Wikipedia:Reference desk/Archives/Science/2016 May 18

= May 18 =

Polypropelyne capacitor marking
I have some PP capacitors marked with the letters MKT. What do these letters mean?--178.106.99.31 (talk) 14:10, 18 May 2016 (UTC)
 * It's a code for the type of capacitor construction. As noted at the Wikipedia article film capacitor and at this table here, MKT is code for "metallized polyester foil".  I don't know that the letters directly stand for anything.  -- Jayron 32 14:21, 18 May 2016 (UTC)
 * Thanks. Couldnt find it in the article before, but found it now. So my capacitors are polyester not polypropylene. It seems the M stands for metal, the T is from polyester and the K means?? So polyprop would be marked MKP. :)--178.106.99.31 (talk) 14:31, 18 May 2016 (UTC)
 * These codes were the German ISO 41379 ; (declared obsolete, ). See altungen this (de)  document: the 'K' would be Kondensator (probably not 'Keramik').  See also in:  (by TDK), as you want to cross-check your deductions. --Askedonty (talk) 15:51, 18 May 2016 (UTC)
 * MKT "Metallisierte Kunststofffolie aus Polyester (Polyethylenterephthalat) als Dielektrikum"
 * MKP "Metallisierte Kunststofffolie aus Polypropylen als Dielektrik"
 * Guess as last letter was already occupied for Polypropylen they picked T for Terephthalat. --Kharon (talk) 22:31, 18 May 2016 (UTC)
 * Ah! Sehr gut mein Herr. Danke schoen.--178.106.99.31 (talk) 23:10, 18 May 2016 (UTC)
 * Yes. 'Kunststoff folie' seems to translate from German as 'plastic film' (or foil). So the K stands for....you guessed it. The WP page on film capacitors in the German edition seems to have more detail than english edition. But I cant read German to that level.--178.106.99.31 (talk) 15:52, 19 May 2016 (UTC)

Seeking a Reference
Can I have some free links to references on continuous and descrete spectra (Quantum mechanics)?Sayan19ghosh99 (talk) 17:04, 18 May 2016 (UTC)
 * Can you be more specific? I'm not sure there's anything in quantum mechanics that wouldn't count as continuous or discrete spectra (of operators). -- BenRG (talk) 19:40, 18 May 2016 (UTC)

Spectral line will talk a bit about discrete spectrum. Hydrogen spectral series gives a specific example of discrete. The Continuous spectrum usually happens because of the present of free electrons which can have arbitrary energy. Graeme Bartlett (talk) 08:15, 19 May 2016 (UTC)


 * Blackbody radiation may also be of interest here. -- Jayron 32 13:04, 19 May 2016 (UTC)

Acctim radio controlled clock module
Does anyone know how to access the 60 kHz signal that these clocks operate on? --178.106.99.31 (talk) 21:59, 18 May 2016 (UTC)
 * See Radio clock. It's just a CW signal, any radio receiver tunable to that frequency can pick it up. Tevildo (talk) 01:32, 19 May 2016 (UTC)
 * This is the detailed specification from NIST for the WWVB signal. Tevildo (talk) 01:51, 19 May 2016 (UTC)
 * You will actually need a specialised receiver, such as a communications receiver. Most receivers will not support frequencies that low, even radios designed for the long wave band. Graeme Bartlett (talk) 08:03, 19 May 2016 (UTC)
 * If you can handle some basic electronics, you can take an ordinary FM/AM radio and manipulate or replace the inductor in the tuner circuit to make it receive other frequencies. Other alternatives are adding a RF amplifier, then couple a signal generator that adds a frequency of say 540 kHz to make a 60 kHz signal have a 600 kHz component which fits the commercial AM band 531–1611 kHz. This mix is then wired to the antenna of the receiver. For the real handy person, just build a tuner circuit for your desired frequency and feed it to an op-amp and then to a sound card etc. Bytesock (talk) 23:39, 21 May 2016 (UTC)

