Hello! I have some confusions about this topic, I'm a physics newbie so my question may have no sense, please have mercy ;). It's supossed that relativity only considers observation as valid "what we see", but observation it's independant of what we know (we can't tell how distant we are from different objects without previous information, we need another relative system for that). Does this mean that relative observation is bidimensional? If so, it would be impossible to calculate absolute parameters whithout changing the observation point? If so the speed of light would be actually slower for some observers right? This thought has got me really intrigued.