### Author Topic: Janus Cosmological Model & FTL travel (and how to introduce negative mass in GR)  (Read 2987 times)

#### flux_capacitor

• Full Member
• Posts: 614
• France
• Liked: 745
• Likes Given: 1020
##### Janus Cosmological Model & FTL travel (and how to introduce negative mass in GR)
« on: 08/03/2017 02:22 PM »
In order to not hijack other threads dealing with the various theories regarding theoretical FTL travel, I have made this thread dedicated to present a particular framework:

The Janus Cosmological Model (JCM) theoretically makes FTL interstellar travel possible, with limited energy source and journey duration compatible with human's lifespan. In order to understand how FTL travel is made possible in the model (superluminal speed being "apparent" and does not actually imply travelling over the speed of light, you'll see why) I have to first present its physical and mathematical foundations.

Indeed, although the Janus model is based on Einstein's general relativity and does not make use of quantum mechanics, it represents a straight departure from current theories, in various aspects :

Mainly, the JCM uses two coupled Einstein field equations instead of one:

Giving several metrics to a single manifold is perfectly legit for mathematicians and geometers.
This system of two coupled field equations introduces negative mass in cosmology with no paradox.

The JCM described the universe as an M4 manifold with two conjugate Riemannian metrics, each one having its own family of geodesics, its own speed of light and where the length between two distant points can be measured as two different distances, according to the metric that is considered. A didactic 2D image:

A 2D surface with two different scales

Classically, when one wants to introduce negative mass in GR, the Newtonian approximation (which gives gravitational potentials and interaction laws between positive and negative mass species) gives rise to the unmanageable runaway paradox:

1- Positive mass attracts positive mass
2- Positive mass moves away from negative mass which chases it
3- Negative mass repels negative mass

The second interaction is called the runaway motion (first described by Hermann Bondi in 1957): the couple would then indefinitely accelerate, while its total kinetic energy would remain constant! This is why negative mass is not seriously considered in general relativity.

This is because the single Einstein Field Equation only describes one side (one metric) for spacetime.

The Janus cosmological model on the contrary implies two sides of the same coin. The motion of positive mass particles and the motion of negative mass particles do not occur in the same sector. Each species evolves along its own family of geodesics, in its own metric. It is as if spacetime had a recto and a verso. Negative mass is among us, but invisible to us, because negative mass emits negative energy photons that follow null geodesics of the metric g(-) distinct from the family of geodesics of our metric g(+). It is as if this negative mass was being located "on the other side of the sheet".

Starting from the two coupled field equations of the Janus model, the Newtonian approximation gives new interaction laws that differ from the classical Newtonian approximation calculated after the single field equation of general relativity:

1- Positive mass attracts positive mass
2- Positive mass and negative mass repel each other (no runaway motion!)
3- Negative mass attracts negative mass (negative mass is not self-repulsive!)

The runaway paradox disappears.
In the JCM, mass is not intrinsically positive or negative, as this concept becomes relative: it depends on which metric you are looking from.

The two coupled field equations reduce to the Einstein field equation for regions of spacetime where positive mass density largely dominates, i.e. where almost all negative mass has been repelled away by the local concentration of positive mass matter (for example on Earth or in the solar system).

Therefore the Janus model encompasses Einstein's general relativity, as general relativity encompassed Newtonian dynamics when considering low speeds v ≪ c and small curvatures.

The two "sheets" of this same universe have opposite arrows of time, like Sakharov's model where they both originate from the same Big Bang singularity:

The origin where the arrow of time reverses is called the Janus Point (see also Julian Barbour's work on the same subject).

The name of the model comes from this distinctive characteristic, as the Romanian god Janus "looks to the future and to the past at once":

The model also integrates a variable speed of light (VSL) framework, and more exactly a joint variation of all physical constants during the highest energy density state of the radiation-dominated era of the universe (just after the Big Bang) as a generalized gauge process, keeping all physical equations invariant.

Excerpts of "Faster Than Light", JP Petit's science comics in the series of "The Adventures of Archibald Higgins"

This primitive "variable constant regime" allows the arrow of time to reverse at the origin and connects the two sheets together at the Big Bang. It also explains the homogeneity of the primitive universe, without resorting to inflation.

The model finally offers an alternative interpretation to the stellar black hole, i.e. when a neutron star reaches its critical mass. How physical constants behave at the Big Bang, what is going on in the center of a neutron star reaching criticality, and the possibility of FTL interstellar travel, are tightly related and will be explained further.

The introduction of negative mass in cosmology, handled by two coupled field equations, could at first appear as lacking of "parsimony" according to Occam's razor. But take into account that the Janus model challenges the standard ΛCDM "concordance" model, which requires these additional tweaks:
- The presence of invisible astroparticles of "dark matter" of unknown nature, to justify the anomalous galaxy rotation curves and gravitational lensing effects.
- The presence of an invisible "dark energy" of unknown nature (resulting from the addition of a cosmological constant to the Einstein field equations) to justify the acceleration of the expansion of the universe.
- The adjustment of six free parameters to fit with observational data.
- The inflation hypothesis, with its inflaton field, invented to justify the homogeneity and isotropy of the primitive universe.

