I had my tongue in my cheek a little bit on my last post, but if you really do want to know, I’d be more than happy to give it a crack. Science isn’t anything more than a hobby for me, but hopefully I can explain it adequately and simply (note: this won’t be brief, and I don’t know what any of it has to do w/ Catholicism or the Eucharist, and I don’t claim technical accuracy so much as I claim the ability to conceptual accuracy)
Special relativity came first in 1905, and it is what gives us E=mc^2. The theory is based on two premises:
- The speed of light is the same for all observers
- All static frames of reference are equally valid with respect to the laws of physics (static=not accelerating or decelerating).
The roots of the first assumption are borne out of a series of late-19th and early 20th century experiments trying to figure out what medium light travelled through - after all, sounds waves are oscillation in the air, ocean waves are oscillations in the water - but what is the “medium” of light? Scientists proposed a number of experiments to verify the existence of a hypothetical medium for light. One easy way to do this is essentially to measure the speed of light at right angles to each other in the direction of the earth’s motion - as the earth moves through this invisible light-medium, one would be facing the medium “head on” and the other “from the side” - the one facing head on would obviously be slower, yet no differential could ever be found. Also, equations on electromagnetics developed by a man named Maxwell implied that the speed of light never changed.
The second assumption is what makes this “relativity.” If you and I are in different spaceships, and I see you move left-to-right across my window at 100MPH, what do you see? Well, you see me moving left-to-right across your window at the same speed. Are we both moving at 50 MPH? Is one of us moving and one of us standing still? There is
absolutely no way to tell. Therefore, it is equally valid for you to say you are standing still and I am moving and for me to say the opposite. Only if one of us is accelerating can we tell any difference. And it doesn’t matter, because the laws of physics are the same, even if we describe events differently.
Say, for instance, I bounced a rubber ball on the floor of my spaceship as you passed. To me, the ball went straight down and straight up, just like it should. To you, the ball moved in a “v” pattern, as it moved both down and up and across your window. Even though the rubber ball travels a longer distance in your eyes, that’s OK since it has more momentum (100MPH worth) relative to your perspective.
continued…