Slashdot Mirror
Researchers Show Parachutes Don't Work, But There's A Catch (npr.org)
Reader Beeftopia shares a report: Research published in a major medical journal concludes that a parachute is no more effective than an empty backpack at protecting you from harm if you have to jump from an aircraft. But before you leap to any rash conclusions, you had better hear the whole story. The gold standard for medical research is a study that randomly assigns volunteers to try an intervention or to go without one and be part of a control group. For some reason, nobody has ever done a randomized controlled trial of parachutes. In fact, medical researchers often use the parachute example when they argue they don't need to do a study because they're so sure they already know something works. Cardiologist Robert Yeh, an associate professor at Harvard Medical School and attending physician at Beth Israel Deaconess Medical Center, got a wicked idea one day. He and his colleagues would actually attempt the parachute study to make a few choice points about the potential pitfalls of research shortcuts.
They started by talking to their seatmates on airliners. [...] In all, 23 people agreed to be randomly given either a backpack or a parachute and then to jump from a biplane on Martha's Vineyard in Massachusetts or from a helicopter in Michigan. Relying on two locations and only two kinds of aircraft gave the researchers quite a skewed sample. But this sort of problem crops up frequently in studies, which was part of the point Yeh and his team were trying to make. Still, photos taken during the experiment show the volunteers were only too happy to take part. The drop in the study was about 2 feet total, because the biplane and helicopter were parked. Nobody suffered any injuries. Surprise, surprise. So it's technically true that parachutes offered no better protection for these jumpers than the backpacks.
They started by talking to their seatmates on airliners. [...] In all, 23 people agreed to be randomly given either a backpack or a parachute and then to jump from a biplane on Martha's Vineyard in Massachusetts or from a helicopter in Michigan. Relying on two locations and only two kinds of aircraft gave the researchers quite a skewed sample. But this sort of problem crops up frequently in studies, which was part of the point Yeh and his team were trying to make. Still, photos taken during the experiment show the volunteers were only too happy to take part. The drop in the study was about 2 feet total, because the biplane and helicopter were parked. Nobody suffered any injuries. Surprise, surprise. So it's technically true that parachutes offered no better protection for these jumpers than the backpacks.
is the dumbest fucking thing I've read today.
My favorite study along these lines was a randomized selection of men, half of whom were injected with steroids and half got no steroids. Neither group showed muscle gains during the study period. Not mentioned in the headline was that neither group lifted weights or engaged in any exercise. So in a sense the headline was true: just taking steroids doesn't give you big muscles. But the guys in my gym who took steroids got big because they were able to recuperate faster from heavier workouts.
....just guess.
This first test involves something the lab boys call 'repulsion gel.' You're not part of the control group, by the way. You get the gel. Last poor son of a gun got blue paint. Hahaha. All joking aside, that did happen â" broke every bone in his legs. Tragic. But informative. Or so I'm told. --Cave Johnson
Meanwhile, the researchers didn't produce anything new, similar "research" was done in the past where researchers didn't know how strings worked in Java.
For some reason, nobody has ever done a randomized controlled trial of parachutes.
It would be unethical to send people to their certain deaths when gravity has been sufficiently tested to the point where it is accepted as a physical constant.
However, I'm sure ethicists would be willing to look the other way if all idiots complaining about a lack of controlled trial were used as the subjects of such a test.
Anons need not reply. Questions end with a question mark.
You illustrate my point perfectly. This study isn't about parachutes. It's about how we abuse science regularly, even in academic circles, although this study isn't about that, and how the media and bad science can work in conjunction to produce, in plain language, falsehoods under the banner of science by using intentionally manipulative language which is technically correct. You can make the average person grok this study, on it's face. But, the face of the study is not the point. Making the average person really get the point and apply it through skepticism when reading about scientific results is difficult to impossible.
So, you are asking yourself "if this study is about abuse of scientific language, why did they need the parachute study? why not just make the point by using concrete examples that already existed?" I work in computer security. Computer security researchers need to perform concrete demonstrations of their findings (new exploits, for example), because, otherwise the CEOs, COOs and PHBs of the world just say "I don't believe you." The study linked here on slashdot could be viewed as a security exploit. It's a widespread OpSec failure of the average person to critical examine critical language in the media. Why do the study? To have a 100% concrete example of just how easy it is to create a headline which is false in plain language but can be justified with specious research. It's a nice proof by construction.
