Wikipedia:Reference desk/Archives/Science/2016 January 25

= January 25 =

Why do Northeast Megalopolis snowstorm records look like this instead of a northern bias?
Boston: 27.6 inches (2003)

New York: 26.9 inches (2006) (27.9" (2016) if the site became the nearest airport in the mid-20th century like the others)

Philly: 31.0 inches (1996)

Baltimore: 29.2 inches (2016) (Baltimore suggests this might just be the record since the airport existed (1950))

Washington: 28.0 inches (1922)

Washington Dulles Intl, Virginia: 32.4 inches (2010) despite this weather station only starting in the 1960s.

Does the distribution of water vapor by latitude have anything to do with it?

How sure are scientists that climate change will make single snowstorm records easier to break in the future? Sagittarian Milky Way (talk) 00:15, 25 January 2016 (UTC)


 * Let me speak to the relationship between how far north (or south, in the Southern hemisphere) you are and the amount of snow you get. The closer to the poles, the lower the temperatures.  At low temperatures, less moisture evaporates from lakes, rivers, and oceans, especially once they freeze over.  This makes for less snowfall.  Therefore, there is very little snow at the South Pole, but, since it rarely melts, you see thousands of years worth of snowfall on the ground at once.


 * Now, this doesn't necessarily affect the snowfall amounts in this particular storm, as many other factors and local conditions are also more important, but it is a general trend. In fact, many of the places with the heaviest snowfalls historically are places which get lake effect snow, where air moves over warm water, picking up water vapor, then depostits it once it moves over colder land.  Buffalo, New York is one such spot, with Lake Erie providing the (relatively) warm water.  StuRat (talk) 00:49, 25 January 2016 (UTC)


 * Locations move. Equipment and methods change.  And the forecast has uncertainty .  There is no reason to believe any of it is related to climate change as climate change has still remained unmeasurable as an observation of weather.  --DHeyward (talk) 05:54, 25 January 2016 (UTC)


 * One might term this ocean-effect snow, as it involved water vapor being swept off the relatively warm ocean surface (warmer this year because it's a strong El Nino year) and meeting an Arctic air mass over the continent. It's a classic (several authorities are saying textbook) example of explosive cyclogenesis and it's a product of North American geography. The warm water of the Gulf of Mexico and consequent moisture streams and the presence of the Gulf Stream favor large snowfalls relatively far south. However, these snowfalls tend to be intense rather than frequent, so total snowfall over a season will be higher farther north where it's colder and stays colder for a longer time, but where there is less access to subtropical moisture. Topography helps too - the Appalachian Mountains lift moisture to colder altitudes and it rains or snows out, leaving places like Pittsburgh relatively dry in these kinds of storms. Some of the same geographic elements give rise to Tornado Alley in the spring. Warm moist marine air meets cold dry continental air, and boom.  Acroterion   (talk)   15:11, 25 January 2016 (UTC)


 * Actually we call it a Nor'easter :) --DHeyward (talk) 16:09, 25 January 2016 (UTC)


 * A rare case of the media not emphasizing an unexpected new name for a common thing making it seem like it's new.. Ocean effect snow! (said in a deep, booming, echoing voice) Does this mean that if this (admittedly high sigma) weather pattern happened 3 weeks ago we could've had even more snow? The sea was warmer then and Manhattan air  reached 11°F. Sagittarian Milky Way (talk) 16:40, 25 January 2016 (UTC)
 * DHeyward is correct, it's a textbook nor'easter, and the "ocean effect snow" is something I just coined to compare it against lake-effect snow, which happens on a smaller scale without needing a storm system. As for more snow, I devoutly hope not. I've been shoveling three feet of snow for the past two days and finally have it so the cars are free, we can take out the trash, get mail and let the dogs out in the back yard without losing them entirely. I think this storm system turned out to be as efficient as it could be. Normally as a nor'easter forms, the air temperature goes up as the wind starts to come from the ocean (i.e., from the northeast). Often that means that it turns to rain as the storm gets wound up. However, if there is a blocking high over the Canadian Maritimes the cold air can't be eroded by the storm and it stays cold enough to snow.. Acroterion   (talk)   18:00, 25 January 2016 (UTC)


 * See here. The prevailing explanation is that increased ocean temperatures causes more moisture to enter the atmosphere, increasing the amount of moisture available for large storm systems (hurricanes, nor'easters etc) thus making them more intense, and more frequent.  -- Jayron 32 18:09, 25 January 2016 (UTC)

Stupid physics question (How can we see things more distant than the age of the universe?)
According to wikipedia, the age of the universe is 13.8 billion years. The origin of the universe was a single point which resulted in a big bang. The size of the universe is 91 billion light years. Nothing can go faster than the speed of light. In 13.8 billion years the size of the universe should be 13.8 light years right? Brian Everlasting (talk) 00:34, 25 January 2016 (UTC)


