Mini hunt for extra dimensions

The idea is to launch a mini solar system to test whether gravity spans into other, hidden dimensions.

The concept of hidden spacial dimensions, beyond the three we experience, is central to some radical theories (dark energy, dark matter, string theory) that seek to unify two currently unreconciled branches of physics. There's only one extant universe, so science describing it should agree right? The problem is that theories that depend on hidden spacial dimensions are untestable, that is there's no way of measuring dimensions outside your own.

As a Universe Today article puts it, "How do you test for 4 dimensions of space when you've only got a 3-dimensional ruler? One idea is to use gravity, a force that might actually reach across an extra dimension."

In a new paper, two scientists propose a way to test for hidden dimensions after all. Two Pioneer spacecrafts launched in the 80s are off their predicted trajectories, even accounting for known external forces like solar winds and dust. These two scientists think the unaccounted factor is gravity pulling from extra dimensions.

To test this they want to create a model of the solar system and send it into space inside a capsule (inside a lagrangian point, for the advanced buffs). (A small laser onboard can correct for any initial misdirections in launching the mini solar system bodies into their orbits.) The mini solar system would allow scientists to track any orbital abnormalities that accumulate over time with high precision. Since the protection of the capsule would eliminate known external variables, if orbital amomalies emerge it would be strong support for the theory of extra dimensions. (via digg)

[Update: Note, the "mini solar system" does not actually need to be a complete model for this test, although the article in UT does not make that clear.]