How plausible is a computer simulation of the laws of the universe as we know them today?

Question

With what humankind knows today of the laws of physics, is it possible or plausible to create a virtual universe that obeys the same laws we do? How great of an effect would you speculate the unknown laws have on the universe? When it comes to a functional model, how important are the little things? Could the laws be practically entered into a computer simulation that replicated our universe?

Answer 1

With millions of lines of codes and thousands of years of programming, yes, but it is very impractical.

Answer 2

I guess the answer to your question depends on the scope of your question. If you are trying to simulated the entire universe, then you will fail. Our knowledge of what is in our universe and how it actually works is a minuscule fraction of  what actually exists. Furthermore, we don't have a 'universal theorem' that applies to all of our physics observations. Theories that hold true when dealing objects on an astrological scale often do not hold true on a quantum physics level. The opposite is often true as well. Theories dealing with atomic particles, subatomic particles, and anything else in quantum physics often do not hold true when dealing with observations on the astrological scale. Furthermore, without our current computing power, even the larges computer cluser (super computer) would not come close to simulating the events of an entire universe, even if we did have all the laws of physics.

However, if we limit the scope, we can predict the way certain events will take place in pre-specified situations. Pharmaceutical companies use simulations such as these to predict how certain chemicals will interact to predict the creation of medicine and their effect of certain illnesses or diseases. Given, they still have to create it to actually test it because their simulations are not perfect. However, simulations allow many more things to be 'tested' without wasting the money on the actual creation of the drugs.

Tire companies use physics simulations to predict how tires will handle different situations. They take many parameters into play (tire temperature, surface conditions, tire pressure, tire material, suspension, weight of vehicle, angles in road surface, etc, etc). By limiting the scope of the physics to only deal with thing that will affect the vehicle and tires, Simulations can be created.

Many other simulations for different types of things exist (folding of genetic proteins, weather, chemistry, etc). these simulations can run great and fairly accurately when all details related to that event are taken into account. By limiting the scope of the project, we can remove unnecessary theories and insure that relevant theories in physics are accounted for. However, we do not have the knowledge or computing power to simulate things on a very large scale. Furthermore, the more accurate a simulation is, the more calculations are required which can take a long time. I run the Folding@home distributed computing project on my computer. My computer has only a fraction of the computing power that most supercomputers that are used for simulations do. However, it is still a decent system. My system can require a few hours to complete a data simulation for a series of protein folds used in nature in the reproduction of DNA and genetic information. These events normally take place in a fraction of a second, even though it can take a few hours on my system due to all of the calculations. There is no way to simulate a universe with our current computer technologies.