View source for Wikipedia:Reference desk/Archives/Science/2018 January 15

<noinclude><!-- From archive header-->
{{#ifeq:{{PAGENAME}}|Special:Undelete| |{{#if:|<div style="display:none;">}} {{#ifeq:{{NAMESPACE}}|Wikipedia|{{#switch:{{NAMESPACE}}|= |<div style="display:none;">}}|{{error:not substituted|Archive header}}<div style="display:none;">}}}} {{#if:|</div></div>}}{| width = "100%"
|-
! colspan="3" align="center" | [[Wikipedia:Reference desk/Science|Science desk]]
|-
! width="20%" align="left"  | &lt; [[Wikipedia:Reference desk/Archives/Science/2018 January 14|January 14]]
! width="25%" align="center"|&lt;&lt; [[Wikipedia:Reference desk/Archives/Science/December 2017|Dec]] | [[Wikipedia:Reference desk/Archives/Science/January 2018|January]] | [[Wikipedia:Reference desk/Archives/Science/February 2018|Feb]] &gt;&gt;
! width="20%" align="right" |{{#ifexist:Wikipedia:Reference desk/Archives/Science/2018 January 16|[[Wikipedia:Reference desk/Archives/Science/2018 January 16|January 16]]|[[Wikipedia:Reference desk/Science|Current desk]]}} &gt;
|}
{| align=center width=95% style="background: #FFFFFF; border: 1px solid #003EBA;" cellpadding="8" cellspacing="0"
|-
! style="background: #5D7CBA; text-align: center; font-family:Arial; color:#FFFFFF;" | '''Welcome to the Wikipedia Science Reference Desk Archives'''
|-
| The page you are currently viewing is {{#ifexist:Wikipedia:Reference desk/Archives/Science/2018 January 25|an archive page|a [[Wikipedia:Transclusion|transcluded]] archive page}}. While you can leave answers for any questions shown below, please ask new questions on one of the [[Wikipedia:Reference desk|current reference desk]] pages.
|}


__TOC__
</noinclude>
= January 15 =

== How much care is exercised in naming new concepts in quantum physics? (e.g. "wave function collapse") ==

I understand naming standards like ISO for computer science and IUPAC for organic chemistry, but I don't know any details about the process of naming terms & concepts in quantum physics. Those I've asked in discord/reddit have said quantum physicists have bigger egos than computer scientists or chemists, which I find irrelevant. Hoping to find a more helpful answer here... Thanks, [[Special:Contributions/67.233.34.199|67.233.34.199]] ([[User talk:67.233.34.199|talk]]) 16:15, 15 January 2018 (UTC)
:The basic answer is that the person who invents a concept has the right to name it, and often exercises little care in doing so, because people don't usually realize that their new concepts will turn out to be important. The result is that lots of things get poorly named. One of the most egregious examples is [[theory of mind]], which is not actually a theory. Computer science is not by any means immune to this. Standardized naming only applies to things that fall into recognized groups, such as file formats. New concepts, such as [[agile testing]], are named by whoever thinks they are worth naming. The history of the word [[interface]] -- as central a concept to computer science as you can find -- is particularly interesting: it came into use because some engineer back in the 1950s couldn't think of anything better. [[User:Looie496|Looie496]] ([[User talk:Looie496|talk]]) 17:09, 15 January 2018 (UTC)
:It is also worth considering that much of quantum mechanics was originally developed in languages other than English.  Important concepts are embodied with non-English words like [[eigenfunction]], [[ansatz]]; and even words like the [[photon]] and the [[Action (physics)|action]] and even the [[quantum]] are at best "technically" part of the English language, though they all derive their modern application in physics by way of other modern languages, followed by subequent retranslation into our own English-like technical jargon.
:When you read about wave function decomposition in German, it reads a lot more like plain language.  I frequently wonder if American students of physics would have an easier time if we never used the word-fragment "eigen" for any purpose; many modern math curricula use the word "characteristic" in its place.
:The jury is still out on how effective any of this stuff is.  Some research implies that students learn better if we vary the vocabulary while teaching the concept.  Contrarily, some research implies that students learn worse if we vary the vocabulary while teaching the concept.  Here's a research brief from a group recommending that we make introductory-level students write essays about physics vocabulary: [https://web.phys.ksu.edu/papers/2003/NARST03-VocabOfIntroPhysImpactonLearning.pdf ''The vocabulary of physics and its impact on student learning''].
:In my experience, I have found that the pioneer researchers do not automatically obtain the privilege of naming the concepts: on the contrary, they reap fame and credit, but it is the forgotten, nigh-anonymous authors of the best textbooks who ''actually'' get to name the concepts.
:Though you surely believe that Newton and Leibniz invented calculus, you almost certainly recognize the mathematical vocabulary and the symbolic equation conventions used by [http://stewartcalculus.com Stewart].  I challenge any novice to read ''Principia Mathematica'' and make a concerted effort to recognize when and where our esteemed author applies [[substitution of variables|u-substition]]!  And the very same applies to more advanced physics: just a few weeks ago, here on Wikipedia, we did an etymological dive into the etymological history of quantum mechanics: [https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives/Science/2017_December_2#Who_first_analyzed_the_'particle_in_a_box'_model? ''Who first analyzed the 'particle in a box' model?'']  Again, most readers of Schrodinger's actual writing will not recognize the Schrodinger equation that we all know from our textbooks.  Which author actually came up with that name?
:And if you read that paper, why, it's right there in plain German, with no bizarre or fancy techno-babble jargon!  There is no "quantization," and the author takes pains to avoid the word "whole," explaining in his opening that the quantization is the ''natural consequence'' of the system.  Now!  This is troublesome, because in the English language, a [[whole number]] is a mathematical word for a [[natural number]] (or integer); how can we possibly translate this concept into our language, in which the ''natural number'' occurs ''naturally'' without ''a priori'' requiring it to be a ''whole number''?  The trick is to first learn German, and ''then'' to learn quantum physics, and it will save you a lot of conceptual headaches - especially when you study [[Translational symmetry|translational invariance]].
:[[User:Nimur|Nimur]] ([[User talk:Nimur|talk]]) 23:48, 15 January 2018 (UTC)

