Wikipedia:Reference desk/Archives/Science/2022 May 8

= May 8 =

How does a baby toucan fit into its egg with that beak?
Question as topic. You've seen the size of their beaks, I guess. I know a macaw that has a crooked beak because he was apparently too big for his egg, so I'm not sure how toucans manage with their proportionally larger beaks... --Iloveparrots (talk) 01:24, 8 May 2022 (UTC)


 * This article says "Toucan babies do not have a large beak when they hatch from the egg but it is wide and heavy compared to other baby birds". This youtube video also shows newly-hatched toucans have pretty small beaks relative to the proportions seen in adulthood. JoelleJay (talk) 02:29, 8 May 2022 (UTC)
 * Same with pelicans. Shantavira|feed me 08:16, 8 May 2022 (UTC)


 * Surely, the egg size should accommodate the bird within??, (versus the other way around), large beak and all! That's the purpose of the egg shell...otherwise, a non-accommodating shell would spell the end of a species. Happy for toucans.. and pelicans, etc.  Tribe of Tiger  Let's Purrfect!  09:52, 9 May 2022 (UTC)
 * what if the Toucan emerges from its beak? I've never seen a Toucan egg... Have you? Regards, Zindor (talk) 11:21, 13 May 2022 (UTC)
 * Well, I have just seen many Toucan eggs, and they look like....chicken eggs. (Not sure about size) Google "toucan eggs". This site shows hatching & newly hatched, and day/weeks later, images for growth comparison. The beaks are relatively negligible at birth, the size & color start to develop within days/weeks! I don't understand your first question, "what if the Toucan emerges from its beak", as they emerge from the eggshells. Anyway, thanks for the questions, which prompted me to look & find these fascinating images! Hope you will enjoy them, too! Best,  Tribe of Tiger Let's Purrfect!  19:52, 13 May 2022 (UTC)
 * Thanks, that website was fascinating but the content is faker than the moon landing. An egg is a protective casing, and a beak could be purposed as such, so it would make sense the mother toucan produces the beak as the protective casing in which the baby toucan then emerges from. This would be far more efficient than the baby toucan producing its own beak. Are these beaks even attached? Again, regarding efficiency, the toucan perhaps leaves its beak in a tree, flies about without the added weight, then puts it back on when needed for photographs. Zindor (talk) 20:32, 13 May 2022 (UTC)
 * Ha, ha! Yep, they could store their beaks, and put them on and off, like the Groucho Marx glasses, with an attached nose. Beaks for every occasion! We should purchase stock in Toucan, Inc. Best,  Tribe of Tiger Let's Purrfect!  22:25, 13 May 2022 (UTC)

Maximum hair length in human male
Can I ask how the hair length of a (white, northern European, if that makes a difference) man is determined if he just lets his hair grow out? I have had long hair for about 15 years and it has never grown further than about 2.75/3 feet. Is there some preset length for each individual person before it stops growing? I think it's true that women can grow their hair longer (have seen women with knee or shin length hair but never men), but I'm not sure. 146.200.128.101 (talk) 07:31, 8 May 2022 (UTC)


 * See Maximum hair length.--Shantavira|feed me 08:18, 8 May 2022 (UTC)
 * I wonder how many individual strands, if any, would eventually fall out naturally, assuming no hair-loss disease? --←Baseball Bugs What's up, Doc? carrots→ 08:36, 8 May 2022 (UTC)
 * All of them, eventually. Each hair follicle has a cycle (not co-ordinated with neighboring follicles) of hair growth, 'regression', and resting/shedding (in which the no-longer growing hair is eventually pushed out by the emergence of a new hair). The durations of each of these stages can vary greatly between individual people, and as one's overall head of hair comprises an aggregate of hairs at all of them, the duration of the individual's average growth stage will determine their average/maximum hair length. OP, see also Human hair growth.
 * My own white, northern European male hair hasn't been cut for more than 21/2 years, and seems to be peaking at around 16": 4–5 decades ago in my youth I could manage about 20", so (being a Metal fan) I envy the OP. His question about the maximum cannot really be answered for him except by his own observations, because it varies greatly between individuals, and seemingly over an individual's lifespan. {The poster formerly known as 87.81.230.195} 90.208.88.97 (talk) 13:02, 8 May 2022 (UTC)
 * I don't know if I ever measured my (blond male) hair before just now! Last cut was over three years ago, and I reach 15ʺ. In my teens it could sometimes reach my waist if I bent my neck back; it's too stiff to try now. (Testing: ½ &frac12;) —Tamfang (talk) 06:10, 12 May 2022 (UTC)

