypothesis were made. And this despite the very revolutionary character of these hypothesis.

Try to think of someone living in the early 1900s and you get two "crackpots" like Planck and Einstein who come up with their crazy theories. How long did it take before the first experimental confirmations came ? A few years. How long before general scientific consensus that they had found something really interesting, a bit longer.

I watched the debate between Smolin and Damour online, and this issue of the criticality of speed in the experimental confirmation came up.
This is precisely the main objection to String theory, people have been working on it for more than 25 years, and still no light of any experimental confirmation... This never happened in the past.

I think you're looking at the trees rather than the forest here (taking/*looking at* specific examples rather than the larger overview of the 'history' of most initial/starting points of a thought to 'some' additional supporting data)




-----------------------------

Again, I am not a string/MWI person. I like the classical, semi-quantum, causality with a perspective/touch of relativity view.

 

[Anonym]

As you can see, science progressed fundamentally because of it's failure to understand experimental results which had already been carried.

I believe we have now a BEAUTIFUL case of the same : our failure to understand the cosmological constant problem.

What is the experimental value of the cosmological constant?

Apparently you miss a point. There are always tons of the experimental results which we fail to explain and understand (yet). Some high IQ people choose simply to ignore them. But this is not a matter. The matter is how to extract the universal experimental result crucial for formulation of the adequate physical theory.

I will give you three examples related with A. Einstein and one after his death:

1.The inertial and gravitational mass is identical (known about 400 years since Galileo).
2.The pattern of black body radiation (the peaceful coexistence of CED and QED, known since I.Newton). It was demonstrated by Y.B. Zeldovich et al that with the gravitation the situation is the same.
3.The collapse of the wave packet called The Measurement Problem (known since the 1920s).

and

4.The stability of proton (known since 1980s; the existence of QM ground state in the QCD).

Let me define the experimental result crucial for formulation of QG: the universe is 4-dim space-time continuum with the signature {+,-,-,-}. Only the consideration which will naturally contain the explanation of that has chance to be adequate after the proper development.

If you believe that without deep understanding of QM you will be able to understand anything in gravitation you are hopelessly naïve.

Indeed, any kind of the scientific research is legitimate, except one: it seems that your QG friends (ST, LQG, Cosmology model makers, etc) are involved too much in the PR activity, which has nothing to do with the science (compare with the ugly history of EPR).

Regards, Dany.

 

[chrisina]

Rewebster, sorry to say, but you are again missing my point :

before Newton, there was a lot of experimental data about the movement of the planets, but no theory which could explain it. Newton came up with a new theory (the word is even too small), and it din't take long for a wealth of experimental data (unknowns of the past + new predictions) to confirm that it was a "good" theory. The fact that it took 300 years before Einstein could improve it doesn't eliminate the fact that Newton's proposal was right on and very quickly confirmed by experiments.

About the greeks and the atoms, I do not call a vague supposition a scientific theory. For example, I can make a supposition like :
" the universe is actually a giant atom", but I'd need to substantiate it with some scientific theory.

About the experimental value of the cosmological constant, I just don't understand what that sentence means. The cosmological constant has no experimental value per say. It's like saying, "what's the experimental value of Planck's constant".
My point was, there are experiments, called WMAP, COBE, etc... that seam to indicate that there is a small cosmological constant, but there does not exist today any quantum field theory which can explain its value, by orders of magnitude...

About your affirmation that the apparent fact that we live in 4d space time continuum {+,-,-,-} is the most important experimental result for the formulation of QG, I will refrain from any comments...

 

[Anonym]

About the experimental value of the cosmological constant, I just don't understand what that sentence means. The cosmological constant has no experimental value per say. It's like saying, "what's the experimental value of Planck's constant".

and

there are experiments, called WMAP, COBE, etc... that seam to indicate that there is a small cosmological constant.

Ask your grandma to give you the calmative tablets.

Bye.

