In 1994, Miguel Alcubierre proposed a method for changing the geometry of space by creating a wave that would cause the fabric of space ahead of a spacecraft to contract and the space behind it to expand. The ship would then ride this wave inside a region of flat space, known as a warp bubble, and would not move within this bubble but instead be carried along as the region itself moves due to the actions of the drive. In a recent study, physicist Dr Erik Lentz outlined a way that a rocket could theoretically travel faster than light – or over 186,000 miles per second. At that speed, astronauts could reach other star systems in just a few years, allowing humanity to colonise faraway planets. Current rocket technology would take roughly 6,300 years to reach Proxima Centauri, the closest star to our Sun. So-called “warp drives” have been proposed before, but often rely on theoretical systems that break the laws of physics. That’s because according to Einstein’s general theory of relativity, it’s physically impossible for anything to travel faster than the speed of light. Dr Lentz, a scientist at Göttingen University in Germany, says his imaginary warp drive would operate within the boundaries of physics. While other theories rely on “exotic” concepts, such as negative energy, his gets around this problem using a new theoretical particle. These hyper-fast “solitons” can travel at any speed while obeying the laws of physics, according to a Göttingen University press release. A soliton – also referred to as a “warp bubble” – is a compact wave that acts like a particle while maintaining its shape and moving at constant velocity. Dr Lentz said he cooked up his theory after analysing existing research and discovered gaps in previous warp drive studies. He believes that solitons could travel faster than light and “create a conducting plasma and classical electromagnetic fields”. Both of these concepts are understood under conventional physics and obey Einstein’s theory of relativity. While his warp drive provides the tantalising possibility of faster-than-light travel, it’s still very much in the idea phase for now. The contraption would require an enormous amount of energy that isn’t possible using modern technology. “The energy savings would need to be drastic, of approximately 30 orders of magnitude to be in range of modern nuclear fission reactors,” Dr Lentz said. The research was published in the journal Classical and Quantum Gravity.

1. HOW TO BUILD FASTER-THAN-LIGHT SPACESHIPS
THE SECRET OF INTERSTELLAR FLIGHT IS
to increase the speed of light locally by an electric field above the Schwinger limit
INTRODUCTION
Interstellar flight is not an impossible dream, it is not a task capable of defeating the most
sophisticated technologies, it is the destiny of humanity. The technology needed to change the speed
of light locally will appear, if we are lucky, in the next few decades: interstellar flight will then
become handy. In this site you will see how this is possible, which physical phenomena, in my
opinion, underlie this possibility: it is not a site for physicists, it is instead a site for everyone. The
site is divided into four micro-sections:
* Scharnhosrt effect
* Schwinger effect
* The main idea: recompose
the puzzle
* Astronomical
observations

2. SCHARNHORST EFFECT
From Wikipedia: "The Scharnhorst effect is a hypothetical phenomenon in which light signals travel
slightly faster than c between two closely spaced conducting plates. It was first predicted in a 1993
paper by Klaus Scharnhorst of the Humboldt University of Berlin, Germany, and Gabriel Barton of
the University of Sussex in Brighton, England. They showed using quantum electrodynamics that
the effective refractive index, at low frequencies, in the space between the plates was less than 1
(which by itself does not imply superluminal signaling). They were not able to show that the
wavefront velocity exceeds c (which would imply superluminal signaling) but argued that it is
plausible.
Owing to the Dirac sea, an empty space which appears to be a true vacuum is actually filled with
virtual subatomic particles. These are called vacuum fluctuations. As a photon travels through a
vacuum it interacts with these virtual particles, and is absorbed by them to give rise to a
virtual electron–positron pair. This pair is unstable, and quickly annihilates to produce a photon like
the one which was previously absorbed. The time the photon's energy spends as subluminal
electron–positron pairs lowers the observed speed of light in a vacuum.
A prediction made by this assertion is that the speed of a photon will be increased if it travels
between two Casimir plates. Because of
the limited amount of space between the
two plates, some virtual particles present
in vacuum fluctuations will
have wavelengths that are too large to fit
between the plates. This causes the
effective density of virtual particles
between the plates to be lower than that
outside the plates. Therefore, a photon
that travels between these plates will
spend less time interacting with virtual
particles because there are fewer of them
to slow it down. The ultimate effect
would be to increase the apparent speed
of that photon. The closer the plates are,
the lower the virtual particle density, and
the higher the speed of light."
Another article easy to find:
"The Scharnhorst Effect: Superluminality and Causality in Effective Field Theories"
From the abstract: "Indeed, SCET implies the interaction between the Casimir vacuum and the
propagating photon to be such that the latter would have the same phase velocity irrespective of its
frequency. This in turn would entail that its signal velocity would be equal to this phase velocity,
which is faster-than-c."

