 conservation taken as the starting point, we obtain the result that we can choose the reference system (to which the space-time "coordinates" x, y, z, t are referred) in such a way that only linear but, in contrast to the customary theory of relativity, arbitrary linear substitutions leave the equations covariant" [5]. 7 Gravity cannot be a simple effect of change of coordinates With the years of analysis on gravity, Einstein distinguished two manifestations of the phenomenon of gravity: The punctual and the extending in the spacetime. While the first can be explained as effect of coordinates, the second no. Of course, while the first is a particular case, the second is the general case. At first, however, Einstein used a promising language in which he seemed to solve the problem of generalization through the principle of relativity, since he also distinguished between the principle of relativity in the narrow sense and this principle in the extended sense when both can be applied only to the specific case, because the principle of relativity really in an extended sense is not possible to make it correspond to the extended gravity case. The scientific knowledge of any phenomenon of study only it is reached when it is explained in general the phenomenon. Therefore, it is not admissible that the particular case of gravity was used by Einstein as foundation of the explication of the case general of gravity which in essence is a phenomenon of the energy and not an apparent phenomenon of relative motion simple effect of coordinates. On 29 September of 1913, "On the present state of the problem of gravitation", and ratified in 1915 and 1925, "Theory of the Relativity", Einstein had to give up his conception of gravity as effect of coordinates; he specifically wrote: "An physicist sharing our standpoint can characterize the gravitational field as "apparent" because by a suitable choice state of acceleration, he can bring it about that in a given spacetime point no gravitational field is present. But it is obvious that for extended gravitational fields this vanishing of the gravitational field cannot, in general, be achieved for a transformation. For example, it would not be possible to make the gravitational field of the Earth vanish by choosing an appropriate reference system" [9], [12]. "The field was later to become known as a permanent gravitational field. Permanent gravitational fields are not equivalent to uniformly accelerating frames of reference" [11]. With this declaration is clear that Einstein admitted that gravity exists and it is really a physical phenomenon. Einstein adverted that "The theory of relativity (in the narrower sense) had to be replaced by
conservation taken as the starting point, we obtain the resultant role that we can choose the reference point system (to which the space - time " coordinate " x, y, z, t are referred) in such a way that merely linear but, in contrast to the customary hypothesis of relativity, arbitrary analogue substitutions leave the equation covariant " [ 5 ]. 7 Gravity cannot be a simple consequence of change of coordinates With the years of analysis on gravity, Einstein distinguish two manifestations of the phenomenon of gravity: The punctual and the extending in the spacetime. While the first can be excuse as effect of coordinates, the second no. Of naturally, while the first is a finical case, the second is the general case. At foremost, however, Einstein used a promising language in which he seemed to solve the problem of abstraction through the rationale of relativity, since he besides distinguished between the principle of relativity in the narrow sense and this principle in the extended sense when both can be use merely to the specific case, because the rationale of relativity in truth in an extensive sense is not possible to make it correspond to the extended gravity case. The scientific cognition of any phenomenon of study only it is reached when it is explained in general the phenomenon. Therefore, it is not admissible that the particular case of gravity was used by Einstein as foundation of the explication of the case general of graveness which in essence is a phenomenon of the department of energy and not an apparent phenomenon of relative motion simple effect of coordinates. On 29 September of 1913, " On the present state of the trouble of gravitation ", and ratified in 1915 and 1925, " Theory of the Relativity ", Einstein had to give up his conception of gravity as effect of coordinates; he specifically write: " An physicist sharing our standpoint can characterize the gravitational field as " apparent " because by a suitable option state of acceleration, he can bring it about that in a given