I like computers, really I do. Computational physics is a good thing. However, there is a small problem. The problem is that there seems to be a large number of people out there that treat numerical methods and simulations as something different than theoretical calculations. You can tell who these people are because they refer to simulations as "experiments". But what do these simulations really do in science? What is science really all about?
**Science**
To me, science is all about models. Making models, testing models, upgrading models. Models. Some examples are the model of gravity. One such model is that there is a gravitational force between any two objects with mass. This force is inversely proportional the square of the distance between them. (This is Newton's model). Is this model perfect? No. Is this model the truth? No. How did this model come about? Experimental evidence.
**Models**
Well, how do you make models and what form can they take? To make a model, you collect some observations. The model should agree with these observations. This model could be a physical model (like the globe). It could be a mathematical model (like V=IR). It could be a numerical model - like a [vpython](http://vpython.org) program of a baseball trajectory with air resistance. These are all models.
**8th graders**
What does any of this have to do with 8th graders? I claim that any numerical calculation or simulation could be done with a group of 1000 8th graders rather than a computer. What does a computer do? (a computer program really) A program takes a problem and breaks it into a bunch a really small steps. It then does each of these steps and combines them together in some way. Just like a group of 8th graders with TI-89 calculators. Clearly, they are just computing something - they are not a separate type of science (other than theory and experiment).
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Thank you for writing about computational physics! I am teaching 2nd-year HS physics to a group of kids who liked first-year physics so much they signed up for a second course in it...as seniors! I am also thinking of assigning my first and second year students to read your blog and start a physics blog of our own. May I link to your blog on my website?
I plan to do some computational physics work with my 2nd-year students, using vpython, since we do not have access to 1000 8th-graders, and we don't have the patience to explain to even 100 8th graders how to do the calculations we want done and them make sure they are doing it correctly. One of the advantages of the computer over 8th graders is that you only have to tell the computer once what to do, whereas some 8th graders won't listen and others won't bother doing what you've asked them to, instead they will type "58008" and see if it spells what they hope it does when they turn the calculator upside down. I think it is more like having 1000 young women looking at astronomical photos and looking for anomalies, as they are probably more careful and methodical than the average group of 8th graders.
I look forward to reading more from you, thank you again!
Also, the more particles you need to keep track of, the more complex your model, the harder it would be to use 8th graders. The instructions are just too complicated. In addition, in doing the computational work you may find out that your model produces results different from reality...or different from theory. This gives you important information that you might otherwise miss.
Well, I am not a working physicist, and my highest physics degree is a BA, so I will not try to convince you that computational physics should be considered as an addition to the traditional dyad of theoretical and experimental physics. However, I will continue to believe that up-and-coming physicists should learn methods of computational physics as part of their training.
I should let you know that I have had a number of conversations with Bruce Sherwood of NCSU, who is passionate on this topic.