 * It's actually a very common question. The answer is that the space between large-scale structures in the universe expanded by a process called Inflation (cosmology).    D b f i r s   00:38, 25 January 2016 (UTC)
 * This is wrong. The boundary of the visible universe is only affected by expansion since the CMBR last scattering time, around 380,000 years after the big bang. It is unrelated to inflation, which ended 10−something seconds after the big bang. -- BenRG (talk) 01:41, 25 January 2016 (UTC)
 * Yes, of course! Light didn't start out until after inflation stopped, so it is entirely Metric expansion of space (and that is speeding up).    D b f i r s   09:56, 25 January 2016 (UTC)
 * (EC)see Cosmic Inflation. The part that makes it super confusing is that you would be correct IF the universe actually "big banged" INTO pre-existing space, but it didn't, SPACE it self formed along with the big bang. Vespine (talk) 00:40, 25 January 2016 (UTC)
 * There's also the complication of Metric expansion of space but this is minor by comparison .   D b f i r s   00:44, 25 January 2016 (UTC)
 * The key point is that relativity says nothing can travel faster than the speed of light (in a vacuum) through spacetime. It says nothing about how quickly spacetime itself can move. This distinction is crucial for understanding things like inflation, but such nuance tends to be omitted from pop science descriptions, which tend to say almost-true-but-subtly-misleading things like "nothing can travel faster than light". --71.119.131.184 (talk) 00:55, 25 January 2016 (UTC)
 * Also in that vein, the size of the observable universe is 91 billion light-years. The size of the universe as a whole may be infinite: see shape of the universe. --71.119.131.184 (talk) 00:57, 25 January 2016 (UTC)
 * Someone deleted my time dilation and Theory of Relativity comment, but I don't see any changes in the View History tab. Willminator (talk) 01:08, 25 January 2016 (UTC)
 * What I was trying to say in my deleted comment is that time is relative according to the Theory of Relativity. Gravity affects time. For example, if someone were to approach a black hole, from the observer on Earth looking up, it would look like the person has slowed down for thousands of years, but from the person's point of view, only seconds would have passed. The light of a star that's let's say, 1000 light years away from Earth doesn't necessarily have to travel 1000 years to Earth from the perspective of an observer on Earth. Willminator (talk) 01:24, 25 January 2016 (UTC)
 * Embedded_LambdaCDM_geometry.png image on the right shows how this works geometrically. Later times are at the top. The brown line (on the left) is Earth, the yellow line (on the right) is a distant quasar, the diagonal red line is the path of light from the quasar to Earth, and the orange line is the distance to the quasar now. You can verify by counting grid lines (which represent 1 billion (light) years each) that the quasar is 28 billion light years away along the orange line though the light took only about 13 billion light years to reach us. -- BenRG (talk) 01:49, 25 January 2016 (UTC)
 * It's kind of funny though. I mean, the quasar is expected to be 28 billion ly away, but we don't know it didn't sprout a star drive and is coming on right behind the light ray.  And in the frame of reference of the light (or someone arbitrarily close to lightspeed) no time at all has passed, and the distance is zero!  (We're all just foreshortened a lot)  Of the two, the frame of the lightspeed traveller is at least one we could be in, while the other distance is a spacelike estimate, so surely it is more meaningful to say it is 0 ly away than 28, right?  :)  Honestly though, what confuses me greatly with that diagram is what happens if something moves away from us.  What exactly does it look like when a galaxy, after space cleared, has simply moved far enough away that by the time we look at it its light is almost infinitely redshifted and unable to reach us at all?  (this is related to something else I don't understand, which is why the lines for us and the quasar diverge at such a sharp angle on that figure, rather than each moving down a line of "longitude" on that horn thingy. Wnt (talk) 15:51, 25 January 2016 (UTC)
 * Wnt, if you look more closely, you'll see that the brown and green lines for us and the quasar are each "moving down a line of "longitude" on that horn thingy". (Don't confuse the diagonal-ish red line of the light from the quasar to us with the brown line on the far left for us.) The "lines of longitude"" show static positions in space that are moving apart as time progresses "upwards" only because "space" itself is stretching.
 * On this scale, only something moving at a substantial fraction of light speed for a long time will show up as moving across rather than "along" the static "longitude" lines.
 * As for your galaxy that is "almost infinitely red-shifted", this does occur and means the galaxy is close to being beyond the Observable Universe from our point of view (as we are from its). {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 23:04, 25 January 2016 (UTC)
 * The boundary of the visible universe is the cosmic microwave background. Its redshift is about 1100, large but still infinitely far from infinity. Any astronomical object we can see will have a redshift smaller than that (unless it's retreating very rapidly relative to the Hubble flow). The CMB is the boundary simply because the earlier universe was opaque to light. But it was transparent to neutrinos and gravitational waves, so I guess "visible universe" is a better name than "observable universe". -- BenRG (talk) 00:44, 27 January 2016 (UTC)