*The history of the names of [[quark]]s[https://www.etymonline.com/word/quark] and [[gluon]]s[https://www.merriam-webster.com/dictionary/gluon] are instructive here.  --[[User:Jayron32|<span style="color:#009">Jayron</span>]][[User talk:Jayron32|<b style="color:#090">''32''</b>]] 00:57, 16 January 2018 (UTC)

==trying to identify a plant by pictures==
{{multiple image
 | width = 
 | image1 = unidentified-1,20.10.17.jpg
 | caption1 = unidentified plant from Caesarea, Israel
 | image2 = unidentified-1(2nd),20.10.17.jpg
 | caption2 = unidentified plant from Caesarea, Israel
 }}
I'm trying to identify a plant, shown in the following pictures, which resembles [[arecaceae]], but it isn't a member of this family. The pictures were taken somewhere in ancient [[Caesarea]] in Israel, in October 2017. Also the purple cluster shown doesn't look familiar, at least to me. I'll be glad to get clear & professional identification. Some [[Yucca]], may be ? Not sure.
[[User:בנצי|בנצי]] ([[User talk:בנצי|talk]]) 15:12, 15 January 2018 (UTC)

:Not identical, but ''[[Yucca baccata]]'' leaves and fruit have a similarity (but a long way from home). [[User:Alansplodge|Alansplodge]] ([[User talk:Alansplodge|talk]]) 19:38, 15 January 2018 (UTC)
:The fruit look like those of [[Yucca aloifolia]] - not native to the Middle East, but widely planted and naturalised in some Mediterranean countries. [[User:Wymspen|Wymspen]] ([[User talk:Wymspen|talk]]) 21:57, 15 January 2018 (UTC)

{{clear}}
::a. I don't know who aligned the pictures - thank you (you saved me another question, a technical one, regarding this).
::b. I tend to agree with the 2nd identification - Yucca aloifolia. It seems the only Yucca bearing such fruit cluster, in shape & color as well. Also the comment you make regarding acclimatizing the plant to the region sounds true to me.
::c. In [[Yucca]] appears the following wonderful Yucca species, but with no name - who knows which one is this (see below) ?
::[[File:Yucca-closeup.JPG|thumb|Yucca near [[Carlsbad Caverns National Park]] in [[New Mexico]]]].
::[[User:בנצי|בנצי]] ([[User talk:בנצי|talk]]) 17:57, 16 January 2018 (UTC)
:::Could be [[Yucca neomexicana]] - right colour, and right location. [[User:Wymspen|Wymspen]] ([[User talk:Wymspen|talk]]) 21:45, 16 January 2018 (UTC)

