How can one explain, according to the postulates of the theory of relativity, that the property of particles to have velocity in the range of values only v <c or only v = c is absolute, that is, does not depend on the choice of an inertial frame of reference.
According to the second postulate: In nature, there is a maximum speed of propagation of any interactions, absolute in absolute value, it has the same value in all IFRs.
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