 * You're right that the notion of "distance now" is somewhat dubious since we don't know what has happened in the last umpteen billion years, and the spacetime interval to everything we see is zero. But, for better or worse, when astronomers are quoted in the popular press saying that an astronomical object that they just saw is X billion light years away, the orange line is what they mean.
 * In the diagram the Earth and quasar are both assumed to be stationary relative to the Hubble flow. This is approximately correct for Earth, and it's almost certain to be approximately correct for any distant object that's bright enough for us to see, because its speed is an average of the original speeds of the huge number of particles that make it up. If an object is moving significantly relative to the Hubble flow then its redshift is the special-relativistic redshift/blueshift of the source object relative to the Hubble flow, times the cosmological redshift, times the (small) redshift/blueshift of Earth relative to the Hubble flow. -- BenRG (talk) 00:44, 27 January 2016 (UTC)

Liquid non-Newtonian fluids?
Which non-Newtonian fluid or fluids would be considered only a liquid, not a plastic solid nor a colloid that involves liquid mixed with solid particles unless there's a colloid that is considered to be only a liquid, nothing in between? I have learned that not all fluids are liquids, but that all liquids are fluids. A couple of examples of non-Newtonian fluids are toothpaste, ice in the case of moving glaciers, ketchup, lava, pitch, and much more. They don't flow easily and consistently like water and other Newtonian liquids do. I read that pitch is said to be the world's densest liquid, but it is also considered to be a viscoelastic, solid polymer. What does that mean? Is it always a liquid? Can one look at the molecular structure of non-Newtonians fluids to determine which ones are truly liquids? Willminator (talk) 01:05, 25 January 2016 (UTC)


 * Is shampoo enough of a liquid for you? I don't think mine has any solid particles in it, but some might. The Kaye effect is a cool demonstration of the non-newtoniannness of shampoos and soaps, check the video refs at the bottom of our article. Also oobleck is indeed a colloid, but you can make it so that it flows nearly as easily as water. At that point, it requires a lot of force to see the shear thickening though. Check out shear thinning and shear thickening if you haven't, they discuss some additional examples and comcepts. SemanticMantis (talk) 14:45, 25 January 2016 (UTC)


 * What about ketchup, mustard, and toothpaste? Also, what does it mean for pitch to be a viscoelastic, solid polymer if it is supposedly the highest viscous liquid? Is it a liquid always or not? Willminator (talk) 03:23, 27 January 2016 (UTC)

Are long underwater submarine cruises harmful to human health?
AFAIK the effect of low gravity on bone density means that being in space is fundamentally harmful to humans, and no matter how fit and well-trained they are, this imposes a limit on how long astronauts can stay in orbit. Is there a similar physiological reason why long underwater cruises on a nuclear submarine would be harmful to the crew, and if so roughly how long could they stay underwater? Or would the food run out before anything else became an issue? I guess a modern sub is able to carry some gym equipment; what about sunbeds to replace exposure to sunlight? 94.12.81.251 (talk) 11:56, 25 January 2016 (UTC)


 * This is a review of medical problems for naval personnel in the Royal Navy's Vanguard-class submarines. Their routine patrols are about 3 months in duration. Mikenorton (talk) 12:30, 25 January 2016 (UTC)


 * That's an interesting study - but it doesn't really tell us much because it's only run over 3 month patrols. Over 74 patrols, each with a 150 man crew (340,000 man days) they only had to pull someone out of the boats 5 times - twice were appendicitis, once for a "Chemical eye injury", once for a seizure and once for severe traumatic hand injury.  I'd bet that the eye and hand injuries related to the work being done and the seizure and appendicitis cases are probably within the norms for 340,000 man hours of any other human situation.


 * Looking at the problems that were not sufficient to cause the crewmember to be evacuated - we have lots of other injuries - things like chest pain - and "acute opiate withdrawal". But, again, nothing that looks like problems due to being cooped up in a submarine for three months.


 * So from a cursory glance, there are no issues that would prevent longer missions (except of course that the submarine can't carry enough food for longer trips).


 * I think we'd need data from much longer trips. But a lot has to depend on monitoring and initial crew quality.  The guys who are going to spend a year on the ISS get studied in minute detail before being launched up there.  Submarine crews also get health checks - but I can pretty much guarantee that it's nothing like as careful as with ISS crews.  That's evident from the crewmember who suffered from "opiate withdrawal"...I can't imagine that being remotely possible with ISS crews.


