Wikipedia:Reference desk/Archives/Science/2015 January 9

= January 9 =

Trustworthy sources of Windows builds of open source software?
Some of the open source software I use is hosted at Sourceforge. I've stopped downloading Windows installers from SF since reports came out in 2013 that installers hosted there were bundled with extra/unwanted software. Are there trustworthy alternative sites for Windows builds of open source software, ones that don't bundle extra stuff in the installers?

Are there ways to confirm that no unwanted extras are bundled with an installer? --134.242.92.2 (talk) 16:02, 9 January 2015 (UTC)
 * Are you talking about malware, or just spam-like junk? ←Baseball Bugs What's up, Doc? carrots→ 16:22, 9 January 2015 (UTC)


 * Not sure about what's bundled in the case of SF, but I do want to avoid both categories.
 * *** I inadvertently posted the question here instead of the Computing RD. I've moved the question there. Please post follow-up there. --134.242.92.2 (talk) 16:26, 9 January 2015 (UTC)

";" issue
Can some review this section please (https://en.wikipedia.org/wiki/Human_evolution#Divergence_of_the_human_clade_from_other_great_apes). Iss ";" in the end of the last word, an error? -- (Russell.mo (talk) 16:58, 9 January 2015 (UTC))


 * Yes, that was a typo, and I fixed it. I'm now a little confused by the styling of "Ardipithecus ramidus" as "Ar. ramidus" - normally we only use the first letter of a genus name when describing the species, and the article for A. ramidus just says "A. ramidus" as I would expect. Our style guide Manual_of_Style is silent on the issue. Before I change these to single letter abbreviations for genera does anyone want to defend the abbreviations as they are currently used in this section? I can see the desire to avoid confusion with e.g. Australopithecus, but the two-letter genera still looks wrong to me... SemanticMantis (talk) 17:12, 9 January 2015 (UTC)
 * Ok I've found this style advice that says the two letter abbreviations are to be avoided but are tolerable in some publications to avoid ambiguity:, citing "Butcher’s Copy-editing" as the style guide. SemanticMantis (talk) 17:17, 9 January 2015 (UTC)
 * Thank you for clarifying the issue. In regards to the point you mentioned, I'm not a science student, whatever knowledge I acquired so far, is from Wikipedia. Personal point of view: I think "A." is used for the Australopithecus, well this is what I've come across so far in my readings. -- (Russell.mo (talk) 10:49, 10 January 2015 (UTC))

Damages caused by too much staring at a screen (be it TV, computer or smartphone)
What could happen to my eyes, when we spend many hours starring at a screen? (I mean a modern TFT or LED backlight, not that old TVs.). Is this associated with any illnesses, poor vision or whatever? How can I know whether High-energy visible light is real or just a urban legend? How can I know if screens will cause another illness down the road? After all we didn't evolve starring at an illuminated screen. — Preceding unsigned comment added by Noopolo (talk • contribs) 18:25, 9 January 2015 (UTC)


 * At the very least, there's the problem of literally "staring" (not "starring") at a screen too much, be it TV or your computer screen, in that you might not blink enough, and your eyes might tend to get dry. ←Baseball Bugs What's up, Doc? carrots→ 20:20, 9 January 2015 (UTC)


 * See eye strain, computer vision syndrome, and this link from the Mayo clinic . SemanticMantis (talk) 21:10, 9 January 2015 (UTC)


 * Oh and you can tell that high-energy visible light is not an urban legend because you can check the references at High-energy_visible_light - many of which are peer-reviewed scientific literature. You can also presumably see the color blue. SemanticMantis (talk) 21:12, 9 January 2015 (UTC)


 * One problem is always having the same focal distance to the screen, which means you don't exercise the focusing muscles in your eyes and they atrophy. StuRat (talk) 22:31, 9 January 2015 (UTC)


 * Source please? This is simply not how the physiology of this organ works.   S n o w  talk 02:41, 10 January 2015 (UTC)


 * See vision therapy. There is some evidence that exercising the eyes helps, but more is needed. StuRat (talk) 05:10, 10 January 2015 (UTC)


 * That article is not at all relevant to the issue here, or the mechanism of atrophy you proposed. Vision therapy is for those who have per-existent conditions (such as motor disorders or those involving binocular coordination) not for people whose muscles "atrophied" because they weren't focusing at enough different varieties of distance, as you speculate.   That's an absurd suggestion for many more reasons than I'm going to take the time to address here, but I will point out this much: the eyes are constantly in motion and constantly making minute changes to focus that we are not consciously aware of.  As you stare at your monitor reading this message, your eyes are actually darting back and forth and focusing at/upon different points on the screen even when you are not willing them to.  What we see and what we think we see are two very different things, as the visual cognition centers of the brain are applying many layers of filters to compose a perceptual image around that tiny little space that your eyes are focused on at any given time; the brain takes previously acquired optical information and uses color and shading ques and a huge array of assumptions to create the composite your conscious mind perceives as the field of vision you are experiencing -- but the truth is that, at any given instant, you are only "seeing" (in the sense of receiving visual information directly from that eye in that instant) a fraction of what you perceive yourself to be seeing, and the eyes themselves are almost never at rest to any significant degree (even when you have your eyelids closed).