The universe is no longer described as in the days of Einstein, Schwarzschild, Hilbert who could elegantly explain the anomalous observations of that time (precession of the perihelion of Mercury, deflection of light by the Sun) with exact solutions to general relativity. Nowadays the universe has become some kind of a recipe where 95% of its ingredients are of unknown nature:

Well, the Janus model still uses plain-vanilla GR, but does not need such ingredients, although it naturally fits with observations. Unlike other alternative gravity theories like MOND, emergent gravity, MiHsC the Janus model does not have to modify Newton's law according to some distance, nor rely on some unproved quantum phenomena. However it could be integrated in (is compatible with) other GR theories like the Gravitational Absorber Theory (modern version of the Hoyle-Narlikar theory of gravity), to cite only one example.

See the wikipedia section about the Janus cosmological model for a summarized description of the theory and to download peer-reviewed papers cited in references, in particular the last four papers (published in 2014 and 2015).

I attach two science comics below, made by Dr Petit in 2008 to popularize this 40-year-long work: the first presenting this bimetric approach (The Twin Universe) and the second one the VSL aspects of the model (Faster Than Light). Both comics include at the end a scientific appendix for physicists and mathematicians.

Before reading the various peer-reviewed papers, these two documents are a good start to learn the basis of the theory, along the YouTube videos subtitled in English that Dr Petit is now making on YouTube, presented in the next post.

 For the problem of the introduction of negative mass in cosmology and how the Janus model resolves the Runaway paradox, and why T-symmetry reverses the mass of a particle, see this prior post I made in another thread.

 For Sakharov's model about two mirror universes with opposite arrows of time as a solution to the baryon asymmetry of the universe, CPT symmetry, CP violation during baryogenesis and the missing primordial antimatter (theory included in the Janus model) see this prior post. It also describes the nature of the four types of matter (positive mass matter and positive mass antimatter, as well as negative mass matter and negative mass antimatter).

 The negative pressure content of the universe drives the accelerating cosmic expansion. To learn why such a negative pressure is caused by the negative energy density of the universe's second sector, i.e. because of the global distribution of negative mass matter in the universe (and NOT because of some "repulsive power of the vacuum" of positive energy that classically results from the addition of a cosmological constant): see this post.

 To see how the Janus model fits so well with latest observational data showing an accelerating expansion, the result being an exact solution with no had hoc parameter, see this post.

If you have any comment on the theory (that would be welcomed!) please comment in this dedicated thread from now on.
« Last Edit: 12/04/2017 04:56 PM by flux_capacitor »

#### flux_capacitor

• Full Member
• Posts: 614
• France
• Liked: 745
• Likes Given: 1020
##### Re: Janus Cosmological Model & FTL travel
« Reply #1 on: 08/03/2017 02:23 PM »
NEW 2017 VIDEOS

Astrophysicist Jean-Pierre Petit, 80 years old in 2017, is now making a series of Youtube videos to popularize the Janus cosmological model and explain the basic concepts.

There are 27 videos to date but the 11 first ones rather talk about the history and evolution of astrophysics and cosmology through time, from antiquity to modern days. The foundations of the Janus model are broached from video #12.

In order to share and expand the Janus model among scientists outside of France, where the climate is not favorable to the birth of novel ideas in cosmology, Dr Petit has decided to subtitle his videos in English. The difficulty is not to answer critics (critics are welcomed), but to be heard above the ambient noise, including the noise generated by trending theories backed up by the media. The difficulty is to be read, and most importantly to be understood. If Dr Petit manages to explains his model in various international conferences he plans to attend, and share his videos directly with the people interested, maybe an international collaboration with other scientists over the world could be triggered.

By the way, you can post here but also post questions in the comment section of YouTube under each video, as JP Petit read the posts there, and as he speaks and write English he could answer.

Here is the Janus English YouTube playlist: https://goo.gl/MnGTHa

And its description:

Quote from: Jean-Pierre Petit
In this series of videos, astrophysicist and cosmologist Jean-Pierre Petit explains the Janus Cosmological Model.

JCM is a bimetric theory of gravity based on general relativity with a system of two coupled field equations, involving the presence of positive and negative masses in cosmology.

It describes the universe as an M4 manifold with two metrics. The first metric g(+) or "positive sector" refers to a family of geodesics with positive mass and positive energy particles, while the second metric g(-) or "negative sector" refers to another family of geodesics with negative mass and negative energy particles. Negative mass particles emit negative energy photons that follow null geodesics of the metric g(-) hence cannot be seen.

The Newtonian approximation provides the interaction laws: particles whose masses own the same sign mutually attract through Newton's law, while particles whose masses have opposite signs mutually repel through anti-Newton's law. This solves the unmanageable Runaway paradox, which arises when one tries to include negative masses in Einstein's model.

