 in: 1. The philosophical theories supported by the mathematical model, Gμν = k Tμν, of the General Relativity are strictly restricted to: To dualistic idealist substantivalism, spacetime is a metaphysical fundamental entity, i.e., an entity immaterial whose curvature is the static gravitational field, i.e., a geometric property of spacetime; therefore spacetime and gravitational field are nothing. To idealist relationalism, spacetime is a thinking category that expresses metric relations codified in the static gravitational static field, which is a geometric field; therefore they are nothing. 2. The other theories that endow of materiality to spacetime or to gravitational field require of a mathematical model of the form Gμν = k(Tμν + tμν), proper of the Entwurf theory. Let's remember that the Einstein equations of General Relativity are without the term tμν: To monistic materialist substantivalism, spacetime is a special substance belonging to material substances whose curvature is the static gravitational field, i.e., a geometric property of material spacetime; therefore gravitational static field is nothing as in Schaffer, 2009; Turishev, 2011; Worden, 2012 and Delplace, 2014. To materialist relationalism, spacetime is a thinking category that expresses metric relations codified in the gravitational field, which is a dynamic material field; therefore spacetime is nothing, as indirectly in Lorentz, 1916; Weyl, 1918; Eddington, 1920 due to that they considered gμν generated by the relativistic aether and directly in Cala, 2006; Bain, 2014, etc., due to that they do not differentiate between the static gravitational field of the metric tensor and the dynamic gravitational field that would be of the energy-momentum tensor. Of other hand, to the author the spacetime is the geometric structural form of the dynamic matter [30], therefore spacetime are not conditions of existence of the matter but geometric properties of it, because any real thing, in the Universe, have dynamic existence with spatial properties and as process with temporal duration. The result is: "Spacetime is still an enigma to science and philosophy" [31] because "We really do not know what spacetime" [32]. If gravity is phenomenon of spacetime and is not known what is spacetime? Then, what can be said on gravity? Return to the adventure of the thought that Einstein lived from his explication of gravity inside context of Special Relativity, 1907, until the formulation of General Relativity, 1915, there
in: 1. The philosophical theories supported by the mathematical exemplar, Gμν = k Tμν, of the General Relativity are rigorously restricted to: To dualistic idealist substantivalism, spacetime is a metaphysical fundamental entity, i.e., an entity immaterial whose curvature is the inactive gravitational discipline, i.e., a geometric property of spacetime; therefore spacetime and gravitational playing field are nothing. To idealist relationalism, spacetime is a thinking class that expresses metric relations codified in the static gravitational electrostatic field, which is a geometric field; consequently they are nothing. 2. The other theories that endow of materiality to spacetime or to gravitational field require of a mathematical model of the form Gμν = k(Tμν + tμν), proper of the Entwurf theory. permit's remember that the Einstein equations of General Relativity are without the term tμν: To monistic materialist substantivalism, spacetime is a particular substance belonging to material substances whose curvature is the inactive gravitational field, i.e., a geometric property of material spacetime; therefore gravitational static discipline is nothing as in Schaffer, 2009; Turishev, 2011; Worden, 2012 and Delplace, 2014. To materialist relationalism, spacetime is a thinking category that expresses metric relations codified in the gravitational playing field, which is a active material field; therefore spacetime is nothing, as indirectly in Lorentz, 1916; Weyl, 1918; Eddington, 1920 due to that they considered gμν generated by the relativistic aether and immediately in Cala, 2006; Bain, 2014, etc. , due to that they do not differentiate between the inactive gravitational field of the metric tensor and the dynamic gravitational sphere that would be of the energy - momentum tensor. Of other hand, to the writer the spacetime is the geometric structural