Thanks greatly Phil,
The universe doesn't look quite homogeneous to me, but I didn't remember about LeMaitre, though I probably learned he was working with other models. I know Hubble had his doubts about the expanding universe notion, and looked at other ideas just as seriously. Working assumptions were adopted by the mainstream, and once held long enough became principles, just as you say.
Emergent spacetime is likely what's real; the question is "from what?"
All the Best,
Jonathan
Thank You Vladimir,
I have a photograph of Zeilinger standing in front of a slide showing the book page regarding Einstein's letter expressing doubts about the light corpuscle theory. I got the sense from Zeilinger's lecture that he was telling folks don't trust anything to be true with absolute certainty, but suggesting photons might be wave-like after all. Keep an open mind.
Decoherence theory paints a different picture as well. The suggestion there is that the underpinning is wave-like nature, and that probabilistic surface appearances are a direct result of the fact that observation takes place from a localized framework, which induces the appearance or occurrence of a local collapse of wave-like nature into particle-like natures with probabilities.
I looked briefly at your essay, which has cool drawings as I recall, and I will comment further on your forum page.
Regards,
Jonathan
Thanks Gene,
I appreciate the kind thoughts.
I note that Shannon's information entropy has the same equation as that for thermodynamic entropy, except without Boltzmann's constant. Professor Leff takes the question up in the last article in his 5-part series, suggesting that information loss is an important dynamic to complement the spreading metaphor and include other forms of entropy.
My thought is that if we expand the spreading metaphor into spreading in possibility space this could be seamlessly merged into quantum mechanical interactions. I'll get to reading your essay soon, and comment on your pages.
all the best,
Jonathan
Dear Johnathan,
I want to let you know that I have read your essay and found a lot to agree with, which probably comes as no surprise. Well done. It seems to be what the competition asks for, accessible, enjoyable, relevant, well written. It ticks the boxes. I wish I could be even more enthusiastic and inspired to discuss its content. Unfortunately I have spent far too long on this web site talking about how I regard the many problems and how I think they can be resolved. Like Israel Perez' excellent essay, it feels to me like the inspiring team talk before the match. When what I'm really itching to see is the match started. Not your fault, entirely mine. Good luck in the competition. I hope lots of people read your essay and are inspired by its important message.
Thanks Georgina,
Rest assured that the match is on and the game is afoot for me already. While it may seem like I was casting about in this essay, and ticking the boxes, there is a big picture in my mind for which many of those scattered bits of information serve as evidence. I am working on a paper right now, spelling that thesis out. It is intended for publication, but I am not ready to post a draft here yet.
As to the other matter, I think being inspired by Science and wanting to learn about it go hand in hand. It is a real challenge for some teachers to make the subject interesting and exciting enough to hold kids' attention. I think making Science more fun should be a real goal in itself, as that is the prevailing attitude among those scientists who actually 'get the gold.'
I wish more kids were inspired to compete, though the demands of a field like Physics are necessarily rigorous, rather than sit and watch on TV (if at all). But I got the Science bug at an early age, and it's hard to pull me away once I get into some ideas and questions. I'd be an FQXi junkie, if I had more time.
all the best,
Jonathan
Hi Jonathan,
Great point about getting kids into science early. I have had the honor the past three years, of serving as a Cyberguide for middle school students, in an annual science competition program sponsored by the US Army. The kids are enthusiastic, serious and motivated -- the teacher sponsors are selfless with their time. I take every opportunity I can to tell scientists and teachers -- volunteer in any capacity you can. You will get as much if not more satisfaction from it, as the students.
Tom
There you are,
Thanks for making my point Tom, and it does sound like fun. If we get the kids started thinking about Science while their minds are still open to being inspired, the next generation will produce some very able scientists.
All the Best,
Jonathan
Your essay is food for thought. When experiments lead to difficulties it can often be the case that our postulates are incomplete or wrong.
Cheers LC
Thanks Lawrence,
I'm glad my essay provided inspiration for further thoughts. Getting a new perspective is what progress is all about, or how advances in Physics happen. Having experimental evidence in contrast with past observation breaks the pattern and is a wake up call - alerting us to the need to learn more, before we can truly understand.
Then the question becomes "which of our postulates got us into trouble?" So there is always something more to learn.
Regards,
Jonathan
Hi Jonathan,
i find your essay is great, well-elaborated, entertaining and informing at the same time on a well-founded, easy to understand and intuitive level.
My appreciation to this pice of analysis, i can subscribe every sentence of it!
Best wishes,
Stefan
Should read "piece" instead of "pice", sorry!