x-ray equipment
I have sometimes wished I could x-ray a piece of electronics or the like. I'm sure x-ray equipment (even like what the TSA uses) is expensive and maybe regulated, and DIY'ing it has to be dangerous, especially since the only natural source of x-rays I can think of is neutron stars ;). I suppose I could ask my dentist to x-ray something (no idea if they would accomodate), but is there a more general way to get access to this sort of thing without spending a fortune?  No idea if the equipment itself is financially approachable for a maker space that has stuff outside the typical hobbyist budget (laser cutter etc.), but not anything like an industrial lab.  Thanks. 2601:648:8202:350:0:0:0:4671 (talk) 20:09, 8 May 2022 (UTC)


 * I strongly doubt just anyone can X-ray stuff without medical/dental supervision. You could accidentally zap people, pets etc. This Japanese Ministry of the Environment article says "X-rays have high penetrating power and travel several tens to hundreds of meters in the air." Clarityfiend (talk) 04:11, 9 May 2022 (UTC)
 * Obviously there are dangerous radiation levels at least inside the test chamber, but x-rays are frequently used for non-medical purposes, such as electronic component and welding inspections, to say nothing of luggage examination at the airport. Yes there would (I hope) be some fairly serious regulations about building and operating such machinery, but medical personnel would usually not be involved.  I doubt there are doctors on hand at airport security when they x-ray your carry-on bag.  They also (foolishly) use backscatter X-ray on humans there, and there were even attempts to deploy it on trucks for pedestrian traffic.  I'm imagining some kind of shielded chamber where you put in a test sample and press a button.  It doesn't sound inherently more dangerous than a thermal or microwave oven.  Just don't put your hand inside while it's running, etc. 2601:648:8202:350:0:0:0:4671 (talk) 05:37, 9 May 2022 (UTC)
 * I remember pedoscopes being operated in shoe shops before they were banned. The risks of "soft" X-rays are considerably smaller than those of "hard" X-radiation, but the ability to "see inside" an object being scanned is accordingly diminished. See also here about the low risk of "modern" X-ray machines. --Lambiam 06:52, 9 May 2022 (UTC)
 * ,I remember having my feet "X rayed" in shoe stores, as a child in the 1960s, etc. Had forgotten about this, pleased to know about the pedoscope article, thanks!  Tribe of Tiger  Let's Purrfect!  07:37, 9 May 2022 (UTC)
 * Hackaday are sensibly nervous about this DIY x-ray machine and the follow-up DIY CT scanner. Card Zero  (talk) 07:08, 9 May 2022 (UTC)


 * There seems to be a market to buy those things. I would guesstimate a cost of $10000 - another page from the same vendor says that there are units for "thousands of dollars", but my experience in the lab sensor market makes me doubt that (I totally believe a pricing along the lines of "one unit for $10000, ten for $15000"). That seems like a high price tag for a hobby.
 * I would rather suggest to search around your local university, around the mechanical engineering / material science department. They either have a scanner that would fit your need, or subcontract the scanning to some external shop (that you would not know how to find on the internet). The external shop is the ideal case - their whole business is giving quotes and doing some lab work for money. If the scanner is in-university, the range of outcomes is more varied - from "free to use if you make friends with the technician, just don’t kill yourself on the premises" to "fight the administrative hydra to sign a consultancy contract". In either case, you probably end up with a $100/scan price tag (no, I don’t know the actual cost of doing an X-ray scan, but that’s the administrative cost of anything that is quick to do but requires uncommon equipment - see "experience in the lab sensor market", supra). Tigraan Click here for my talk page ("private" contact) 12:01, 9 May 2022 (UTC)