Cat in a new home
Hi everybody, I have recently adopted an indoor cat from a lady who has had to return home to China. I was wondering what period of adjustment I should allow for the cat to get used to his new home and people, and if it would possible for him to be tempted to venture outdoors. I live in a fairly quiet part of the countryside in the UK, where it's normal for cats to go outdoors, and would like to give him the benefit of a natural cat lifestyle. Also, any advise on helping him to settle in would be appreciated. He is neutrered, microchipped, vaccinated and 9 months old. Thanks in advance --Andrew 22:16, 18 May 2016 (UTC)


 * He'll go out if he wants to, and vice versa. Fit a cat flap.--178.106.99.31 (talk) 22:44, 18 May 2016 (UTC)


 * If he's a totally indoors cat, letting up go outside could prove fatal. And if not, he could bring fleas into the house. But that's up to you. ←Baseball Bugs What's up, Doc? carrots→ 00:17, 19 May 2016 (UTC)


 * Yes, the benefit of a cat going outside is pretty much early death. As for getting used to new circumstances, cats can take months to make that sort of adjustment. - Nunh-huh 00:27, 19 May 2016 (UTC)


 * I guess if your speaking as Americans, it's a cultural norm for cats to be kept indoors, across the pond. Here in Britain we see things differently, and you're in the minority if you own an indoor cat. Given that I live in a rural part of the country, I don't see any risks with his wellbeing, and see the benefits of him going out and being able to exhibit his natural behaviours. To me, there's nothing more unusual than seeing a cat on a leash, they love to be free to roam outdoors --Andrew 01:43, 19 May 2016 (UTC)
 * I'm not talking about cultural norms, I'm talking about an actually shortened life. Average lifespan of an indoor cat is 12-15 years. Average lifespan of an outdoor cat is 2 to 3 years less.   You could Google "Indoor and Outdoor Cat Life Expectancy Differences" to see if there's anything magical about being in the UK that reverses that. - Nunh-huh 04:17, 19 May 2016 (UTC)
 * Well I suppose one advantage of living in the United Kingdom over the United States is the almost total absence of any predators that would like to eat the cat, except foxes, which aren't well known for attacking cats at all. In America, there's an abundance of predators --Andrew 17:49, 20 May 2016 (UTC)


 * Are you doing this for the cat, or for you? Are there any roads near your place? Any large dogs? Any wild animals like foxes or coyotes? Are you OK with the fact your cat could be dead within days or even hours? ←Baseball Bugs What's up, Doc? carrots→ 02:07, 19 May 2016 (UTC)
 * I think that might be a little backwards. Cats really want to go outdoors.  If you keep them indoors long enough, they sometimes forget there's such a thing as the outdoors, but they'll mourn heartbreakingly for a while until that happens.  I wouldn't want to be kept prisoner just because I'm safer that way &mdash; why would I expect my cat to?
 * Letting a cat out is hard on the owners, though, when the cat doesn't come back at the time expected. If you have an indoor/outdoor cat, expect to have to worry sometimes. --Trovatore (talk) 02:45, 19 May 2016 (UTC)
 * In my experience, cats who have spent time outdoors want to be outdoors, and they'll pester you to let them out. Cats who have spent their entire lives indoors don't. They are not interested in the outdoors except to observe it through the windows. ←Baseball Bugs What's up, Doc? carrots→ 09:31, 19 May 2016 (UTC)


 * There are compromises between inside and outdoors cats. You can have a fenced-in yard, and a cat door, so they can escape into the house if anything attacks.  Being neutered keeps them from wandering quite so much.  You can also sit in the yard with them, as they explore.  Or, for the most paranoid, keep them inside, just open the window, but keep the screen in, so they get a good sniff.  That does wonders for their mood with very little danger. StuRat (talk) 02:27, 19 May 2016 (UTC)


 * That's pretty funny Nunh-huh. My cats are happy outside and acclimatise to new things, such as moving house, within days. Obviously you have very special cats. Greglocock (talk) 02:38, 19 May 2016 (UTC)
 * Yes, well I guess you have genius cats and mine are a bit slow. Their inability to adjust to change may or may not be related. - Nunh-huh 04:17, 19 May 2016 (UTC)


 * As for how long it takes to adjust, it depends on the personality of the cat. I've had them take over a year to do so.  Expect them to spend most of their time hiding until then.  They might become comfortable with one person but not the rest of the family, first.   I'd avoid letting them out then, as they might "go home" to their old house. StuRat (talk) 02:33, 19 May 2016 (UTC)


