Wikipedia:Reference desk/Archives/Science/2018 February 21

= February 21 =

what is the U-shaped piece of wire in the front for?
example: https://en.wikipedia.org/wiki/File:Makita_DJV181.jpg All (newer) power jigsaws seem to have it. My old tool (90's) doesn't. What is this thing for? Thank you in advance 78.50.150.23 (talk) 12:40, 21 February 2018 (UTC)
 * As a general rule of thumb, modifications along the lines of "all the old ones don't have this, and all the new ones do, and I can't quite see what it does" are often safety-related, and result from either a regulatory change or an expensive lawsuit. (Rarely, changes to improve the safety of equipment result from manufacturer initiative&mdash;but that's not usually how capitalism works.)
 * In this particular instance, the bit of wire is a safety wire or guard wire (see the parts diagram and list, item 10). It's to help keep stuff – stray junk, power cords, the user – clear of the moving parts of the jigsaw.  I expect a wire is used rather than a solid window because it's light, it's cheap, it's durable, and it won't get clogged up with sawdust. TenOfAllTrades(talk) 12:56, 21 February 2018 (UTC)
 * Thank you! I had downloaded like 3 manuals from different companies (Bosch, Einhell and Ryobi) but none had such a nice diagram. The purpose of the wire is not immediately obvious so I was wondering. Thanks again! 78.50.150.23 (talk) 13:28, 21 February 2018 (UTC)
 * It just kills me the old saw has become unusable because of a tiny part (blade pick-up clip) they for some reason chose to make from some brittle zinc or aluminium type stuff... and that I could probably machine myself -- if I had the tools 78.50.150.23 (talk) 13:40, 21 February 2018 (UTC)

What is a direct-view portable TV?
I don't have a lot of time when I'm at libraries to search for these things. But Wikipedia doesn't seem to have the information. Here is where I saw the term. At home, I try to stay away from unfamiliar sites.— Vchimpanzee  •  talk  •  contributions  •  21:37, 21 February 2018 (UTC)
 * Literally, it's quite simple: it means it was a portable TV where you looked directly at the screen. Seems obvious now, but this wasn't how the previous ones had worked.
 * In particular, Sony's was the second portable TV (counting the well-known ones) and the first had been the Philco Safari . This used a tiny tube, and to make it appear larger it was set inside the case, projecting onto a screen. To make the case more compact, that in turn had needed the tube to be pointed vertically and the image turned with a mirror. Sony achieved a couple of things: the screen was big enough width-wise to be visible when viewed directly, it was still short enough (the deflection angle needed to be big enough, despite the limits of tube technology) to not be a huge case and then it was still efficient enough to work as a portable set. Andy Dingley (talk) 21:59, 21 February 2018 (UTC)


 * Thanks for the intelligible reply Andy Dingley, could something be added to our History of television article about non-direct-view TV sets like these for example as there doesn't seem to be any mention at present? Alansplodge (talk) 13:02, 22 February 2018 (UTC)
 * That was my objective as well. Thank you. My first memory of Sony was of a very small TV in a restaurant.— Vchimpanzee  •  talk  •  contributions  •  19:29, 22 February 2018 (UTC)