posted by [identity profile] skreidle.livejournal.com at 08:48pm on 2007-04-01
How would you isolate mass of hair vs other bodily mass--aside from, perhaps, shaving oneself completely bald, head to toe, nook and cranny, and repeating periodically (followed by cleaning, drying, and measuring)? And even that doesn't take into account variation on growth rate due to skin irritation from shaving, among other potential factors.
 
posted by [identity profile] jmax315.livejournal.com at 01:42am on 2007-04-02
"...variation on growth rate due to skin irritation from shaving, among other potential factors."

Shave bare.
Wait a day.
Shave bare again, carefully collecting hair in cleverly designed filtration apparatus. Dry and weigh hair.

Repeat, increasing interval to 2 days, then 3, etc., graphing data as collected. When the curve flattens out, you've gotten beyond the point where growth rate variations matter.

Report results, scratching stubble and reflecting upon the sacrifices one makes for science. Attempt to induce friends to repeat the experiment, in the interest of collecting comparative data.

Of course, if this were _real_ science, one would simply coerce grad students into the itchy, tedious business.
 
posted by [identity profile] dglenn.livejournal.com at 08:28am on 2007-04-02
The thing to watch out for there that I thought of is that the longer the growth period, the more hair will be lost outside of the sample collection area due to natural fallout and everyday abrasion. Probably not much, but we won't know that for sure without experimentation ...

(If I undertand hair growth correctly, sometime after a hair has grown as far as it's going to and sat there for a while, it'll spontaneously fall out before the follicle starts a new one ... right? So presumably even if all that's grown out is a fraction of an inch of stubble, some substantial fraction of those [what's the simple noun that 'stubble' is a collective for?? 'Stub'?] stubs will be ready to fall out while the subject is going about his or her extra-lab activities. So unless I plan to spend the entire duration of the experiment in a controlled environment where everything that falls off my body is collected -- presumably naked the whole time both to minimize friction-induced losses and to avoid contaminating the samples with fibers rubbed off of clothing -- at some point incidental extra-laboratory loss of sample will may become significant. But I don't know how long an intra-shaving interval makes the extra-lab losses enough to worry about.)

Another caution brought up by the Sheepie on the phone: hair growth rate is also going to be affected by hormonal fluctuations, cyclic and otherwise, and possibly also by the weather. So to get a good average, the entire experiment, including varying the intra-shave interval, will need to be repeated several times.


The more I think about this, the more I like the idea of coercing grad students into it.
 
posted by [identity profile] dglenn.livejournal.com at 08:12am on 2007-04-02
"perhaps, shaving oneself completely bald, head to toe, nook and cranny, and repeating periodically"

Yup. When I said "the obvious experiment", what I had in mind was pretty much what you described here and [livejournal.com profile] jmax315 refined: shave bare, wait a day, shave again in an environment that allows for careful capture of all the removed hair, figure out how to separate the hair from skin flakes and shaving aids (water, shave gel, etc.), weigh the results, repeat.

I hadn't thought about effects of shaving on hair growth rate, but with one additional caveat, I see that [livejournal.com profile] jmax315 addressed that.

A related question that had occurred to me a day or two earlier would be marginally easier to answer, since one wouldn't have to spend quite as much time shaving or endure the "no eyebrows" look while waiting for stuff to grow back: which removes more skin during shaving, a safety razor, a straightrazoer, or an electric razor? (Not counting nicks, just scraping effects.) What I suspect will be "the hard part" is the same: isolating the substance of interest -- skin here or hair above -- from everything else that accumulates in the sample collection area.
 
posted by [identity profile] dptwisted.livejournal.com at 02:17pm on 2007-04-02
Eyebrows would be tricky devils. If they grew constantly, we'd all have to trim them regularly or they'd be down around our knees by now. OTOH, if you shave them off, they will eventually grow back to their original length and stop. It seems that some hairs (eyebrows, eyelashes, arm hairs) have a fixed length, while head & facial hairs don't.
 
posted by [identity profile] madbodger.livejournal.com at 03:56am on 2007-04-04
I admit I wondered myself, as no particular (practical) experiment seemed particularly
obvious to me. After some thought, I settled on a wildly arcane idea that would have
appealed to you greatly. But 'twas too weird and I lost it.

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