 * Regardless, you're not going to find a source out there supporting your guess that any issues with vision that arise from starting at monitors too long proceeds from atrophy. Quite the opposite, in fact -- the eye strain involved comes from the manner of exertion, not the lack of it.  Stu, please, we've been down this road a million times; please don't post outright speculation in responding to issues upon which you have no first-hand knowledge and no sources to back you up.   S n o w  talk 05:38, 10 January 2015 (UTC)


 * Here's one source: . Not a very good source, but it does show it's not just me making up stuff, as you seem to think.  I heard this from multiple sources, so will try to track down some better ones. StuRat (talk) 05:54, 10 January 2015 (UTC)


 * Convergence insufficiency is also somewhat related. StuRat (talk) 06:14, 10 January 2015 (UTC)


 * That ref is not just a mediocre source, it's a three paragraph non-scientific fluff piece in a fad health e-mag recommending "eye yoga" that doesn't even discuss the physiology of the eye or even really relate to this topic. Even that description somehow doesn't do justice to how silly virtually every word in it is and how much it is working against you here in establishing that you aren't speculating wildly.  As for convergence insufficiency, it is another example of a motor condition which has nothing to do with atrophy.  Look, if you heard this from multiple sources I can only guess that it must be a piece of folk science making the rounds, because the physiology of the eye is not an area of trivial interest for me and I'm telling you that what you are suggesting is not consistent with the actual science.   CVS is simply not caused by atrophy -- again, it's much closer to the opposite.   S n o w  talk 11:16, 10 January 2015 (UTC)


 * Apparently, Medieval teenagers were also the demographic to stare at illuminations all day until they grew too old and blind. But at least they were reading. InedibleHulk (talk) 02:53, 10 January 2015 (UTC)
 * Haha, that first link made my day, Hulk. That's some funny marginalia, a rare thing.  S n o w  talk 12:10, 10 January 2015 (UTC)

What's the problem of putting metal objects into a microwave oven?
I get that a sharp object will release sparks, but what would happen if I put a metal bowl with a metal top and water inside into the microwave? Would it get hot and heat the water, while blocking the microwaves that won't heat the water directly?--Noopolo (talk) 19:49, 9 January 2015 (UTC)


 * Microwave oven explains the consequences of putting metal objects in the microwave. ←Baseball Bugs What's up, Doc? carrots→ 20:17, 9 January 2015 (UTC)


 * On rare occasions, you can also get the same arcing without metal. I managed to get it with a saltine with a jalapeno pepper and cheese on top. StuRat (talk) 22:27, 9 January 2015 (UTC)


 * Olives make cool sparks and jump around, if it's just them in there. InedibleHulk (talk) 03:02, 10 January 2015 (UTC)


 * I'd love to see an explanation for how certain nonmetallic objects cause arcing in the microwave oven. Salty brine seems to be one necessary ingredient.  StuRat (talk) 05:01, 10 January 2015 (UTC)


 * If you cut a grape almost in half, so that the two halves are connected with a thin strip of skin and lay them with the cut faces uppermost in a microwave, you get quite impressive sparks. I'm sure there is some salt in a grape - but hardly very much.  You can see it in a rare example of a YouTube video that isn't faked: https://www.youtube.com/watch?v=DrY0aC81wxI
 * The stuff that happens in a microwave is frequently hard to figure out - so unless the specific situation you're thinking about has been written about, I doubt we could come up with a definitive answer. SteveBaker (talk) 05:59, 10 January 2015 (UTC)
 * There are many (not quite scientific) experiments about what happens to a variety of things in the oven at Is It a Good Idea to Microwave This? InedibleHulk (talk) 00:05, 11 January 2015 (UTC)


 * Yes, if you build a Faraday cage in a microwave, it will prevent EM radiation from entering. But water already does that and is a reason it heats.  A microwave oven has numerous TE and TM modes of standing waves inside the cavity (the oven is much larger than half a wavelength).  Low resistance metal forces the field to be zero and the field gradient can be large (causing arcs) and also causing electrical current in the metal.  See TEM mode but only TE and TM modes are excited in the cavity.  --DHeyward (talk) 05:57, 11 January 2015 (UTC)