“Such is how Science makes progress: not destroying the past, but learning from it, and building on it.”

“Subjectivity is strange to Science, while Relativity is an objective part of it.”

“The notion of Local Inertial Frame is crucial to understanding Nature and, in particular, General Relativity. Notwithstanding, very few popular science books (not even textbooks) emphasize enough its fundamental character.”

“The past and the future are not a collection of instants shared by all space, but a collection of events that correspond to a possible relation of causal order with the present event.”

“It is worth noting that a wrong folkoric definition of an Inertial Frame in the Popular Science literature (even in text books) reads that 'it is a frame in uniform motion'. We know very well by now that the idea of motion requires a frame of reference, so that such a definition of an Inertial Frame has no meaning whatsoever, confusing the reader because it tacitly reaffirms the idea of absolute motion -- when the goal of every didactic exposition of Relativity Theory should be precisely the opposite.”

“Without causality in the world, there is no point in educating people, or making any moral or political appeal.”

“It is also worth noting that the earth gravitational field though locally ‘vertical’ is globally radial as the centrifugal field in the carrousel is. However, the big difference between the two is that the former decreases in intensity with distance from its center, while the latter increases its intensity with distance from the rotation center. But … (think about it a little), the farther from the center of rotation, the closer we are to the rest of the Universe!”