The Multiverse, the Initial Conditions, the Laws and, Mathematics by Laura Mersini-Houghton

Dear Laura

Thanks for the warning about confusion. I do remain confused, but less so than the SM. A well written and original essay, but I may be a little more interested in how you derive the large scale Planck anisotropies via entanglement, largely as I've worked on the same (from the 'observational cosmology' view). I hope you'll study some of the the valuable (Green/Red) fruits in my essay.

On the multiverse; do you consider that anything so mundane as 'multiverses' in separate spatial and temporal domains may be a solution? 'Temporal' merely as sequential recycling of ours, and spatial at a far greater scale range than human minds can normally conceive, in fractal-like 'steps'. i.e. in the 'big' direction we then have 'infinitely' many universes like galaxies with perhaps true vacuum between?

If you feel we need more (after reading my essay) can you identify why?

Many thanks

Peter

I found this an extremely stimulating article. It boldly goes beyond the frontiers of established physics and does so in a reasonable understandable way. However, I had great difficulty making sense of the layer of laws as something with some kind of separated existence beyond space-time. prescriptive laws may have an existence separate from the matter to which gthey are applie. But the laws of physics are not prescriptive. I can't make sense of a separate layer of lws for any branch of established physics. So I see no basis for extrapolating this to idealized future physics

Ed. MacKinnon

Dear Professor L. Mersini-Houghton,

Great thought provoking essay, I have a couple of comments/observations if you dont mind.

I would have to agree your answer to "Does the multiverse exist?" given your definition of the multiverse "contains all the universes, domains, matter and particles, energy and vacua, and any other object you can think of embedded in its spacetimes.". If the multiverse doesn't exist, where are the particles?

Regarding "If there is a multiverse, what does it look like?", you provide a significant amount of material for the reader to digest, but perhaps I am left a little confused. We all want answers, just tell us what it looks like so we dont have to think so hard about it. I am joking of course, not all question in physics have been complete answers at this time, otherwise there would be no jobs for physicists.

WRT the role of mathematics in physics, I thought your comment "can nature contain laws and axioms that cannot be written in a mathematical language, yet still exist?" provided a solid basis to think about the role of mathematics in physics.

Best of luck in the contest, and if so inclined, you can read my essay here. You will see a view of the world that quite different from yours. Regardless of the difference, I really enjoyed your essay and thought it was very well done and a pleasure to read.

Regards, Ed Unverricht

Dear Professor Mersini-Houghton,

I posted a comment at your site that was unnecessarily contemptuous and devoid of the civility all contributors are entitled to. I deeply regret having done so, and I do hope that you can forgive my slurring of your fully deserved reputation.

I suspect that I may be suffering a relapse of Asperger's Disorder. While this might explain my distasteful action, it cannot in any way justify it.

Respectfully,

Joe Fisher

Dear Laura,

Marvelous essay, and one that hits the bull's-eye of today's most profound issues.

Besides holding steadfastly to extending the general relativity solution ("Scientific progress is incremental and at this time we have reached the stage of investigation into fundamental aspects of spacetime") I agree that the multiverse model naturally follows from the identification of time with information theory.

Where we might diverge, is in our opinions on the origin of branching universes. You favor hierarchies -- what I find, on the other hand, is that nature cannot respect any vacuum state without respecting all vacuum states. No hierarchy.

Deserved highest mark from me. I look forward to dialogue.

All best,

Tom

Dear Laura,

It is intriguing that, as you write, the multiverse paradigm agrees with three major physical theories: QM, cosmic inflation and string theory. I like that you describe your point very elegantly, without technicalities and in connection with Planck satellite experiments. As I am a pedestrian in cosmology, I cannot judge if one needs the multiverse hypothesis for the CMB giant cold spot and the CMB additional anisotropies. I heard that another 'church' propose a Poincaré dodecahedral space for the latter effect (J.P. Luminet).