 * This process is even easier and safer than you imagine - you can hire a commercial service who have machines and expert consultants and let them handle the radiation hazard. Here's one commercial service that offers Computed Tomography ("X-Ray") for electronics failure-analysis:
 * NTS: CT Scanning
 * One can just call up their sales- and service- representative, and work out an arrangement, cost, schedule, and so on; they have the machinery and the technicians who know how to use it. Whether their services meet your budget depends on ... your budget.
 * If you need help finding commercial services, you can search the web for "non-destructive testing", "electronics failure analysis", "computed tomography" for electronics, and so on... one typically finds these kinds of services by way of industrial or commercial contacts, but if you subscribe to a trade magazine like IEEE Transactions on Components, Packaging and Manufacturing Technology, you'll spot big and small kinds of service-companies in the advertisements.
 * "Annoying Disclosure" - Do not play with X-ray radiation in your home lab! It is not a joke - it entails very real and very substantial hazards.  It should not be attempted in a home-laboratory, nor even in an uncontrolled commercial setting!  X-ray radiation goes right through walls, and if you're even thinking of fooling around with it, you're creating hazards for yourself and for your neighbors - not to mention all the other ancillary hazards that go along with these machines - hazards like lead toxicity from the ... substantial amounts of lead they use when they build X-ray machines; extraordinarily high voltage electrocution-hazards (because most X-ray machines use extraordinary, crazy high voltage inside of the apparatus - way higher voltage than any other machine you use in normal life, including old-fashioned televisions; danger of electrical fire (because some of these machines need industrial electrical supplies, which you won't find in ordinary household wiring - they don't build your light-switches and outlets and residential circuit-breakers to handle X-ray machinery!)  And the list goes on and on!  It's almost certain that your home laboratory is not suitable for using an X-ray machine - even if you manage to acquire such a machine, which turns out to be pretty easy in many parts of the world.  You should receive safety training before you buy stuff like this, but ... "it's a free country", as they say in a lot of countries where dangerous products are sold each day without significant oversight.
 * One of the case studies in "do not play with radiation in your home laboratory" is the Goiânia accident. That machine was a totally different kind of apparatus - it was not a conventional x-ray or CT machine like we would typically use in an electronics test lab - but my point is, "look what happens when untrained individuals try to use exist in proximity to complicated lab-machinery in uncontrolled settings."  People die.  Horribly.  And the consequences stick around for years.  (Thought-experiment - if you buy a lab machine, what is your plan to safely dispose of it in ten, twenty, or thirty years after you stop needing it?  You have budgeted for a HAZMAT / electronic-waste / industrial-machinery disposal guy to pick it up later, right?  I mean, you weren't planning to just toss that device into a trash-bin and hope for the best... .... right?)
 * If you ever do work with radiation, you ought to take some (often legally-mandated) training - and you'll probably learn alllllll about the Goiânia accident.
 * Nimur (talk) 14:44, 9 May 2022 (UTC)
 * Long ago when I worked in a hospital, the X-ray tech who maintained and repaired the X-ray equipment regularly put things in the X-ray machine like his key fob, his cell phone, a hamburger, etc... Then, he would post the pictures on some media thing like Twitter or Facebook. So, get a job like that and you can likely X-ray many different things. 97.82.165.112 (talk) 16:39, 9 May 2022 (UTC)
 * Please don't. I strongly suspect such things are regulated, and just because someone else is violating rules doesn't mean it's a good idea for others to do so also.  -- Jayron 32 17:16, 9 May 2022 (UTC)
 * Meh, the TSA goons at airport security x-ray the same stuff 1000s of times a day. Anyway, don't worry, I have absolutely zero interest in having x-ray equipment at home.  Besides its cost, I don't have the space for it.  The question was more along the lines of whether an electronics workspace could afford it and run it in a way conforming to all relevant regulations and good safety practices, and the answer sounds like "well, kind of maybe perhaps with a bit of a stretch".  But, the idea of going to an external service sounds better.  Alternatively, for the specific stuff I want to test, destructive testing with a bandsaw would work too. 2601:648:8202:350:0:0:0:4671 (talk) 20:39, 9 May 2022 (UTC)