It's making a point about medical researchers making assumptions and/or cherry picking situations/test candidates that will skew results towards a preferred/anticipated outcome. The Christmas issue of BMJ is intentionally lighthearted, something that probably should have been made clearer in TFS to avoid the amount of "WHOOSH!" that's going on.
UNIX? They're not even circumcised! Savages!
In the Rama story, a group of people jumped from a cliff into water, using their clothes as a braking mechanism.
I've actually calculated this; and it COULD work.
I won't be trying it unless there's no other option, but it goes like this:
Terminal velocity in the atmosphere is ~120mph in a "Spread Eagle" orientation, about 180mph in a pike position.
Hitting water at 180 will spatter you, but 120mph is right at the edge of what's possible; the guys that cliff dive are going close to that speed.
Hitting the water flat is going to splatter you, so you would have to use any available clothing to reduce your speed as much as possible, and transition to a CLEAN PIKE position as you hit the water.
Truth isn't Truth - Guliani
The point is that flawed assumptions about "common sense" stuff are a major cause of flawed results.
Indeed, it's the primary cause of irreproducible results.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
IgNobels have been issued for this sort of work before - fish in brain scanners, anyone?
I'd be horrified if they awarded another for what is basically repeat work.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Not if it reminds people how they are constantly lied to via fancy language and assumption manipulation...
BLS numbers on the economy? Every politician ever? Parse them carefully and many take this to high art - not actually lying but saying things in a way that you thought you heard what you wanted to hear. All marketing? Man, I tried all that aftershave, toothpaste, hair gel and treament, still didn't "get the girl"...(you're supposed to know that's a joke).
Why guess when you can know? Measure!
Then you didn't understand it. Which, in all honesty, doesn't reflect on them.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
"Doing God's work" is how Lloyd Blankfein described Goldman Sachs as they accepted huge bailouts from the taxpayers they claimed they didn't even need (under oath in congress which I watched) - because AIG was bailed and paid them - they double dipped on "God's work". These days you gotta be careful you're not quoting a villian.
Why guess when you can know? Measure!
"Intellectual but Idiot" IbI - which I'd thought of it, but Nassim Taleb did.
Why guess when you can know? Measure!
Push them? And did he yell Ãoebyeà on the way out?
Somebody didn't read the summary.
I'm not a complete idiot... Some parts are missing.
If someone doesn't inherently understand what the real takeaway from this story is, then I question their IQ, their capacity to think critically, or both.
So someone paid (bet it was taxpayers) to research the efficacy of parachutes vs. backpacks in jumps from a height of two feet from a stationary object.
WTActualF?
The point is that flawed assumptions about "common sense" stuff are a major cause of flawed results.
Except that the "common sense" assumption about the outcome of this experiment is exactly what actually happened.
Nobody with "common sense" would assume a parachute would be helpful for a two foot drop.
Nope, he yelled "Get off my plane!"
#DeleteFacebook
Clearly you didn't read the article either.
My favorite study along these lines was a randomized selection of men, half of whom were injected with steroids and half got no steroids. Neither group showed muscle gains during the study period. Not mentioned in the headline was that neither group lifted weights or engaged in any exercise. So in a sense the headline was true: just taking steroids doesn't give you big muscles. But the guys in my gym who took steroids got big because they were able to recuperate faster from heavier workouts.
My favorites are medical studies on vitamins and supplements and other related.
For example, a 4-week study of Glucosamine/Chondroitin supplements that had no effect on joint pain of Rheumatoid Arthritis patients.
Conclusion? G/C supplementation has no effect.
Reality? We don't really know. 1) G/C supplementation is to make stronger and healthier joints by supplying building blocks not otherwise found in the diet, and 2) Joints have no blood vessels, so change very slowly. Typically 7 weeks or more would be needed to see an effect.
