What does modeling and simulation mean in science?

Answer 1

Many times in the sciences, an experiment will be run and observations will be made.

Scientists like to be able to estimate and explain those observations, and to do that, they will often come up with a mathematical or causal relationships which attempt to explain these observations in terms of other things which we are more familiar with. The relationships themselves form the model.

Once we have a model, we can attempt to make predictions of how observations will turn out, and we can test the accuracy of our model by checking how close we are.

Simulation one way of attempting to predict observations. In simulations (as opposed to emulations), a scientist or engineer will attempt to recreate the underlying mechanisms that govern a system.

For example, to predict the paths of objects in space, scientists may simulate a model of the solar system. This model can be simple or can be very detailed, and will have to take into account things like the masses of objects, gravity, pressure from stellar winds, tidal friction,etc. The model will have taken into account all of these different factors to come up with an equation for the objects as a function of time. The simulation's job is to solve these equations (perhaps repeatedly for different points in time).

An emulator (as opposed to a simulator), is something which will attempt to recreate the outwardly measurable properties of the system. This means that simulators are emulators, but emulators are not necessarily simulators.

For example, in a computer game you can emulate gravity simply by having all objects accelerate downwards at the same rate. A simulator for the same thing, however, would need to first take into account the masses and locations of all objects, determine the field strength, and then calculate an acceleration for each item based on the calculated fields.