Like Andrei Sakharov's model, the second sector is a CPT symmetry of the first one, linked together by the Big Bang, and explains the apparent lack of primordial antimatter.

Dynamical group theory demonstrates that the reversal of the arrow of time equals energy inversion, and provides the nature of negative species.

The negative sector contributes to the gravitational field and negative pressure and replaces both dark matter and dark energy of the concordance model and its six free parameters, without ant ad hoc parameter.

The model challenges dark matter as it explains the formation of galactic spiral structures, their confinement and their anomalous rotation curves. It also explains the formation of galaxy clusters and the large-scale structure of the universe, the giant voids and the Dipole Repeller effect. Mirage effects around galaxies and galaxy clusters are due to a negative gravitational lensing effect.

The model challenges dark energy, giving an exact solution referring to the matter-dominated era, which exhibits an accelerating expansion process for positive species and fits very well with available observational data.

During the radiation-dominated era, the universe undergoes a variable constants regime, with a variation of the speed of light (VSL) and of all the constants of physics, involved in a generalized gauge process. Then the horizon grows like the space scale factor. This explains the homogeneity and isotropy of the primitive universe with no need to resort to the inflation hypothesis and the inflaton field.

The two sectors have different speeds of light and scale factors. If a space probe could achieve a mass inversion process and cruise at a relativistic velocity following geodesics of the negative sector, the travel duration could be three orders of magnitude shorter than a corresponding conventional relativistic trip in the positive sector. The model suggests that interstellar travel in a limited time inferior to human's lifespan becomes theoretically possible.

The Janus model has been published in peer reviewed scientific journals.

I will edit this post with more of the previous Janus videos once they are subtitled in English. Here they are (expand videos fullscreen to display subs correctly):

 JANUS 13: Dynamical group theory. Time reversal equals energy inversion
Time reversal goes with inversion of energy and mass. Consequence: there are two kinds of antimatter, of opposite mass. The invisible components of the universe are copies of classical particles, but with negative energy and mass.

 JANUS 14: A bit of geometry first. The negachip curvature
The physical foundations of the Janus Cosmological Model involves familiarizing the audience first with the geometry aspects resulting from the introduction of negative masses in cosmology.

 JANUS 15: Two coupled field equations instead of one
The two coupled field equations of the Janus Cosmological Model. Geometrical notion of positive and negative curvatures. Newtonian approximation and interaction laws of positive and negative masses.

 JANUS 16: Why the cosmic expansion is accelerating
How the Janus Cosmological Model explains the accelerating cosmic expansion, challenging dark energy. The accelerating expansion is caused by the negative pressure of the invisible negative mass content of the universe. The nature of such negative energy constituents is described and incidentally identifies the nature of the mysterious dark matter and the missing primordial antimatter.

 JANUS 17: The only consistent interpretation of the Great Repeller
The Janus Cosmological Model provides the only consistent interpretation of the Dipole Repeller. It also explains the flat rotation curves of galaxies, their confinement and their spiral structure, as well as the large-scale structure of the universe, challenging dark matter. Mirage effects around galaxies and galaxy clusters are due to a negative gravitational lensing effect.

 JANUS 18: Why the primitive universe is so homogeneous
The current standard model justifies such homogeneity with a cosmic inflation due to an inflaton field. We present another explanation, already published in Modern Physics Letters A in 1988 and in 1995 in Astrophysics and Space Science. During the radiation-dominated era, the universe undergoes a variable constants regime, with a variation of the speed of light (VSL) and of all the constants of physics, involved in a generalized gauge process. Then the horizon grows like the space scale factor.

 JANUS 19: The speed of light had to be infinite at the Big Bang
Sakharov's model can't be geometrized with a constant speed of light, which must be infinite at the Big Bang. The arrow of time becomes zero then reverses. The initial singularity is cancelled and replaced by a structure shown to have an elliptic geometry. The question of time near the Big Bang becomes meaningless and chronology is identified with entropy.

 JANUS 20: Falsifiability of the theory with negative weak lensing
Any model should be "falsifiable" in the sense of Popper, i.e. it has to propose a test able to disprove or confirm the theory. Such a test of the Janus Cosmological Model, based on a negative weak gravitational lensing effect, is presented.

 JANUS 21: Dark matter, about time to break the deadlock
A 30-year sterile quest after dark matter and supersymmetry. Pierre Salati, theoretical physicist at LAPTh, CNRS, says what others only think: they no longer believe. He concludes that we have to look in other directions.

The next video JANUS #22 is a big one as it is split into 5 parts. It deals with the Schwarzschild original solution, historically and mathematically, and exposes the problem with the classical black hole model, and offers a new interpretation. This mini video series will have its own dedicated post below once it has been subtitled in English.
« Last Edit: 12/04/2017 03:55 PM by flux_capacitor »

Tags: