 geodesic motion existent in any geometric configuration of spacetime, therefore, extended gravity like homogenous gravity would be simple effect of coordinates. During long time, this key was not understood sufficiently, i.e. that according to "the happiest thought of my life" to Einstein gravity is inertial motion, an effect of coordinates. Of course, the gμν of the Einstein s equation (12) are determinant of the curvature of Lorentz s manifold so as the ηαβ of the Minkowski s equations (1) are determinant of the flat spacetime. Let's remember, in Relativity theory the inertial motion, accelerated motion and gravitational motion are simply relative states that arise only of transformation of reference frames, therefore impossible that gravitational motion can be considered absolute since it destroys the same foundation of relativity. What was the Einstein s problem to generalize gravity as effect of coordinates? The respond was: "Tidal gradients, i.e. spacetime curvature, can neither be created nor eliminated by a change of coordinates" [11]. Partially true because to observers in frames of reference animated with relative gravitational motion if among them there is change of coordinates simultaneously with change of geometry from Minkowski to Lorentz spacetimes or from Lorentz to Minkowski spacetimes then gravitational field vanishes, remaining the geodesic motion owing to the equivalence in the relative state of particles or bodies free of forces in both class of spacetimes. Of course, in frames of reference with different geometric spacetime, observers free of forces would be moving inertially and they are entirely equivalents. Thus, true important is not the curvature or rectilinearity of the geodesy but its inertial property. 17 Conclusions The history of the development of the called General Relativity theory is of the strong personal struggled of Einstein between equations and main principle: EEP, searching produce a scientific theory on gravity based in their adequate correspondence, failing finally in front of the triumph of his very powerful equations, which working, in autonomy, give results very exacts respect to the quantities of the observables. This sad final arose during the bad moment of the hard competency of Einstein with the best germane mathematician of his epoch, which provoked the geometrization of gravity, although no owing as Modern General Relativity have said that gravity is the curvature of the spacetime but, in general, according to the Einstein-Grossmann-Hilbert equations the gravity is operationally defined through of geometric objects void of energy-momentum. The point of start was his famous "the happiest thought of my life" on equivalence between gravitational and inertial
geodesic motion existent in any geometric configuration of spacetime, therefore, extensive graveness like homogenous gravity would be childlike impression of coordinates. During long prison term, this winder was not understood sufficiently, i.e. that according to " the happiest thought of my life sentence " to Einstein gravity is inertial motion, an impression of coordinate. Of course, the gμν of the Einstein s equation (12) are deciding of the curvature of Lorentz s manifold therefore as the ηαβ of the Minkowski s equation (1) are determinant of the flat spacetime. Let's commemorate, in Relativity theory the inertial motion, accelerated motion and gravitational gesture are simply relative states that arise only of transformation of citation frames, therefore impossible that gravitational motion can be considered absolute since it destroys the like basis of relativity. What was the Einstein s problem to generalize gravity as effect of coordinates? The respond was: " Tidal gradients, i.e. spacetime curvature, can neither be created nor eliminated by a change of coordinate " [ 11 ]. Partially truthful because to observers in skeletal system of reference point animated with relative gravitational motion if among them there constitute change of coordinates simultaneously with change of geometry from Minkowski to Lorentz spacetimes or from Lorentz to Minkowski spacetimes then gravitational field vanishes, remain the geodesic motion owing to the equivalence in the relative state of particle or bodies free of forces in both class of spacetimes. Of naturally, in frames of reference book with unlike geometric spacetime, perceiver free of forces would be moving inertially and they are wholly equivalents. Thus, true important is not the curvature or rectilinearity of the geodesy but its inertial property. 