Wikipedia:Reference desk/Archives/Miscellaneous/2015 February 24

= February 24 =

What's the image in this autostereogram?
This is a screenshot from Gravity Falls, and I'm pretty sure that's an autostereogram. Normally I can do those, but when I look at this poster and focus my eyes correctly, there doesn't seem to be anything there. It's just a pattern without an image hidden inside. Others who can view stereograms, do you see anything? --Ye Olde Luke (talk) 03:25, 24 February 2015 (UTC)


 * I cannot see an image inside the pattern, but it looks to me like the poster has a big hole with the horse and dancer being part of the poster while the pattern is behind the poster and seen through the hole. PrimeHunter (talk) 03:40, 24 February 2015 (UTC)


 * FWIW, I can't see anything. I have to cross rather than 'de-cross' my eyes, which usually gives the intended image sunk rather than raised (or vice-versa depending on what's intended) but I'm getting nothing on this one. Hypotheses: (a) it's a bluff; (b) the detail is too degraded in this repro of the original. {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 14:22, 24 February 2015 (UTC)


 * This page claims that it is an autostereogram, but does not say what the intended 3D image is... SemanticMantis (talk) 16:44, 24 February 2015 (UTC)


 * It's an autostereogram of a flat plane. —Tamfang (talk) 19:55, 24 February 2015 (UTC)


 * Nothing there. It's just a tiled pattern that looks like an autostereogram.  Presumably it "is" an autostereogram within the world of the cartoon, just like a white rectangle with lines and squiggles could "be" a newspaper. --Amble (talk) 22:48, 24 February 2015 (UTC)

Black Ink
Why is it that, in the UK, with many official forms you may have to fill in, you are required to write in black ink? Why specifically black? Why not blue? Is it something to do with the copying process they may have (black may stand out more on a scanner, for example)? KägeTorä - ( 影 虎 ) ( Chin Wag )  21:07, 24 February 2015 (UTC)


 * Yea, probably because it copies better. Consider if you were using a 3-color copier that was out of blue toner or ink. StuRat (talk) 21:10, 24 February 2015 (UTC)
 * Yes. Some colors blue do not copy well.  See Non-photo blue  RudolfRed (talk) 21:11, 24 February 2015 (UTC)


 * Not only do some colors not mimeograph well (google), other colors like red may be reserved for use by the office for special mark-up purposes, and they don't want you distracting them. Many modern forms do seem to allow either blue or black ink. μηδείς (talk) 21:16, 24 February 2015 (UTC)


 * Here in the UK, hospital pharmacists use green pens for the same reason that early photocopies reproduced it better than blue. I've recently noticed too that the black pen requirement  for official forms is seldom stated now. --Aspro (talk) 21:33, 24 February 2015 (UTC)


 * I suspect this is now largely a fossilised requirement but, as others have indicated above, early photocopying equipment reproduced blue poorly. In fact, this could sometimes be a feature rather than a bug. In Publishing as there was (perhaps still is) a procedure of of writing instructions on 'camera-ready mechanicals' (which are photographed to produce printing plates) for the Production Department using special sky-blue pencils (see RudolfRed's link above) that were/are not picked up by the cameras used. In the publishing house where I edited, the high-quality (for the period) photocopiers also didn't reproduce these pencil marks, which was useful when trial-copying the material to check that it looked correct.
 * In addition to this, publishing/printing (in the pre-computer era) used different coloured pens for different purposes: green was used by printers on the galley-proofs they produced to indicate their own mistakes that they had already noted, red was used by the editor to indicate the printers' errors for which the publisher was not liable to pay, and (ordinary) blue for amendments to the copy (due to auctorial or editorial changes) which did have to be paid for above a certain percentage. Apologies for digressing from the OP's original point {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 13:23, 25 February 2015 (UTC)


 * I've actually owned digital scanners (home computer peripherals) that wouldn't image all blue inks - so it may be that going way back to when documents were microfiched for archival, the "black ink" only requirement was adopted to make sure all handwritten entries on a given document (initials and signatures, particularly) were captured for posterity. loupgarous (talk) 19:36, 26 February 2015 (UTC)

Fire at The Marina Torch
How was the recent fire at The Marina Torch in Dubai managed in such a way that it caused no casualties, let alone no fatalities? If a building starts burning on the 50th floor, and then spreads to dozens of other floors, what mechanisms are in place to manage this kind of event? The Rambling Man (talk) 21:58, 24 February 2015 (UTC)
 * The fire was only up one side, as far as I can tell. Buildings such as this generally do have multiple stairwells, so evacuation would be able to be carried out as effectively as possible.  KägeTorä - ( 影 虎 )  ( Chin Wag )  22:18, 24 February 2015 (UTC)


 * I worked at 140 West Street, across the street from the North Tower during 9/11, and it was very severly damaged. The building was built in the 20's, yet still had four corner escape stairways with fire doors at each exit.  You'd basically have had to bomb or set on fire each of the four stairwells to prevent safe exit, and although debris from the World Trade Center fell into the building, there were no casualties.  One would assume a more modern building would be at least as well designed. μηδείς (talk) 01:16, 25 February 2015 (UTC)


 * One problem in the evacuation of tall buildings is getting everyone out in a timely manner. The best approach is to do a zone by zone evacuation, where people in the areas of immediate danger are evacuated first, while the rest wait.  This avoids having the stairwells become clogged with people.  There can also be an issue with smoke in the stairwells, but there are emergency ventilation systems to deal with that. StuRat (talk) 02:45, 25 February 2015 (UTC)


 * Stairwells should have auto-closing doors at each of the floors, to minimise smoke getting into them. Rules against propping them open should ideally be strictly enforced. I don't know about other countries, but here in Australia you often see signs saying "fire door. do not obstruct. do not keep open". Of course, in an evacuation, the doors get left continuously open by virtue of the human traffic, but the auto-closing design rule still helps minimise the problem once the floor has emptied. 101.160.63.123 (talk) 09:14, 26 February 2015 (UTC)


 * It probably helped that (according to our article) the fire was at 2 o'clock in the morning - even the most conscientious office worker would have gone home by then. Alansplodge (talk) 11:24, 26 February 2015 (UTC)
 * It's residential building, not an office block, so it would have been full of sleeping people (although some residents did return from partying to find it aflame). — Preceding unsigned comment added by LongHairedFop (talk • contribs) 13:58, 26 February 2015 (UTC)
 * D'oh! Alansplodge (talk) 16:04, 26 February 2015 (UTC)
 * Our article is not very clear, but it appears that only the external cladding burnt, and the fire didn't spread into the building's core. This means that the fire escapes (and other sides of the building) would be safe. LongHairedFop (talk) 14:09, 26 February 2015 (UTC)