 * Looked at another way - it's hard to imagine how submariners could be worse off than the ISS crews. They don't have the gravity problems - or the lowered atmospheric pressure issues that ISS have - they have more space to move around in - and the larger crew presumably makes the mental health issues of being cooped up in a small space more manageable.  Submariners get plenty of exercise and "real" food (well, more real than the ISS crew get) - and they don't generally suffer from things like solar radiation that the ISS crew have issues with.  So you'd expect them to do much better.


 * I think we'd need longer studies and with more controlled crew selection and pre-processing before we could reasonably conclude an amount of time. SteveBaker (talk) 14:19, 25 January 2016 (UTC)
 * Steve remarks that it is "hard to imagine how submariners could be worse off than the ISS crews..."
 * Well, there is, of course, combat in submarine warfare. As unfathomable as it may seem, in this decade, for state-against-state naval warfare to occur, it is a real threat and it is one reason that large Navies still spend lots of resources to train and maintain crews and prepare for undersea warfare.
 * In December, I was gifted a non-fiction book, Pig Boats, about submarine warfare during World War II. It details the raw unpleasantries of the war for submarine crews.  If you can imagine a way to cause health-harm to a human, the submariners had to deal with it at some time during the war.  One advantage the astronauts on International Space Station have is that for the most part, nobody is actively trying to harm or destroy them.
 * Nimur (talk) 14:51, 25 January 2016 (UTC)
 * I also don't think space weather makes the ISS rock and churn on a regular basis, as terrestrial weather does with subs. Last guy I talked to who served on a sub mentioned how some of them hated rising to periscope depth due the increase in motion sickness it could cause. Crew in a nuclear submarine probably also go longer than ISS crew without seeing the sun. This seems like a pretty serious issue, light levels are carefully studied and controlled on subs . While the ISS crews may have their own problems with light, at least they can often look out the window and see the sun. Here's an interesting ref on disorders in circadian rhythms that mentions submarines . SemanticMantis (talk) 15:25, 25 January 2016 (UTC)
 * Our OP is concerned with long underwater cruises on a nuclear submarine - they don't spend much (if any) of that time at periscope depth - so seasickness is not a significant issue. Even if seasickness were a problem - it's a short term, non-life-threatening phenomenon that would not limit the amount of time a person could spend in a submarine - so it's not relevant to answering this question.
 * Similarly, any likelyhood of there being combat missions for these craft has zero impact on the OP's question - which is how long you could live in one of them.
 * Comparisons with WWII submarines is also pretty irrelevant. A typical nuclear submarine is huge...they are not the cramped, cold, miserable places you'd imagine from seeing WWII craft. SteveBaker (talk) 16:56, 25 January 2016 (UTC)
 * I don't care to argue with you. But if you want to actually help OP, you could try supplying references. SemanticMantis (talk) 17:24, 25 January 2016 (UTC)
 * As aside, Steve, I don't think the "acute opiate withdrawal" is what you suspect. (That is, it isn't a situation where someone who got addicted to painkillers while landside, nobody noticed when he came aboard, and then he went into withdrawal when his supply ran out at sea.)  The footnotes indicate that it was a patient who was prescribed opiate analgesia for pain and who abruptly stopped taking his meds without discussing it with his doctor.  Yeah, it's less likely aboard the ISS, but in principle an astronaut could ignore the flight surgeon and stop taking his prescribed meds in orbit, too. TenOfAllTrades(talk) 20:50, 25 January 2016 (UTC)
 * Here's a few more scholarly articles on light and circadian rhythms in submarines, and one naval report . SemanticMantis (talk) 17:43, 25 January 2016 (UTC)


 * Regarding User:SteveBaker comments above, I also fail to see how the ISS could be less detrimental to your health than a functioning nuclear submarine. Unless you are in something like the Russian submarine Kursk. It might seem counter-intuitive, but crews of nuclear submarines are even less exposed to radiation according to this source than people living above the surface. The background radiation is quite low inside a submarine. The health concerns for the ISS is not only the lack of gravity, they are also exposed to cosmic rays. Scicurious (talk) 19:46, 25 January 2016 (UTC)

IR laser line generator.
I have an idea for a commercial application needing a laser line generator. These are tiny little gadgets costing a few bucks that include a low power laser source and a lens to spread the light out like a fan over maybe 60 to 120 degrees, sealed into a cylinder a couple of centimeters long. (You see them in supermarket barcode scanners, for example).

I know that red and green laser line generators in the &lt;5mWatt range are considered to be class 1 or 1/M laser devices - which means that they're "safe for consumer use". A line-laser is considerably safer than a regular laser pointer because the energy is spread over a wider area, hence class 1 or 1/M rather than class 2 like most laser pointers.

But I'm considering switching from a red light laser to an IR line-laser of identical power and beam spread. I realize that IR lasers are invisible - so there is a risk of someone staring into the thing without knowing it's there, they don't invoke the blink reflex or close down the iris.