== Fire containment calculations ==

I was reading our article about the [[Thomas Fire]] and I'm curious about some of the statements made regarding fire containment. How is it calculated? Is it a measure of the active perimeter under control? I understand there's a technical definition being met, but to the layperson saying that a fire is 10% contained is a bit like being 10% pregnant. I assume we have an article about it, but I can't seem to find it, having gone through [[glossary of wildfire terms]], [[wildfire]], [[fire control]], and [[fire suppression]]. [[Fire containment]] just redirects to [[firefighting]]. [[User:Matt Deres|Matt Deres]] ([[User talk:Matt Deres|talk]]) 17:27, 15 January 2018 (UTC)
:Sounds like an article I should think about drafting...
:You are correct in saying that wildfire containment is calculated as a percentage of the active fire perimeter which has, in the view of the incident commander, sufficient fire control line around it. (Note that this does not always mean that line will hold up under any conditions.) These are always somewhat rough calculations, but they are aided by GIS, satellite and aerial tracking methods; major wildfires in the United States are mapped nightly by [[United States Forest Service]] infrared scanning aircraft when available and there are several NASA satellite programs which aid in [[remote sensing]] of wildfire, including the [[Moderate-resolution Imaging Spectroradiometer]] and the [[Visible Infrared Imaging Radiometer Suite]]. Note that the definition of "active fire perimeter" we use might be different than the one laypeople expect — while the TV cameras might have moved on from an area because the fire has burned through, we still consider that area "active" until there is a control line around it. Just because there aren't big photogenic flames anymore doesn't mean there isn't still enough residual heat to reignite under the right conditions. [[User:NorthBySouthBaranof|NorthBySouthBaranof]] ([[User talk:NorthBySouthBaranof|talk]]) 18:08, 15 January 2018 (UTC)

== Nuclear Propulsion Technology (Ships) ==

How long would it take us to create the infrastructure for nuclear propulsion technology for cargo ships on a massive scale? Please direct me to sources showing why or why not we would be able to achieve this goal within the next 20 years or so. Thanks! [[User:HarryOtter|HarryOtter]] ([[User talk:HarryOtter|talk]]) 22:30, 15 January 2018 (UTC)
:Four nuclear-powered cargo ships have been built, starting in the 1950s: [[Nuclear marine propulsion#Civilian nuclear ships]], plus some icebreakers. One of the cargo ships is still puttering around today. Another is moored in Baltimore if you want to go take a look at it. <span style="font-family: Cambria;">[[User:Abductive|<span style="color: teal;">'''Abductive'''</span>]] ([[User talk:Abductive|reasoning]])</span> 22:36, 15 January 2018 (UTC)
:{{ec}}You mean like, ocean-bound cargo ships, but nuclear powered as with aircraft carriers and submarines? Also, do you mean massive scale as in the ships are massive, or the fleet of ships is massive? We have an article [[Nuclear marine propulsion]], that includes a section on civilian use. Experimental nuclear-powered cargo ships have already been built, but it has apparently been repeatedly determined that the infrastructure costs of nuclear power as compared to fossil fuel use are prohibitive, and not offset by how much cheaper uranium is on a per-energy-unit basis. It is also speculated, as described in the article, that a large fleet of nuclear cargo ships could share some of the infrastructure costs and make this less of an issue, but there simply isn't any motivation to do that. [[User:Someguy1221|Someguy1221]] ([[User talk:Someguy1221|talk]]) 22:41, 15 January 2018 (UTC)

