This is a very, very tricky question. We need to discuss it.
A number of worthy arguments have been advanced, pro and con,
but I reckon there are quite a few additional points that need
to be considered. Here is a non-exhaustive list:
1) Modern science began when Galileo showed that the /combination/
of theory and experiment was extremely powerful. Science is a
lattice of theory supported by experiment and vice versa. You
can't have one without the other.
2) One could argue that nowadays science is a three-way lattice
involving computational simulation and visualization in addition
to analysis and experimentation, with each reinforcing the others.
I have seen this in my own work: For instance, I still cannot
look at the equations of fluid dynamics and tell you what they
mean ... except insofar as I remember what the solution looks
like, based on simulation and visualization work I have done.
On the other side of the same coin, I wouldn't have known what
simulations to do if I hadn't spent years studying the equations.
3) However, in the aforementioned three-way lattice, I do not
see simulation as a substitute (50% or otherwise) for real
experimentation. In fact, I tend to see simulation as a
subcategory of theory, not of experiment.
You can maybe draw a faint, dotted, secondary line connecting
experiment to simulation, but this is IMHO a small correction
term, small compared to the primary line that shows simulation
as a subcategory of theory.
To say the same thing another way: I think that a well-rounded
person nowadays should be versed in all three areas:
-- ye goode olde analysis using algebra and calculus
-- simulation and visualization
-- experimentation
... but at the same time, the idea that simulation could ever
be considered a "substitute" for experimentation strikes me
as profoundly wrong. It's not about substitution. Galileo
did not substitute theory for experiment or vice versa. He
showed that all the folks before him who tried to make such
a substitution were profoundly misguided.
It's not about substitution.
It's about reinforcement. Simulation reinforces the algebra
and vice versa. Theory reinforces the experiment and vice
versa.
For more about "substitution", see below.
We need to remember that the purpose of science is to make
predictions about the real world. Using theory to make
predictions about a simulation is a perversion of science.
5) In addition to all the issues mentioned above, this is a
classic case of "the rich get richer and the poor get poorer".
That's because a sophisticated user can look at a simulation
and know which part is an apt model of reality and which is
not. The unsophisticated user is in jeopardy of trusting
the model too much ... or not enough ... or both.
Therefore the students in a "general admission general physics"
course are not the best candidates for a heavy dose of theory,
in the form of simulation or otherwise. They need a good bit
of experimental ground-truth before they can begin building
the desired lattice.
I see this all the time in aviation. Given a sophisticated
simulator, I can hone the skills of an advanced student in
ways that would not be feasible in the real airplane, such
as multiple system failures in harsh weather conditions.
However, my advice for beginning students is to stay away
from simulators, especially mass-market game-type simulators,
lest they develop dangerous bad habits that are hard to
unlearn.
As is so often the case, we know where we want to end up,
but we can't get there in one step, and the first step is
not directly in line with the ultimate goal. I'm not
advocating teaching wrong stuff, such that backtracking is
required, but I am saying that sometimes you need to go
north *then* east, rather than going directly northeast.
6) The current crop of simulations are too idealized. For
example, they tend to be built using the proverbial massless
and frictionless pulleys. Similarly, they allow you to
connect a wire to a bulb and then to a battery just by
clicking ... whereas in the real world it is not so easy
to connect an ordinary wire to an ordinary bulb or battery.
Nonidealities are part of science, as Galileo well knew.
Real experimentation serves as forceful reminder that the
essence of science is to make predictions about the real
world.
This is a moving target. I can /imagine/ elaborate physics
simulations that would include some realistic nonidealities
... but these seem to be quite thin on the ground at the
moment. This is a point that will need to be re-evaluated
from time to time.
7) I said "it's not about substitution" and I meant it.
I am aware of the counterargument is that there must be
substitution, because there are only so many hours in a
day, and if we add one thing we perforce must remove another.
However, I refute that counterargument in two ways:
7a) The idea of simulation is to make the other parts of
the work easier. This allows you to get more done in the
same amount of time. To say the same thing the other way,
no matter what task we are talking about, if computerizing
the task doesn't make the task easier, don't computerize it!
7b) I also said that the well-rounded person should be
versed in a number of areas. The college may (and should)
already have a computer-science requirement in addition to
the physical-science requirement.
So I say again, it's not about substitution; it's about
integration. It's about mutual reinforcement. I vote for
an /integrated/ science curriculum. That means you get to
take all the time that would have been allocated to the
physics course *plus* all the time that would have been
allocated to the computing course *plus* all the time that
would have been allocated to the algebra course. You smoosh
all that together to make an integrated program so that the
students do math and do computing and do lab work *and* see
the connections between all of the above. Each reinforces
the other. The applications help motivate the math, and
the math helps explain the applications.
Princeton has been doing this for years, and the students
seem to like it. I reckon the need for this is even greater
at the community-college level than it is at the Ivy-League
level.
I'm not saying that setting up such a program is easy.
Solving bureaucratic problems is hard. It requires a
different set of skills from solving physics problems.
In general, we have to do both.