Trouble is, I can't figure which class these IR devices belong to and there is no indication on the manufacturer's web site to tell me.

Does anyone know the guidelines about these classes of device? Does the class get better if I limit the power to 3mW or even 1mW?

TIA SteveBaker (talk) 17:15, 25 January 2016 (UTC)


 * I think you'll need to get a copy of ANSI Z136.1 to rigorously answer this question. It does not seem to be freely available. Laser_Institute_of_America, the official secretariat of ANSI in this matter, will sell you a print or electronic copy. Here is the TOC and index. Here  is a comparison of the 2014 standard compared to previous versions. SemanticMantis (talk) 17:34, 25 January 2016 (UTC)
 * The way I learned it in school, every non-visible laser was automatically treated as if it were a Class IV laser. However, if you dig very deeply into, say, OSHA standards, they do not (for the most part) actually distinguish between different classes of laser when specifying workplace safety requirements.  As SemanticMantis correctly pointed out, the ISO, ANSI, and IEC technical specifications that define commonly-used laser classification terminology are neither free nor zero-cost.
 * Invisible lasers are inherently more dangerous: you won't even notice when they malfunction, or when they reflect specularly off a distant object, and so on.
 * Nimur (talk) 19:14, 25 January 2016 (UTC)


 * I can't speak to the accuracy, but laser safety does have charts regarding safe exposure and classification at near-infrared wavelengths. One of the graphs, reproduced at right, suggests that near-infrared wavelengths would be considered Class 1 ("safe under all conditions of normal use") at power levels less than around 0.5 mW and class 3R (or worse) at higher power levels indicating at least some risk of eye injury.   If you are definitely going to work with such lasers, I would strongly recommend you verify such safety information with reputable third parties.  Dragons flight (talk) 12:27, 26 January 2016 (UTC)


 * 0.5mW is really low. I've only found cheap 'near' IR line lasers at 1.0mW - but that's spread out over around 90 degrees of 'line'.  I wonder whether the classification system would be OK with me physically limiting how close someone could get their eye to the laser such that no more than (say) 1/10th of the entire line could impinge on their eye?  Assuming that the light is spread out evenly, that would limit the practical exposure to 0.1mW - which ought to be really safe.


 * The trouble with "reputable third parties" is that they want to charge a lot of money for their services! I'll certainly go that route before making a final product - but if it's clear that an IR line-laser a non-starter then I'd rather not fork over the cash! SteveBaker (talk) 15:08, 26 January 2016 (UTC)


