Best understood in context as a combination of medical humour, and a critique of evidence-based medicine. In this case pointing out the lack of controlled randomized trials of parachutes, and how this would affect the evaluation of the efficacy of parachutes as a life-saving medical intervention.
This must once have been true of seatbelts too, before all the experiments that were done with dummies and cadavers.
One could argue that similar experiments should be done with parachutes: Throwing dummies and cadavers out of aircraft onto various surfaces (rock, grass, woodland etc.)
Interesting engineering problem too (you need a robot to pull the ripcord, but then it needs to get out of the way so it does not interfere with the outcome by causing additional injuries, adding too much weight etc.)
The problem here is that we have a condition ("jumping out of aeroplanes") where, without an intervention ("give the patient a parachute") the consequences are almost certainly fatal (yes, a handful of people have survived falls from altitude without parachutes: but a fatal outcome is sufficiently certain that defenestration has historically been used as a means of execution).
It's a major ethics no-no to expose healthy patients to potentially-fatal environments. It's also a major ethics no-no to withhold known life-saving treatment in the name of continuing a trial. So we can't contrive a proper randomized double-blind placebo-controlled test of the life-saving efficacy of parachutes, where we push people out of planes repeatedly to see how many survive without a parachute vs. with a parachute.
We can't test parachutes any more than we can contrive an evidence-based test of the efficacy of being-rescued-from-burning-buildings-by-firefighters, by arranging for a city's fire department to randomly not rescue half the victims of house fires, so that we can subsequently compare their survival rate with the survival rate of those who were rescued.
Basically, evidence-based assessment of medical treatments breaks down when it hits the edge condition defined by the patients automatically dying if not treated. At best we can compare different types of parachute, or different types of emergency tratment, and see which has a lower associated mortality rate. But we can't, ethically, compare treatment/no-treatment if there's a high likelihood of no-treatment resulting in death.
But the thing is that you can use proxies to study this to an extent.
Amongst rock climbers there is a naturally occurring population of free climbers, and it is possible to note the type and severity of injuries between different types of rock climbers (although i'm guessing your n is going to be low).
The safety of parachutes themselves is an interesting question because they're not used as a preventative mechanism, I think that's the primary difference between them and climbing ropes/harnesses/pitons.
Edit: I just noticed that I didn't address the randomized component. I'd still argue that evidence based medicine can actually include arguments that aren't randomized trials. That said, randomized trials are still one of the strongest sort of argument that can be made. As noted above, seatbelts are another sort of device that I don't think we need randomized trials to test the efficacy of.
p.s. Just finished (and enjoyed) the Apocalypse Codex. The Laundry Files is one of my favorite series of books as someone who's always believed that empiricism and existentialism are reconcilable. Please write more :)
http://www.antipope.org/charlie/blog-static/2012/10/still-un... mentions "Neptune's Brood", space-opera set 5k years after "Saturn's Children" but it sounds like it may not actually be coming out until next year, along with three volumes of Merchant Princes (the existing books, in omnibus editions with minor changes) and maybe a UK edition of "The rapture of the nerds".
"Neptune's Brood" comes out in July 2013. (It's a high-concept space opera and a meditation on the 2007-08 liquidity crisis. Also, nominally, a sequel to 2008's Hugo-nominated "Saturn's Children".) "The Rhesus Chart" is in the pipeline for July 2014. The other stuff is all, effectively, reprints.
> It's also a major ethics no-no to withhold known life-saving treatment in the name of continuing a trial.
The problem with this, of course, is that under certain circumstances terminating trials early for ethical reasons causes them to conclude that the treatment works when it doesn't.
Actually, pretty much all the apparently well thought-out ethical restrictions can lead to disaster, and there's even a set of studies that manages to accidentally demonstrate all of them - the randomized controlled trials into circumcision as a form of HIV prevention in Africa. In addition to rather unwisely terminating the study early, they were also careful to use sterile surgical instruments, made sure to inform the participants that they'd still need to use condoms and give them a supply of condoms and education on how to use them, and ensured that the newly-circumcised individuals refrained from sex whilst their wounds healed. All perfectly reasonable ethical requirements, and not ones we'd want to do away with.
Unfortunately, the actual interventions that have been made based on this study have none of those features. Men are being circumcised with bloody instruments, under the belief that this means they don't have to use condoms anymore, and any funding that's going towards circumcision is funding that's not being used to supply condoms and condom education. The difference between what's actually happening and what can ethically be studied is huge and most likely fatal. I suspect the whole thing's going to end up turning out to be another ill-conceived Western intervention that sows distrust a few years down the line.