3. SCHWINGER EFFECT
From "The Schwinger Effect: non-perturbative particle production from vacuum"
"The quantum vacuum is unstable under the influence of an external electric field, as the virtual
electron-positron dipole pairs can gain energy from the external field. If the field is sufficiently
strong, these virtual particles can gain the threshold pair creation energy 2mc^2 and become real
electron-positron pairs. This remarkable phenomenon was first predicted by Heisenberg and his
student Hans Euler in 1936, based on work of Sauter in 1931, and later formalized in the language
of QED by Schwinger in 1951."
Pair production was first tested on 1997: Scientists Use Light To Create Particles
There are also recent attempts to overcome the Schwinger limit: Physicists are planning to build
lasers so powerful they could rip apart empty space
THE MAIN IDEA
The main idea is as follows:
1) Virtual couples slow down the light.
2) One way to prevent this from happening is to use an electric field (perhaps electrostatic) above the
Schwinger limit to separate the virtual dipoles in electrons and positrons. Since individual electrons and
positrons can not absorb a photon, the slowing effect is prevented.
Instead of an electric field the nature could also use a gravitational field separating virtual dipoles with
tidal forces.
When the value of c changes in a certain space region Lorentz transformations change in agreement. So
if c grows, relativistic effects weaken and the limit speed achievable with a reasonable amount of energy
increases.

4. References:
for the possibility to modify speed of light with a field above the Schwinger limit see Photon-photon
scattering and related phenomena (paragraph 2.2.2)
for the possibility to separate virtual pairs with gravitational tidal forces see The black hole quantum
atmosphere
another interesting article: On the dependence of the speed of light in vacuum on temperature
ASTRONOMICAL OBSERVATIONS
There is a lot of evidence of superluminal behaviour that can be fully understood using the main
idea presented in this web site:
Pulsar bursts move ‘faster than light’
Faster-than-light electric currents could explain pulsars
Superluminal motion
'Lightning' seen sparking from a supermassive black hole appears to break the laws of physics
And for the dependency of speed of light on temperature:
Weird energy beam seems to travel five times the speed of light

5. PROBLEMS AND REFINEMENTS
We have developed some semi-classical models that have shown how fields above the Schwinger limit,
apart from separating some virtual pairs, increase the lifetime of other virtual pairs (It depends on the
internal energy of the pair). Of the two effects, the prevailing one, at all the regimes, is the second for
which the overall effect is that of slowing down the speed of light. (we will hopefully publish soon).
Field so gigantic to break all the pairs (from 10^10 to 10^20 times the Schwinger limit) are theoretically
possible but practically absolutely unfeasible.
Our model is a generalization of the model presented in The quantum vacuum as the origin of the speed
of light where virtual pairs are static.
We are exploring a very promising solution with time varying fields: with time we will publish
everything.
I'll keep you updated.

6. PROPULSION SYSTEM
Up to this point we have dealt with the possibility of reaching arbitrary speeds. Interstellar flight
technology also requires arbitrarily high acceleration. The ability to create a force similar to gravity
allows us to impose arbitrary accelerations on the aircraft without the pilots experiencing any G. An
incredibly silent but very important news is that in recent years there have been developments in the
possibilities of creating gravity through electromagnetic waves. I leave you to the links:
Effect of light on gravitational attraction
Experimental verification of electromagnetic-gravity effect: Weighing light and heat
Source: https://giovannicambria8.wixsite.com/faster-than-light