Thanks so much Stefan!
I had already planned to finish my first read through of your essay shortly, but there was a comment here and I found it was your enthusiastic message above. I am very glad you got something out of my essay and thought I presented my ideas well. There is plenty of interesting material to read this year, but I am happy I made your stop here a pleasant one.
All the Best,
Jonathan
Dear Jonathan,
you really earned this appreciation. Your knowledge of the relevant issues in physics is that broad and you did contemplate all of it. Thanks for having lead me to your essay!
Best wishes,
Stefan
I finally got my voting code, which I did not receive with the acceptance. I will try to reread your paper in the near future.
I indicated to Giovanni Amelino-Camelia the κ-Minkowski and his boost operator should have some connection to twistor theory. The boost operator P_μ that acts on [x_i, x_0] = ilx_i such that
P_μ > [x_i, x_0] = il P_μ > x_i
The coordinates (x_j, x_0) we write in spinor form
x_j = σ_j^{aa'}ω_{aa'}
x_0 = σ_0^{aa'}ω_{aa'},
where ω_{aa'} = ξ_a ω_{a'} ξ_{a'}ω_a. This commutator has the form
[x_i, x_0] = σ_j^{aa'}σ_0^{bb'}[ω_{aa'}, ω_{bb'}]
= iC^{cc'}_{aa'bb'} σ_j^{aa'} σ_0^{bb'} ω_{aa'}
= i|C| σ_j^{aa'}ω_{aa'}
where the magnitude of the structure matrix is |C| = l. In general this may be written for
x_j = σ_j^{aa'}ω_{aa'}
x_0 = σ_0^{aa'}ω_{aa'} iq_{aa'}π^{aa'},
where the commutator [ω_{aa'}, π^{bb'}] = iδ_a^bδ_{a'}^{b'} and the general form of the commutator is then
[x_i, x_0] = i|C| σ_j^{aa'}ω_{aa'} iσ_j^{aa'}q_{bb'}[ω_{aa'}, π^{bb''}
[x_i, x_0] = ilσ_j^{aa'}ω_{aa'} - σ_j^{aa'}q_{aa'}.
The boost operation B = 1 a^l_jP^j on the commutator [x_i, x_0] is then equivalent to the commutation between spinors [ω_a, ω'_b] for ω'_b = ω_b iq_{bb'}π^{b'},
[ω_a, ω'_b] = [ω_a, ω_b] iq_{bb'}[ω_a , π^{b'}]
= C^c_{ab} ω_c iq_{ab}.
Ed Witten demonstrated a "twistor revolution" in string theory. If this connection exists and can be explored further, it might mean that loop variables and other discrete quantum gravity ideas might bridge with string theory. It could then be that the two approaches will fix the various difficulties they have.
Cheers LC
Cheers
Hello Jonathan,
I've returned from holday and reread your essay, enjoyed it very much. Thinking about how we think and progress can be very helpful, and the points about child psychology were interesting. You mention that in cosmology there are sometimes a number of different explanations for the same data, rather than just one. This is similar to a point I make in my essay about how physics is full of equivalence - often more than one conceptual picture is described by the same mathematics.
What I think is sometimes overlooked is a distinction between the conceptual side of physics and the mathematical side - I see this as very helpful in the present situation. The conceptual side has been given too little emphasis for half a century, because the two main theories were very hard to interpret. So interpretations were somewhat devalued, and the focus went to the mathematical side. But if there are missing pieces of the puzzle, and if they're conceptual pieces as I've argued, then there may be a need to find them before we can make real progress. If so, instead of resifting our view of what we know already, and how we look at what we know - which some of your essay seems to cover - there should be a definite search for missing conceptual ideas. The solution to a puzzle is sometimes comparatively simple, once new conceptual elements are found. And without them we might make little progress.
In the questions about time, which may well need a solution before we can get to quantum gravity, it's quite easy to show that there are probably missing conceptual pieces - our present ideas about time do not between them cover enough area to fill the gaps in the picture. So I'd say there's an need to focus much more specifically on the conceptual clues we have. People looking for new ideas often ignore them. Perhaps they're ignored because we tend to assume they can't be interpreted, and would have been already if they could be. But also, the existing view we have makes these clues look like they might be unreal, and part of an illusion. I'd say in analysing how we think about physics, that side of things should be remembered. Anyway, good luck with everything,
Best wishes, Jonathan
Indeed Lawrence,
The 'twistor revolution' in string theory is the most important breakthrough for either twistors or strings in years. It as though String Theory has seen a lot of cloud to cloud lightning, but was stuck in the clouds having no clear path to ground. But Twistor theory provides 'leaders' from ground to air - so the air to ground lightning can connect. This explains a lot of the action we've seen with Nima Arkani-Hamed and his colleagues' work exploiting S-matrix dualities.
