The following is not a theory but only attempt to understand the principles of Special Relativity in connection with the speed of light. Introduction The idea that light waves require luminiferous aether to move through was refuted by Michelson-Morley experiment and that permitted Einstein to postulate that the speed of light in a vacuum is the same for all observers, regardless of their relative motion or of the motion of the source of the light. No one ever considered that the space itself appears as aether for the light waves. Space as distance between two objects is not any different for the light than a fiber cable. Imagine that you accelerate fiber cable through which travels light. The same way we can accelerate space. The only difference is the different speed in these two mediums. Can we accelerate space thus accelerating the light which travels through it? The answer “Yes” may sound stupid on a first though but here is a simple thought experiment, which can be actually performed with the predicted results. The Experiment The above graphic shows the principle of the experiment. A train-car with certain length is moving in right direction with certain constant speed. There is a light source attached at the back of the train-car which sticks out of it. In the front of the train-car there is a mirror, which for the purpose of the experiment we call “observer A”. That will be the frame of reference which we will call “frame A”. Outside this frame is located frame of reference B, which we will call “frame B”. While in motion (with constant speed) the light source on the train-car produces flash toward observer A. The light from the flash needs certain time to reach observer A, during which time the train-car advances in right direction. Knowing the speed of the train-car and the distance between the light source and observer A, we calculate at which place in frame B, observer A will see the light and on the same line in frame B we place observer B, so both A and B will see the light simultaneously. The above graphic is the position of the train-car at the moment of the simultaneously observed light by A and B. Since A is stationary to the source, the distance is measured from the source to the observer. However the distance covered by the light to observer B has to be measured from the place of the emission. In that case the result is two different distances, covered by the light from one emission, and perceived simultaneously by two different observers. Special Relativity would argue the above result with different running clocks in the two frames of reference. The different running clocks though, will not be favorable arguments since B will see the light shifted in the blue spectrum, due to its velocity in respect to the source at the moment of the emission. Let’s extend the experiment and put third observer (observer C) behind the train-car in frame B. Observer C will not see the flash, but only the reflection of the light beam for A and B. These reflections for C will be simultaneous, but also seen with different light frequencies. Conclusion The above thought experiment shows two different distances covered by the light from one emission in simultaneous observation from three different observers. Since the light emission is one, the change of the frequency is due to the different speed of the light in respect to the observer. In other words, observer B measures the speed of light as higher than the measurements of observer A and the result will be seen in the different patterns left by the light. . A question comes to mind after this experiment; can we consider the different light frequency as different speed of the light. The answer is very simple; if two observers perceive the light from one emission with two different frequencies, then their velocity is different not only in respect to the source, but to the light as well. And here is the my thought for the right understanding of the expression “speed of light for different observers”. Light is electromagnetic emission with certain frequency. One electromagnetic wave is not light. Even if we know the precise speed of one photon, that wouldn’t be the speed of light. The speed of light is characterized by the speed, with which every next wave due to the velocity at the moment of the emission approaches the observer. Imagine that the source and the observer are in approaching motion at the moment of the emission. The light waves will approach the observer with speed greater than c and that will shorten the time between the waves. In this case the light frequency is characterized not by wave length, which by my opinion is a wrong understanding about light frequency, but by the time between the light waves. Respectively, different time between the light waves is perceived as different speed of the light and will leave different light patterns when measured. Follows the question, “does the different pattern left by light from stationary sources with different frequencies shows different speed of the light”? No. Two stationary sources with two different frequencies will emit light with the same speed. All sources emit light with the same speed, but the velocity of the light should be measured as any other velocities. The above helps to understand better the events in the Universe and our place in it. We know that a star moves toward us if we observe its light in the blue spectrum, but we can never know the place of the star, since we don’t know the initial frequency of the light and its speed which depends on the velocity at the moment of the emission. Not knowing all this we can never determine the present place of the star whose light we observe. Considering the above, we cannot predict what happens in the Universe right now if we measure all events with same speed for the light. We see the past without knowing the present. In that regard it won’t help much if we do our measurements with different speed for the light, but it will definitely make a change.