# M-theory for the layperson, part II

Okay, say you want to explain M-theory to someone whose only knowledge of strings is that they are 1) fundamental one-dimensional vibrating objects that have replaced the structureless elementary particles (pieces of atoms...), and that 2) their vibrations give rise to elementary particles with different properties, i.e., from matter to energy. Oh, and they know the analogy of a guitar string...
They have a limited - only very basic - knowledge of physics.

How would you explain M-theory to this person, have them stay alert[zz)], and have it make sense at their level of understanding?

Oh, and I mean something more than "a theory that unites all five string theories, and supergravity, within a theoretical framework, but which isn't understood completely yet" ...

I need something with a little more complexity, but without the need for them to run out and enroll in an advanced physics course, nor something that will turn them off to the whole subject.

Think this is possible?

lethe
can you tell me how you want this thread to differ from the previous thread of same title?

quartodeciman
It is most important that you prepare YOURSELF well for this task. Since your auditor is not very well prepared and you don't want to just stick to the simplest stuff, then prepare by reading / printing off all of the following aids. Mix and cook the material into a great intellectual goulash, then prepare yourself to dish it out. Your spiel should include names, history and some odd physics and math facts. If it doesn't quite come out right in the end, so what?

Amsterdam: Nonperturbative String Theory -->
http://turing.wins.uva.nl/~rhd/review.html [Broken]

Caltech: String Theory Basics --->
http://superstringtheory.com/basics/index.html

Caltech: The Second Superstring Revolution -->
http://theory.caltech.edu/people/jhs/strings/index.html

Cambridge: M-theory, the theory formerly known as Strings --->
http://www.damtp.cam.ac.uk/user/gr/public/qg_ss.html

Cornell: Superstring Theory -->

MIT: Superstrings! --->
http://www.sukidog.com/jpierre/strings/

Tata: The Theory of Strings: A Detailed Introduction --->
http://theory.tifr.res.in/~mukhi/Physics/string2.html
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quartodeciman
On second thought, I would substitute the following TV transcript and collateral files for the aged Cornell Superstring Theory page by Greene.

PBS NOVA: The Elegant Universe --->
http://www.pbs.org/wgbh/nova/elegant/

Yes, some of it is corny, and I would avoid stuff like the Quantum Cafe, wormholes and walking through walls. But these people are good explainers and have successfully encapsulated the main issues as far as onlookers are concerned. I especially like discussions of experiments, both done and proposed. That should be emphasized more than the eleven dimension business. Get the Elementary Particles chart and Smashing Pictures slide show.

Quartodeciman, thanks for all the links! Very good stuff in amongst them all... I appreciate the post.

Lethe,
About the last thread with a similar name... Well, it started out okay, but very quickly turned into the topic "did Lubos Motl really develop Matrix theory?" Lubos, himself, did submit some really great links, including a powerpoint production, but almost no one submitted anything I could use to explain M-theory to someone who didn't have at least some knowlege, graduate level, in physics/string theory.

It was a little off my topic, so I thought I would try again.

I'm new at this forum; did I violate anything here?

lumidek
Hypermind

Hi guys,

there is also an introduction at the "Hypermind" server with a lot of pictures with strings and the extra dimensions...

http://www.hyper-mind.com/hypermind/universe/content/gsst.htm [Broken]

Best wishes
Luboš

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HEY LUBOŠ,
Thanks for checking in and for the terrific link(s)!

Here's what's happening with me and why I'm a little stuck...

One of the reasons I'm pursuing this is for a friend. She is writing a book about parallel universes and has very little physics background. I've already put together a brief review of relativity and quantum mechanics, with a couple of simple math equations and explanations for both theories, and sent it off. The next thing I intend to send her is the history of how string theory developed, what strings/branes are, how they work, some predictions, et. al. and a little math with that. All this I'm sure I can explain in simple language.

There are so many explanations of where string theory came from, what strings are, how they do what they do, their size, their shape, their attributes, and, perhaps, most significant, the fact that their discovery opened the way for a new, and, perhaps, unified, theory for how the 'real' world works in a mathematically elegant manner. But, in all my research, I've not quite come up with a comprehensive [I'll call it 'hyper-metaphor'] explanation for all these connections [maybe a 'connect the dots theory'...?] or for the sum (?) of all the different theories for M-theory.

But my ultimate goal is to send her something that explains the connections within M-theory in a format that is not math, not physics and not exactly metaphor. Does that make sense?

Perhaps this is not a doable project, eh?

I don't want to necessarily solve M-theory per se. My hope is to somehow explain all the dualities, the odd-ball connections that work only in certain dimensions, the fact that all six of these parts work together as a whole, but that some don't work with others, but that those others work with some (and the reasons why) - in simple non-graduate-school-physics/math terms that, maybe, just maybe, in a few decades, teachers may be using this in the classroom to teach M-theory (or its successor) to grade school children. Hey, it's just a small request.

(I'd be glad to email you the text of the review that I've already done so you can see, kind of, what I'm talking about)

Thanks again for your input - I feel like I'm on an island out here...

lumidek
Revolution

this story about the book sounds exciting, I hope that you like this sort of work. I would probably be writing what has been written many times - and some of these texts are written in a better way than what I could do. An explanation of connectedness between various string theory can be found e.g. in Schwarz's "Second superstring revolution"

http://arxiv.org/abs/hep-th/9607067
http://arxiv.org/PS_cache/hep-th/pdf/9607/9607067.pdf [Broken]

The same issue is being commented in a paper by Joe Polchinski - page 12 is where the dualities start

http://arxiv.org/abs/hep-th/9812104
http://arxiv.org/PS_cache/hep-th/pdf/9812/9812104.pdf [Broken]

I am happy to tell you something myself, but you would probably have to formulate your question more narrowly because my times is not unlimited.

Best wishes
Luboš

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