why space and time are interchangeable in physics

#SpaceTimeRelationship, #SpeedOfLight, #AstronomicalMeasurements, #LightYear, #PhysicsConcepts, #SpaceTimeExplained, #ScienceShorts, #AstrophysicsBasics, #VelocityAndDistance, #SpaceTimeYardstick, #RelativityForBeginners, #UnderstandingTheUniverse, #SpaceTimeConnection, #PhysicsExplained, #CosmicMeasurements ... https://www.youtube.com/watch?v=38JK4J9zA4k