Your argument was that virtual particles are only mathematical constructs and don't really exist.
That was what my post was addressing.
As far as 'seeing' virtual particles -- they are the size of electrons. We have an awful lot of those, too. Let me know when you can see them, OK?
Hey, I'll even settle for when you can see protons, which are EVER so much larger than electrons or virtual particles!
In other words, your arguments are rather silly. Regarding historical measurements of the speed of light no, it was not a matter of observational error or clumsy mechanics. If it were, then the measurements would have varied on BOTH sides of the current speed of light. They don't. They ALL show higher speeds than now. That is why I quoted some of the work of past physicists -- folks who really knew what they were talking about and whose life study the constants were.
Regarding your last comment about none of the links showing virtual particles absorbing and re-emitting photons, and that that would take time -- that is EXACTLY why the speed of light has slowed! The data is there, and it does not matter how many people try to explain it away. The data sits there. You can be honest about it or not. That's up to you.