Wikipedia:Reference desk/Archives/Science/2019 January 31

= January 31 =

–150°F
Today is one of the coldest days on record in my area and Chicago would get down to –27°F tonight which would tie the all-time cold record. It is appropriate to have a discussion of what would happen if the temperature gets down to –150°F like it occurred in Manhattan in the movie The Day After Tomorrow. I know it's impossible for this to get this cold in my area, but let's imagine if that happens and what would the effects be on people, structures, and things?, such as people freezing to death in less than a minute and cars won't run and widespread power outages. Cash in your opinions, like what would you do if it gets this cold and power goes out and heating system wouldn't run... Planet Star  01:26, 31 January 2019 (UTC)
 * This is not really an opinion page, so there's nothing to cash in. One thing to note is that it can get pretty freakin' cold on Mars, and pretty hot, too, but it seems that our exploration machinery has been designed to survive the temperature extremes. Closer to home, Antarctica has cold temperatures almost as extreme as what you're describing, but the scientists there make do. ←Baseball Bugs What's up, Doc? carrots→ 01:47, 31 January 2019 (UTC)
 * In lieu of idle speculation, here is the Climate Program Office division for Regional Integrated Sciences and Assessements, a part of the U.S. National Oceanographic and Atmospheric Administration. They have published science-guided, forward-looking policy projections for realistic climate change phenomena.  For example, Climate Impacts on the Pacific Northwest.
 * The American Meteorological Society also publishes an annual bulletin, Explaining Extreme Events from a Climate Perspective. Here's a link: from the Bulletin, (PDF) - (though at the time of this writing, their server is having technical problems - you can find the publications mirrored on a few other websites).
 * On an unrelated note - I've been watching and reading a lot about the very cold weather impacting the central parts of the USA and Canada. It's of course very cold.  But I could not find any location where the cold was actually record-setting.  I've read a lot of area forecast discussions for regions like Wisconsin, Minnesota; North Dakota, and so on.  They use words like "dangerously cold."  But I have not yet found even a single instance of all-time record-setting cold.  Most of the sites I researched are still quite a bit hotter than 1966 (among many various other historical events that also set other records).  Here's the Chicago temperature record list; here's the Chicago Forecast Discussion (for the 908 PM CST Wed Jan 30 2019 issue, they list out records in great detail).  If I missed an actual (all-time) record-setter, I would be grateful if someone would let me know!
 * Nimur (talk) 03:13, 31 January 2019 (UTC)
 * The weathercasters I've heard have been saying "coldest in 20 [or 30] years" - that kind of thing. But how would you answer the OP's question about "what if it dropped to minus 150"? I googled "how do they stay warm in antarctica" and a bunch of items came up. Here's one. Here's another, in a conversational style. ←Baseball Bugs What's up, Doc? carrots→ 05:55, 31 January 2019 (UTC)
 * Humans would survive by avoiding exposure to those temperatures, using heaters and insulation to remain warm. If large populations had to protect themselves from such extreme temperatures, on a regular basis, it would be very costly in terms of energy, with catastrophic consequences in terms of economic and ecological impact.  Surely other health effects would be implied.  A quick glance through some cold winter back-issues of CDC's Morbidity and Mortality Weekly bring up epidemiological research on the effects of cold weather on influenza, nutrition, and psychological health, among many others.  Hypothermia, which is obviously a serious health-problem for an affected individual, barely registers as statistically-relevant at the population-level.
 * I am reminded of some of our more off-the-wall questions about earth-science, like "what if" Earth stopped rotating? I have usually summarized the answer to these type of physics questions - "it depends": how would [the earth's temperature drop a hundred degrees below normal]? If you can specify that, we can follow through with the consequences by applying some kind of reasonable scientific extrapolation.
 * On the other hand, if you just want to make something up, "just imagine" that the Earth magically changes its [temperature], all bets are off. We can't meaningfully speculate what consequences follow when one law of physics breaks "because of magic." Anything could happen. Everything we know about the way climate works, and how humans adapt to it, would be off the table.
 * Nimur (talk) 13:28, 31 January 2019 (UTC)
 * That magical force that could stop the earth from rotating could also move the earth's orbit out to around where Mars is. ←Baseball Bugs What's up, Doc? carrots→ 15:58, 31 January 2019 (UTC)
 * For the rest of the world, –27°F is -33°C and –150°F is -101°C. You're welcome. Fgf10 (talk) 08:39, 31 January 2019 (UTC)
 * Thank you. Indeed, we still use Fahrenheit in the United States for nearly all practical purposes, even in the scientific study of weather and climate.  In our defense, it makes certain rules-of-thumb easier to memorize.  For example, we (... all Americans...) have memorized the adiabatic lapse rate, which is conveniently 4.6 degrees Fahrenheit per thousand feet.  As we surely all agree, this is much easier to remember than two degrees Celsius per thousand feet; and far easier to memorize than degrees (of any scale!) per meter; and since we so commonly perform these calculations in our head, instead of consulting our paper-charts for the International Standard Atmosphere, we use a little bit of convenient rounding to gloss over the details of a wet- or dry- airmass and nonlinear thermodynamic variation as a function of pressure-altitude, which is why the various authoritative sources for these data provide different values and/or unit conversions that seemingly don't compute.  Surely our esteemed readers will recall the many times we've discussed units-of-measurement, practicality therein, and the theoretical underpinnings of metrology in the context of realistic constraints on accuracy and precision... but this was supposed to be a discussion about meteorology,...   Nimur (talk) 13:28, 31 January 2019 (UTC)
 * If the OP had asked about a constant 40 below, it would have worked either way. ←Baseball Bugs What's up, Doc? carrots→ 15:58, 31 January 2019 (UTC)
 * Air is actually an thermal insulator so humans in healthy conditions are capable, with some preparation like staying dry and have good isolation, to survive very low temperatures even for days. Elderly, ill and drugged people may be in great danger. --Kharon (talk) 10:43, 31 January 2019 (UTC)

