A alguns meses atras tive o privilegio de visitar pessoalmente Julian Barbour, autor de The End of Time, e fisico teorico que ja trabalhou com grandes nomes da ciencia contemporanea (Carlo Rovelli, Lee Smolin, por exemplo), sendo ele proprio considerado por muitos um nome muito influente na fisica. Suas ideias sao bastante radicais, e ele esta construindo uma teoria que dispensa os conceitos de tempo (como pano de fundo externo) e espaco absoluto (so distancias relativas sao importantes) e trata transformacoes nao observaveis (translacao, rotacao do universo inteiro) como nao fisicos. Os resultados me parecem muito interessantes, particularmente pela filosofia positivista que me atraia bastante ja na adolescencia. A ideia de partir de novas concepcoes da natureza do movimento para chegar a pistas da gravitacao quantica me inspira a fazer o mesmo, e aprofundar as ideias de Barbour, Mach e outros.Tive o prazer de discutiR um pouco sobre algumas ideias minhas. Acima uma foto em College Farm, onde ele conduz suas pesquisas com alguns colaboradores. Escrevi um pequeno essay sobre alguns pensamentos meus e lhe entreguei. Tambem estou estudando teoria das categorias para tentar finalmente expressar matematicamente minha filosofia. Espero conseguir fazer isso antes do deadline do concurso do FQXi desse ano. Ai vai o essay que escrevi para Barbour:A FEW THOUGHTS ABOUT SPACE, TIME AND THEIR INHABITANTSA good deal of philosophical debate on spaceand time has dealt with the question of how is the best way of conceivingmotion. The relational and absolute philosophies are the most famousmethodologies that have addressed this (I don't know of any other verydifferent). I will show more explicitlyhow the relational conception of motion can be seen as an intellectualapparatus built upon questioning the meaning of statements about the physicalworld. This would make it easier to then introduce some novel thoughts at theend. Some typical debate about the relational vs absolute nature of motion goeslike this (lets stick to space and forget the relational conception of time fora moment): 1) Lets try to find whats the meaningof the following statement: (1.a)= ''Physical object 1 has velocity x withphysical object 2 as referential''Let us postulate that(1.b): (1.a) is a true sentence if and only if and only ifphysical object 1 is observed to have velocity x with respect tophysical object 2. Once you define what empirical experiencecorresponds to ''observing physicalobject 1 to have velocity x with respect to physical object 2'' , (1.a) becomesmeaningful and empirically verifiable. Assuming we can observe things, measuretheir relative distances, and calculate the time rate of change of thosedistances, that is fairly easy. 2)(2.a)= '' Physicalobject 2 has velocity x'' (2.b): (2.a) is a true sentence if and only ifphysical object 2 is observed to have velocity x. Itturns out that once you have defined movement and velocity to make sense out of(1.a) in the usual way, (2.a) is never true or false because movement isdefined to relate a physical object to another physical object . There is, bydefinition, no truth or falsehood in statements like (2.a), they are literallymeaningless. 3)(3.a)= ''Physicalobject 3 has acceleration x''(3.b): (3.a) is a true sentence if and