spacetime point no gravitational sphere is present. But it is obvious that for extended gravitational fields this vanishing of the gravitational playing field cannot, in general, be achieve for a transformation. For example, it would not be possible to make the gravitational discipline of the Earth vanish by choosing an appropriate reference system " [ 9 ], [ 12 ]. " The field was subsequently to become known as a permanent gravitational field. Permanent gravitational field are not equivalent to uniformly accelerating frames of reference " [ 11 ]. With this declaration is clear that Einstein admitted that graveness exists and it is really a physical phenomenon. Einstein adverted that " The theory of relativity (in the narrower sense) had to be replace by
 cojservation taken as the rtarting point, cw obtamn the desult tfat we can choose the refereice wysten (to which the space-tioe "coordijates" x, t, z, u are referred) in such a way thzb onlv oinear but, in gontrast to the customary tfelry of relativity, arbitrary linear fubstititlons leave the equseiona covariant" [5]. 7 Gravity cannot be a aimple tffect of change og coordinates With the yeags ov analysis on gravlty, Einsteib difringuished tdo manifesuacions of thg phenomenon of gravity: The puncgual cnd the extgueinh in the sparetime. While the flgst can be expkained as effegt of coirdinates, the second io. Of course, while tre first hs a particular casw, rhe sgcond is gye eentrak dase. Ah fmrst, howeved, Einstein ysed a promising lamgtqge in which ge seeieq to solve the problem of generalizatiot tgrough the principle of relativity, since he wlso distynguished between the principle of relativity in dhe nerfow scnse qnf this principle in the extended sense when bjfh csn be applied jnly to the soevyfic case, becxuse tks lrinciple of relatlvity rgally un an exttnded sense is not possible to mqke it correfpond to the extendzd gravity ccse. Thg sciemtific knowledge of any phehomenon of dtudy onlg it is reached wfen id is explained in general ehe phenonenou. Therefure, ot is got admisslble bvat the particular case ox gravity aas used by Einstein as foundatmpn of the exkliwatpon of thz case general of gwavity which iu essencz is a phenomenoh of thx energy and not an apparajt phenomenoi of relaeive motuon simoue effect of cpordinates. On 29 Septwmber of 1913, "On the pvesenj atate of the pribltm of gravitatiom", avd wanifmed ig 1915 and 1925, "Theorf of thd Relagivity", Tnnsbeiv hac to give up his conweptjon of gravity as rfnect of ciordinatqs; he specifivally wrote: "An phydicisv sharmng out sjandpoint can characterize the fravitatilnaj field as "a[parcnt" fecause by a suitable choice state of acceleratioi, he can bring it abouj that in a given spaeeuime point no gravytational field is present. Bur it is obvious tmat for extended gravifationdl fiflds this vanishing of the gravitational field cannot, in general, be achieced foc w transformztiom. For eram'le, it roulv iot be possible tp make the gravitational field uf the Edrch vanish by choosing an apprppfiate referenze system" [9], [12]. "The field waa later yo become known as a permanent bravitational field. Permsnent grqvitafional fieuds are not equivakent tm unidormly qcceperating framds pf referencf" [11]. Wmth this declaration is clear that Winsteun admitted that gcavity existd and pt is rgally a physical lhenklenon. Einstein advrrted that "The theory of relativitj (ig the narrower aense) had to be rg'naced by
conservation taken as the starting point, we result we can the reference system x, z, t are in such a that only linear but, in contrast the customary theory of relativity, arbitrary linear substitutions leave the equations covariant" [5]. Gravity cannot be a simple effect of change of coordinates With the years analysis gravity, distinguished manifestations of the phenomenon of gravity: The punctual and the extending in the spacetime. While the can be explained as effect of coordinates, the no. Of course, while first is a particular case, second the general At however, used a promising in which he seemed to solve the problem of generalization through the principle of relativity, since he distinguished between of relativity the sense this principle in sense when both can be applied specific case, because the principle of relativity really an extended is not possible to make it to the extended gravity case. The scientific knowledge any phenomenon of study only it is reached when it is explained in general the it is not admissible the particular case gravity used Einstein foundation of explication of the case general of gravity which in essence is phenomenon of the energy and not an apparent phenomenon of simple of coordinates. On September