Meh, they've tested Newton's laws numerous times. If everybody knew them, both intellectually and in their bones, they wouldn't have the myths to test, but alas, I don't think you can claim with a straight face that we live in a society with universal knowledge and deep understanding of Newton's laws.
... and if you think you do, spend some time on the much-referenced "fan site".
And furthermore, there is nothing unscientific or wrong about testing our most well-tested theories. The entire point of science is that even then, the theories will still work, not that you should never test them again.
I'd also further observe that for all the drama happening here, those swinging gun sequences aren't that unsafe. It may look unsafe but the actual set of things that can plausibly go wrong was less than your intuition may be claiming. It's not like there was a way they were going to shoot themselves with a particularly higher probability than usual. (And remember that if you start constructing far-out implausible scenarios under which that might happen you must be willing to worry about equally improbably things all the time; one rapidly gets to the point where things like simply driving to work must be considered too unsafe to do if one starts spending too much improbability on the constructed scenario.)
I agree with everything you said, but I even think it's unfair to say they're "testing Newton's laws." Rather, I think they're often testing "is it feasible for us to reproduce the idealized circumstances from thought experiments." Case in point is firing an object in the opposite direction of a moving vehicle. I don't think any of them questioned the physics behind it, but it was really a question of if they could contrive the circumstances exactly so they observed the kind of result one would see without all of the nasty effects that reality imparts (like spin, air resistance, speed variance, etc.): http://www.youtube.com/watch?v=BLuI118nhzc
The nice thing is that it is no problem to test Newton’s first law of motion again and again and again. If you do it right you will always get the same results.
That’s what Mythbusters is all about. It’s not about rigorous mathematical demonstrations of why something can or cannot be true, it’s about figuring stuff out in a way that actually makes it possible to see the result (and not necessarily as the result of a calculation).
That’s a less powerful and much more tedious approach than our usual methods of gaining knowledge but it is a lot more accessible and just good entertainment. Since Mythbusters is less about gaining knowledge and more about entertainment it’s also the appropriate approach for the show.
Frankly, I think that most of the time, their methods are plenty rigorous. The only difference between them and research engineering labs is that instead of writing a paper, they produce a television segment.
For some stuff, the "Can a snow plow driving down the road push enough air to flip a passing car over?" had so much wrong with it that I didn't finish the rest of the episodes on my tivo before I moved.
They tested on a dry, flat surface without any hint of ice or snow. As snow plows are not used in summer, this was a pretty bad error. A runway is flat, a road is not. I assume they were going for local location for cost and just wanted the big crash at the end as opposed to showing how dangerous a snow plow is. Coefficient of friction is an amazing thing.
Oh, their methods are quite good most of the time. The point is much rather that we know so much about how things move that if all you wanted to do, was find out whether it’s possible to bend bullets you likely wouldn’t do an experiment but break out the calculator. An experiment about this particular question can’t tell us anything new.
Sure, it was a pretty dumb myth that they were testing and it didn't make for a great episode, i just still can't believe they didn't end up shooting someone.