 * One option would be to move to longer wavelengths. I was reading the graph at ~800 nm, but if you can move to short-IR at say 1500 nm, you can apparently go to 10 mW at Class 1.  Not sure what wavelengths of lasers are available though.  As you say, there is probably a fair argument that a line source is much less dangerous than a point source, but I'm not sure how they officially consider such details.  Dragons flight (talk) 15:40, 26 January 2016 (UTC)
 * The key to safety with lasers - or any other energetic item - is not whether the device is safe when used correctly. It's about ensuring high confidence that the product is idiot-proof, accident-proof, and so forth.  Spreading laser energy using a lens or optic does truthfully reduce the hazard - as long as the optic is correctly operating.  If the laser is only eye-safe when the beam is spread into a large angular pattern, then what would happen if the device is dropped or misaligned, and the same laser light energy no longer travels through the optic?  Now the device has become unsafe.
 * This is why lasers are classified for safety, and fully-assembled optical systems are not: the beam-spreader may reduce hazard, but the laser itself is still a Class IV, (or whatever).
 * And when your laser light is invisible - you will not see it when the beam escapes from its designed optical path.
 * Steve runs a small business - he doesn't have a corporate training department to provide a mandatory Laser Safety class; he doesn't have some weaselly guy from Health and Safety department running around telling him what he may and may not do; he doesn't have a collared shirt from the legal department telling him how to reduce corporate liability or ensure compliance in every municipality where his business might be construed to operate; and Steve is (as evidenced by his comments) interested in cutting costs. Steve, I really try to avoid interjecting pure, unreference-able advice when I contribute to the reference desk, but here's some free advice from a person who has worked with lasers; err on the side of caution.  Do not try to manufacture or sell or use an invisible laser.  If you want to play with something safer, try removing the blade-guard from a circular saw, or dumping the charge out of shotgun shells, or generally anything else where you can see and avoid the hazard.
 * Nimur (talk) 17:31, 26 January 2016 (UTC)
 * I think that's a little unfair. My wife and I use a couple of 100 Watt IR lasers every day - in machines that I hand-built from plans (and then heavily modified).  So, yeah - I know that lasers are decidedly dangerous, and invisible ones, doubly so and I have a ton of respect for them.  Which is why I'm asking the question rather than just building something that might expose someone to danger!  My thought processes for this design go like this:
 * Is it even plausible that an IR laser can be considered "safe" for consumer use?
 * Is it more plausible that an IR line laser can be considered "safe"?
 * Does it matter how I enclose it to limit the fraction of the laser line that could impinge on the eye?
 * If all of those things suggest that this concept is feasibly something that would pass regulatory/safety muster - THEN I can go spend a pile of cash to get an expert to sign off on the design.
 * If the expert says it's OK - I can make and sell my gizmo.
 * The point being that steps (1) through (3) need to be considered BEFORE I spend money on step (4) or proceed to step (5). If it's very obvious from available public data that a 1mW IR laser line generator cannot be considered safe for a consumer product - then I can dump the idea and go back to a red laser line generator which I know is class 1M because the manufacturer says so.  If it seems likely that an IR laser would also be legal/safe - then I can spend the money to (hopefully) rubber-stamp that answer...with a suitably low probability that I'll be paying money to get a "No!" answer!
 * 16:22, 27 January 2016 (UTC)
 * Steve, I know you're a smart guy and I trust your judgement... even your step-by-step procedural thought process makes sense. But what I'm trying to say is that the answers to steps 1 through 3 are "no, no, and no;" and if you did have a giant corporate bureaucracy-machine, they'd be the ones telling you "no, no, no, run away screaming."
 * For perspective, take a long, hard, un-biased, non-fiction look at how a real DVD player protects its laser diode. Disregard fictional videos and "tutorials" from internet enthusiasts who believe that they have "taken out the laser" to play with it.
 * Can you still go ahead and do it? Sure.  Sometimes, great innovation takes place because a smart person pushes beyond the envelope of normal procedure.  Maybe once every few decades, a great leap forward occurs in commercial applications for laser optics.  But, a lot more often, somebody goes permanently blind, and a giant lawsuit bankrupts everybody involved.
 * For what it's worth, I definitely did recall that you have a powerful cutting laser, and it's probably among the most dangerous items in your house, or even in your entire neighborhood; so you probably aren't chomping at the bit to encourage members of the public to borrow time on it. It's not a toy.  There are lots of things in your house that you wouldn't want people playing with.
 * Nimur (talk) 16:57, 27 January 2016 (UTC)
 * Yeah - improperly handled, a 100W IR laser is a terrifying weapon! It's not for no reason that our two machines are labelled "The Death Ray of Ming the Merciless" and "Illudium Q36" respectively.  However, once they are mounted in a nice opaque metal box with magnetic switches to disable the power when the lid is opened, or the smoke extractor isn't pulling air, or the water chiller isn't producing adequate flow rates and appropriate temperature water...they are really pretty idiot-proof machines.  Of course, if you do happen to encounter an idiot - then you shouldn't expect them not to be able to bypass the safeties and do extreme amounts of damage - but that's true of very many other things one has around the house.  There is no doubt in my mind that a small family car is by far more dangerous than a suitably enclosed 100W laser.
 * Anyway - I'm convinced that there isn't enough evidence that a 1mW IR laser line generator is considered (legally) safe (although I'm pretty sure it would actually be safe in practice) - so I guess I'll stick with the red laser this time around. SteveBaker (talk) 23:23, 27 January 2016 (UTC)

Little bugs in uncooked pasta
On more than one occasion, I have noticed little bugs in boxes of uncooked pasta. I see them as soon as I open an otherwise unopened box. Or when I put the pasta in boiling water, I see the little bugs rise to the top. Needless to say, it's disgusting. Where did they come from? How did they get there? And how do I prevent this in the future? I have done a Google search and got a lot of mixed and contradictory results. Help! Thanks. 2602:252:D13:6D70:6441:F28D:D981:B287 (talk) 18:01, 25 January 2016 (UTC)


 * What do they look like? All kinds of pests might infest a pantry, and there may be some slight differences in how to treat. A common one is the pantry moth AKA Indian mealmoth. Does that look like the right bug? Another common pantry pest is the flour beetle. One thing to look into is whether you are buying contaminated goods or if the pests are getting in to your food at your house. If it's the former, buy different things. If it's the latter, there are steps you can take. Here are some reliable sources for how to treat and prevent pantry pests: UC Davis, Clemson , Utah State Extension . Transferring things like pasta to airtight containers is a good first step. SemanticMantis (talk) 18:08, 25 January 2016 (UTC)


 * Hard to describe. They are so tiny, they are about the size of a pencil-point tip.  Perhaps it is that pantry moth AKA Indian mealmoth that you linked above?  (I assume the photos in that link are magnified many, many times over?) I have read that they are already in the pasta (as eggs? or larvae?) and that they then hatch after they come into the house.  In other words, they are already in the box when I buy it at the store.  Help!  Thanks! 2602:252:D13:6D70:6441:F28D:D981:B287 (talk) 18:19, 25 January 2016 (UTC)