 

[rewebster]

Anyone at anytime is living in the 'present'---by living in the 'present' , we have the ability to look at 'history' in hindsight (with *mostly* 20/20 vision).

before Newton, there was a lot of experimental data about the movement of the planets, but no theory which could explain it.

but, they did try to come up with different theories

Newton's proposal was right on and very quickly confirmed by experiments.

A lot his were observations of the physical--different story, different set of knowledge for the time

You, chrisina, (and all of us really) have the ability to pick and choose your topics and your comparisons of all that has come before, look at them from a 20/20 hindsight, AND compress them (compress the timeline) to make the comparisons. Looking at string/MWI, WE ARE living in the time when it is now being looked at (very little 20/20 hindsight and time compression to work with). Some of your comments about the 'lack' of any progress/discoveries with string/MWI sound more like personal frustration rather than seeing the 'bigger picture' of how long 'some' ideas and theories take to have some/any substantiation.

Do you have some reason why you keep using "experimental value of the cosmological constant" as an example?


From my personal viewpoint, string/MWI may NEVER have any experimental data related on a grand scale (as a complete system/theory), but there may be small related outcomes that are generated from experiments that were initially started as 'research' into string/MWI. It's been over a hundred years and we have made no 'macro' object come even close to c (speed of light) to get data/conclusive experimental results about that part of relativity.

And IF I am still 'missing your point'--sorry, you're not still defining the 'point' you're trying to make clear enough. I think part of the problem is that you wanted/posted what/how/why string/MWI has produced (for granma), and you're also bringing into conversation points that bother you.

 

[chrisina]

Yes, you are right, it does bother me a bit that there still has been no experimental confirmation of string theory.
I mean, like many, I had been attracted to it via the media PR touting that it was "the theory of Everything"...
Now, it is clearer to me that it is just work in progress and I think it should be communicated that way. I agree that in the future, it could be that String theory is shown to be the right approach, or as you say that new roads emerge thanks to string theory which become the right approach.

My point in the earlier posts had been that experimental confirmation of "good" theories had followed relatively quickly. Which is probably what explains a growing "unease" of parts of the scientific community towards string theory.

As far as the cosmological constant problem is concerned, I referred to it as an example of an apparent experimental result which had no theoretical explanation so far. The link with String Theory being that some people (eg L. Süsskind- sorry if I misspell) are now advocating the fact that out of the 10^500 (or whatever) versions of ST possible, one could be compatible with the universe we live in, and with the value of the cosmological constant observed so far.
And, yes, this bothers me as an explanation. But to be perfectly honest, it's just gut-feal...

 

[marcus]

...
About the experimental value of the cosmological constant, I just don't understand what that sentence means. The cosmological constant has no experimental value per se. It's like saying, "what's the experimental value of Planck's constant".
My point was, there are experiments, called WMAP, COBE, etc... that seem to indicate that there is a small cosmological constant, but there does not exist today any quantum field theory which can explain its value, by orders of magnitude...

Hi chrisina, I think you are saying something interesting here which may need clarification. I don't want to get involved in arguments with the other posters---I just want to satisfy my curiosity.

I agree that Planck's constant is not a dimensionless number, so per se (by itself, purely of itself) it has no experimental value. Perhaps the most obvious value for it to have is 1, exact unity :-) but no experiment I can imagine would establish this.

If this is what you are saying about Planck's constant, I certainly agree. But I am not sure of what you are saying about the cosmo constant. It is a fascinating quantity.
I like to imagine it as a curvature-----or as an area, inverse of that curvature----or as a length, the square root of that area.

also as an energy density of about 0.6 joules per cubic kilometer,
or as a pure number of around 10^-120, when one makes
G = hbar = c = 1.

and perhaps it does not even exist!

(I found the recent paper "The Dark Side of a Patchwork Universe" by Martin B. provocative----in there the cosmo constant is merely an illusion and the observed acceleration comes from correction in the kinetic term of hamiltonian---it is appealingly simple and also shows a humorous teasing aspect of nature, that one could picture as a playful "see, I fooled you" smile.)

So I am hoping you will say a bit more about your point of view on the cosmo const. I think I might be interested in what you have to say.