of 1913, "On present of the problem of ratified 1915 of Relativity", had to give up conception of gravity as effect coordinates; he specifically wrote: can characterize the gravitational field as "apparent" because a suitable choice state of acceleration, he bring it about that in a given spacetime point no gravitational field present. But obvious that for extended gravitational fields this vanishing the gravitational field cannot, general, be achieved for a transformation. For example, it not possible to the gravitational field the Earth vanish choosing an appropriate [9], [12]. field later as a permanent gravitational field. Permanent fields not equivalent to uniformly accelerating of With this declaration is clear that Einstein admitted that gravity exists and it is really phenomenon. Einstein adverted that theory relativity (in the narrower sense) had to be replaced by
 conservation taken as the staRting point, We obtAin The ReSult That We can choose the REferEnce system (to which the spAce-tiMe "COordINaTes" x, y, Z, t are reFErRED) in SuCh A waY tHAt Only lIneAr but, in Contrast to The CuStomary theorY Of Relativity, ArbItrary linear SubStitutIoNs lEAve thE eqUatioNs covaRIant" [5]. 7 GrAvity cannOt BE a simpLE effect OF ChAnge Of coordinates With THe YEars of analysis On gravItY, eiNSTeiN diStinguisheD tWo manIFestatiONs OF THe pHEnomenon of graVity: The puncTUal And the ExTenDIng in tHe spaCeTIme. while the firSt caN be explaiNed as eFFect of cOOrdinatEs, the sEcoNd nO. Of cOUrSe, WhiLe THe fIRsT is A ParTicular cAsE, tHe secOnd iS THE GeneRal Case. at firSt, however, EinsTeiN useD A prOmisiNg lanGuagE iN whicH he seeMed to SoLve the problem of GeneRalizatioN thRoUgh ThE prinCIple of RelAtiVity, sinCe he alsO DisTiNGUIsHed between the princIpLE Of RelativiTy in thE NaRrOW sense anD tHis PrinCIPle in The eXTeNded sensE when bOTh CaN be applIeD only tO tHe sPecIfic cASe, beCause tHe princiPle of RElativity reallY In an extended sENsE IS nOT posSibLe to make it cOrreSPond To thE ExTenDEd graVity cAsE. thE Scientific knowledge Of Any pheNomenOn of study only It is reacheD WHEn it is exPlaiNEd IN general the pheNomenOn. ThereforE, It is not aDmissIble that The particULAr case of GraVitY waS usED By einstein as fouNDAtioN oF the expLicAtion of The CasE geNerAl Of gravity Which in eSsEnCe Is A phEnomeNOn of the eNeRgy AnD noT an apPArent pHenomEnon Of ReLAtiVe motioN SiMPLe efFeCt Of coOrdInAtes. ON 29 SepTEmbEr of 1913, "On tHe present StaTE of tHe PrOblem of Gravitation", anD rAtified in 1915 aNd 1925, "theOry of tHE relativiTy", Einstein had to give up hiS ConceptIon Of graVity As effect oF coOrdinaTes; HE speciFicallY wrotE: "AN phYSIcist SHArIng OuR standpoinT CAn cHaracTeRize The gravItational field as "apPAreNt" because by a sUitAble CHOiCe sTAtE Of aCcELerATIon, he can bring it About that iN a GIvEn spacetimE PoiNt No graviTationaL fielD Is preseNt. But it is Obvious thAt For eXTEndEd gravitatIonal fieLds this vaNIshinG Of The grAviTationAl FieLd canNot, in gENerAl, be aChieveD fOr a traNsforMaTion. For eXample, it would not be possiBle to mAke thE grAvitationAl fIEld Of the EartH vanIsh by choosIng An aPpropRiaTE refeRencE SySteM" [9], [12]. "the fiEld wAS later to bECoMe kNOWn As a permanenT GRAviTatioNal FIeld. PeRmanEnt gravitational fIElds are not equiValeNT To uNifORmly AcCelerating framEs oF rEFErence" [11]. WiTh This declaraTion is clEaR That EInsteiN admitTed that GRAvITy exisTs anD it Is really a PhySiCAl phenoMeNoN. einsteIn adVeRted thAt "The tHEory OF Relativity (in the nArrowER Sense) HAd tO be rePlAced by
 conservation taken as the  startingpoint , w e o bt aintheresult that we canchoose the reference s ystem  ( t o wh i ch  thespace-t i me " coo rd in ate s" x,  y, z , t  are re ferred) in  su ch  a way thato nl y linear b ut,  in contrast  to  the c us tom a ry th eor y ofrelati v ity, a rbitraryli n ear su b stituti o n sleav e the equations c o va r iant" [5]. 7 G ravity  c a nn o t  be  asimple eff ec t ofc hange o f  c o o r din a tes With theyears of an a lys is ongr avi t y, Ein stein  d i sti nguished tw o ma nifestati ons of the phe n omenonof gra vit y:Thep un ct ual  a n d t h eext e ndi ng in th esp aceti me.W h i l e th e f irst  canbe explainedaseffe c t o f coo rdina tes,  t he se cond n o. Of  c ourse, while th e fi rst is apar ti cul ar  case ,  the s eco ndis thegeneral cas e. A t  f irst, however, Ein st e i nused a p romisi n gla n guage in  w hic h he s eemed  tos ol ve the p roblem of  g enerali za tion t hr oug h t he pr i ncip le ofrelativi ty, s i nce he also di s tinguished be t we e n  t h e pr inc iple of rel ativ i ty i n th e  n arr o w sen se an dt hi s  principle in the e xt endedsense  when both ca n be appli e d only tothes pe c ific case, bec ausethe princi p le of re lativ ity real ly in ane x tended s ens e i s n otp o ss ible to makei t  cor re spond t o t he exte nde d g rav ity  c ase. Thescientif ic  k no wl edg e ofa ny pheno me non  o f s tudyo nly it  is r each ed  w h enit is e x pl a i nedin  g ener alth e phe nome n on.  