Without Mercury or Venus, how would science differ?

[Destructionator XV]

So often when thinking about other intelligent life in sci-fi, we look at the factors that would let them survive biologically, but I want to think for a moment what factors would change our knowledge of science.

Suppose the solar system was different in that it didn't have Mercury and Venus. Other than that, it is the same. We think about the mythology associated with the planets and the stars, but what about the discovery of scientific principles?

One of the big evidences for the heliocentric model of the solar system was the phases of Venus that Galileo saw through his telescope. One of the supporting evidences for general relativity is perturbations in the orbit of Mercury.

So if those planets were not there, how would it affect the development and adoption of these theories and others? What secondary effects would that have on the development of technology and society?

[Batman]

CAN the solar system be the same with the sole exception of Mercury and Venus not being there? I admittedly suck at math (and science in general) but I suspect the removal of two planetary masses is going to have some effect on the makeup of the system.

[Mayabird]

All other things being equal (which they probably wouldn't be), there would be no slightly non-Newtonian orbit of Mercury which needs relativistic effects to explain. That's all I can think of off the top of my head.