Essentially linear? Hm, no not really.
I think the pattern is similar to that of evolution: Long periods of subtle adjustment and refinement, short periods of radical change, followed by subtle and refinement of this changed state.
What remains are the building bricks of science, the observations. These observations have to be explained by the new.
The view of our solar system is a good example of this:
First, there's our Earth in the middle of it all, surrounded by perfect spheres on which Moon, Sun, etc. circle around it. Than further obervations are made: Some of the celestial bodies don't move in the way it is suggested by the spheres. So, more spheres are added which circle inside the old spheres. - Adjustment and refinement.
Along come Kepler and Galileo, basically saying: Nice theory, explains the facts (more or less) but far to complicated. Let's put the sun in the middle and all the other planets in orbits around the sun and voilá, same (or even better) level of explanation, but far less complicated. - Radical change
After that, the circular orbits become oval, gravity is put into the picture. - Adjustment and refinement.
[BTW, even if a new theory (eg. Eintein)comes along which is more accurate than the old (in this case Newton), the old theory can still be used as far as its model is pragmatic for the cirumstances. Newton is alright and even accurate as long as you don't apply it to things which move at some respectable fraction of lightspeed.]
Same goes not only for science but for technology, society, ecosystems, etc.: Long periods of bordedom followed by short periods of excitement.
As far as I know, there's even a science discipline out there for this kind of behavior, called "Sciences of Complexity" or "Theory of adaptive complex systems". One main player is the Sana Fe Institute. Quite interesting stuff, but so far I haven't really looked deep into this (or any other form of systems theory). The only book I really read is "Complexity: The Emerging Science at the Egde of Order and Chaos". It's the history of this young science.
With this, I hope, I have made myself a bit clearer. I'm really looking forward to any comments on this "History of Sciences".
Be well,
Jens
