e8_and_level_iv

[quote]There are ample future prospects for testing and perhaps ruling out these multiverse theories. In the coming decade, dramatically improved cosmological measurements of the microwave background radiation, the largescale matter distribution, etc., will test Level I by further constraining the curvature and topology of space and will test level II by providing stringent tests of inflation. Progress in both astrophysics and high-energy physics should also clarify the extent to which various physical constants are fine-tuned, thereby weakening or strengthening the case for Level II.

If the current world-wide effort to build quantum computers succeeds, it will provide further evidence for Level III, since they would, in essence, be exploiting the parallelism of the Level III multiverse for parallel computation (Deutsch 1997). Conversely, experimental evidence of unitarity violation would rule out Level III. Finally, success or failure in the grand challenge of modern physics, unifying general relativity and quantum field theory, will shed more light on Level IV. Either we will eventually find a mathematical structure matching our universe, or we will bump up against a limit to the unreasonable effectiveness of mathematics and have to abandon Level IV.[/quote]
This sounds interesting. So, Level IV would be made more likely if and when we find a "mathematical structure that exactly matches our universe". It hadn't been found Don't worry- you don't have to wait long. In 2007, four years after Tegmark's article, surfer-physicist A. Garrett Lisi published a paper called [i]An Exceptionally Simple Theory of Everything[/i]. It sparked minor controversy among the physics community for its expression of gravity in the same terms as electromagnetism and the strong and weak nuclearforces although they operate on vastly different scales. Furthermore, he lumped together fermions, particles that don't spin in whole integers and have mass, and bosons, force-carrying particles with whole spins. Lisi performed a TED Talk on the subject entitled [url=https://www.youtube.com/watch?v=y-Gk_Ddhr0M]The Beauty of Particle Physics[/url]; watch it to get a rough idea of what the theory states. (A more detailed explanation can be found at either [url=http://science.howstuffworks.com/science-vs-myth/everyday-myths/theory-of-everything.htm]this HowStuffWorks article[/url] or [url=http://www.cs.virginia.edu/~robins/A_Geometric_Theory_of_Everything.pdf]this Scientific American article[/url].)

In case you haven't figured, this unified field theory is centered around the simple exceptional Lie group E8, hence the theory's name: E8 Theory. It leans heavily on [url=https://en.wikipedia.org/wiki/Pati%E2%80%93Salam_model]the Pati-Salam grand unification theory[/url] and [url=https://en.wikipedia.org/wiki/MacDowell%E2%80%93Mansouri_action]the MacDowell-Mansouri description of gravity[/url]. Most importantly, this theory can be tested, as it predicts 22 new bosonic particles, which could and should be detected by the Large Hadron Collider in Switzerland within the next few years. It has the potential to revolutionize physics. No conclusive evidence for or against the theory has been gathered as of yet (although the fact that it makes [url=http://i913.photobucket.com/albums/ac331/shademaker65/Sacred%20G/E8_overlay4_sm.jpg]beautiful[/url] [url=http://i913.photobucket.com/albums/ac331/shademaker65/Sacred%20G/E8_overlay_5sm.jpg]alignments[/url] with the Flower of Life pattern certainly doesn't hurt), so it still stands as a proposition to be investigated.

So: what does this have to do with Tegmark's Level IV multiverse? Well, everything. [url=http://science.howstuffworks.com/science-vs-myth/everyday-myths/theory-of-everything3.htm]The conclusion of the HowStuffWorks article on the E8 Theory[/url] contains this almost irrelevant-seeming sentence:[quote]If his idea proves correct, it could be that the E8 structure provides the infinitely small and unobservable framework for all matter and forces in the universe. It is also possible that the E8 is an image of what our universe as a whole looks like.[/quote]
Let's revisit that: If Lisi's E8 Theory is correct, E8 could be the framework for all matter and forces in the universe, and maybe be an image of what our universe looks like.

A mathematical construct as an image of our universe as a whole.

Does that sound familiar?

I rest my case.

Seraph