Here is a question which can seem stupid to a lot but it has stuck it my mind and i can not move forward. There are two points to it. 1 - The speed of light is same in all inertial frame of references. So if an observer is moving with a relative velocity 'v' withrespect to another stationary observer and a light bulb is switched on both of them will see the bulb light at the same time. 2 - The simultaneity is always relative. If some one states that two events are relative then the same events can not be relative to another person. To prove this i have the following example in the book Two events happen, sally is moving with a relative velocity 'v' to sam. So sam measures both of the events to be simultaneous and sally measure the event Red to happen first. My Problem. Now the problem in my mind is if the speed of light is same in all inertial frame of references, THEN the speed of light and in result event measurement for sam and sally should be same irrespective of the Relative velocity between them. So why does sally measures event Red to happen first if Light is traveling at the same speed.