A-Time Beats No Time. A Response to Brian Leftow

In this paper, I present a new argument against the compatibility of human free will and divine timelessness when conceiving of eternity in terms of an additional dimension as presented by brian leftow. The paper is organized as follows: After giving a brief sketch of leftow’s model, I argue that assuming libertarianism, free will presupposes presentism, since metaphysical indeterminism is only compatible with a presentist A-theory of physical time. Given this result, I make a case for the incompatibility of presentism and divine eternity modelled as a frame of reference, implying the incompatibility of the latter with human free will

A new kind of cyclic universe

Combining intervals of ekpyrotic (ultra-slow) contraction with a (non-singular) classical bounce naturally leads to a novel cyclic theory of the universe in which the Hubble parameter, energy density and temperature oscillate periodically, but the scale factor grows by an exponential factor from one cycle to the next. The resulting cosmology not only resolves the homogeneity, isotropy, flatness and monopole problems and generates a nearly scale invariant spectrum of density perturbations, but it also addresses a number of age-old cosmological issues that big bang inflationary cosmology does not. There may also be wider-ranging implications for fundamental physics, black holes and quantum measurement.Comment: 7 pages, 3 figure

The anamorphic universe

We introduce "anamorphic" cosmology, an approach for explaining the smoothness and flatness of the universe on large scales and the generation of a nearly scale-invariant spectrum of adiabatic density perturbations. The defining feature is a smoothing phase that acts like a contracting universe based on some Weyl frame-invariant criteria and an expanding universe based on other frame-invariant criteria. An advantage of the contracting aspects is that it is possible to avoid the multiverse and measure problems that arise in inflationary models. Unlike ekpyrotic models, anamorphic models can be constructed using only a single field and can generate a nearly scale-invariant spectrum of tensor perturbations. Anamorphic models also differ from pre-big bang and matter bounce models that do not explain the smoothness. We present some examples of cosmological models that incorporate an anamorphic smoothing phase.Comment: 35 pages, 3 figures, 1 tabl

Inflationary schism after Planck2013

Classic inflation, the theory described in textbooks, is based on the idea that, beginning from typical initial conditions and assuming a simple inflaton potential with a minimum of fine-tuning, inflation can create exponentially large volumes of space that are generically homogeneous, isotropic and flat, with nearly scale-invariant spectra of density and gravitational wave fluctuations that are adiabatic, Gaussian and have generic predictable properties. In a recent paper, we showed that, in addition to having certain conceptual problems known for decades, classic inflation is for the first time also disfavored by data, specifically the most recent data from WMAP, ACT and Planck2013. Guth, Kaiser and Nomura and Linde have each recently published critiques of our paper, but, as made clear here, we all agree about one thing: the problematic state of classic inflation. Instead, they describe an alternative inflationary paradigm that revises the assumptions and goals of inflation, and perhaps of science generally.Comment: 7 pages, 2 table

NEC violation in mimetic cosmology revisited

In the context of Einstein gravity, if the null energy condition (NEC) is satisfied, the energy density in expanding space-times always decreases while in contracting space-times the energy density grows and the universe eventually collapses into a singularity. In particular, no non-singular bounce is possible. It is, though, an open question if this energy condition can be violated in a controlled way, i.e., without introducing pathologies, such as unstable negative-energy states or an imaginary speed of sound. In this paper, we will re-examine the claim that the recently proposed mimetic scenario can violate the NEC without pathologies. We show that mimetic cosmology is prone to gradient instabilities even in cases when the NEC is satisfied (except for trivial examples). Most interestingly, the source of the instability is always the Einstein-Hilbert term in the action. The matter stress-energy component does not contribute spatial gradient terms but instead makes the problematic curvature modes dynamical. We also show that mimetic cosmology can be understood as a singular limit of known, well-behaved theories involving higher-derivative kinetic terms and discuss ways of removing the instability.Comment: 7 page

Stability and the Gauge Problem in Non-Perturbative Cosmology

In this paper, we describe the first steps towards fully non-perturbative cosmology. We explain why the conventional methods used by cosmologists based on the ADM formulation are generally inadequate for this purpose and why it is advantageous instead to adapt the harmonic formulation pioneered and utilized in mathematical and numerical relativity. Here we focus on using this approach to evaluating the linear mode stability in homogeneous and nearly homogeneous backgrounds and devising a valid scheme and diagnostics for numerical computation. We also briefly touch on the relevance of these methods for extracting cosmological observables from non-perturbative simulations.Comment: 43 page

