Wednesday, 29 May 2013

Learning point

You really do learn something everyday, don't you? And today's step towards enlightenment provides a scientific explanation for why a good hairbrush punches above its weight in the disciplinary sphere.
Physics was a real problem for me at school. Or put it another way, I was a real problem for my physics teacher (sorry Mr Hindmarch).
But since I discovered The Big Bang Theory I have been trying to understand what makes the universe tick, so today's insight was especially pleasurable. I stumbled across it while wasting a little work time in Tumblr-land at a blog called Who's Sorry Now, where Spanked2Tears appears to be mostly concerned with the interface between male bottoms and hairbrushes (in female hands) - but I guess the physics is much the same.
A blog visitor asks: "Why a hairbrush, does it have anything to do with it just being available? Doesn't look like its going to hurt actually."
And Spanked2Tears answers: "My personal take on it, is that the bristles act as delayed mass. In other words they continue to decelerate after the wood has stopped."

I was a bit puzzled at this point. Delayed mass? If only Mr Hindmarch had held my attention (or been more persuasive in demanding it). But S2T goes on to add: "Extending the duration of the impact. If you have ever seen a shot hammer it’s the same theory. The hollow head of the hammer contains small, loose lead balls. They land a moment after the head of the hammer does and cause the blow to generate far more energy than a regular hammer of the same weight..."
So, it's as simple as that - bristles extend duration of impact. I feel I now need to buy two identical hairbrushes, take the bristles off one and then get SO involved in some citizen science. 
How would it work? A dozen with one brush on one butt cheek and a dozen on the other with the other brush, then rate redness?
Spanked2Tears does end on a point that's more about psychology than physics, saying: "I think that the allure of the hairbrush is that it is such a common domestic item." And all that delaying of mass aside, that for me is what makes a good old-fashioned hairbrush THE number one implement for TTWD.
It's an object that is so fearfully stingy, but at the same time is so sweetly innocent. It can sit around the house, or the handbag, and mean nothing to the majority, but everything to those of us in the know.


  1. I don't know if the physics are correct here. The "shot hammer" is usually called a "dead-blow hammer" (here in the US) and is designed to use as a mallet (more than a hammer) and to have an "anti-rebound" effect (the shot in the head of the hammer, suspended in oil or silicone having a dampening effect on the hammer blow). I don't know that this type of hammer or mallet necessarily has any more energy delivered to the target than a solid head hammer of the same weight, though I suspect it does. The intent though, isn't to deliver more force than it is to diminish or eliminate rebound.
    As far as the hairbrush is concerned, bristles vs. no bristles, I suspect the effect would be difficult to gauge without some fairly sophisticated instruments. I think the effect of the hairbrush is largely psychological in that it most likely the first instrument, other than the maternal palm, that we are likely to be spanked by and thus has a strong "memory" effect on us. Just seeing one on a dressing table or in a more innocent setting can still bring up vivid memories of strict maternal discipline...

  2. I too doubt the delayed mass theory. I suspect that the effect is the same bristles or no bristles.A a hairbrush is just a flat wooden paddle with bristles on one side. At the end of the day a wooden
    implement like that is going to sting like hell when applied to a plump soft bare bottom

  3. I never took Physics in school. Maybe that's why the delayed mass theory is lost on me. My intuition says that a spanking implement will hurt if it's made of a dense, solid variety of wood and has some weight to it. If the size and shape of the object focuses all of that weight narrowly, the target is greatly impacted. I don't believe the hairbrush was chosen for convenience---many household items are available---but for its effect. It's as if the size and shape of a brush was designed for the size and shape of the intended target. Does a good hairbrush pack more wallop than its weight would suggest? I don't know, but if the bristles add weight to the object, then they add weight to the spanking.

    I buy the psychological aspects. I think for many into TTWD, the hairbrush is a symbol of maternal dominance and power. Imagine if you learned early in life that you had better behave or else mother will use the hairbrush. The object fits so comfortably in her hand, and with little effort, she is able to rule your world. Any female can harness this power if she has the determination to do so.

  4. Well, I guess it's always nice to see a bit of science on a Tumblr spanking site - even if, as seems to be the case here, it's bad science. For the bristles to add significant 'delayed mass', they'd have to have some significant mass themselves - which (unless I've just been buying the wrong hairbrushes!) I'd say they generally don't. Now, if you were to empty the lead shot out of that hammer and attach it to the back of the hairbrush.. but that's a project for a very rainy afternoon.

    Not being a whip 'n' leather kind of guy, my implements of choice have always leaned toward the domestic too - and this is from someone who (at least as far as I remember) was never spanked with an implement growing up. I reckon in descending order or preference, my favourites are the belt, the hairbrush and the slipper. I'd say there's a detectable pattern there. :) Regarding the hairbrush, it is a very maternal implement - and I suppose it has greater resonance than its big brother (sister?), the wooden paddle, because it implies greater intimacy. Being smaller and with a short handle, it's also much easier to control - which means that the user can impart a nice sting just exactly where he or she wants it.