 

[rewebster]

Most theories (probably the ones that you 'like' that have had some 'confirmation') -that are used- are based on observations, thoughts on observations, flukes in experiments that led to theories, etc., and after the initial theory, variations/interpretations can follow. String/MWI isn't--it's origins, from all that I've read, are math based (the origin is a math equation)-then related to observables. To me, its like saying, 'I've found this equation that looks like its important, "1=1"!, and THEN relating it to the entire universe.

I still think the "experimental confirmation of "good" theories had followed relatively quickly" are the ones that 'stand out' and that 'you like' and 'can relate to', and a lot of them take a while to 'confirm' in the time line.


by the way, did you ask granma if she had any 'good' stories from back 'when'?


------------
OOOps---I was writing and posted the above when the one you (marcus) posted appeared---My "1=1" didn't refer to your post at all. co-incidence!

 

[Anonym]

I just want to satisfy my curiosity.

You may satisfy your curiosity reading a good high school introductory textbook in physics.

 

[chrisina]

I think there is a misunderstanding (probably because of the word "value")
I stated in post #31 :

"As you can see, science progressed fundamentally because of it's failure to understand experimental results which had already been carried.
I believe we have now a BEAUTIFUL case of the same : our failure to understand the cosmological constant problem.
If the only way we can explain it is to resort to the anthropic landscape of string theory, me will miss on an opportunity to discover fundamentally new things. "

To which Anonym replied (post #36)
"What is the experimental value of the cosmological constant?"
and Rewebster (post #39)
"Do you have some reason why you keep using "experimental value of the cosmological constant" as an example? "

which I tried to answered in post #37 and #40.

I agree with you, Marcus, I find the Cosmological Constant problem absolutely facinating., so much so that I have been reading everything I can found related to it over the past 12 months. I did read the recent Bojowald paper on the patchwork universe and loved it.

I've been trying to come up with something similar for quite some time, except that I am not using any LQG results but a simpler deformable cubic lattice where I make use of probabilistic number theory (the riemann zeroes playing an important role) to see if I can get to a density matrix which is compatible with the standard parameters and coupling constants. It is still too immature, but I am not loosing hope. Why I am so interested with Lambda, is that it is the only parameter that I use in the model, the rest is just pure geometry and number theory.
But its still not working...

 

[chrisina]

Anonym, please stop being insulting with everybody...

 

[Anonym]

Anonym, please stop being insulting with everybody...

You miss my intention. I agree with Rewebster that your comments sound like personal frustrations. And I do not see any reason for that now, but imagine what may happen after 10 or 20 years. With dimension consideration you (as well as Marcus) did rough physical mistake. The choice of the natural units and physical meaning of that is really discussed in high school, but if you shame I suggest A.B. Migdal “Qualitative Methods in Quantum Theory”. You will not be cleverer denying mistake, it is nothing bad to return and check the point again.

I agree with you, Marcus, I find the Cosmological Constant problem absolutely facinating., so much so that I have been reading everything I can found related to it over the past 12 months.

I only attract your attention that A.Einstein studied that point and came to conclusion that lambda=0. Do what you want, but remember that A.Einstein understood something in physics in general and in gravitation in particular.

I think that this thread is over.

 

[rewebster]

About the greeks and the atoms, I do not call a vague supposition a scientific theory.

But...at that time, they (some Greeks) probably THOUGHT it was the most important breakthrough of the day.


and as far as: "a vague supposition a scientific theory."---'they' may be saying that about Einstein in 50 or 100 years.

All the work on String/MWI theory may be like on the work done on pre-Copernican astronomy.

 

[marcus]

... make use of probabilistic number theory ... to see if I can get to a density matrix which is compatible with the standard parameters and coupling constants. ...

Chrisina, do you know the conjecture of Smolin that the standard model parameters, including coupling constants, are well adapted to produce a lot of black holes?

Together, the constants of cosmology and particle physics, are at a local optimum for the condensation of galaxies and stars culminating in the collapse of stellar remnants to form black holes-----this is the hypothesis.

