Wikipedia:Reference desk/Archives/Miscellaneous/2021 July 8

= July 8 =

electric razor vs razor by hand
https://www.youtube.com/watch?v=IzcnX-1Mi0I&t=464 1. I see that this barber use 3 razors, one electric the other a knife like razor. why can't electric razor cut close as manual knife like one? 2.I thought that #0 in electric razor is actually removing all hair above the skin meaning actually it is at 0 zero height (or as close as it can be). How long in mm actually #0 is in electric razor?


 * Electric razors do not shave, but clip, like scissors. Scissors can only clip to the thickness of the lower blade. In the case of electric clippers the lowest they can cut is the width of the bottom comb, which is about a millimetre. In the case of an electric razor (foil type), the lowest they can clip is the width of the foil, maybe about 0.05mm. The combs on a rotary shaver are rather thicker than this.--Shantavira|feed me 09:04, 9 July 2021 (UTC)

Retractable ship decks
Were there any ideas to make retractable decks on aircraft carriers (or other ships), that would extend whenever neccessary (e.g. to assist landing aircraft) and retract back when not needed? 212.180.235.46 (talk) 20:35, 8 July 2021 (UTC)
 * Ideas? probably. Serious plans were made to create aircraft carriers from ice. However, I doubt it will have advanced further for several reasons:
 * the design effort would likely be large, as the deck for a landing aircraft needs to absorb the impact of that plane (and similarly in the catapult or ramp for take-off).
 * the functionality would suffer compared to a fixed deck, as valuable space is needed for the folding/retracting mechanism
 * Additional weight on the top of the ship would make it less stable. Making it lighter makes the two issues above worse...
 * With this in mind, I think the "simple" design seems to be much more advantageous than any retractable design. Rmvandijk (talk) 07:05, 9 July 2021 (UTC)


 * Furthermore, I don't see an upside to the above points on the downside. What problem will be addressed by having retractable decks? --Lambiam 09:19, 9 July 2021 (UTC)
 * Yes, I agree with that. I'd think that something like this would be relevant only for some "combination vessels" (e.g. a submarine aircraft carrier). Even there, a floatplane/helicopter/autogyro/VTOL would probably be easier than adapting the vessel. Rmvandijk (talk) 10:31, 9 July 2021 (UTC)
 * Not just ideas, but patents have been applied for (like this). The primary issue is that the runway length only became a major issue in the Doolittle raids. The aircraft found on aircraft carriers are designed to use the catapult and hook system instead of runway length for takeoff and landing. In the Doolittle raids, they used aircraft that was not designed for the carrier, so they had to improvise. 97.82.165.112 (talk) 14:23, 9 July 2021 (UTC)


 * Not really what you're asking, but one dead-end idea of the 1950s was the flexible flight deck, a rubber mat over inflated fire hoses that would cushion the landing of of a jet aircraft on a carrier and do away with the need for undercarriage - a British invention which was also tested by the US Navy. Because the pilot had to actually stall the aircraft over the mat, it was found that only the most skillful test pilots could actually land safely. The Supermarine Scimitar was designed for flexible deck landing and they had to add some wheels on later when the idea was abandoned. Alansplodge (talk) 17:49, 10 July 2021 (UTC)


 * I can just hear the stewardess now: "Please unretract your deck in the horizontal position as we come in for a landing." Clarityfiend (talk) 21:29, 12 July 2021 (UTC)