# Harold White warp drive experiment

• Nabla_101

#### Nabla_101

Hi all,

I read an article about Harold White's Warp drive experiment at Nasa (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110015936.pdf)

I understand the basic idea of the experiment - to try to create small pertubation in spacetime and measure it using the interferometer - but I don't understand the approach to try to create this pertubation.

It says in the paper (in the picture of experimental setup) that they are using a toroidal capacitor ring to try to create a spherical field - and in the text it says:

"Based on the expected sensitivity of the rig, a 1cm diameter toroidal test article (something as simple as a very high voltage capacitor ring) with a boost on the order of 1.0000001 is necessary to generate an effect that
can be effectively detected by the apparatus."

From my limited understanding they are using ceramic capacitors (I read that somewhere else) because they take the form of two parallel plates (or in this case some kind of toroidal construction or ring array of parallel plate ceramic capacitors), and the parallel plates (or other geometry depending on what they've used) allow a Casimir force, and the existence of some small amount of negative energy density in the region of spacetime around the capacitors?

This is my interpretation of the article since the casimir effect is the only known occurance of negative energy, and negative energy would be required for a warp drive using the alcubierre metric - so this is what they are trying to create and measure?

If this is the case then I don't understand why a using a high voltage across the capacitors would increase the magnitude of the negative energy (increasing the spacetime warping to a measurable amount). My understanding is that the casimir effect/force happens because there is a boundary condition on the plates that the magnitude of the electric field must be equal to zero at the plates surface so between the two plates separated by distance r, only waves with λ = (r*n) / 2, where n ∈ℕ, r∈ℝ... can exist between the plates, so the pressure from virtual photons on the inside of the plates is reduced compared to the usual level of vacuum energy in free space. i.e. there are countably infinite number of waves between the plates, but uncountably infinite number outside the plates - an infinite sum compared to an infinite integral.

My questions are:

1. Are they actually trying to create a spacetime warping using negative energy density in the experiment, or just a spacetime warping using positive energy density like the usual case of a positive mass like a planet warping spacetime?

2. If the answer to my first question is negative energy, then how could applying a high voltage to the capacitors help them? I would guess they are trying to change the boundary condition of the plates somehow to decrease the pressure of photons even further, to increase the amount of negative energy density - but wouldn't the high voltage increase the positive energy density within that region anyway?

3. Does anyone have any more detailed information about the "high voltage capacitor ring" they are using - experimental setup and underlying theory - I'm assuming there is at least shred of valid theory behind this experiment if NASA have endorsed and funded it.

Thanks,
and Merry Christmas / Happy New Year :)