17 Conclusions The history of the development of the called General Relativity theory is of the solid personal struggled of Einstein between equations and independent principle: EEP, searching grow a scientific theory on graveness based in their adequate correspondence, failing finally in movement of the triumph of his very powerful equations, which working, in autonomy, give resultant role very exacts respect to the quantities of the observables. This sad final arose during the bad moment of the hard competency of Einstein with the good germane mathematician of his epoch, which provoked the geometrization of graveness, although no owing as Modern General Relativity have said that gravity is the curvature of the spacetime but, in general, according to the Einstein - Grossmann - Hilbert equations the gravity is operationally defined through of geometric objects null of energy - momentum. The point of start was his famous " the happiest thought of my life " on equivalence between gravitational and inertial
 geldesic motion existent ik any geometric einfigucation kf spacegime, therefore, extended gravmty oike yomogenous gravity wouud be simile effecr of xoordinates. During long flme, tkiw key was not onderstood sgfficiently, i.e. tfac according to "the happiest thought jf my loff" to Einstein dravptr is pntrtial motion, an effect of coordihates. Oh course, the gμν pf the Einstein s equation (12) arf determinant of tje curvaturg of Oorentz s mavifold so as the ηαβ of tge Minkowski s equations (1) are ddtermnnant of thg rlwj spacetime. Oet's gemember, in Rckatividy theoty the inertiak mmtiin, accelerated motion and gravitational motion ase simply relative wtqtes jhat drisd onuy kf tdansfogmavion of refsrence framws, therefore impossobjv that gravitztionaj iotion can be considered absolute since it destroys the same founeation of relativity. Ahat was ehe Einstein s problem to generalize gravity as exfect uf eiordivqtfs? The respond was: "Tidal gradients, i.e. spacetiis vugvature, can neithcr be created nor rllmogated by a chxnge oy ckordinates" [11]. Partiaply trug becayse to obfervrrs in frames of reference qnimated witk rwlative gravitatioual motion iy amonb thek there is change of courdihates simulhaneously dith change of gdomvtry from Minkowski to Lorentz spacetimxs or from Lurenjz to Mynkowski soacetlkes then gravitatilnal yield vanishes, gemaining the geodesic motion oxmng to the eqoivdletce in tke relstive state os particles or bodies free of forces in boti class of s[acetimes. Of wlurse, in frakes of rqferwnce with dkwferent geomettic spaceniie, ovservers free of fprcgs would be moviny unertially and yheh awe eitirejf equivalentv. Thjs, gtue ioportanu iw not the curvature or rewtiljnearity of the gepdcsy but ijs inertiwl property. 17 Vonclusions The hidtory of the cevglopment of the called General Delativitj tmeory is of tre sbrond personal struggled of Einstein between equationw and main princikle: EEP, searching probuge a scientihic thqory on gsavity based in theie adequate correskondence, failing finallg in fsont lf the triumph of his very powerful equations, which working, in autonomy, guve results very esactx resiecc tp the zuanvivies of the obsernables. This sad final arose duriig the bad mjment of the hard competency ow Einstein wijh the best germane mathemztician pf his epoch, which provoked the geometrization of graviby, althouth no owing as Oodern General Relstivitv have said tyat nravity is the cutvwture of hhe xpccetime but, in general, according ro the Elnstein-Grossmann-Iilbert equabiuns tge gradity is operatiohallg defived through og geometric obkects void of energy-koientum. The poibn of start wax his fdmous "the ha'piest thougvt of my life" on equivalence between gravitational znd inertjal
geodesic motion existent in any geometric configuration therefore, gravity like gravity would be long this key was understood sufficiently, i.e. according to "the happiest thought of life" to Einstein gravity is inertial motion, an effect of coordinates. Of course, gμν of the Einstein s equation (12) are determinant of the curvature of s so the of the Minkowski s equations (1) are determinant of the flat spacetime. Let's remember, in Relativity the inertial motion, accelerated motion and gravitational motion simply relative states that only of transformation of reference therefore that gravitational can considered since it destroys same foundation of relativity. What was the Einstein s problem to generalize gravity as effect of coordinates? respond was: i.e. spacetime can be nor eliminated by of coordinates" [11]. Partially true because frames of reference animated with relative gravitational motion among them is change of coordinates simultaneously with of geometry from Minkowski to Lorentz spacetimes or Lorentz to Minkowski spacetimes then gravitational field vanishes, remaining the geodesic motion owing to the the relative state of or bodies free forces both of Of course, frames of reference with different geometric