Unless god changed the laws of physics from their current values, how are these visible?
To suggest He changed it means we assume it was the same then. There is no reason to assume that in science. Is there? I think people just look to the past as if it were the same, and proceed from there.
The real question, that science depends on totally, and that cannot be answered, is 'why would they'? There has to be a reason, or all is in vain that is built on that premise. My experience so far says that there is no reason at all. The wizard of Oz is a silly, weak old man.