Roberson's Interminable Ramble

Man, I love science. And one of the things I love best is how the simplest tests can often be performed to prove the most complicated hypotheses. An example I've recently come across that bowled me over was Vilayanur S. Ramachandran adapting a simple test used to diagnose color blindness to prove whether a subject has synaesthesia (numbers are scattered around an image, seemingly at random, but synaesthetes who see numbers as colors immediately recognize hidden patterns).

Now, sending a spacecraft out to the Lagrange point L2 just to set a little tungsten orrery in motion might not seem the simplest test, but damned if it couldn't prove some pretty far reaching notions.

Once at the Lagrange point, the artificial solar system would be set in motion inside the spacecraft. An 8-centimetre-wide sphere of tungsten would act as an artificial sun, while a smaller test sphere would be launched 10 cm away into an oval-shaped orbit. The miniscule planet would orbit its tungsten sun 3,000 times per year.

If gravity is leaking into extra dimensions, the slight change in its force should cause the planet's oval-shaped orbit to rotate, or precess, slowly. Sahni and Shtanov calculated the effect for a theory called the Randall-Sundrum model, which says that our universe is a 3D slice of a bigger, higher dimensional universe. They find the orbit would precess by 1/3600° per year – "a reasonable quantity to try and measure," they say.

As the article points out, not only could this experiment be used to test the unseen spatial dimensions that underlie everything from multidimensional cosmology to M-Theory, but it could also test Modified Newtonian Dynamics, an alternate theory of gravity that could eliminate the need for dark matter in cosmological models. And all from a couple of tungsten spheres only a few centimeters across. How awesome is that?