How faithful picture of string theory do the media offer? Let's look at this sample from the last 48 hours or so. ;-)

- "EinsteinFest" at the Perimeter Institute attracts 18,000 people
- Vanishing Netgear rebate proves additional dimensions predicted by string theory
- India Daily has another experimental proof of extra dimensions
- India Daily had yet another article "String Theory" one day earlier
- Brian Regan's brain exploded when he watched string theory on PBS
- It is argued that the rest of the show "Girlfriends" looks like string theory
- Emerson Quartet that became famous for joining Brian Greene plans to perform Mendelssohn and Mozart
- Steel string theory is going to perform in Ohio
- Alan Lightman thinks that artists are like scientists because they also like string theory
- Ancient neutrinos described in a crackpot paper may prove either loop quantum gravity, string theory, or a required diet for Schrödinger's cat
- Computer simulations indicate that type IIA vacua with orientifolds of six-tori produce one MSSM-like model per one billion of backgrounds

## snail feedback (3) :

Hi Luboš,

Great news about extra dimensions being discovered in India! This makes a fool of me, I had given up on extra dimensions.

One thing I want to ask here is this. In general relativity, Feynman pointed out that the contraction term physically means a 1.5 mm compression of the earth's radius, without affecting the circumference (he doesn't give a derivation, but I've done that on my home page, available from my blog - my home page was a top hit for "mechanism gravity" on Google for months, but they suppressed it when I used the fact of its popularity as an argument for Wikipedia linking to it for its "gravity" page).

Anyway, in GR there is a radial contraction which Feynman's handwaving lectures - backed by my rigorous math, show is (1/3)MG/c^2 = 1.5 mm for earth's mass.

This means that the fourth dimension is really a mathematical convenience for the purpose of accounting for the variation of Pi which occurs when gravity (as spacetime fabric pressure) compresses the radial distance around mass while leaving the transverse distance (circumference) unchanged.

Pi = circumference/diameter.

The 1.5 mm shrinkage of earth's radius this increases Pi beyond its normal value of 3.14159265...

This property of the spacetime fabric scares the hell out of me.

Pi is a mathematical constant, but general relativity can increase it!

Is the universe really mathematical? is God a pure mathematician? Is the fourth dimension a reality or just a mathematical convenience? I think the role of the 4th dimension is to preserve the value of Pi at the pure mathematical value, not allowing an increase due to radial compression. However, the radial compression is equivalent by Einstein's equivalence principle to the Lorentz compression, indicating the reality of a Higgs field which causes compression in the direction of motion of moving objects.

Do you have any comments?

I think the traditional teaching of GR is wrong, and is like saying that latitude "curves" space to cause the Coriolis force. This is what you would have to do if you denied the earth's absolute rotation. But because the rotation of the earth is real, there is a mechanism for the Coriolis force, which causes the spin of tornadoes and hurricanes.

The math of GR is OK, but needs a physical mechanism to understand it, see my site. This directly affects the understanding of the 4th dimension, which is the only additional dimension widely accepted as being real. Therefore you should really look into it.

Best wishes,

Nigel

Dear Lumos,

Just in case you are "hard of understanding" let me simplify a bit. The curvature of spacetime by another dimension would keep Pi at the normal value 3.14159265...

However, Feynman points out that an easier way to grasp GR is that spacetime fabric pressure compresses masses (in addition to simply pushing masses together, gravity). The compression, which is ignored by Newton's math, is (1/3)MG/c^2 = 1.5 mm for earth's mass. The pressure from a perfect fluid spacetime fabric is only in the radial direction toward the centre of mass, and it permeates the interatomic spaces without sideways diffusion, so it is only a contraction in the radial direction, as Feynman points out in his Lectures, c42 p6, where he gives his equation 42.3 correctly for excess radius being equal to predicted radius minus measured radius, but then on the same page in the text says ‘… actual radius exceeded the predicted radius …’ Talking about ‘curvature’ when dealing with radii is not helpful and probably caused the confusion. The use of Minkowski light ray diagrams and string ‘theory’ to obfuscate the cause of gravity with talk over ‘curved space’ stems to the false model of space by the surface of a waterbed, in which heavy objects roll towards one another. This model when extended to volume type, real, space shows that space has a pressurised fabric which is shielded by mass, causing gravity.

We are used to the fact that if we squeeze something, the circumference remains the same, so it wrinkles up or distorts. However, this contraction of radius does not affect the circumference at all. This is physically the fourth dimension taking some curvature to keep Pi intact. Otherwise, Pi will increase. On the Earth's surface the increase in Pi due to the earth's mass is by the factor (earth's radius + 1.5 mm)/(earth's radius) = 1 + (2x10^-10). Hence, Pi is increased by 0.00000002 % (2x10^-8%).

Why does the variation of Pi get ignored by pure mathematicians?

Best wishes,

Nigel

feynman gravity home page

Feynman gravity blog

Cheers,

Nigel

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