Chicago was for a time colder than the South Pole, with a forecast of -10F/-21F that day. True, it's summer in the South Pole and not in Chicago, and the list of weather records includes a -129 F for Vostok Station. Some consideration of their situation might therefore shed some light on what is possible, at least. Wnt (talk) 04:05, 1 February 2019 (UTC)


 * There is already allot of historic and scientific data and theory about the Late Antique Little Ice Age and the Little Ice Ages just a few 100s of years ago. So such extreme Weather conditions seem quite common. We seem to live in a lucky timeframe regarding our Climate. --Kharon (talk) 08:31, 1 February 2019 (UTC)

What's the reason for two different colors of figs in the same tree?
If I'm not mistaken (base on my memory a long time ago), figs can be totally green or totally dark color (something like black) on the same tree, on the same time while they are ripe. If it's true then what's the explanation for that? Are there more trees like that? 93.126.116.89 (talk) 11:14, 31 January 2019 (UTC)


 * Some fig varieties have two crops of figs in the same year, one set called breba figs growing on the previous year's shoots, while the main crop grows on the same year's shoots, so you could get two sets figs of different colour on the same tree, but not ripe at the same time. Mikenorton (talk) 12:29, 31 January 2019 (UTC)

ancient site
hello, long time ago I watched a documentary about some "mysterious" site, I think in Miami, something like the plan of an ancient city, or maybe out-of-place artifacts like ancient piping, or something of the sort, and they initially didn't know if it was pre-Columbian or modern and they mentioned some financial goings-on where someone bought it for like 1 dollar. I skimmed this and this pages in the hope it would help my memory along but nothing rings a bell. Does someone by chance know what I'm talking about Aecho6Ee (talk) 15:19, 31 January 2019 (UTC)
 * Might it have been a site of the Miami people rather than the Florida city of Miami? The city in Florida only has a coincidental name; the name of that city is named for an entirely unrelated people group with a similar name.  The Miami of the Great Lakes region and the South Florida city are often confused, but are not related.  -- Jayron 32 16:27, 31 January 2019 (UTC)


 * Any chance it was Baigong pipes? Matt Deres (talk) 19:48, 31 January 2019 (UTC)


 * Miami Circle? —2606:A000:1126:28D:0:98F2:CFF6:1782 (talk) 04:57, 1 February 2019 (UTC)
 * YES! this. thank you so much! Thanks, everyone! Aecho6Ee (talk) 04:00, 2 February 2019 (UTC)

Photo of early man stone tool rejected
I am a professional photographer and amateur archaeologist who is frustrated that you will not allow me to contribute my PERSONALLY PHOTOGRAPHED image of a stone tool I FOUND. Your "solutions" require hours to understand, and make the entire process of contribution IMPOSSIBLE. Ny the way I have contributed financially for many years, and am insulted that my professional images are rejected by your complex process - which only a coder would appreciate.