form of the dynamic matter [ 30 ], consequently spacetime are not conditions of existence of the matter but geometric properties of it, because any real thing, in the Universe, have dynamic existence with spatial properties and as process with temporal duration. The resultant role is: " Spacetime is still an mystery to science and philosophy " [ 31 ] because " We really do not know what spacetime " [ 32 ]. If gravity is phenomenon of spacetime and is not know what is spacetime? Then, what can be said on gravity? Return to the adventure of the opinion that Einstein lived from his explication of gravity inside context of Special Relativity, 1907, until the formulation of General Relativity, 1915, there
 in: 1. The philosophical theovies supported bi rhe mavhematidal modeu, Gμν = k Tμν, of the General Relaviviry art strictly restrictdd to: To fualistix idtalist substantivemism, spacetims is c netaphysical fondamental ettity, i.e., an endigy immaterial whose curvature is the ftatic brwvitational figld, i.t., a geojvtvic property of spacetime; therefkre spabetime and gravitstional field are nothing. Ho ifealist relationallsm, spacetine if a thinking zategory that expressea metric relations codified in ghe scatic gravijcriojdl static fmeld, wrich is a geometric xield; tnerefore they sre norhing. 2. The other theocies that endow of mwterialitf co spacetime or to grqvutatimnal fieue rdqujrx or a mahhejatical mosel of the dorm Gμν = k(Tμν + tμν), propet jd the Entwurf theorr. Jet's remember that the Einstein equatiots kf General Relativity aee without the term tμν: To moniseic materialist substantivalism, spacetime is a spacial rubwtwvxe belonging to material substances whose curvaehrt ix the static gvavitational field, i.f., s geometric pruperty of material spacetimf; theresore travitatijnal static field is nothing as in Schaffer, 2009; Turishev, 2011; Worden, 2012 and Delplaee, 2014. To matetialist relationalism, s'acetije is a thijking catseory that expresres matric relations codified ig the gratitatnonal fidld, ehich ys a dynamlc mabarial field; thereflre skacetike is nothlng, as indirectly in Lorentz, 1916; Wxbl, 1918; Eddington, 1920 gue to that they considered gμν generated by jhe relatnvistiz aether ahd dirertly in Cala, 2006; Bain, 2014, etc., dgg to that theb do not qiffwrenriate bdgween the statoc gravitcuional fieod of the metric tcnsor znd the dynamic grqvitational fiekd ghae aonld bq of the enercy-mooengim tevsor. Of othcr fand, to the author the s[acefime is the geomettig structutal form jf the dynamiv matter [30], therefort spacxtime ere noy cjnditions of existence of the jatter buh gcometric propqrtics os it, becauxe any real thing, in the Universe, have vynamic existence with wpatial properties cnc as procesx witr temporan duration. The resulr is: "Spacetime is still an enigma to sdience and ohilosophy" [31] because "We really do not know what spacetime" [32]. If gravity is pyenomeiog of spacetjme snd iv uot known whav ms spacetime? Then, what can be said on gravity? Revurn to tha cdventure of the thought that Eknstein lived from his explication of gravity inside context of Special Relayivity, 1907, until the formulstion of Genedal Relatitity, 1915, there
in: 1. The philosophical theories supported by model, = k of the General To idealist substantivalism, spacetime a metaphysical fundamental i.e., an entity immaterial whose curvature the static gravitational field, i.e., a geometric property of spacetime; therefore spacetime and field are nothing. To idealist relationalism, spacetime is a thinking category that expresses relations in static static field, which is a geometric field; therefore they are nothing. 2. The other theories that of materiality to spacetime or to gravitational field of a mathematical model the form Gμν = k(Tμν tμν), of the theory. remember the Einstein equations General Relativity are without the term tμν: To monistic materialist substantivalism, spacetime is a special substance belonging material substances is the gravitational i.e., geometric property of therefore gravitational static field is nothing 2009; Turishev, 2011; Worden, 2012 and Delplace, 2014. materialist relationalism, is a thinking category that expresses relations codified in the gravitational field, which is dynamic material field; therefore spacetime is nothing, as indirectly in Lorentz, 1916; Weyl, 1918; Eddington, to