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Harold White's warp drive and OA
The Pdf on the NASA site was taken down, but I still have his paper on my computer (it was freely accessible on the NASA site). This is the bit I found most interesting. His version acts as a FTL "booster" for a more conventional propulsion system. Basically, he seems to be saying that a fusion rocket that travels at *edit* .2c will be boosted up to 20c *edit*.

"The concept of operations as described by Alcubierre is that the spacecraft would depart the point of
origin (e.g. earth) using some conventional propulsion system and travel a distance d, then bring the
craft to a stop relative to the departure point. The field would be turned on and the craft would zip off
to its stellar destination, never locally breaking the speed of light, but covering the distance in an
arbitrarily short time period of time just the same. The field would be turned off a similar standoff
distance from the destination, and the craft would finish the journey conventionally. This approach
would allow a journey to say Alpha Centauri as measured by an earth bound observer (and spacecraft
clocks) measured in weeks or months, rather than decades or centuries.
A paradox identified in [6] is an issue that arises due to the symmetry of the energy density about the x
= xs surface. When the energy density is initiated, the choice in direction of the +x-axis is mathematically
arbitrary, so how does the spacecraft “know” which direction to go? Comparing Figure 1 to Figure 2
visually displays the asymmetry of the York Time and the symmetry of the energy density. Both sets of
three frames were purposely aligned to make direct comparison easier. This asymmetry/symmetry
paradox issue can be potentially resolved when considering the canonical form of the metric derived by
using a gauge transformation in [6] as shown in equation 4.

Using this new information, a modified concept of operations is proposed that may resolve the
asymmetry/symmetry paradox. In this modified concept of operations, the spacecraft departs earth and
establishes an initial sub-luminal velocity vi, then initiates the field. When active, the field’s boost acts on
the initial velocity as a scalar multiplier resulting in a much higher apparent speed, <veff>= γ vi as
measured by either an earth bound observer or an observer in the bubble. Within the shell thickness of
the warp bubble region, the spacecraft never locally breaks the speed of light and the net effect as seen
by earth/ship observers is analogous to watching a film in fast forward. Consider the following to help
illustrate the point – assume the spacecraft heads out towards Alpha Centauri and has a conventional
propulsion system capable of reaching 0.1c. The spacecraft initiates a boost field with a value of 100
which acts on the initial velocity resulting in an apparent speed of 10c. The spacecraft will make it to
Alpha Centauri in 0.43 years as measured by an earth observer and an observer in the flat space-time
volume encapsulated by the warp bubble. While this line of reason seems to resolve the paradox, it also
suggests that the York Time may not be the driving phenomenon, rather a secondary result. In this
physical explanation of the mathematics, the York Time might be thought of as perhaps a Doppler strain
on space as this spherical region is propelled through space. A pedestrian analog to use to help envision
this concept would be to consider the hydrodynamic pressure gradients that form around a spherical
body moving through a fluid – the front hemisphere has a high pressure region while the rear
hemisphere has a low pressure region. Analogously, the warp bubble travelling through space-time
causes space to pile up (contract) in front of the bubble, and stretch out (expand) behind the bubble.

Messages In This Thread
Harold White's warp drive and OA - by Sim Koning - 04-20-2013, 09:09 AM
RE: Harold White's warp drive and OA - by Tachyon - 04-29-2013, 03:48 PM
RE: Harold White's warp drive and OA - by Sim Koning - 05-08-2013, 12:05 PM
RE: Harold White's warp drive and OA - by Tachyon - 06-06-2013, 04:12 PM
RE: Harold White's warp drive and OA - by Dalex - 12-30-2013, 09:13 AM
RE: Harold White's warp drive and OA - by Tachyon - 02-07-2014, 08:08 PM

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