Learning to shave or a gravity-driven, single-degree-of-freedom impact system
I wasn’t taught to shave by my father, but by the internet instead. It isn’t his fault. As a teenager, I had severe anxiety about asking for help with almost anything. I tried, more than once, to use a straight razor, and it never really worked. I cut myself. I bled. I learned nothing except embarrassment. I never asked for guidance, and that failure has become one of those loose memories that rolls around in my head, bumping into others when the lights are low.
I don’t think about it often. But some mornings, while shaving, the memory tumbles down from the highest shelves of my mind with the certainty of gravity and cuts into my awareness. That this happens while I am pressing a safety razor to my face is inconvenient, but it is mostly bittersweet now. A thought of my father, unexpectedly threaded through the other static of the day: work, politics, the general low-grade noise of living in unsettled times.
I, as a well-honed nerd, learn from diagrams, strangers, optimization, and failure. From systems designed to work regardless of who stands beneath them.
Force from a straight-line wedge shape
/\
/ \ ← wedge faces
---•---- ← edge radius
The first time I used a straight razor successfully enough to matter, I also managed to cut my thumb badly enough to stop for a while. The blade punished ignorance efficiently. I would press at angles incorrectly, drag directions against a well-developed grain. More blood. More thought. I learned that a razor blade does not cut because it is sharp; it cuts because extreme sharpness concentrates force into a vanishingly small area. Sharpness is what the we think about because force just doesn't happen here. Not in my bathroom.
If you remove motion and rely on downward pressure alone, the required force becomes very large very quickly, even for a razor.
Forces, areas, and the stress
Cutting is a calculation of stress. Force divided by area. Razor blades work by reducing that area until the stress exceeds what the material can tolerate. Less force is needed when the contact point is small enough.
But the material being cut matters. Skin is fibrous. It tolerates compression extraordinarily well. You can press on it for a long time before it fails. Once a blade breaks the surface, the flesh collapses along the sides of the wedge, and it takes increasingly more force to continue cutting if applying pressure straight down.
We know this. Razors work better by sliding, not pressing. This is shear rather than compression. Compression demands endurance. Shear addresses structures.
Shear does not ask permission from the material. It redirects force sideways, to where resistance is weakest. It's the most effective way to reach your goals. Your shaving goals.
Angle creates motion
|\
| \
| \ ← angled cutting edge
| \
|____\ ↓ direction of motion
By tilting the cutting edge, the material being cut is forced to move along the blade. Motion is created without asking for it. Shearing stress replaces blunt pressure. This allows you to design a cutting device that can be compact, mechanically simple, and devastatingly effective.
This insight is not new. It was once refined with terrifying clarity: a tall frame, an angled blade, gravity, and a mechanism that required no strength, no skill, and no discretion. Only alignment.
Angle transformed weight into motion. Gravity supplied the force. Shear did the rest. It was efficient, repeatable, and indifferent to who stood beneath it. Pressure-based authority had failed. Geometry succeeded.
Every modern safety razor quietly inherits this lesson. It bakes motion into design so the user does not need to press harder, does not need to be stronger, does not need to know very much at all. The system works because the forces are aligned correctly.
This, too, is contemporary.
Some systems rely on endless pressure: more rules, more force, more weight applied from above. Others change the angle. They make resistance irrelevant. They turn accumulated mass into motion and let gravity finish the argument.
Every morning, with a safety razor in my hand, I am reminded that some problems are not solved by pressing harder. They are solved by changing the angle at which force meets flesh.