 * Don't sound like it. You should be able to see the light coloured segmented larvae (grub) (which may look slightly similar to a Maggot) if they were Indian mealmoths. By the time they are fully grown, the size may be about the size of a broken of pencil tip i.e. perhaps 5 mm-10mm long, not simply the point. You'll also see their waste (the threads). And if you've been having the problem for a while it's likely you'll see the months around your house. I think it's more likely to be some sort of Flour beetle from your description. Or maybe a Wheat weevil or some variety of Oryzaephilus or something like that. Nil Einne (talk) 18:47, 25 January 2016 (UTC)


 * Yes, it does sound more like the Wheat weevil. Yes.  What do I do?   2602:252:D13:6D70:186C:D475:39EF:E0EC (talk) 18:41, 25 January 2016 (UTC)


 * (EC) Note that if they are Indian mealmoths, you should transfer even opened containers since they are great at piercing plastic bags. Even then, you may find they make their way into containers which seem airtight. (It's possible the food or container was already infested with eggs but I'm not convinced it always was. There's also the fact that sometimes you see signs of the infestation, but no dead larvae or moths despite the product not being opened in a while.) Freezing generally kills the eggs and some people recommend it even if you're planning to throw out the food, particularly if your rubbish won't be picked up for a while. (If you're home composting you definitely want to freeze. Indian mealmoths are not something even helping your composting.) All these combined mean even if it only a localised infestation, it can be quite difficult to get rid of and may require a fair amount of stuff to be thrown out. Nil Einne (talk) 18:28, 25 January 2016 (UTC)


 * I don't mind throwing the old boxes out. No problem.  But what do I do with the new boxes?  The ones that I bring home from the store?  Thanks.  2602:252:D13:6D70:186C:D475:39EF:E0EC (talk) 18:45, 25 January 2016 (UTC)
 * Did you read my three last links above? They tell you very clearly how to deal with pantry pests. The short version is: buy food without pests, and store food properly. While it can happen that goods are infested before you buy them, things are more likely colonizing the food in your pantry. Invest in some airtight containers, and inspect your food as soon as you get it home. If you detect pests in the food when you first get it, return it to the store and complain. SemanticMantis (talk) 18:49, 25 January 2016 (UTC)


 * (EC) I was mostly referring to Indian mealmoths. But the point is to remove the infestation. If you've successfully removed the infestation (it will take a few weeks or months to be sure), there shouldn't really be anything much to do other than taking resonable precautions like storing food in airtight containers, keeping an eye out for reinfestation and not buying too much food (i.e. using the food fairly fast). As was mentioned by SemanticMantis, if the food is infested at point of purchase, it's probably better to simply buy food that isn't infested. If you really want to treat infested food, I suspect freezing will work for most insect pests (particularly multicyclic freezing). Nil Einne (talk) 18:53, 25 January 2016 (UTC)


 * We've dealt with them by putting grain products into metal bins as soon as they come in from the store, and by using pantry moth traps (available at your favorite home improvement store) that use a pheromone lure to a sticky trap. They also help to monitor whether you've got a problem. Use cans and traps for a couple of life cycles and you should be free of them.  Acroterion   (talk)   18:55, 25 January 2016 (UTC)


 * Home-stored product entomology Anna Frodesiak (talk) 19:01, 25 January 2016 (UTC)
 * Thanks for the indent and sorry for just dumping the link there. I couldn't reach they keyboard because I was snuggled up under the blanked with only a mouse because it's like -54 Kelvin here. By the way, consider zipping over to the Home-stored product entomology talk page about that article and it's big 5 pests (more than that, me thinks!). Anna Frodesiak (talk) 00:08, 26 January 2016 (UTC)

Thanks. If I buy a box of pasta, can I just throw it in the freezer? If so, would I throw it in the freezer as is (in the original box)? Or put the contents of the box in some other container? And, if I freeze it, what do I need to do when I want to cook it? Thaw it? Defrost it? Or just cook it right from the frozen state? Thanks! 2602:252:D13:6D70:186C:D475:39EF:E0EC (talk) 19:23, 25 January 2016 (UTC)