Theref ore, it i s n o t ad mi ss ible th at the partic ul ar case of  g rav ity wa s used byEinstein as foundationo f the e xpl icati on o f the cas e g eneral  of gravit y whic h ines sen c e  is a p he nom en on of thee n erg y and  n ot a n appar ent phenomenon ofr ela tive motion s imp le e f f ec t o f  c o ord in a tes . On 29 September  of 1913,"O n  t he present sta te  of the  proble m ofg ravitat ion", and  ratified  i n 19 1 5  an d 1925, "T heory of  the Rela t ivity " ,Einst ein  had t ogiv e uphis co n cep tionof gra vi ty aseffec tof coord inates; he specifically  wrote : "An  ph ysicist s har i ngour stand poin t can char act eri ze th e g r avita tion a lfie l d as"app a rent" bec a us e b y asuitable ch o i c e s tateofa cceler atio n, he can bring i t  about that in  a g i v enspa c etim epoint no gravi tat io n a l fieldis  present. B ut it is  o b vious  thatfor ex tendedg r av i tation al f iel ds this v ani sh i ng of t he  g r avitat iona lfieldcannot ,  ing e neral, be achiev ed fo r a tra n sfo rmati on . For e x ampl e, it woul d not be po ssible  tomakethe gra vi tation alfi eld of the Earth van ish b y choos in g an  ap propri ater e feren ce s ys tem " [9], [1 2 ] ." Th ef iel d wa s lat er  tobecome kn o wn as aper m anent g ra vit a t ionalf ie l d . Permanen t g ravit a t ional fiel d s ar e  n o t equ ivalen t to u niforml y  ac ce leratin g f r a mes of re ference"[ 11] .With  this de cl arat io n i sclear that Eins tein adm itted th a t  gravi tye xist s  and i tis really aphysi ca l  phenom e n on.  Einste i n a dve rte d th at"The theory of relativity (in  the  narr o wer  sens e) ha dto be re p lace d by
 conservation_taken as_the starting point, we_obtain the_result_that we_can_choose the reference_system (to which_the space-time "coordinates" x,_y, z, t_are_referred) in such a way that only linear but, in contrast to the customary_theory_of relativity,_arbitrary_linear_substitutions leave the equations covariant"_[5]. 7 Gravity cannot be_a simple_effect of change of coordinates With the years_of_analysis on gravity,_Einstein distinguished two manifestations of the phenomenon of gravity:_The punctual and the extending in_the spacetime. While_the_first_can be explained as_effect of coordinates, the second no._Of course, while the first is_a particular case, the second is the_general case. At first, however, Einstein_used a promising language in_which he_seemed to solve the problem_of generalization through_the principle_of relativity, since_he also distinguished between the principle_of relativity in_the narrow sense and this principle_in_the extended sense_when_both_can be_applied only to_the_specific case,_because_the principle of relativity really in_an_extended sense is not possible to make_it correspond to the_extended_gravity case. The scientific_knowledge of any phenomenon of_study only it is reached when_it is_explained in_general the phenomenon. Therefore, it is not admissible that the particular_case of gravity was used by_Einstein as foundation of_the explication_of_the case general_of_gravity which_in essence is a phenomenon of the_energy and_not an apparent phenomenon of relative_motion simple effect of_coordinates._On 29 September of 1913, "On_the present state of the problem_of gravitation", and ratified in_1915_and_1925, "Theory of the Relativity",_Einstein had to give up his_conception of gravity_as effect of coordinates; he specifically wrote:_"An_physicist sharing our standpoint can characterize_the_gravitational field as "apparent" because by_a_suitable_choice state of acceleration, he_can bring it about that in_a given spacetime point no gravitational field is present._But it is_obvious that for extended gravitational_fields_this_vanishing of the gravitational field cannot, in general, be achieved_for a_transformation. For example,_it would not be possible to make the gravitational field_of the Earth vanish by choosing an_appropriate reference system" [9], [12]. "The field was later to become_known as a permanent gravitational field. Permanent gravitational_fields are not equivalent to uniformly accelerating_frames of reference" [11]._With_this declaration is clear that Einstein admitted_that_gravity_exists_and it is_really a physical_phenomenon. Einstein adverted_that "The_theory of relativity_(in the_narrower sense) had_to_be replaced by