But the larger issues of emergent spacetime and building bridges allowing us to redefine loop variables and other causal elements that arise when considering Quantum Gravity need considerable work, at this point. It remains promising but, as I state in my essay, I think the Octonions also offer a natural approach to spacetime evolution. I thank you for the analysis of important terms in the above comments; unfortunately, I still have not read Giovanni's essay - so I have to trace these references back once I do.
all the best,
Jonathan
Wow Jonathan!
You hit the nail on the head, that conceptual models are somewhat lacking and should always inform our Math in Physics. In my research, I have encountered plenty of examples of the opposite - things which arise from pure Math that appear to have connections to, or applications in, Physics.
But without a clear conceptual model, these mathematical explorations have no connection back to the real world. There is always room for more than one conceptual model in my perception of the universe. As you point out, several conceptual representations can express the same Physics, or be coded by the same equations.
But modern adults tend to forget what children know intuitively. One Cognitive Science researcher I cite, Alison Gopnik, refers to this as the "Lantern vs Searchlight" phenomenon. While children shine their lamp here and there, in search of knowledge, adults say let's shine a LIGHT on it, in a narrowly focused way. Sadly, this cancels out a lot of healthy exploration.
all the best,
Jonathan
Hi,
Well as you say, an approach of general enquiry is good, rather than with too many presumptions. But I also don't mind shining a light in a particular direction, because I think there are specific clues to be examined on the conceptual side.
I think we forget how much conceptual progress can simplify the picture. Within the mathematics, people tend to say, well we haven't found any simple answers, so let's look for more complicated ones. To me there's a bit of that in your idea that the dimensionality of the universe is evolving. It's true that at present our theories disagree on the dimensionality of the universe, but I suspect that with conceptual progress, we might find it doesn't have to be as complicated as an evolving picture. That's my opinion - the simplicity of some of the mathematics suggests it. Anyway, let me know if you have any thoughts on my essay, I'd be grateful to hear them.
Best wishes, Jonathan
Hello to both of you,
I beleive that Mr Witten has very relevant ideas. The strings are a good idea for the computing.Intersting also for our extrapolations. But and there is always a but :)it is not sufficient. It lacks the quantization of this gravitation. My equations and my theory helps. I beleive that the convergences can be very relevant with a correct projective geometrization spherization. The domains when we speak about our pure realism must be taken with the biggest determinism. If we want to simulate correctly the Universe for example, the 3D is essential and the spheres also and the rotations also and the volumes also. It is so evident. I find very relevant the fact that we can quantize this mass, the SR and the GR are harmonized. It was time no? :) The strings so can be correlated with the rotations proportional with mass.
The space time evolution is a system which needs spheres and rotations and volumes.It permits to have the correct simulations of evolution.The entropy increases due to this evolution. The quanternions and octonions are mathematical tools. That is all. My spheres, them are real. I ask me if it is possible to create a 3D holographic sphere and after we insert the spheres inside. I beleive that it is possible to simulate this space time evolution correctly in 3D. with a real holographic sphere. We could change the parameters and variables.We could insert the duration and the volumes more the spinal speed and orbital speed.We could insert all the elements and their rules. If we differenciate the fermions and the bosons with two sense of rot.So it is relevant for the understanding of the light and its linearity. The volumes of cosmological spheres more the volumes of quantum spheres become relevant. I discussed with Dr Corda about the singularities. I Beleive strongly that the space can be inserted in this 3D holographic sphere with the same line of reasoning. It is intriguing to see that the space and the light and the mass are the same in fact. The lattices between spheres so become a key for the two scales.
Mr Witten can perhaps create this 3D holographic Universal sphere.The universal sphere can be made in 3D in fact.It is a little if I said that we can create our card of the sky really. The beauty of sciences is to discover our universal sphere and its secrets.And the 3D is essential for our contemplations of creations.
Regards
Johnatan
In my essay i catch new sense of Planck mass
See http://fqxi.org/community/forum/topic/1413
My conjecture: There are Base Fermion and Base Boson of the Universe. Value of Planck mass is Geometric Mean of Values Mass of Proton(Neutron) and Mass of Hawking Black hole
Base Fermion is proton(neutron) ;Mpr=10^-24 g
Base Boson is Hawking primordial black hole ;Mhbl=10^16 g
Mpl=sqrt(Mpr x Mhbl)=10^-4g
Rounding values.