So far no one has been able to refute it----that is, no one has been able to think of a small change in one of the parameters which would cause the universe to be richer in astrophysical black holes.

Smolin has proposed ways to empirically falsify this hypothesis by astronomical observation (measuring the masses of neutron stars) but so far it has not been falsified by observation.

This is in the same spirit as your research interest, but by different means. You both want to see a PATTERN in the parameters of cosmology and particle physics, which might some day lead to a physical understanding.

Smolin's hypothesis is Chapter 20 of a new book from Cambridge University Press, called Universe or Multiverse edited by Bernard Carr, a professor of mathematics and astronomy at Queen Mary London.
http://www.cambridge.org/catalogue/catalogue.asp?isbn=9780521848411
I don't think I would like the entire book, but I have Chapter 20 separately and like it very much.

 

[marcus]

I see one of the posters on this thread says "THIS THREAD IS NOW OVER!"

But actually Chrisina I think you asked a very interesting question, which has not been very adequately addressed. I think that to make it more convenient to answer one should divide it into two steps.

How to explain to my grandmother the EFFECTS of the recent epoch of string dominance in theoretical particle physics...?

And only as a secondary issue, in what sense can one consider these effects to have been beneficial?

If you want to talk about the first of these two questions---the value-neutral part---then I would be willing to give it a try. I would simply ignore posts by people who do not seem to "get" it, otherwise such a discussion can become too much work. Everybody can express their views and if there is a difference, fine! There does not have to be complete agreement, nor need there be arguing or altercation either.

But if you are already tired of discussing the effects of the string epoch on physics, we can let it drop. I would certainly be content with that as well.

 

[chrisina]

Well Marcus, I think it is a good idea to split the question into two, parts, a value neutral one and a more sujective one. Would welcome here the inputs of some advocates of String theory.

I haven't started this thread in order to prove a point, ie String theory has had many benefits, or hasn't had many benefits.
I started this thread with a "genuine" question, that of my Grandmother : what are the benefits ?

I actually also like the discussion with Rewebster because it is very helpful to look at the history of science in order to find some parrallels with what is happening today with String Theory.

His point about the greeks and the atoms is a very interesting one when we look at it in the context of String Theory.

Let me try to explain my point of view :

1. there is no doubt in my mind that ST has done a lot in establishing a new conceptual framework and in the advancement of pure mathematics. These are clear benefits from a scientific viewpoint.

2. However, and this is the crutial point, the press has not chosen to communicate these benefits, but rather has chosen to portray ST as THE solution to the quest for a "theory of Everything".

3. The question then is, why did this happen ? In my view, this essentially has to do with what is implied with the word "benefit" in the mind of the press, the general public, and, my grandmother : would they accept the explanation given in point 1. as benefits ? I don't think so.

Fundamental physics has very much been portrayed in the past as the mother-science for the technological advancement of humanity (and this especially during the first half of last century). Einstein, Planck, Bohr, Schrödinger, and I'd say up to Feynman where all very well known by the general public and were seen as heroes.

The general public is not dumb. If physics is so detached from reality, they loose interest. So they only want to know, and that is the only question they keep asking again and again, is String Theory the "theory of Everything ?". In other words, is it going to have an impact on our lives and that of future generations ?
And the problem is, theoretical physisicts know very well that without experimental confirmation, that question will remain unanswered.

So coming back to the greeks and the atom, the parrallel with ST is in my view quite striking :
. as Rewebster mentionned, the greeks purposed the atom more than 2000 years ago. Did this have any benefit on peoples lives ? No, because they didn't have the means to experimentally verify it. One had to wait first for completely unrelated ideas to develop (Newtonian mechanics, then Maxwell, then Planck, then Einstein) until finally we had the means to verify it, and then only it started to have an impact on people's lives.