Compare with: St. John's Wort depression studies lasting less than 4 weeks (medical depression meds sometimes take as much as 6 weeks to show an effect), Omega 3 fatty acid supplementation studies in healthy adults (instead of children/adults with behavioral issues), and so on.
Nutrition studies are particularly useless. My favorite example is the guy making Soylent started out by asking the simplest question: what nutrients do we actually need to be healthy?
The answer is: No one knows, the literature is a bewildering mess of confusing and contradictory results, and nutrition experts have differing views.
(If you don't believe me, see if you can determine a) the *minimum* amount of vitamin D needed daily to prevent disease, and b) the *optimum* amount needed for best health. Bonus points if you can determine whether mega doses of Vitamin D are toxic. Supplemental bonus points if you can determine whether mega doses of Iodine are toxic.)
Their point was that the results of my medical study very much depend on which patients are selected for the study.
Those who are likely to recover probably won't show much benefit from the treatment, because they were going to be okay anyway. Those who have a really bad prognosis may not show much benefit because they are past the point of no return, beyond help. In other studies, using patients who have a bad prognosis may exaggerate the benefits of the treatment by neglecting to include the fact that most people would be fine without the treatment. That is, the study might seem to indicate "the treatment doubles your chance of survival", but that's not true if the 90% of people with mild cases aren't included in the study.
Here, they used subjects with a very mild case of "jump out airplane". The study showed that parachutes provide no benefit - but only because the study participants had a very mild degree of the problem. One could also do a study of extreme cases and discover parachutes don't work for jumping out of an SR-71 at cruise. The study would need to include participants with varying "a priori" prognosis, and probably run stats for each class - good prognosis, bad prognosis, and in between.
Scientists do not only have a duty to perform good research (many do not, sadly), but also to inform the general public about the meaning of their results. This study is perfectly valid (if scientifically worthless) and nicely demonstrates that an experiment or study may not imply the things a non-expert may think it does. As such, it serves as a nice warning. Another one about as ingenious is this one here: https://blogs.scientificameric...
I hope that this study wins an IgNoble as well. Note that the IgNoble in no way implies that the research so honored is bad. Dunning and Kruger won one for what is perhaps the most important discovery in Psychology of the last century. It just implies that something is really, really messed up. In this case it is the way _other_ studies using the same, standard methodology are interpreted and generalized by the press and other non-experts.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Simple: Education does not create insight or understanding. Look at all the spelling-nazis for example. They managed to learn something, but they completely mistake the importance of it. They think form is more important than function and that never, ever is the case (except in art). What you need to be smart is intelligence, a will to use it on everything (I call that "wisdom") and, as a booster to that, education. Education by itself does absolutely nothing except to make the people that have it (but nothing else) dangerous fools except only fools.
Now, if you refer to the study at hand, that is not the result of failed education. It is what a group of really, really smart people do with it: Demonstrate its limits. And as demonstration of the limits of the standard approach to medical studies, it does not get much more ingenious than this: It is clear to everybody, it clearly is a valid study and it is clearly utterly meaningless. As such it very nicely demonstrates that generalizing medical stidies is very, very tricky and cannot be done by non-experts (such as the press).
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Some average people will get it. That is enough to make this a very worthwhile undertaking. The ingenuous thing is that getting this does not require much intelligence or education. It requires just an ability to see truth. Sadly, humans in general do not have that and high intelligence or education does not create it.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
I mean, unless I've missed it, there doesn't seem to be any post here thinking about how to make this "true".
Sure, the study was ridiculous and intended to make a unrelated point, but the nerds should be focusing on the fact that there have been survivors of high falls without parachutes. So the most important barrier to serious R&D has been broken - the possibility is provably there!
In looking at many of the accounts on the web of high falls, I have to discount those that had parachutes that didn't open properly or were likely within the wreckage of an aircraft for most of the fall. Those were likely slowed down by things like the drag of a defective parachute or the body of a plane.
The more intriguing accounts are the falls from high buildings. In most cases, they seem to have been helped by landing on something that absorbed some of the shock of landing. Several landed on roofs. A very intriguing one landed on the roof of a car after a fall of 22 stories and "walked away" with only a broken elbow.