Robert Marcos Here's my work: http://www.robertmarcos.com/macro/ — Preceding unsigned comment added by Robert Marcos 2010 (talk • contribs) 16:07, 31 January 2019 (UTC)
 * Sorry, Mr. Marcos, but when I check your contributions here at English Wikipedia, I can find no record of you having uploaded any image here. Perhaps you uploaded it to Wikimedia Commons instead?  While both sites are under the Wikimedia umbrella, English Wikipedia and Wikimedia Commons are separate websites with completely different user bases, administrator corps, policies, and the like.  If you did upload it to Commons and are having trouble there, can I suggest you ask for help on that website?  The Commons Help Desk is the correct place to get help with that website.  If this is not what happened, perhaps you can explain, in more detail, the nature of the problem you had with uploading your photograph?  The process can be a bit arcane at times, and I, or someone else here, can help walk you through it.  I hope we can help you, Mr. Marcos.  -- Jayron 32 16:24, 31 January 2019 (UTC)
 * I don't see any contribs for that account name in Commons, either. ←Baseball Bugs What's up, Doc? carrots→ 16:43, 31 January 2019 (UTC)
 * I think the original poster is saying that he wants to contribute an image, but that the process is hard to understand and he has been unable to properly "jump through the procedural hoops". --Khajidha (talk) 16:48, 31 January 2019 (UTC)
 * It has become a minor nightmare, which is one reason why I've contributed no pictures for a few years now. It used to be much easier. ←Baseball Bugs What's up, Doc? carrots→ 17:19, 31 January 2019 (UTC)
 * It strikes me as a difficult question for a person, like me, who just reads the various guides available at Commmons and isn't an expert in copyright law. Robert Marcos 2010 found and photographed the stone tool. He has copyright in the photograph and can license it to Wikimedia readers, no problem there. But should we consider the tool a utilitarian object that is not subject to copyright, or a sculpture? Since Mr. Marcos found it, it may very well be unpublished. If it were created after the concept of common law copyright became established in Mr. Marcos' location, it might be protected by copyright. I don't know if a creative work created before the concept of copyright came to be can be eligible for copyright or not. Jc3s5h (talk) 19:16, 31 January 2019 (UTC)
 * The tool was created by a person who is older than several thousand years old. No known copyright law, under any conditions, can protect the copyright for an unknown person who died thousands of years ago.  The oldest copyright protections in the world don't last longer than about 70 years past the life of the creator.  I may be wrong on the number "70", but it certainly isn't "10,000".  Under no circumstance is there any extant estate which could own the copyright on a stone tool, or a neolithic cave painting, or anything like that.  -- Jayron 32 19:25, 31 January 2019 (UTC)
 * If there is, that would be a genealogical coup. ←Baseball Bugs What's up, Doc? carrots→ 20:23, 31 January 2019 (UTC)
 * There's no definitive answer, but the best estimate we have for the most recent common ancestor to every human on earth probably lived in the first millenium BCE (see here), which means that anything older than that is, quite literally, the intellectual property of all of humanity. Which again, makes knowing who owns the copyright entirely pointless.  -- Jayron 32 21:10, 31 January 2019 (UTC)
 * I agree that assuming this is indeed an old stone tool (and not simply a reproduction or fake) there is zero chance of any copyright concern which means including zero chance anyone competent on commons will complain. But I'd be careful with 70 years being the longest. I think perpetual copyright still exists in some limited circumstances in at least one jurisdiction (Singapore), although it's only going to cover recent works. BTW, per public domain and List of countries' copyright lengths there is 100 years for Mexico albeit I'm a little uncertain if it covers all post 2003 works. Nil Einne (talk) 01:21, 1 February 2019 (UTC)
 * Yeah, as I noted, I wasn't confident on the 70, but even if a few places have 100, that's still a few orders of magnitude less time than the age of the stone tool in question; also AFAIK, the concept of perpetual copyright cannot be applied retrospectively, so any work that has been in existence longer than the law would not be eligible. And the stone tool has been in existence longer than Singapore.  -- Jayron 32 12:02, 1 February 2019 (UTC)
 * Getting back to the point, my suggestion (not TPTB's suggestion, but perfectly fine) is to choose "Plain form for local uploads", and in the summary add " " and a sentence saying where and when you found it, the approximate age, and where and when you photographed it. Then ignore the officious people (or more likely robots) who will then plague your talk page insisting you use their preferred format. HenryFlower 21:25, 31 January 2019 (UTC)
 * Although you'd significantly limit re-users of the image if you licence them GFDL only. Nil Einne (talk) 00:49, 1 February 2019 (UTC)


