A mad scientists constructs a device which changes Pi instantly from 3.1415... to something like 4.7182...; it is still an irrational number but it is different.
What changes would happen?
The things that I have thought of already are:
Earth gets a different circumference and volume, meaning an increase in mass and higher gravity.
Cars and bicycles become faster because while wheels rotate at the same speed, they cover a larger distance.
Atom structures are changed due to a change in the orbits of electrons.
The orbit of the earth gets longer, meaning a longer year. However, because the Sun's mass is increased, the gravity is increased, meaning that the earth's orbital speed increases.
Or will the entire universe just break?