One can imagine that these folks likely benefited from some combination of positioning their bodies for high drag and/or maneuvers that translated vertical speed to horizontal speed that was bled off by traversing more air distance and landing in some particular way on a surface that absorbed a lot of the shock.
So how might a compact device that could be carried at all times enhance the possibility of surviving something like this?
A smartphone app could detect the freefall as well as that it is still on the person. If connected to cameras around the area it might be able to spot the best surface to hit. Guiding the arms and legs of the person to positions that will fly them toward that while minimizing downward airspeed would be problematic. That would seem to require either an exoskeleton (maybe a soft motor one) built into clothing or some muscle control interface like those being experimented with on paralyzed people. So that's a stretch today. As for having to find a roof or car to hit, that might be made less necessary with something like a personal explosive airbag and some means of ground proximity detection.
It is an interesting rabbit trail that could have application in something like the construction industry, as a failsafe for climbers, military, etc.
Condoms are no more effective than helmets at protecting from football injuries while eating ice cream on the sidelines.
My sausage tree didn't grow, does that make me a bad mommy?
it is the same with a lot of testing and reviews when published. everything you read is so bias these days so you never get the whole picture.
You jest.. that's exactly what my they are trying to get people to notice.. A catchy headline, a result backs it up. All to produce a study that is clearly crafted to get the reaction and attention desired, all while being essentially crap under the surface.
Good point. We clearly need more studies like this, given the quality of statistical understanding in America.
"First they came for the slanderers and i said nothing."
This story reminds me of the old joke about the scientists who proudly announced that their experiments proved that dogs and cats could live underwater ... just not very long.
I'll just miss the point the other way around, and point out that they could've got usable data by using crash test dummies. And indeed, observational studies of people who fell without parachute vs. those who fell with would easily point both the expected safety benefits and the folly of running a controlled trial. This same problem exists for a lot of automotive safety issues (Not that there aren't a LOT of willing people to test not using a helmet on bike, seatbelt on car etc. but studies don't just hurl people at a wall at high speed with and without helmets and compare the results). Any medical studies are generally interrupted if the difference is so overwhelming that it would be unethical to continue, and prior observational studies would fit that bill.
Since some commenters appear to have misunderstood the point of the article it's worth quoting from the BMJ paper (I recommend actually reading the entire paper and/or this BMJ blog):
...
The study also has several limitations. First and most importantly, our findings might not be generalizable to the use of parachutes in aircraft traveling at a higher altitude or velocity. Consideration could be made to conduct additional randomized clinical trials in these higher risk settings. However, previous theoretical work supporting the use of parachutes could reduce the feasibility of enrolling participants in such studies.
...
Finally, although all endpoints in the study were prespecified, we were unable to register the PARACHUTE trial prospectively. We attempted to register this study with the Sri Lanka Clinical Trials Registry (application number APPL/2018/040), a member of the World Health Organization’s Registry Network of the International Clinical Trials Registry Platform. After several rounds of discussion, the Registry declined to register the trial because they thought that “the research question lacks scientific validity” and “the trial data cannot be meaningful.” We appreciated their thorough review (and actually agree with their decision).
The PARACHUTE trial satirically highlights some of the limitations of randomized controlled trials. Nevertheless, we believe that such trials remain the gold standard for the evaluation of most new treatments. The PARACHUTE trial does suggest, however, that their accurate interpretation requires more than a cursory reading of the abstract. Rather, interpretation requires a complete and critical appraisal of the study. In addition, our study highlights that studies evaluating devices that are already entrenched in clinical practice face the particularly difficult task of ensuring that patients with the greatest expected benefit from treatment are included during enrolment.
...
Those who need to be reminded they are being lied to, are not the kind that will understand it no matter how much you tell them. They just need another dream to follow. That is all one can do for them. Lead the horse to water etc.
That's a lot these days. :D
And no one called me out for misspelling Asimov. (You did spell it correctly above, tho.) :)
I'd definitely give it a shot, if I were falling from a plane, gravity difference or not; you KNOW what happens without trying it, lol.