Those are called static lines, but your parachute is open within seconds of leaving the aircraft. That doesn't allow you any freefall time in an "experiment."
Skydivers have had Automatic Opening Devices available for years, and some people use them. They're set to open at a specific altitude if you haven't already opened. The idea is that you may have lost consciousness from a medical problem or collision with another skydiver.
Aside: I used to skydive way back in the day. At the time the skydiving community was making the transition from round parachutes for students to square parachutes(the question had already been settled for experienced skydivers). My home drop zone did some testing with a few models of square parachute and a weighted dummy. They called it Elmer Thud.
We used to throw a dummy from the plane arranged to crash behind the hanger where we taught the skydiving intro class. Students would get horrified until a "rough up" skydiver (who hid behind the hanger earlier) came out limping and cursing " my f%$%# chute did not opened again!" :)
TL/DR: dark skydiver humor.
Skydivers been using automatic safety openers for a very long time (the 80's at least). We basically install them on our reserve chute so if we pass below opening altitude at a fast rate of descent it automatically trigger the emergency chute.
It's saved many, many lives that I can personally recall.
Similar to how in computing the 80s is like a millennia ago, skydiving has changed dramatically since the 80s in regards to both equipment and the skills on which skydivers concentrate.
You never see round parachutes, rigs without reliable Automatic Openers on the reserve, dacron (a material used for lines). The parachutes are half the size or less for average jumpers. As for behavior, people intentionally increase their speeds on landing for more fun, wingsuiting is fairly common, and there are sub-disciplines of freefall were people spend the entire portion of the skydive upside down.
> This must once have been true of seatbelts too, before all the experiments that were done with dummies and cadavers.
Surprisingly enough, it was true of airbags after those experiments too: in the late '80s and early '90s, it was noticed that the airbag fatality rate was shockingly high compared to what had been projected, so they went back to the drawing boards and revised the designs. A quote from a RAND study on autonomous cars:
> This tension produced "a standoff between airbag proponents and the automakers that resulted in contentious debates, several court cases, and very few airbags" (Wetmore, 2004, p. 391). In 1984, the US DOT passed a ruling requiring vehicles manufactured after 1990 to be equipped with some type of passive restraint system (e.g., air bags or automatic seat belts) (Wetmore, 2004); in 1991, this regulation was amended to require air bags in particular in all automobiles by 1999 (Pub. L. No. 102-240). The mandatory performance standards in the FMVSS further required air bags to protect an unbelted adult male passenger in a head-on, 30 mph crash. Additionally, by 1990, the situation had changed dramatically, and air bags were being installed in millions of cars. Wetmore attributes this development to three factors: First, technology had advanced to enable air-bag deployment with high reliability; second, public attitude shifted, and safety features became important factors for consumers; and, third, air bags were no longer being promoted as replacements but as supplements to seat belts, which resulted in a sharing of responsibility between manufacturers and passengers and lessened manufacturers' potential liability (Wetmore, 2004). While air bags have certainly saved many lives, they have not lived up to original expectations: In 1977, NHTSA estimated that air bags would save on the order of 9,000 lives per year and based its regulations on these expectations (Thompson, Segui-Gomez, and Graham, 2002). Today, by contrast, NHTSA calculates that air bags saved 8,369 lives in the 14 years between 1987 and 2001 (Glassbrenner, undated). Simultaneously, however, it has become evident that air bags pose a risk to many passengers, particularly smaller passengers, such as women of small stature, the elderly, and children. NHTSA (2008a) determined that 291 deaths were caused by air bags between 1990 and July 2008, primarily due to the extreme force that is necessary to meet the performance standard of protecting the unbelted adult male passenger. Houston and Richardson (2000) describe the strong reaction to these losses and a backlash against air bags, despite their benefits. The unintended consequences of air bags have led to technology developments and changes to standards and regulations. Between 1997 and 2000, NHTSA developed a number of interim solutions designed to reduce the risks of air bags, including on-off switches and deployment with less force (Ho, 2006). Simultaneously, safer air bags, called advanced air bags, were developed that deploy with a force tailored to the occupant by taking into account the seat position, belt usage, occupant weight, and other factors. In 2000, NHTSA mandated that the introduction of these advanced air bags begin in 2003 and that, by 2006, every new passenger vehicle would include these safety measures (NHTSA, 2000).
Contributors GCSS had the original idea. JPP tried to talk him out of it. JPP did the first literature search but GCSS lost it. GCSS drafted the manuscript but JPP deleted all the best jokes. GCSS is the guarantor, and JPP says it serves him right.
