"Warp drives in Einstein's general theory of relativity provide a unique mechanism for manned interstellar travel. It is well-known that the classical superluminal soliton[0] spacetimes require negative energy densities[1], likely sourced by quantum processes of the uncertainty principle. It has even been claimed by few that negative energy densities are a requirement of superluminal motion. However, recent studies suggest this may not be the case. A general decomposition of the defining variables and the corresponding decomposition of the Eulerian energy are studied. A geometrical interpretation of the Eulerian energy is found, shedding new light[2] on superluminal solitons generated by realistic energy distributions. With this new interpretation, it becomes a relatively simple matter to generate solitonic configurations, within a certain subclass, that respect the positive energy constraint. Using this newfound interpretation, a superluminal solitonic spacetime is presented that possesses positive semi-definite energy[3]. A modest numerical analysis is carried out on a set of example configurations, finding total energy requirements four orders of magnitude smaller than the solar mass[4]. Extraordinarily, the example configurations are generated by purely positive energy densities, a tremendous improvement on the classical configurations. The geometrical interpretation of the Eulerian energy thus opens new doors to generating realistic warp fields for laboratory study and potential future manned interstellar travel."
0: Soliton - A "single bump" wave that propagates. See youtube for examples in water. These are (well-studied) solutions to the wave equation. In spacetime, we want some local "warp bubble" bump that is capable of moving/propagating around.
1: Negative energy density: Colloquially, this is like requiring negative mass. Nobody knows if this exists; most aren't hopeful.
2: Nice pun.
3: Positive semi-definite energy: I.e. non-negative (>=0)
4: So we're still talking mass-energies of Jupiter-(ish)-sized planets
This is very cool stuff. Definitely going to read the whole paper after work. Current questions:
- Is this really superluminal? Famously, the Alcubierre "warp bubble" solution doesn't actually propagate you superluminally unless you start it off that way.
- Is there a Minkowskian interior? The warped part of space is like your engine. We also need to have it carry around some flat space if we want it to be capable of carrying passengers.
- Can we construe this into PoC tests? How much energy do we need to detect warping (e.g. laser deflection) with current tech? Could some large-scale LIGO-like setup achieve detection?
As a non physicist, the first question sounded like yes there is an ability to adjust speed if you can adjust the energy density distribution. I didn’t see an answer on the second beyond that the energy density required at the center is zero which leaves hope for a place to put a vehicle there at least, your question of flat space aside.
This could serve as a method of generating acceleration without modifying the total energy on the hypersurface. One could start with a finite energy distribution highly concentrated and uniformly distributed in a spherical shell around a spacecraft. The energy density is then increased
behind the spacecraft and decreased in front, without destroying or creating any additional energy. This increases the shift vector magnitude in the region where the spacecraft is located, transporting it to non-zero speeds relative to faraway observers. If the energy density is sufficiently concentrated behind the central observer, the relative speed becomes superluminal. This then operates as a tuneable solitonic configuration capable of superluminal speeds.
0: Soliton - A "single bump" wave that propagates. See youtube for examples in water. These are (well-studied) solutions to the wave equation. In spacetime, we want some local "warp bubble" bump that is capable of moving/propagating around.
1: Negative energy density: Colloquially, this is like requiring negative mass. Nobody knows if this exists; most aren't hopeful.
2: Nice pun.
3: Positive semi-definite energy: I.e. non-negative (>=0)
4: So we're still talking mass-energies of Jupiter-(ish)-sized planets
This is very cool stuff. Definitely going to read the whole paper after work. Current questions:
- Is this really superluminal? Famously, the Alcubierre "warp bubble" solution doesn't actually propagate you superluminally unless you start it off that way.
- Is there a Minkowskian interior? The warped part of space is like your engine. We also need to have it carry around some flat space if we want it to be capable of carrying passengers.
- Can we construe this into PoC tests? How much energy do we need to detect warping (e.g. laser deflection) with current tech? Could some large-scale LIGO-like setup achieve detection?