Mythbusters broke Buster into pieces dropping him from a crane, trying the 'break the surface tension with a hammer" thing.
But he landed pretty badly off axis, so IDK.
Truth isn't Truth - Guliani
Jumping out of a plane with an empty backpack.
I can already see some stable genius out there using this study to defund parachutes in the military
This is why you shoot a man before throwing him out of an airplane.
How is the Riemann zeta function like Trump rallies? Both have an endless number of trivial zeros.
Let me guess: it was either psychologists or nutritionists.
and here you go:
https://www.bmj.com/content/36...
and finally, the most pressing question answered from the article itself:
"Funding: There was no funding source for this study."
So, some fun was had by many, discussion was sparked, but no (direct) taxpayer money wasted. Might even make a useful point, if anyone remembers it where relevant:
"Conclusions Parachute use did not reduce death or major traumatic injury when jumping from aircraft in the first randomized evaluation of this intervention. However, the trial was only able to enroll participants on small stationary aircraft on the ground, suggesting cautious extrapolation to high altitude jumps. When beliefs regarding the effectiveness of an intervention exist in the community, randomized trials might selectively enroll individuals with a lower perceived likelihood of benefit, thus diminishing the applicability of the results to clinical practice."
.
Ignoring the fact you missed the point of the study, you're right about people not wanting to jump out of aircraft.
A colleague's father was an RAF fighter pilot during WWII. He received a commendation for bravery for flighing a heavily damaged aircraft back. In reality he apparently went to bail out, got his legs over the side and went "fuck that, there's no way I'm jumping", and nursed the aircraft home.
The article was going on about how it was a counterpoint to the medical community's set of treatments for which they believe a trial is not necessary because you "wouldn't create a trial on the necessity of parachutes." A trial like that would be impossible to conduct and unethical.
So, here they conducted one.
It's strange because it *supports* the point that not only could you not conduct a trial on the necessity of parachutes, but you can abuse the system to create a trial where you can demonstrate the ineffectiveness of parachutes.
This seems to say that medical researchers *should* assume things are so rather than even trust papers which demonstrate that it is *not* the case. I mean, what kind of argument can this paper be used for?:
But hey, it's not my field. Not even a layman here, just a passer-by. Seems like a funny paper, but I think it's in poor taste because of the weird anti-research conclusion.
Are you sure about this? Just that I just joined a couple of hundred people in voluntarily jumping out of an aircraft and they seemed a pretty representative bunch, covering a wide range of ages, nationalities and wealth levels.
Anecdotally but fully aligned to this beautifully written up study, wearing a parachute would have saved none of them from severe injury or death either.
not actually lying but saying things in a way that you thought you heard what you wanted to hear.
Like if I took a kg of 100% beef, and a kg of sawdust, and mixed them together and made hamburger patties, I could say my hamburgers were "Made with 100% beef".
All marketing?
I recently say a jug of juice that said "100% Juice", and underneath that in smaller letters "and other ingredients".
This isn't just about scientific method or research publication; taken as a larger whole for language in general, it shows that context is king, and the half truth can be more misleading than an outright lie.
Language is easy to manipulate.
Look back up at my post, now look back down, you're on the Internet. Now look back up. I'm a signature.
Companies will uses the psychology experiment as an excuse to make things less safe.
https://www.youtube.com/c/BrendaEM
Yep, you get it. Too bad we couldn't make a drinking game out of this while watching almost any media where pols or other marketers are speaking. We'd all die of alcohol poisoning. Me, I just got to the point of mostly ignoring it and being cynical, kind of knowing about the sad realities, but not especially wanting to be constantly reminded (chickenshit, I know, but damn...you gotta be able to smile a little sometimes).
Why guess when you can know? Measure!
Did they really get funding? They should have been fired on the spot for even suggesting a test like this. Now, let's do the real test and get the plane up in the air, and let's see which one protects you better.. Any volunteers? maybe the researchers who did this 'research' as they are so confident the backpack will protect them just fine....
I am a big fan of medical CBD products and have recently purchased pure cbd vapors to fight stress. You know, it really helped me clear my head and relax. I will definitely sometimes take vaping for relaxation after a hard day's work.