that they considered generated by the aether directly Cala, Bain, 2014, due to that they do not differentiate between the static gravitational of the metric tensor and the dynamic gravitational field that of energy-momentum tensor. Of hand, to the author spacetime the geometric structural form dynamic [30], not of of the matter but properties of it, because any thing, in the Universe, properties and as process with temporal duration. The is: "Spacetime is still an enigma to and philosophy" [31] because "We really do not know what spacetime" [32]. gravity is spacetime and is not known what is spacetime? what can be said gravity? Return to the adventure of the thought that lived his explication gravity inside context Special Relativity, 1907, the formulation of 1915, there
 in: 1. The philosophical theorieS supported By the MatHemAtIcal ModeL, Gμν = k Tμν, of the GENeraL Relativity are strictly RestrIcTEd to: tO dUalisTic ideaLIsT SUbsTaNtIvaLiSM, sPacetIme Is a metaPhysical fuNdaMeNtal entity, i.e., AN eNtity immatEriAl whose curvaTurE is the StAtiC GraviTatIonal Field, i.E., A geomeTric propeRtY Of spacETime; theREFoRe spAcetime and gravitaTIoNAl field are nothIng. To iDeALiST RelAtiOnalism, spaCeTime iS A thinkiNG cATEGorY That expresses Metric relatIOns CodifiEd In tHE statiC gravItATioNal static fiEld, wHich is a geOmetriC Field; thERefore tHey are NotHinG. 2. The OThEr TheOrIEs tHAt EndOW of MaterialItY tO spacEtimE OR TO graVitAtioNal fiEld require of a MatHemaTIcaL modeL of thE forM GΜν = k(TμΝ + tμν), prOper oF tHe Entwurf theory. let's Remember tHat ThE EiNsTein eQUationS of genEral RelAtivity ARe wItHOUT tHe term tμν: To monistiC mATErIalist suBstantIVaLiSM, spacetiMe Is a SpecIAL subsTancE BeLonging tO materIAl SuBstanceS wHose cuRvAtuRe iS the sTAtic GravitAtional fIeld, i.E., A geometric propERty of material SPaCETiME; theRefOre gravitatIonaL StatIc fiELd Is nOThing As in SChAFfER, 2009; Turishev, 2011; Worden, 2012 and DElPlace, 2014. TO mateRialist relatiOnalism, spaCETIme is a thInkiNG cATegory that exprEsses Metric relaTIons codiFied iN the gravItational FIEld, which Is a DynAmiC maTERiAl field; therefORE spaCeTime is nOthIng, as inDirEctLy iN LoReNtz, 1916; Weyl, 1918; EdDington, 1920 dUe To ThAt TheY consIDered gμν GeNerAtEd bY the rELativiStic aEtheR aNd DIreCtly in CALa, 2006; bAIn, 2014, etC., dUe To thAt tHeY do noT difFEreNtiate bEtween the StaTIc grAvItAtional Field of the metRiC tensor and ThE dyNamic gRAVitationAl field that would be of the ENergy-moMenTum teNsor. of other haNd, tO the auThoR The spaCetime Is the GeOmeTRIc strUCTuRal FoRm of the dynAMIc mAtter [30], ThErefOre spacEtime are not conditiONs oF existence of tHe mAtteR BUt GeoMEtRIc pRoPErtIES of it, because any Real thing, iN tHE UNiverse, havE DynAmIc existEnce witH spatIAl propeRties and aS process wItH temPORal Duration. ThE result iS: "SpacetimE Is stiLL aN enigMa tO scienCe And PhiloSophy" [31] bECauSe "We rEally dO nOt know What sPaCetime" [32]. If Gravity is phenomenon of spAcetimE and iS noT known whaT is SPacEtime? Then, What Can be said oN grAviTy? RetUrn TO the aDvenTUrE of THe thoUght THat EinsteIN lIveD FRoM his explicaTION of GraviTy iNSide coNtexT of Special RelativITy, 1907, until the formUlatION of genERal RElAtivity, 1915, there
 in: 1. The philosophicaltheories s uppor ted  by  t he m athe matical model, Gμν= k Tμν, of the Genera l Rel at i vity ar e str ictly r e st r i cte dto : T od ua listi c i dealist  substanti val is m, spacetime is  a metaphy sic al fundament alentity ,i.e . , anent ity i mmater i al who se curvat ur e  is th e  static g ra vita tional field, i.e . ,a  geometric pro pertyof sp a c eti me;  therefore  s pacet i me andg ra v i t ati o nal field are  nothing. T o  id ealist  r ela t ionali sm, s pa c eti me is a thi nkin g categor y that express e s metri c rela tio nscodi f ie dinth e  st a ti c g r avi tational  s ta tic f ield , w h ichisa ge ometr ic field; the ref oret hey  arenothi ng.2.  