:Here is a 1999 report from RAND on the implications to the nationwide industrial base, to help the Navy decide whether to build non-nuclear or nuclear versions of what are now the [[USS Ronald Reagan]] and the [[USS George H.W. Bush]]: [https://www.rand.org/content/dam/rand/pubs/documented_briefings/2005/DB272.pdf ''Industrial Base Implications of Nuclear and Non-Nuclear Options''].
:Those are just two vessels.  However, the report explains that building ''merely two vessels'' will have strategic impact on the entire industrial base.  In particular, it impacts things like the total number of nuclear engineers needed in the entire world.  Where will you buy your fuel?  [http://www.imdb.com/title/tt0088763/quotes "I'm sure that in 1985, plutonium is available in every corner drugstore, but in 2018, it's a little hard to come by."]  For example, did you consider than in 1999, almost all of [https://www.bwxt.com BWXT]'s work force was due for retirement?  Unless somebody starts getting the young kids to start taking degrees in nuclear engineering, who will design, build, and sell fuel rods to your fleet of ships?  (It sure is a bummer that our society pays engineers more money to build software toys than to make nuclear reactors - one of many flaws of a western-style capitalist economy.  What smart young whippersnappers  are going to want to take on a difficult, high-risk, hazardous, low-transferrible skillset, when they can get paid [http://www.salarylist.com/company/Facebook/Software-Engineer-Salary.htm 500% more money to spread Russian propaganda]?  Besides, nuclear physics is hard, even if you're ... like, really smart!)
:So, unless the Government steps in to ...ahem, "reequilibrate" the invisible free hand of the economy - you know, [[Reaganomics|all Reagan-style]], like they did in the 1980s, [[:File:Federal Spending by President - Carter to Obama - v1.png|back when the Government didn't interfere with the economy]] - our best and brightest just don't want to do the jobs that our world requires to sustain a nuclear-powered economy.
:With a twenty year lead time, we could probably train a new cohort of nuclear scientists and engineers... so don't worry, it isn't like we have a twenty-year backlog of crushing the hopes and dreams of aspiring nuclear scientists.  We've only been doing that for, um, [[Superconducting Super Collider|darn it, thirty years]]?  Man, I'm getting old ''and'' crochety!
:[[User:Nimur|Nimur]] ([[User talk:Nimur|talk]]) 23:46, 15 January 2018 (UTC)
::When we learn to manage stable [[Nuclear fusion]] there will be a good chance for broad civil use. Current nuclear technology is to dangerous, regulated and complicated for civil use, with a few exceptions where it has so huge benefit that it makes sense again, like in nuclear medicine, large scale electrical power generation and as capital icebreaker propulsion. --[[User:Kharon|Kharon]] ([[User talk:Kharon|talk]]) 02:34, 16 January 2018 (UTC)
:::"Dangerous" my ass -- just compare how many nuclear meltdowns there have been (only THREE so far -- Three Mile Island, Chernobyl and Fukushima, and ONLY Chernobyl caused any loss of life) versus how many refinery fires happen each year, and see for yourself! [[Special:Contributions/2601:646:8E01:7E0B:C81D:59C2:9A63:53DF|2601:646:8E01:7E0B:C81D:59C2:9A63:53DF]] ([[User talk:2601:646:8E01:7E0B:C81D:59C2:9A63:53DF|talk]]) 06:01, 16 January 2018 (UTC)
::::Three?  You mean 20?  [[Nuclear meltdown#Nuclear meltdown events]].  The meltdown at the military's [[Stationary Low-Power Reactor Number One]] (SL-1) in 1961 was the first time a nuclear meltdown proved unambiguously fatal, killing three operators.  Generally most people only talk about the meltdown events that breach the containment vessel and spread radiation into the general population, but reactor failures resulting in partial or total meltdown have happened more often than just the three you mention.  [[User:Dragons flight|Dragons flight]] ([[User talk:Dragons flight|talk]]) 08:06, 16 January 2018 (UTC)
:::::No matter -- compare the miniscule loss of life in nuclear accidents vs. the thousands who die in accidents involving oil production and refining, and see for yourself that nuclear power is NOT dangerous! [[Special:Contributions/2601:646:8E01:7E0B:C81D:59C2:9A63:53DF|2601:646:8E01:7E0B:C81D:59C2:9A63:53DF]] ([[User talk:2601:646:8E01:7E0B:C81D:59C2:9A63:53DF|talk]]) 10:36, 16 January 2018 (UTC)
::::::Keep telling yourself that. ←[[User:Baseball Bugs|Baseball Bugs]] <sup>''[[User talk:Baseball Bugs|What's up, Doc?]]''</sup> [[Special:Contributions/Baseball_Bugs|carrots]]→ 14:07, 16 January 2018 (UTC)
::::::The biggest problem with nuclear incidents is that [[Futaba]] still has a population of zero, just like [[Chernobyl]].  It is one thing to have an accident that kills a few people, even a few hundreds of people, but it is something else again to draw a circle around a 24-mile diameter chunk of a country and say nobody can live there any more.  Nobody wanted those nuclear cargo ships in their docks -- that was one of the main obstacles to their service.  Also, remember the Fukushima disaster was really pretty moderate, only a "level 7 nuclear disaster" or so with multiple reactors leaking.  Had they failed to prevent the vast numbers of stored waste fuel rods on site from catching on fire and burning, I'd call it more like a "level 8".  (They don't actually have that ... our article [[International Nuclear Event Scale]] claims numerically it would be more like 10 or 11 even as it was) [[User:Wnt|Wnt]] ([[User talk:Wnt|talk]]) 16:44, 16 January 2018 (UTC)
:::::::The earth's surface in on the order of hundreds of millions of km<sup>2</sup>. I'd say a few thousand km<sup>2</sup> lost in learning mistakes are vastly preferable to systematically destroying the whole ecosystem. (different IP) [[Special:Contributions/93.136.7.174|93.136.7.174]] ([[User talk:93.136.7.174|talk]]) 03:35, 17 January 2018 (UTC)
:::Rather than participating in the infighting, here's a link to the [http://nrl.mit.edu/outreach/tours MIT Reactor public tours website].  Act now!  Tours re-open in February.  It's one of the largest reactors that you can visit.  Be sure to pick up some souvenier alternate-periodic-table-of-the-elements wall posters while you're there, arranged by radiochemistry instead of electron configuration (like [http://www.nndc.bnl.gov/chart/ this digital copy] from BNL).  Those posters are hard to find outside of the private collections of the ever-so-small cabal of esoteric nucleon science enthusiasts!
:::And if you, like I, should have the opportunity to take a ski vacation to the Rockies, [http://coloradogeologicalsurvey.org/mineral-resources/metallic-minerals/uranium/ don't forget your geiger counter].  In all seriousness, pick up (and study) a geology field guide and be careful what you carry home - ''thar be real radioisotope in them hills!''  Many rock-collectors have accidentally obtained concentrated uranium in their collections; and while sporadic exposure is probably okay, keeping a source of ionizing radiation in your house leads to all sorts of problems - ''especially'' that most invisible foe, [[Health effects of radon|carcinogenesis]] by chronic inhalation and bioconcentration of radiogenic [[radon]].  It's never the obvious hazards that get you!
:::[[User:Nimur|Nimur]] ([[User talk:Nimur|talk]]) 16:22, 16 January 2018 (UTC)
:::: My landlord placed several sources of ionizing radiation in my house, americium to be precise, hidden in plastic containers. He claimed that the state ordered him to do it. He calls them "smoke detectors". -[[User:Arch dude|Arch dude]] ([[User talk:Arch dude|talk]]) 17:08, 16 January 2018 (UTC)

