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On the uncertain philosophical context of my recent hammerin’ theme

September 25, 2005 at 10:42 am · Filed under Uncategorized

Remember being taught about the six simple machines? Like the wedge, the inclined plane, the screw? We were taught about them in elementary school, probably around age 10.

So perhaps my memory fails in the reddening light of early middle age: Where’s my hammer? On the list, I mean? The one you use to hit things with.

My wife points out she thinks it’s a “tool” not a “machine”. Shyeah, right, and a ramp is a machine how? Because you do so much with it?

If a ramp is a machine for moving mass against an energy gradient, then dammit a hammer is a machine for increasing the impulse applied to a fixed object. Or something like that.

dave said,

September 25, 2005 @ 11:46 am

it definitely seems like a hammer is simpler than a screw. perhaps the difference is that the six simple machines can be used as components in larger machines?

do you know where this category of six simple machines originated?

Andre said,

September 25, 2005 @ 12:11 pm

The hammer is actually included in this list of six simple machines that “scientists have identified” but not for bashing. Instead, it’s included as a lever. All these simple machines reduce the force required to do some work by spreading it over a longer distance (or angle in the case of the screw).* That’s also true of a hammer in bashing mode, but the spreading out is also separated from the work you want to do (i.e. driving a nail) in time. Maybe they thought that was just too hard to explain?

*Except the simple pulley which simply changes the direction you have to pull. Maybe they meant to include a compound pulley?

Bill said,

September 25, 2005 @ 12:27 pm

I’m thinking the “six simple machines” is some sort of cultural residuum from the educational model of the 1960s. We don’t hear it much, anymore, for some reason. Maybe because it was broken; maybe because it’s old….

Indeed, the thing that reminded me of the grouping was the fact that I was just thumbing through Tom Weller’s amazing book Science Made Stupid again the other day, and came across his table, which includes the “Disinclined Plane” and the “Screwup”. Anyway, the book mocked “How and Why”-style science-for-kids books of the 1960s, and that’s where I doubtless learned the six myself.

Andre said,

September 25, 2005 @ 11:00 pm

Sorry if the last comment sounded a bit pedantic, that wasn’t really my intention. I had a brief look for some history of simple machine teaching and didn’t really find much. But I did find out that a hammer is included in the six as a lever of the third kind… Lot’s of vocabulary for little understanding.

By the way, any chance your copy of Science Made Stupid will make it to your list of books for sale?

Bill said,

September 26, 2005 @ 6:04 am

Nothing extraordinarily pedantic noted. Come; we’re all pedants here….

I’m thinking I need to look into the History of Education literature, if I ever get serious about the question.

[Anyway, yes, one of my copies of Weller's book is on sale. When I saw them back in the 1980s, I bought all I could for gifts, and nowadays we need to downsize the household inventory. Be warned: it's out of print....]

PhilipJ said,

September 26, 2005 @ 2:22 pm

My significant other is an elementary school teacher, and the “simple machines” theme is alive and well. In Newfoundland it is taught at least twice (kindergarten, grade 5), and here in B.C., it is taught at least once (kindergarten).

Son2 said,

September 27, 2005 @ 8:55 pm

PhilipJ is totally right. During my K-12 “education” in NC public schools, I bet as much classtime was spent teaching me the six simple machines as teaching me evolution, thermodynamics, or integration by parts.

I grant the obvious objection that elementary school (where we did units on “simple machines” several years running) is a glorified daycare in NC and can’t be compared to high school (where we did units on those topics in my biology, chemistry, and calculus classes, respectively). Granted. But maybe that’s the comment? Is it necessary to treat our K-7th graders like infants?

Also, the word “machine” is *defined* (in part) by those “simple machines.”

Bill said,

September 27, 2005 @ 8:57 pm

So a hammer is not a machine. Except for the claw part. So some hammers are machines. The rest are… things to hit machines with?

Steve said,

September 30, 2005 @ 8:35 am

But a hammer isn’t a machine if you use it right. The simple machine part of the poorly written elementary science textbooks is always just after the definition of “work” (mass*distance). Most textbooks miss the definition of a machine, and then they go off in whatever non-tangential direction the educators “reviewing” the book wish to take it. A simple machine should be fefined as a device which translates the direction of the applied force to do work. Thus a screw transfers circular motion to linear, a wedge (or an inclined plane) transfers x-axis motion of the wedge to y-axis motion of the target. My favorite textbook (3rd grade) proudly states that a wedge is for pushing things apart and a screw for holding two things together. MY son’s teacher could not reconcile this with the nails holding together my house and the screw jack lifting her car off the ground. (I question her science, but I helped change her flat tire)

The hammer transfers x-axis energy in an x-axis direction. Good tool, not a machine.

And if Weller’s book was such a great gift in the 80’s, how come I never got one?

dsquared said,

October 2, 2005 @ 6:16 pm

the simple machines are the machines that you would need in a simple Newtonian world of rigid bodies with no friction. A hammer is a complicated machine.

Bill said,

October 4, 2005 @ 7:58 pm

And if Weller’s book was such a great gift in the 80’s, how come I never got one?

Wellll… it wasn’t clear how good it was in the context of the 80s themselves.

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