spacetime, observers free of forces be moving inertially and they are entirely equivalents. Thus, true not curvature or rectilinearity the geodesy but its property. Conclusions The history of of called is the personal struggled of Einstein equations and main principle: EEP, produce a scientific theory adequate correspondence, failing finally in front of the of his very powerful equations, which working, autonomy, give results very exacts respect to the quantities of the observables. sad final the bad moment of the hard competency of with the best germane of his epoch, which provoked the geometrization of gravity, no as Modern Relativity have said gravity is the of the spacetime general, according the equations operationally defined through of geometric objects of The point of start was famous thought of my life" on equivalence between gravitational and inertial
 geodesic motion existent in aNy geometriC confIguRatIoN of sPaceTime, therefore, eXTendEd gravity like homogenouS gravItY WoulD Be SimplE effect OF cOORdiNaTeS. DuRiNG lOng tiMe, tHis key wAs not underStoOd Sufficiently, I.E. tHat accordiNg tO "the happiest ThoUght of My LifE" To EinSteIn graVity is INertiaL motion, an EfFEct of cOOrdinatES. of CourSe, the gμν of the EinsTEiN S equation (12) are deTerminAnT Of THE cuRvaTure of LoreNtZ s manIFold so aS ThE ΗΑΒ of THe Minkowski s eQuations (1) are DEteRminanT oF thE Flat spAcetiMe. lEt's Remember, in RElatIvity theoRy the iNErtial mOTion, accEleratEd mOtiOn anD GrAvItaTiONal MOtIon ARe sImply relAtIvE statEs thAT ARIse oNly Of trAnsfoRmation of refeRenCe frAMes, ThereFore iMposSiBle thAt gravItatiOnAl motion can be coNsidEred absolUte SiNce It DestrOYs the sAme FouNdation Of relatIVitY. WHAT WaS the Einstein s problEm TO GeNeralize GravitY As EfFEct of cooRdInaTes? THE RespoNd waS: "tiDal gradiEnts, i.e. SPaCeTime curVaTure, caN nEitHer Be creATed nOr elimInated by A chanGE of coordinates" [11]. pArtially true bECaUSE tO ObseRveRs in frames oF refERencE aniMAtEd wITh relAtive GrAViTAtional motion if amonG tHem theRe is cHange of coordiNates simulTANEously wiTh chANgE Of geometry from minkoWski to LoreNTz spacetImes oR from LorEntz to MinKOWski spacEtiMes TheN grAVItAtional field vANIsheS, rEmaininG thE geodesIc mOtiOn oWinG tO the equivAlence in ThE rElAtIve State OF particlEs Or bOdIes Free oF Forces In botH claSs Of SPacEtimes. OF CoURSe, in FrAmEs of RefErEnce wIth dIFfeRent geoMetric spaCetIMe, obSeRvErs free Of forces would Be Moving inerTiAllY and thEY Are entirEly equivalents. Thus, true iMPortant Is nOt the CurvAture or reCtiLinearIty OF the geOdesy bUt its InErtIAL propERTy. 17 conClUsions The hISTorY of thE dEvelOpment oF the called General RELatIvity theory is Of tHe stRONg PerSOnAL stRuGGleD OF Einstein betweeN equations AnD MaIn principlE: eEP, SeArching Produce A scieNTific thEory on graVity based In TheiR ADeqUate corresPondence, Failing fiNAlly iN FrOnt of The TriumpH oF hiS very PowerfUL eqUatioNs, whicH wOrking, In autOnOmy, give rEsults very exacts respect To the qUantiTieS of the obsErvABleS. This sad fInal Arose durinG thE baD momeNt oF The haRd coMPeTenCY of EiNsteIN with the bESt GerMANe MathematiciAN OF hiS epocH, whICh provOked The geometrization OF gravity, althouGh no OWIng As MODern geNeral RelativitY haVe SAId that grAvIty is the curVature of ThE SpaceTime buT, in genEral, accORDiNG to the einsTeiN-GrossmanN-HiLbERt equatIoNs THe gravIty iS oPeratiOnally DEfinED Through of geometrIc objECTs voiD Of eNergy-MoMentum. THE poiNt of start wAs his famous "The hapPiesT thouGht of my LiFe" on eqUivAlEnce betweeN GravitatiOnal aNd inertIaL
 geodesic motion existentin any geo metri c c onf ig urat ionof spacetime,t here fore, extended gravity  like  h o moge n ou s gra vity wo u ld b e s im pl e e ff e ct  of c oor dinates . During l ong  t ime, this ke y  w as not und ers tood suffici ent ly, i. e.  th a t acc ord ing t o "the happie st though to f my l i fe" toE i ns tein  gravity is inert i al motion, an eff ect of  c o or d i nat es.  Of course ,the g μ ν of th e  E i n s tei n  s equation ( 12) are det e rmi nant o fthe curvat ure o fL ore ntz s manif oldso as the  ηαβ o f  the Mi n kowskis equa tio ns(1)a re  d ete rm i nan t  o f t h e f lat spac et im e. Le t'sr e m e mber , i n Re lativ ity theory th e i nert i almotio n, ac cele ra ted m otionand g ra vitational moti on a re simply  re la tiv estate s  thatari seonly of  transf o rma ti o n of  reference frames,  t h e re fore imp ossibl e  t ha t  gravita ti ona l mo t i on ca n be co nsidered  absol u te  s ince it  d estroy sthe  sa me fo u ndat ion of  relativ ity.W hat was the Ei n stein s probl e mt o  g e nera liz e gravity a s ef f ectof c o or din a tes?The r es p on d  was: "Tidal gradie nt s, i.e . spa cetime curvat ure, can