:It's not a technology issue, rather a security, economic and risk issue.  Warships are heavily guarded and overmanned.  Container ships are lightly guarded and lightly manned. In general, efficiency for economic reasons tends to move towards less manpower which nuclear does not do at the ship level (even in the Navy, only the largest aircraft carriers are nuclear powered).  Economy of scale is limited to propelling a single ship and no shipping vessel will want a crew complement equivalent to the security and engineering on an aircraft carrier.  The holy grail of course is batteries with the energy density of fuel oil that could be recharged by nuclear power at a port.  --[[User:DHeyward|DHeyward]] ([[User talk:DHeyward|talk]]) 00:47, 17 January 2018 (UTC)
::Actually the main issue would be [[Refueling and overhaul|general maintenance and regular checks]] that puts these vessels into the docks for weeks or even months on a regular interval, similar as its done at nuclear powerstations. That is no problem for military vessels or icebreakers, which are expected to come back home frequently or on a seasonal basis.
::But cargo ships are generally expected to never stop. Especially the big ones, which would make most sense to equip with nuclear propulsion, need to make their [[Return on Invested Capital]] in competition to any other investment. You can not send such a big ship to the docks for one month every year for mentioned and revision while cheaper build big ships in competition, with usual diesel engines, just keep making money. Better fuel economy can not make up the difference. Unless you are the CEO of your privately owned shipping company you will be in huge trouble with all the extra costs. --[[User:Kharon|Kharon]] ([[User talk:Kharon|talk]]) 03:11, 17 January 2018 (UTC)

More advanced reactors that are more than twice as efficient as current designs could make civil nuclear ships feasible. See [[Fission fragment reactor]] [[User:ScienceApe|ScienceApe]] ([[User talk:ScienceApe|talk]]) 20:26, 17 January 2018 (UTC)