 * How are you trying to upload images? Personally, I feel that the commons upload wizard is not actually that complicated for your own images. Have you tried it Commons:Special:UploadWizard? It does not require anything I would call 'coding. It does require a small amount of reading and thinking about stuff you may not have thought about before but this may be a good think. For example, do you understand that if you choose to upload your images, you are not simply contributing them to wikipedia? Anyone anywhere is legally free to use them in accordance with the terms of the licence, whether commercially or whatever. This includes modifying them in any way they wish, recolours them, removing watermarks, cropping out what you photographed and putting onto a video etc. There are some licences e.g. the GFDL which make re-use in some contexts (such as printing them on a shirt or on a mug) less likely but ultimately you should expect they may be re-used. On the other hand, if you're happy for this to happen, maybe it will be better to choose the default licence Creative Commons Attribution ShareAlike 4.0. This is almost (we use 3.0) the licence primarily used by wikipedia for textual contributions nowadays. If you're happy with that licence, it's offered by default for your own work, so you don't have to worry about choosing licence. Note that in case where what you photographed is natural, or so old that it's clearly not under copyright, it would likely be simplest if you choose 'own work' in the wizard. Nil Einne (talk) 02:16, 1 February 2019 (UTC)
 * BTW, if you want use to upload your images on your website for you from your website, this adds a lot of complexity since there is no indication on your website that your images are suitability licenced. We would have to contact you via your website, and you would need to email and confirm a suitable licence. It's likely far easier if you simply upload them yourself. Nil Einne (talk) 01:03, 1 February 2019 (UTC)

Wikipedia (and sister projects) has issues with people who will upload images and claim to own copyright or a license on them but don't. So they have a process WP:OTRS to try to verify if there really is permission, and demand it be followed when some new account shows up and uploads a bunch of pictures off a potentially unrelated website. However, there is another way to get your images on Wikipedia, which is to give them a Creative Commons license on your original website. Then any Wikipedian knows he can upload them and anyone can verify they are free for Wikipedia to use. Note that the license has to be unrestrictive like CC-BY or CC-BY-SA, in particular CC-BY-NC (noncommercial use only) isn't good enough because Wikipedia wants to allow general reuse by all comers. Wnt (talk) 03:57, 1 February 2019 (UTC)
 * "Cross-wiki upload filter" at [//commons.wikimedia.org/w/index.php?title=Special:AbuseLog&wpSearchUser=Robert+Marcos+2010] indicates you tried to upload the images with a toolbar on an edit page at the English Wikipedia. This upload method has problems. Try commons:Special:UploadWizard instead. If the upload works then see Help:Files for how to add the image to an article. PrimeHunter (talk) 23:54, 5 February 2019 (UTC)

Alternating current waveform creation application for MacOS
Good evening. I was thinkinking about a project to study intervals, and wavelengths of alternating current. What application should I use to draw alternating current waveforms on MacOS? Vs6507 23:26, 31 January 2019 (UTC)


 * Matplotlib and NumPy provide powerful free-software mathematical graphing tools. Nimur (talk) 00:04, 1 February 2019 (UTC)


 * GNU Octave and Scilab also work well, and if you are not a programmer may have a less steep learning curve than Python. If you are a programmer they may drive you batshit crazy. Greglocock (talk) 00:59, 1 February 2019 (UTC)


 * The OP will find the spreadsheet program Excel (available on both PC and MAC) useful and easy. It can produce good quality graphs suitable for a project report from numbers that it has set up in tables by calculating from a formula that the user enters. Here are 3 suggestions: 1) An ac waveform. Enter the formula v = sin (60 x 6.283 x t) where t is a column of time values, say 0 to 0.17 in steps of 0.01 seconds, and v is a column of results. "SIN" is a standard function in Excel and v will turn out to have values in the range -1 to 1. The graph v against t is the waveform of an ac voltage of 1V peak and the 60 Hz mains frequency used in the USA. You will see the waveform period (= interval) as the distance on the time axis between points where the curve crosses it in the same direction (or double the distance between zero crossings). To investigate: what must you change to calculate and plot the ac waveform in Europe which is 50 Hz? 2) Interdependence of period and frequency. The formula is t = 1 / f. This is a reciprocal formula so be prepared to get very large and very small values. Therefore choose a small range of f values at first. You can choose from this enormous range of frequencies that are used in radio. The formula gives a wide range of t values but they vary in the opposite direction to f, i.e. increasing f reduces t. To investigate: How do the prefixes m (milli-) c (centi-) k (kilo-) M (Mega-) G (Giga-) T (Tera-) help in expressing large and small values? 3) Radio wavelength. The formula is λ = C x t = C /f where C = Speed of light, for graphing purposes C = 300,000,000 meters/second. Exercise: Suppose you have built a radio receiver. How would you draw a tuning scale for your radio that lets you find broadcasts from transmitters that may announce either their frequency or wavelength? DroneB (talk) 16:53, 1 February 2019 (UTC) To help you get started: The constant 6.283 is needed in the ac waveform equation because, in Excel, SIN is a function of angles in radians. The period of 60 Hz will turn out to be near 0.017 seconds, that of 50 Hz is 0.02 seconds. The symbol for wavelength λ is greek lambda. DroneB (talk) 14:31, 2 February 2019 (UTC)
 * If they don't want to spend money purchasing a Microsoft product like Excel, Google Sheets is free and has the same functionality. -- Jayron 32 19:45, 1 February 2019 (UTC)