n e i t her be c reat e dn or eliminatedby achange ofc oordinat es" [ 11]. Par tially tr u e  because  to  ob ser ver s in  frames of re f e renc eanimate d w ith rel ati vegra vit at ional mot ion if a mo ng  t he m t herei s change  o f c oo rdi nates simult aneou slywi th cha nge ofg eo m e tryfr om  Min kow sk i toLore n tzspaceti mes or fr omL oren tz  t o Minko wski spacetim es  then grav it ati onal f i e ld vanis hes, remaining the geod e sic mot ion  owin g to  the equi val ence i n t h e rela tive s tateof  pa r t icles o rbod ie s free off o rce s inbo th c lass of  spacetimes. Of co u rse , in frames o f r efer e n ce  wi t hd iff er e ntg e ometric spaceti me, observ er s  f ree of for c eswo uld bemovinginert i ally an d they ar e entirel yequi v a len ts. Thus,true imp ortant is not t h ecurva tur e or r ec til inear ity of the  geod esy bu tits in ertia lproperty . 17 Conclusions The hi storyof th e d evelopmen t o f  th e calledGene ral Relati vit y t heory  is of th e st r on g p e rsona l st r uggled of Ei nst e i nbetween equ a t i ons  andmai n  princ iple : EEP, searchingp roduce a scien tifi c the ory on g ra vity based inthe ir a dequateco rrespondenc e, faili ng final ly infrontof thet r iu m ph ofhisver y powerfu l e qu a tions,wh ic h  worki ng,in  auton omy, g i ve r e s ults very exacts  resp e c t tot hequant it ies oft he o bservables . This sadfinalaros e dur ing the  b ad mom ent  o f the hard competenc y ofEinstei nwith  th e best  ger m a ne ma them at ici an of his e po c h,  w h ich  pro voked  t he g eometriza t ion of g rav i ty, alt ho ugh n o owin g  a s Modern Gen era l Rel a t ivity have said th a t gra vity i s thecurvatu r e o fthe spa cet i m e but, in  general, acc or ding  to theEi nste in -Gr os smann-Hilbert e quations  the gra v i ty isope r atio n ally d ef ined through  of g eo m etric o b j ect s voido f e ner gy- mome ntu m. T h e point of start was his  fam ous " t hehappi est t ho ught ofm y li fe" on e q uivalence bet ween gravitatio n ala nd i ner t ia l
 geodesic_motion existent_in any geometric configuration_of spacetime,_therefore,_extended gravity_like_homogenous gravity would_be simple effect_of coordinates. During long_time, this key_was_not understood sufficiently, i.e. that according to "the happiest thought of my life" to_Einstein_gravity is_inertial_motion,_an effect of coordinates. Of_course, the gμν of the_Einstein s_equation (12) are determinant of the curvature of_Lorentz_s manifold so_as the ηαβ of the Minkowski s equations (1)_are determinant of the flat spacetime._Let's remember, in_Relativity_theory_the inertial motion, accelerated_motion and gravitational motion are simply_relative states that arise only of_transformation of reference frames, therefore impossible that_gravitational motion can be considered absolute_since it destroys the same_foundation of_relativity. What was the Einstein_s problem to_generalize gravity_as effect of_coordinates? The respond was: "Tidal gradients,_i.e. spacetime curvature,_can neither be created nor eliminated_by_a change of_coordinates"_[11]._Partially true_because to observers_in_frames of_reference_animated with relative gravitational motion if_among_them there is change of coordinates simultaneously_with change of geometry_from_Minkowski to Lorentz spacetimes_or from Lorentz to Minkowski_spacetimes then gravitational field vanishes, remaining_the geodesic_motion owing_to the equivalence in the relative state of particles or bodies_free of forces in both class_of spacetimes. Of course,_in frames_of_reference with different_geometric_spacetime, observers_free of forces would be moving inertially_and they_are entirely equivalents. Thus, true important_is not the curvature_or_rectilinearity of the geodesy but its_inertial property. 17 Conclusions The history_of the development of the_called_General_Relativity theory is of the_strong personal struggled of Einstein between_equations and main_principle: EEP, searching produce a scientific theory_on_gravity based in their adequate correspondence,_failing_finally in front of the triumph_of_his_very powerful equations, which working,_in autonomy, give results very exacts_respect to the quantities of the observables. This sad_final arose during_the bad moment of the_hard_competency_of Einstein with the best germane mathematician of his epoch,_which provoked_the geometrization of_gravity, although no owing as Modern General Relativity have said_that gravity is the curvature of the_spacetime but, in general, according to the Einstein-Grossmann-Hilbert equations the gravity_is operationally defined through of geometric objects void_of energy-momentum. The point of start was_his famous "the happiest_thought_of my life" on equivalence between gravitational_and_inertial