Magyarország a virtuális vízpiacon

A virtuális vízszemléletre épülÅ‘ vízkészlet-gazdálkodási döntésekhez szükséges minimális információk egy ország szintjén a következÅ‘k (Európai Regionális Jelen¬tés, 2009): hol, mikor, mekkora és milyen minÅ‘ségű hasznosítható vízkészlet áll rendelkezésre, ezeket a vízkészleteket hol és mire használják, mi történik az elhasznált vízzel, mennyi virtuális víz hagyja el az országot az exportált termékek révén, illetve mennyi virtuális víz érkezik az országba az importált termékekkel? Amennyiben ezek az információk hozzáférhetÅ‘k, úgy további fontos következtetéseket lehet levonni a jövÅ‘beni cselekvési irányokat tekintve, segítve az ország döntéshozóit a fenntarthatóbb vízkészlet-gazdálkodás kialakításában. Ezen túl bizonyos kereskedelempolitikai megfontolások révén – melyek virtuális vízkereskedelmi stratégián alapulnak – nemzeti vagy akár globális szintű vízmegtakarítások is elérhetÅ‘k a vízhatékonyabb eljárásokat alkalmazó országok termékexportja révén. Mindezeket összevetve látható, hogy a virtuális víz koncepció nagy segítség lehet a nagy krízisek (energia- és élelmiszerválság, éghajlatváltozás) megértésében, össze¬függéseik felismerésében, a feloldásukra tett és azoktól független politikai, gazdasá¬gi intézkedések elÅ‘készítésében. Ezen felül ötletekkel szolgálhat alternatív megoldási javaslatok kidolgozásához és végrehajtásához. A virtuális víz koncepció felhívhatja továbbá a figyelmet az indokolatlan, pazarló, telhetetlen fogyasztás veszélyeire és az okozott súlyos környezeti károkra. ErÅ‘s érzelmi hatásokat is kiválthat a mindennapi életben felhasznált virtuális vízmennyiségek nagyságának érzékeltetésével, például annak bemutatásával, hogy egy csésze reggeli kávé biztosításához fürdÅ‘ kádnyi vízre van szükség. A környezettudatosság erÅ‘sítéséhez például jó eszköz lehet valamiféle – ökocímkéhez hasonlatos – vízcímke alkalmazása is. Napjaink egyik legfontosabb és legsürgetÅ‘bb problémája a hozzáférhetÅ‘ vízkészletek megÅ‘rzése, jó állapotban tartása (VKI), a folyamatos ivóvízellátás biztosítása. A továbbiakban ezért minden vízzel kapcsolatos kutatásnak – és így a virtuális víz elképzelésekkel kapcsolatos kutatásoknak is – óriási szerepe lesz és lehet utóbbi problémák megoldásában. Azt is meg kell említeni azonban, hogy olyan megoldási javaslatok felbukkanása is lehetséges, melyek nemhogy elÅ‘revinnék a társadalmat és segítenék a bioszféra megóvását, de egyenesen nagy károkat is okozhatnak. Fontos ezért minden ilyen törekvés körültekintÅ‘ és rendszerszemléletű mérlegelése. A társadalomnak komoly kérdésekben kell irányt választania. Ãltalánosságban elmondható, hogy a megszokott struktúrák (a pénzügyi rendszer, az energiapiac, a jogrendszer, a társadalmi intézmények) fenntarthatósága – legalábbis jelenlegi formájukban – erÅ‘sen megkérdÅ‘jelezÅ‘dött. Fordulóponthoz közeledünk, ahol ha merünk változtatni, akkor egy magasabb fejlettségi szintre lépünk. Amennyiben továbbra is ragaszkodunk majd bizonyos „rossz†és berögzült szokásainkhoz, preferenciáinkhoz és az azok fenntartását szolgáló, általunk létrehozott rendszerekhez, illetve megmaradunk az elméletek, ideák szintjén, melyeket tett nem követ, úgy a nagyobb rendszer (Föld) valószínűleg ki fogja vetni magából a diszfunkcionális alrendszert (emberiség). ------------------------------------------ The minimum information needed to make decisions on a national level based on the concept of virtual water is as follows (European Regional Report, 2009): where, when, how much and what quality water stock is available, where are these water stocks used and for what, what happens to the water after it is used, ho much virtual water leaves the country in exported goods, and how much virtual water is received by the country in imported goods. If this information is available, important conclusions can be derived concerning future lines of action, to help the nation’s decision-makers create a more sustainable water stock management policy. Also, through certain commercial policy measures based on a virtual water trade strategy, water may be saved on the national or even global level via goods exported by countries applying more water-efficient procedures. All this makes it clear that the concept of virtual water can be of great assistance in understanding big crises (energy and food crisis, climate change) and in preparing political and economic measures to resolve such crises, as well as other measures. It may also be the basis for alternative solutions and ways of execution. The concept of virtual water may also draw attention to the risks of unjustified, wasteful and in satiate consumption and the serious environmental damages resulting from it. It may also trigger strong emotional response when presenting water quantities used in everyday life – for example by showing that a bathtub of water is needed to ensure one’s morning cup of coffee. Environmental awareness could be improved by using some sort of an water label, similar to eco labels. Preserving existing water stock and protecting its quality, as well as ensuring the continuous supply of potable water, is one of the most important and urgent tasks of the present day. All future water-related research, including research into virtual water, will therefore have a huge role in resolving the latter issues. It should be mentioned, however, that some suggested solutions may lead to serious damage rather than help social progress and the preservation of the biosphere. Therefore it is important to examine all such attempts carefully. Society has to make decisions on serious issues. In general, the sustainability of familiar structures (the financial system, the energy market, the legal system, the social institutions) is strongly questionable, at least in their current form. We are approaching a turning point which may lead us to a higher level of development if we have the courage to make changes. If we continue to be bound to certain ‘bad’ and old habits and preferences, and the systems created to support such habits, and continue to deal with ideas and theories without taking action, the larger system (the Earth) will probably detach itself from its dysfunctional subsystem (humanity).virtuális víz, koncepció, piac, gazdálkodás, krízisek, virtual water, concept, market, management, crises, Agricultural and Food Policy, Environmental Economics and Policy,

Integral water management

Population growth, growing food and energy demand, changing climate, water shortages – great challenges for society. Water resources management also needs to become more resilient in order to adapt. This article offers a new way of looking at water related problems. The special approach of integral water management (not to be mistaken for integrated water management) shows hidden linkages behind water related processes. Water problems are human problems and are not to be solved without understanding the human factor behind. This way cause and effect becomes clearer and the wider understanding offers a higher opportunity to find the right solutions