 * Ah, faulty generalization fallacies... "the TSA scans things, so..."   (... hasty conclusion drawn from detailed knowledge of their operational and engineering safety controls, right?)
 * In the same manner that a quadcopter and a Boeing 747 are both regulated by the FAA - both require at least a small amount of training in proper use - both are conveyances that fly through the air, ... the scanners in common use at airport security checkpoints are also "machines similar to those used in electronics laboratories," machines commonly employing X-ray radiation; machines that are also regulated; machines that also require training for proper use,...
 * Yet, in the same way that toy planes differ from airliners, those scanning machines have more differences than similarities...
 * One of the things that really struck me during formal training is how "the public" perceives risk differently than "trained scientists." Perhaps the most hazardous thing of all is the meta-fact that the "unique hazards" of radiation sources are really hard for the public to grok.  The hazards are invisible and uncommon.  Humans have no innate biological evolutionary instinctual ability to cope with these kinds of nonnatural hazards.  So, they severely suffer from misunderstanding and misevaluation of the risk.  Because if you can't see it, if it's invisible, it can't ... hurt, ... right?  And as you know, if it's produced in a small machine, it's less powerful than the hazard from a larger machine ... right?  (No, the answer to these rhetorical exercises is "no, no, no no no."  Without formal training specific to the device, you have no way of knowing the radiation hazard, and the machine-size has no relation to its hazard, and while it may be safe to stand next to one type of machine, it may be deathly dangerous to stand next to a different machine in a similar-shaped box).  To put a precise point on this: when and where exactly is it safe to stand near an X-ray emitting device?  You planning to figure that out by ... looking at the outside of the box?  Or by trial and error, pressing the big buttons on the front?  Hint - this is not how physicists and engineers assess risks or design operational specifications.
 * The ensemble of these problems are captured in the discipline of human factors. Why are humans so bad at understanding risks, especially risks from physical phenomena that are not part of normal daily life?  What can we do to reduce these risks and train people to understand them?  Maybe we put a great big logo with death-skull and person running away on the side of the machine to try to scare people, filling in that chasm between the cognitive- and non-cognitive human factors that seems to be the only effective way to condition the judgement of the proletariat?  Or maybe we make veiled allusions to the shriveling effects that the machine might have on your personal gonads, because one way or another, we need people to take precautions and not fool around with radiation.
 * Quoting from one Cornell University's Laboratory Safety Manual : "the human body cannot sense exposure to ionizing radiation. Nonetheless, absorption of ionizing radiation energy by body tissues causes changes to the chemical makeup of living cells." "X-rays... penetrate easily through most materials."  You can not, do not, will not, be able to feel the X-rays as they permanently damage your health.  At the airport security-checkpoint, you are trusting the experts who are trained in the safe operation of the machinery, in the exact same manner as you trust the pilot to safely shepherd the next machine you'll likely use.  They know what to do, and they do it safely.
 * And while many people might jest about the TSA's trustworthiness or credentialing, there's really no scientific reason to do so. TSA maintains and operates its equipment safely, and you don't have to trust them alone - they have outside oversight from multiple different Government agencies and from unaffiliated third-party private-sector experts.
 * I think the point is, equating a security-scanner with abuse of lab equipment is a really really really bad comparison.
 * Nimur (talk) 18:42, 10 May 2022 (UTC)
 * I could not make sense of that. The TSA goons who scan your luggage at the airport are not trained experts by any stretch of the imagination.  They are basically burger flippers, except they look at a screen while stuff goes through on a conveyor belt.  It is reasonable to hope that the people who built the machine knew what they were doing, but that is a lot different than the ones who operate it.  2601:648:8202:350:0:0:0:738F (talk) 19:52, 10 May 2022 (UTC)
 * 2601, will you stop being so vicious, please? No need to call anyone a goon.

