query: How do we know the maximum speed of conventional matter is the same as the speed of light?
positive_passages.docid: 14036
positive_passages.text: What is so special about speed of light in vacuum?
negative_passages.docid: 69464
negative_passages.text: Do we know why there is a speed limit in our universe?
negative_passages.docid: 35663
negative_passages.text: Is there a formula that gives the position of an object depending on the time, but which doesn't allow the object to surpass the speed of light?
negative_passages.docid: 17152
negative_passages.text: Do all massless particles (e.g. photon, graviton, gluon) necessarily have the same speed $c$?
negative_passages.docid: 119953
negative_passages.text: What is the meaning of speed of light $c$ in $E=mc^2$?
negative_passages.docid: 128506
negative_passages.text: How do we know that the laws of physics are invariant in all inertial frames?
negative_passages.docid: 58728
negative_passages.text: Why does the speed of light in vacuum have no uncertainty?
negative_passages.docid: 120679
negative_passages.text: Rømer's determination of the speed of light
negative_passages.docid: 8367
negative_passages.text: What do physicists mean when they say "speed of light"?
negative_passages.docid: 17771
negative_passages.text: Is speed of light and sound rational or irrational in nature?
negative_passages.docid: 116728
negative_passages.text: Why does speed of light have to be constant?
negative_passages.docid: 4350
negative_passages.text: Rotate a long bar in space and get close to (or even beyond) the speed of light $c$
negative_passages.docid: 35331
negative_passages.text: How can an object's instantaneous speed be zero and it's instantaneous acceleration be nonzero?
negative_passages.docid: 64822
negative_passages.text: Why is speed defined like it is?
negative_passages.docid: 16362
negative_passages.text: How does matter know to obey physical laws?
negative_passages.docid: 7054
negative_passages.text: What ultimately determines the speed of electrical media
negative_passages.docid: 10781
negative_passages.text: Accelerating particles to speeds infinitesimally close to the speed of light?