My impression is that many enigma (not in a philosophical range) as the dark energy or the smallness of cosmological constant need an unifying scheme. I am not (yet?) convinced that one needs the many worlds for QM (except for restoring the classical space time). I am also reluctant to accept that the 'laws' are a layer in real world, I tend to favour a cognitive process of humans

in their evolution without further ado. But I agree that it is again a credo without proofs.

Thank you for guiding me into the multiverse hypothesis and good luck (I try to boost your essay). I hope you will have enough time to follow me into the Monstrous World of finite groups.

Michel

Dear Laura

When you enumerating arguments for Multiverse, you could add also Darwinian evolution and Tegmark's mathematical multiverse.

It seems to me, that Linde's multiverse is very possible. Esspecialy, because a reason for big bang does not yet exist. But I do not believe in many worlds interpretation of quantum mechanics. Becase this means that free will does not exist. But this is strongly against my intuition. I hope that this can be possible to prove also mathematically.

I think that physical laws should be simple and this is a little in contradiction with anthropic principle, because any reduction of physical laws means reduction of anthropic principle. Reduction means, for instance, that G, h, and c cause that physics is dimensionless. Admittedly, when this simplification is not clear, there it is free space for anthropic principle. What do you think about this? I also do not believe in Tegmark's multiverse. My intuition says that QG theory should be written on t-shirt.

You addressed also a question of consciousness, which is important to explain physics.

Otherwise, I am more positivist, but, for instance, I disagree with positivists, for instance I claim, if a cause of Big Bang is not explained, Multiverse is possible.

My essay

Best regards,

Janko Kokosar

Dear Laura,

I think Newton was wrong about abstract gravity; Einstein was wrong about abstract space/time, and Hawking was wrong about the explosive capability of NOTHING.

All I ask is that you give my essay WHY THE REAL UNIVERSE IS NOT MATHEMATICAL a fair reading and that you allow me to answer any objections you may leave in my comment box about it.

Joe Fisher

Dear Laura Mersini-Houghton,

I like your clear style and the optimistic outlook, but must confess that your essay did not persuade me in the end.

For instance, you write that you find it hard to accept it as a coincidence that in different branches of modern physics the idea of a multiplicity of world has surfaced. However, agreeing that it is not a coincidence does not need to imply that this idea corresponds to the ultimate structure of reality. It could, for instance, simply be a lack of human imagination, or a common response to certain theoretical limitations, and of course once an idea is launched within a branch of physics it will more easily spread to other branches of the same discipline.

In addition, I wonder what you think of the naturalistic approaches (there are quite a number of essays that take this stance, although they develop it in various ways): these take language, mathematics, and science as something that co-evolved with humans. Do you think ideas of this kind are compatible with the levels you refer to?

Best wishes,

Sylvia Wenmackers - Essay Children of the Cosmos

Dear Laura,

I like that you are tackling the initial conditions problem, as I agree it is a vexing one. This is not only a problem in physics but also in other sciences, including biology where the "specialness" of initial conditions seems to be fairly acute. However, there you can in principle (I think) get around it by coupling laws to states, i.e., having state-dependent dynamics (note this also yields interesting features such as path-dependence seemingly characteristic of life). This is interesting to me as it suggests what the true divide inhibiting reconciliation of physics with biology is that in physics we tend to strictly separate laws from states, and in biology that boundary is blurred. I am curious if you have ever thought on state-dependent dynamical laws as a solution to the initial condition problem (its sounds almost like your dynamic landscape model might be approaching this).

All the best,

Sara

Dear Laura,

I like your point of view. One of the reason is there is not any antropological based sign , even argument which doing us more or less for important for universe itself.

Every good theory need a lot of test: So Did you test your prediction with holographics principle ?

Can be your wave function of our universe holographicaly extended to be by-us seen universe ?

If yes, for optical hologram we need two sources-streams of light. What kind of streams do you need to create hologram from wave of our universe ?

Thanks ahead

Jan