 * I think you can freeze it in the original container and toss it right in the boiling water from there. If there's any left, you might want to seal the closed package in a plastic bag, to prevent freezer odors from being absorbed.  You might use the plastic bag right from the beginning, too, as pasta boxes don't seem to be properly sealed to me (which is probably how bugs keep getting in).  You might try another grocery store and another brand of pasta, as one or the other obviously has an insect problem. StuRat (talk) 19:51, 25 January 2016 (UTC)
 * Yeah, the solution to bugs in your pasta is not freezing all your pasta forever. It's buying pasta with better quality assurance and using proper storage... SemanticMantis (talk) 20:17, 25 January 2016 (UTC)
 * I don't see the need to freeze indefinitely. The point of freezing is kill the eggs. If you don't have an existing infestation and practice decent vigilance and do your best to, you'll hopefully not get another one if you kill eggs before an infestation can take hold. (There is a risk that freezing won't kill all eggs particularly if the food has a lot of them and you are buying a lot of food that is infested. It's also likely some species have eggs that are hardy enough to survive freezing, or even cyclic freezing.) I do agree that this doesn't seem the smartest solution as opposed to just avoiding products that are infested. Nil Einne (talk) 13:34, 26 January 2016 (UTC)

A few people have said that I should buy food that is not infested. That is obvious. But, how do I know that when I am at the store? I don't see or notice these bugs until after I get home and open the box and start to cook. So, at the store, how would I have seen/noticed this? Obviously, one does not open up the box of pasta in the store. It sits at home until the day I decide to use it. 2602:252:D13:6D70:186C:D475:39EF:E0EC (talk) 20:56, 25 January 2016 (UTC)


 * I suggest you start opening them when you get home, to determine if they have bugs, because, if they do, those bugs might infest other items in your kitchen, like cereal boxes. You may already have an infestation problem, in which case you would have to take action to clear that up.  Another alternative, once you've found the pasta to be clean, is to store it in glass or tin containers, which, unlike those paper boxes, seal tightly enough to keep bugs out. StuRat (talk) 21:04, 25 January 2016 (UTC)


 * As already mentioned, you should be storing your food in airtight hard containers if you are having problems. It's ideal if you do this from the getgo since some insects can pentetrate the plastic bags. If you open your food and find it is already infested, and return it to the store. If this happens often or they refuse to accept returns purchase the same (or nearly the same) day when they are clearly defective and unless you're giving them older items must have been defective when purchased you should do what's already been suggested and shop somewhere else. (If they do accept returns and it happens often and you still want to shop, I guess they'll probably know they have a problem and so keep letting you make returns despite the fact you're always doing it. If they do start to make problems, I guess you could say you'll open it in front of the staff.) Nil Einne (talk) 13:31, 26 January 2016 (UTC)


 * Storing non-perishables in your refrigerator should be a good test. If it still has bugs, they most likely came from the store or the manufacturer, not from your hone. ←Baseball Bugs What's up, Doc? carrots→ 16:34, 26 January 2016 (UTC)

My refs above
Sorry, it looks like I've inserted some references where they shouldn't be, and I can't seem to delete them. Can anybody more experienced with wiki editing remove those 3 links please? Thanks Mike Dhu (talk) 21:02, 25 January 2016 (UTC)


 * I changed them to bare urls, so that they don't appear at the bottom of the page - I hope that's what you wanted. Mikenorton (talk) 21:08, 25 January 2016 (UTC)
 * Great, thank you, I need to learn more about how to edit wikipedia, I must have selected the wrong tag for the references. Sorry, I'll stick to sandbox for a while :-/ Mike Dhu (talk) 21:16, 25 January 2016 (UTC)


 * There's a way to embed references within a section on a talk page, but the exact syntax is not coming to mind just now. ←Baseball Bugs What's up, Doc? carrots→ 21:30, 25 January 2016 (UTC)


 * Please see this edit.—Wavelength (talk) 21:49, 25 January 2016 (UTC)
 * Yes, one of those previous edits, before Mikenorton kindly corrected my mistake, was my reply to a question where I wanted the references to appear, but they were appearing at the bottom of the ref desk. I used the 'ref' tag instead of square brackets, but realise now they are used for different purposes. I should probably post the rest of this reply as a question on the computing ref desk but I'll ask here first out of courtesy as this is where I made the mistake. I'll be spending a bit of time in sandbox now, but would it be possible to change the tooltips to give more information? Whenever I hover over any wiki markup it just displays a tooltip that I should click on it to insert it, without explaining specifically what the markup is for. I appreciate that for those of you who have spent a bit of time editing wikipedia it's second nature to know what tags to use, but more info on tooltips would make it easier for newcomers. Thanks Mike Dhu (talk) 00:22, 26 January 2016 (UTC)
 * There's no need for self-deprecation; in many ways, the problem is with this page and not anything you did "wrong". Considering that we're ostensibly here to supply references, we're not actually well set up to provide them in the same manner that articles do. Matt Deres (talk) 15:50, 26 January 2016 (UTC)
 * I didn't think I was being self-deprecating, just acknowledging that I made a mistake while I'm still learning how to edit wikipedia, but thank you. It would be nice to have more info from the tooltips though, so I'll post a question on the computing ref desk about that. Mike Dhu (talk) 22:07, 26 January 2016 (UTC)