How long will it take before we have the means to experiment at Planckian scales ? I have no idea. But it seems to me that before that, we will need to develop new areas of Physics, for example Physics of Dark Energy. Is it related to Quantum Gravity ? Is it the theory of Everything ? Maybe not. But Dark Energy is a concrete new physical phenomena that has been discovered and has no theoretical model. And experiments can be made by improving the resolution and mesuring polarisation of the cosmic microwave background. So why not attack this problem first before one makes suppositions on grand unification ?


Check these two videos :

http://nobelprize.org/cgi-bin/asxgen.asx?id=79&type=interview&year=2006
(Interview with the 2006 Nobel Laureates in Physics, John C. Mather and George F. Smoot, 6 December 2006, the discoverers of the CMB signal.)

http://nobelprize.org/nobel_prizes/physics/laureates/1999/veltman-interview.ram
(Interview with Professor Martinus J.G. Veltman, Nobel Prize winner, in December 1999. Listen to what he has to say about "grand unification")

Well that's all folks, its just a point of view, and welcome the debate.

 

[chrisina]

(in the first video, the most interesting starts in my view at about the 20th min.)

 

[rewebster]

First of all, to mjsd, no, my grandmother was not being cynical, but genuinely interested in the question. I had just shown her this "elegant universe" TV show that I found via this forum. The thing, you should meet my grandma, she's going on her 95th birthday but is still very alert and loves to keep up to date ... maybe the fact that, as a young woman she was between 1932 and 1939 the secretary of a certain Louis de Broglie at the Paris University is for something...
Secondly, I do not buy in the "fun / sexiness" arguments. I am passionately convinced that we are living some of the most exciting years in Physics since the 1920s, because there seems to be so much we need to understand again. I mean so much Fundamental we need to understand.

Hey---

---YOU haven't answered MY questions first!---did granma REALLY work for de Broglie ?------AND does she have any juicy* stories about the times there that she is WILLING to share (or unwilling even)?

-------------------------

juicy*----I mean, related to PHYSICS, of course

 

[chrisina]

no, I'm not joking, she really worked for him before the war.
She wasn't a Physicist, she was only his secretary. De Broglie didn't speak good English, so she had to translate all the time.
Those days, De Broglie was organising a regular seminar in Paris on what was then called wave mechanics. In this context, she remembers meeting with most of the greatest names of this century (Einstein, Heisenberg, Pauli, Schrödinger,Born, Fermi...etc). What was clear to her then, was how De Broglie and Einstein were so close (from a frienship and philosophical standpoint) and shared the same views on causality / determinism. They were always in one camp in the debates, against all the others.
It's strange in a way that this debate is still not over now, especially when you look at the current debate between people like Smolin / Rovelli and people like Süsskind / Polchinski on Background independence or not.

 

[rewebster]

Well, just a suggestion along this thing---I would get all the memories of everything that she can remember (set up a video camera as a type of video diary) --as she recalls different things over the next months. There's not too many people left in the world that have been in her situation and it would be a great loss to you (and all of us) if it isn't recorded for history.

 

[Fra]

I think Chrisina has some good reflections.

I think that if anyone senses that some proposed ultimate answer doesn't seem to match the ultimate question of their preference, that answer doesn't have very much value from their point of view, even if it is possible to devise a question to which it is the answer.

I have lately had a strong impression that there is something wrong, not only with the theories, but with the application of the scientific method.

When model complexity increases, the number of possible routes of expansion naturally also increases to the point where the originally not very sophisticated guessing routines gets quite inefficient, and the chances are that unless we can evolve some higher level of sophistication to make progress we will die. I think this requires not only looking at new formalisms, but also looking at new methods for looking.

So what is the ultimate tool a lifeform needs? A grand unification of all physical forces in nature? I hardly think that's it, is it? I think we need to revise the questions we are trying to answer.

Experience tells us that usually one answer often results in follow up questions by some desire to reach out further. So the ultimate question seems to be, what the next question should be. Because the response of the first answer is usually another question.

I've been called philosopher a lot but to speak for myself I do not believe in anything such as ridicilous as the ultimate answer, or the ultimate question.

