# Faster-than-light

Faster-than-light (also superluminal or FTL) communications and travel refer to the propagation of information or matter faster than the speed of light. Under the special theory of relativity, a particle (that has rest mass) with subluminal velocity needs infinite energy to accelerate to the speed of light, although special relativity does not forbid the existence of particles that travel faster than light at all times (tachyons). On the other hand, what some physicists refer to as "apparent" or "effective" FTL[1][2][3][4] depends on the hypothesis that unusually distorted regions of spacetime might permit matter to reach distant locations in less time than light could in normal or undistorted spacetime. Although according to current theories matter is still required to travel subluminally with respect to the locally distorted spacetime region, apparent FTL is not excluded by general relativity. FTL travel of non-information Daily sky motion Light spots and shadows Related:  Faster than Light Travel

Alcubierre drive Two-dimensional visualization of the Alcubierre drive, showing the opposing regions of expanding and contracting spacetime that displace the central region. The Alcubierre drive or Alcubierre metric (referring to metric tensor) is a speculative idea based on a solution of Einstein's field equations in general relativity as proposed by theoretical physicist Miguel Alcubierre, by which a spacecraft could achieve faster-than-light travel if a configurable energy-density field lower than that of vacuum (i.e. negative mass) could be created. Rather than exceeding the speed of light within its local frame of reference, a spacecraft would traverse distances by contracting space in front of it and expanding space behind it, resulting in effective faster-than-light travel. History Alcubierre metric The Alcubierre metric defines the warp-drive spacetime. Mathematics of the Alcubierre drive where is a positive definite metric on each of the hypersurfaces. and with arbitrary parameters .

Wormhole A wormhole, also known as an Einstein–Rosen bridge, is a hypothetical topological feature of spacetime that would fundamentally be a "shortcut" through spacetime. A wormhole is much like a tunnel with two ends each in separate points in spacetime. For a simplified notion of a wormhole, visualize space as a two-dimensional (2D) surface. In this case, a wormhole can be pictured as the 2D surface of a tube that connects different parts of the surface. The mouths of a wormhole are analogous to the holes at either end of the tube in a 2D plane. Researchers have no observational evidence for wormholes, but the equations of the theory of general relativity have valid solutions which contain wormholes. The American theoretical physicist John Archibald Wheeler coined the term wormhole in 1957; however, in 1921, the German mathematician Hermann Weyl already had proposed the wormhole theory, in connection with mass analysis of electromagnetic field energy.[12] Definition Time travel

Faster than Light Travel New Wormhole Theory Uses Space Photon Energy “Fluid” A new theory expands on other theories and adds photon energy “fluid” as a way to support wormholes. The introduction to the paper states the following. Wormholes are hypothetical geometrical structures connecting two universes or two distant parts of the same universe. For a simple visual explanation of a wormhole, consider spacetime visualized as a two-dimensional (2D) surface. “A possible cause of the late-time cosmic acceleration is an exotic ﬂuid with an equation of state lying within the phantom regime, i.e., w = p/ρ < −1. FIG. 1: The plot depicts the function H(x, a), for α = 1/2 and where the parameter x = r0/r, lying in the range 0 < x ≤ 1, has been deﬁned in order to deﬁne the entire spacetime. By using this theory an advanced civilization would , in theory, be able to mine photon “fluid” for Phantom Energy to construct micro worm holes for such things as transportation. Please enter the url to a YouTube video. 1. Related In "NASA"

White–Juday warp-field interferometer Motivation for the experiment The NASA research team lead by Harold White and their university partners currently aim to experimentally evaluate several concepts, especially a redesigned energy-density topology as well as an implication of brane cosmology theory. If space actually were to be embedded in higher dimensions, the energy requirements could be decreased dramatically and a comparatively small energy density could already lead to a measurable (i.e. using an interferometer) curvature of spacetime.[1] The theoretical framework for the experiment dates back to work by Harold White from 2003 as well as work by White and Eric W. Davis from 2006 that was published in the AIP, where they also consider how baryonic matter could, at least mathematically, adopt characteristics of dark energy (see section below). Theoretical framework The metric derived by Alcubierre was mathematically motivated by the cosmological inflation. Interferometer experiment Results 

NASA Starts Work on Real Life Star Trek Warp Drive Daydreaming Beyond the Solar System with Warp Field Mechanics This article was authored by Harold “Sonny” White and Catherine Ragin Williams Sure and is a submission of the Exotic Research Group of Icarus Interstellar. Sure, the Red Planet or an asteroid are enticing destinations, but what if one day we wanted to go really, really far out? With the technology we have today, it’s not in the realm of possibility. But it could be … and the Eagleworks Laboratories at Johnson Space Center are doing the mathematics and physics required to find the answers that defy traditional Newtonian laws. Enter: The space warp. It’s the same space, and the same standard of time, but if we can theoretically manipulate it for our purposes, interstellar flight could be an option on a future technology roadmap. Back in the 1970s, the British Interplanetary Society looked into what it would take to send a robotic probe to reach Barnard’s Star, about 6 light years (or 380,000 AU) away, within 50 years. The loopholes, amazingly, can be found in mathematical equations.

NASA Admits They Are Working To Travel Faster Than The Speed Of Light NASA is currently working on the first practical field test toward the possibility of faster than light travel. Traveling faster than light has always been attributed to science fiction, but that all changed when Harold White and his team at NASA started to work on and tweak the Alcubierre Drive. Special relativity may hold true, but to travel faster or at the speed of light we might not need a craft that can travel at that speed. The solution might be to place a craft within a space that is moving faster than the speed of light! It’s easier to think about if you think in terms of a flat escalator in an airport. What is the Alcubierre Drive? This type of concept was also recently illustrated by Mathematician James Hill and Barry Cox at the University of Adelaide. It was once believed that Einsteins Â theory of special relativity means that faster than light travel is just not possible. At the same time, we have to look at other factors that are now coming to light. Sources:

New data confirms: Neutrinos are still traveling faster than light "It is worth pointing out, however, that the latest arXiv preprint lists 179 authors, while the original lists 174. Would you ever classify five people as "most of" 15? To make things more confusing . . . "four new people" have decided not to sign, according to Science. The original 174 include a duplicate " F. The new 179 includes 10 new names that didn't appear on the old paper.

Gravitational-wave finding causes 'spring cleaning' in physics Detlev van Ravenswaay/Science Photo Library Artist's rendering of 'bubble universes' within a greater multiverse — an idea that some experts say was bolstered with this week's discovery of gravitational waves. On 17 March, astronomer John Kovac of the Harvard-Smithsonian Center for Astrophysics presented long-awaited evidence of gravitational waves — ripples in the fabric of space — that originated from the Big Bang during a period of dramatic expansion known as inflation. By the time the Sun set that day in Cambridge, Massachusetts, the first paper detailing some of the discovery’s consequences had already been posted online1, by cosmologist David Marsh of the Perimeter Institute for Theoretical Physics in Waterloo, Canada, and his colleagues. Cosmologist Marc Kamionkowski of Johns Hopkins University in Baltimore, Maryland, agrees that some axion models no longer work, “because they require inflation to operate at a lower energy scale than the one indicated by BICEP2”. Linde agrees.

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