Rich (talk) 02:19, 13 May 2022 (UTC)
 * (Although if you had an unpleasant experience with overzealous TSA officials, you would be understandably resentful).Rich (talk) 19:46, 14 May 2022 (UTC)
 * What's the source for your claim that TSA agents are not trained. --←Baseball Bugs What's up, Doc? carrots→ 21:42, 10 May 2022 (UTC)
 * 2601:... did not say "TSA agents are not trained", but "TSA agents are not trained experts". It seems fairly obvious that jobs that pay less than literal burger-flipping, with a ~15% turnover (from that ref: ~16000 quit within two years, vs. Transportation Security Administration says there are 47000 agents), do not attract and retain radiation safety specialists. Clearly there must be some training about how to use the machine, but presumably not a week-long course on radiation safety.
 * Furthermore, the TSA’s detection rate for red team exercises (i.e. an undercover agent poses as a passenger and tries to smuggle a gun through security) is abysmal: less than 5% in 2015, which is the latest year for which there are newspaper sources. (There is that source with the same rate for 2017, but it’s a biased source about a single airport, and the newspaper it cites is a 404.) I speculate that this might have improved up to a stellar 10% in recent years (TSA caught about twice as many guns in 2019 than in 2015 - assuming that is mostly due to passengers forgetting a gun in their carry-on luggage, and that this happens at a constant rate [actually it probably increased due to the increase in passenger numbers], that means the detection rate (recall) doubled.).
 * Presumably, the training and processes are optimized for "don’t let people go through security with a gun" rather than for esoteric radiation safety issues. Failure at the former seems a rather good predictor at failure at the latter (because the underlying "human factor" causes are the same). The only thing that meaningfully prevents radiation incidents is therefore the engineering controls on the scanners themselves. Tigraan Click here for my talk page ("private" contact) 09:31, 12 May 2022 (UTC)
 * In the 90s, I flew from Glasgow, (close by Lockerbie) Scotland to US annually. Their "TSA" type staff were very thorough. Every time, I seemed to have "something" that raised alarms. The 1st was a hand blown lead-glassware perfume bottle, round shaped, looked like a bomb on the X-ray. Other weird items followed. I (and my husband) didn't mind the extra attention, obviously if they were checking us, so closely, we hoped they were insuring our safety by checking other passengers with the same dedication. I don't think I could have smuggled a gun in my luggage, at that time. Is there a comparison of effectiveness of "TSA" from country to country?  Tribe of Tiger Let's Purrfect!  20:44, 13 May 2022 (UTC)
 * I would usually agree with the advice of "stop doing this, you’re not qualified" because radiation safety is not a "fuck around and find out" field.
 * But here, the OP mentioned they have a laser cutter. That is orders of magnitude more dangerous than whatever airport security uses, so presumably they have a high tolerance to risk times competency value. If anything, the fact that the TSA process was checked by people who knew what they’re doing makes it more likely that the machine itself is usable by a dummy - because I am sure any decent safety inspector knows that technical solutions should be preferred to telling users what to do.  Tigraan Click here for my talk page ("private" contact) 08:48, 12 May 2022 (UTC)
 * The mention of a laser cutter was in the context of it being a typical thing to find in a hackerspace, also known as a maker space. (My local space has one, along with a giant metalworking lathe and a vending machine filled with Arduinos and air-curing silicone.) The hopeful enquiry is whether an outfit like that might also have an industrial x-ray scanner. Card Zero  (talk) 16:24, 14 May 2022 (UTC)