You are making a lot of mistakes about what happens when the mind "moves" to the Sun or someplace else.
One is that the Sun you're thinking of is not the Sun, it is an image of the Sun. The Sun is not in your mind. Your mind is inside your skull, or certainly inside your body (including your whole nervous system, not just your brain) which would take light far less than 8 minutes to travel through.
Another mistake is that thinking of the Sun is instantaneous. It takes the chemical, electrical and other changes in your brain and body actual time to think of the Sun. Since none of those parts of your body move anywhere near the speed of light, even the short distance among them takes milliseconds for the interacting parts to move through. But it's still not the Sun.
Still another mistake is that science is a subset of Buddhism. While there might indeed be interpretations of existence that (some) science and Buddhism could agree are accurate, most notably the fundamentally subjective nature of events requiring an observer to have any definite state or condition, there is not a hierarchical relationship. There is a common philosophical attitude derived from making experience the basis of existence, while noting that there is more to existence than to experience.
So while there is interesting food for thought in comparing the speed of thought to the speed of objects, trying to find Buddhism superior to science by contradicting it is really just a self indulgent sophism. Which both Buddhism and science would agree is a waste of time or worse.