This simply and obvious observation has lead my to think that any candidate GUT that is to make much sense at all, must at least aspire to implement and explain this evolutionary rule, and therefore I think the answer is not a infinite dimensional monster model, I think it is a basic evolutionary rule. At the same it should also be clear that at each level of evolution, there is most certainly possible to find a fixed model that explains everything. But if we have reason to think that new questions will eventually be asked whose answer is outside this model, it should become almost obvious that the larger and more complex the model becomes, the more essential is it that is has the able to respond to this request and evolve accordingly.

So, in addition to the falsification property, I think any sensible theory should at lest TRY to implement an emergency response to the unexpected. At least in my personal quest for scientific answers, I have hard to take anything that ignores this as even possibly fundamental.

All the thinking I've done suggest that these evolutionary ideals is a deep thing, and is far more than just some analogy with biology. I would say it is not really an analogy with biology, except in our heads, it's deeper than that.

This is also something that I think would be understandable to the public.

/Fredrik

 

[chrisina]

cannot agree more with you Fra, evolution seems to be a fundamental aspect of nature that particle physicists and cosmologists have not really taken into account so far... if it applied to organic molecules, why not to the fundamental constituents of our universe ?

I like to study the history of science, there are some jewels :

at the very end of the 19th century, Ludwig Bolzmann was asked "are there things that science still cannot explain ?" He replied, "there are two small things that puzzle me, where does the law of blackbody radiation come from, and why doesn't the Michelson-Morley experiment work"

Well we all know what happened next. These were the two fundamental trigger points which gave birth to most of the 20th century physics.

You see, I'm stuck in the same way of thinking (maybe I should have lived in the 19th century) :

there are two "small" things we do not understand :
1. where do the parameters from the standard model come from,
2. and what is this dark energy / cosmological constant that seems to constitute more than 90% of what the universe is made of.

String theory developed in an attempt to answer question 1, and question 2. was not known at that time.

Now it seems that string theory is saying that the best answer to these questions is a form of quasi infinite landscape of parameters and some form of anthropis explanation.

I am afraid that if we would have invoked the same "anthropic principle" to Ludwig Bolzmann's questions, I wouldn't be typing on this damn computer, because the interent, electronics, etc would not have been invented.

 

[rewebster]

What have you told your grandma so far?


or, Is she a 'classical'/'quantum' woman?

 

[Careful]

I don't know if anyone said this already but first I would explain my grandma about gauge theories which are universally accepted (shut up about the problems in the formulation of a quantum field theory, keep everything on the classical level). Then, I would pick out the solution of the vector potential for a point particle in an external electric field in Lienard Wiechert form, and show her explicitely where hidden strings and two branes can be found. Next, I let her imagine how pure radiation interacting with matter could be seen as scattering of closed strings (on something else) and then I would tell her about the work which has been done in the eighties on string gauge duality and how to derive fermions from bosons (because I don't want to explain her Grassman calculus).

Probably I would first have to tell her about the hypothesis of atomism versus a spacetime field theory though (since I keep everything classical).

 

[Fra]

I went through Smolin's paper on alternatives to the anthropic principle listed by marcus in https://www.physicsforums.com/showthread.php?t=166703 and while I think he has som good points, I can help finishing the paper very unsatisfied.

I sense there is a very categorical tone of reasoning, and that some things are simply true and some are false, based on not crystal clear reasoning. I would have thought that modern physiscs should have suggested that the better way of reason is to consider degrees of truth. Where complete certainty and complete uncertainty are really only extremals, and these extremals is almost all you've got back in the classical world. For various reaasons, for example finite resolution of measurement and finite data storage, I think it doesn't make sense to reduce the degrees of support to true and false. Moreoever, I think it should also seem clear that degrees of truth can be relative, or subjective if you want. This makes me doubtful about Smolins categorical use of the term "shared evidence" because upon closer investigation in my opinion at least, this is not as easily defined as in classical world.

/Fredrik

 

[Fra]

The main problem I have with the categorical reasoning is that it risks overseeing other seemingly "unlikley" (but still possible) possibilities, that in the boolean reasoning are simply taken to be false.

/Fredrik