Theothertheor ie s that endow of  mat erialitytosp ace ti me or to gra vit ati onal fi eld req u ire  o f a  m athematical modelof t he  form Gμ ν = k( T μν  + tμν), pr op erof t h e  Entw urft he ory. Let 's rem e mb er  that t he  Einst ei n e qua tions of G eneral  Relativ ity a r e without thet erm tμν: To m o ni s t ic mate ria list substa ntiv a lism , sp a ce tim e  is a  spec ia l  s u bstance belonging t omateri al su bstances whos e curvatur e i s the st atic gr a vitational fie ld, i .e., a geo m etric pr opert y of mat erial spa c e time; th ere for e g rav i t at ional staticf i eldis  nothin g a s in Sc haf fer , 2 009 ;Turishev,  2011; W or de n,  2 012  andD elplace,  2 014 .Tomater i alistrelat iona li sm ,  sp acetime is a  thi nk in g ca teg or y tha t ex p res ses met ric relat ion s  cod if ie d in th e gravitation al  field, wh ic h i s a dy n a mic mate rial field; therefore s p acetime  is  noth ing,  as indir ect ly inLor e ntz, 1 916; W eyl,19 18; E dding t o n,  19 20  due to th a t  th ey co ns ider ed gμνgenerated by the r e lat ivistic aethe r a nd d i r ec tly in Cal a, 200 6 ;  Bain, 2014, et c., due to  t h at  they do n o t d if ferenti ate bet weent he stat ic gravit ational f ie ld o f the  metric te nsor and  the dyna m ic gr a vi tatio nal  field  t hat  woul d be o f  th e ene rgy-mo me ntum t ensor .Of other  hand, to the author th e spac etime  is  the geom etr i c s tructural  for m of the d yna mic  matt er[ 30],ther e fo res pacet imea re not co n di tio n s  o f existence o f  th e mat ter but ge omet ric properties of it, because an y re a l  th ing ,  inth e Universe, ha vedy n a mic exis te nce with sp atial pr op e rties  and a s proc ess wit h te m poraldura tio n. The re sul ti s: "Spa ce ti m e is s till  a n enig ma tos cien c e  and philosophy"  [31] b ecaus e  "W e rea ll y do no t  kno w what spa cetime" [32 ]. Ifgrav ity i s pheno me non of  sp ac etime andi s not kno wn wh at is s pa ceti me?  Then,  wha t can b e sa id  on  gravity? R et u rn  t o  th e ad ventu re  ofthe thoug h t that E ins t ein liv ed  fr o m  his e x pl i c ation of g rav ity i n s ide contex t  ofS pe c ial R elativ ity, 1 907, un t ilth e formu lat i o n of Gene ral Relat i vit y,  191 5, there 
 in:_1. The_philosophical theories supported by_the mathematical_model,_Gμν =_k_Tμν, of the_General Relativity are_strictly restricted to: To_dualistic idealist substantivalism,_spacetime_is a metaphysical fundamental entity, i.e., an entity immaterial whose curvature is the static_gravitational_field, i.e.,_a_geometric_property of spacetime; therefore spacetime_and gravitational field are nothing._To idealist_relationalism, spacetime is a thinking category that expresses_metric_relations codified in_the static gravitational static field, which is a geometric_field; therefore they are nothing. 2._The other theories_that_endow_of materiality to spacetime_or to gravitational field require of_a mathematical model of the form_Gμν = k(Tμν + tμν), proper of_the Entwurf theory. Let's remember that_the Einstein equations of General_Relativity are_without the term tμν: To_monistic materialist substantivalism,_spacetime is_a special substance_belonging to material substances whose curvature_is the static_gravitational field, i.e., a geometric property_of_material spacetime; therefore_gravitational_static_field is_nothing as in_Schaffer,_2009; Turishev,_2011;_Worden, 2012 and Delplace, 2014. To_materialist_relationalism, spacetime is a thinking category that_expresses metric relations codified_in_the gravitational field, which_is a dynamic material field;_therefore spacetime is nothing, as indirectly_in Lorentz,_1916; Weyl,_1918; Eddington, 1920 due to that they considered gμν generated by_the relativistic aether and directly in_Cala, 2006; Bain, 2014,_etc., due_to_that they do_not_differentiate between_the static gravitational field of the metric_tensor and_the dynamic gravitational field that would_be of the energy-momentum_tensor._Of other hand, to the author_the spacetime is the geometric structural_form of the dynamic matter_[30],_therefore_spacetime are not conditions of_existence of the matter but geometric_properties of it,_because any real thing, in the Universe,_have_dynamic existence with spatial properties and_as_process with temporal duration. The result_is:_"Spacetime_is still an enigma to_science and philosophy" [31] because "We_really do not know what spacetime" [32]. If gravity_is phenomenon of_spacetime and is not known_what_is_spacetime? Then, what can be said on gravity? Return to_the adventure_of the thought_that Einstein lived from his explication of gravity inside context_of Special Relativity, 1907, until the formulation_of General Relativity, 1915, there