 * Guys, cats are dumb animals and they're not all the same. I'm saying that as a cat person.  My cat back home thought that the house was "outside," and thought that outside was Unknown Kadath.  The one time I brought her outside (for all of five seconds at night), she buried herself to my chest nervously for the first three seconds, and upon seeing a tree taller than our house, clawed over my shoulder (only time she ever did that) to run back into the house.  Once inside, she bolted to the end of the house furthest from the door and hid, coming out an hour later still shaky with a puffy tail and back hair.  The few times she tried to explore outside before that, she saw the bright South Carolina sunlight and decided "screw that, I'll just sleep in Ian's lap for another hour."
 * That said, yes, cats were bred to live outdoors and get all sorts of endorphins killing local wildlife (they're hunters, deal with it). The difference, from the cat's perspective, is pretty much "would you rather spend your nights carousing with friends or staying home and planning a responsible diet?"  The difference for the owners is really "do I want to put more work into their emotional well being or their physical well being?"  Emotional?  Indoor.  Physical?  Outdoor.  No work?  Don't get a pet.
 * As for OP's question, nine months old is basically a teenager. Yeah, sure, their entire world has been replaced, but they're still at an age to get used to it.  Heck, my cat (14 years old, pushing 15) completely adjusted to my granddad's house after about a week.  Ian.thomson (talk) 05:11, 19 May 2016 (UTC)


 * I react the same way when forced outside (except for sleeping in Ian's lap, that is). StuRat (talk) 05:28, 19 May 2016 (UTC)


 * Best you provide food at an specific time and place each day and not to much. After a few weeks your cat will tune in and unpaiciently expect to be fed in sense of comming to and walking around you at that time. I guess then you are pretty save your cat has accepted his/her new home. --Kharon (talk) 06:43, 19 May 2016 (UTC)


 * Most cats don't seem to overeat, especially if given dry food. (If I had to eat that, I wouldn't overeat either.)StuRat (talk) 15:52, 19 May 2016 (UTC)


 * My last six cats quickly made themselves at home, at ages ranging from three months to eight years. (The youngest was a bit feral and took a week or so, iirc.)  The present pair are my first indoor-only cats; once in a while (including today, as it happens) they get out but quickly return when they find the Big Room to be chilly and strange. —Tamfang (talk) 09:28, 19 May 2016 (UTC


 * There is some advice on the subject here. Perhaps respondents to this thread should read this discussion about the pros and cons of the indoor/outdoor lifestyle and the difference in attitude in the UK and US or Australia. Richerman    (talk) 09:37, 19 May 2016 (UTC)


 * Agree with Richerman. Here in the UK we usually advise to keep them in for a period of time - maybe 6 weeks - until the cat is used to their new surroundings and to you as well. Then maybe let the cat out. Make sure the cat is microchipped - and if she already is, update the details on the chip record. Your vet will be able to do this for you. --TammyMoet (talk) 12:20, 19 May 2016 (UTC)


 * A cat's instinctive priority is to remain close to a 'reliable' food source. That is how cats domesticated man. When our forbears became farmers and stored cereal grain that attracted rodents -the cats moved in and have been with us ever since. Three weeks should be more than sufficient to establish the notion that you are providing  such a reliable food source. Then, during the times when one is at home, leave the doors open. By then it will have become accustomed to your voice calling it for meals  (I take it that you call its name when your ready to feed it). Once cat is back inside again one  can close the doors. If you do not want to fit a cat-flap  make sure there is a way for the cat to get on to a window ledge  or someway that it can look through a window  and attract you attention when it wants to be let in again. Foxes are on the increase in many parts of Britain so whether or not you fit a cat flap,  look around to see if the cat has somewhere to climb to. If the house cat become secure in the feeling that it always has a safe refuge there is no reason why it should suffer acrophobia. Let the cat expand its horizons naturally.  Also, a cats natural diet and metabolism requires meat protean. Not this modern pet food stuff that contains more than 50% vegetable protean with added vitamins. Per 100 grams it is cheaper to go to the supermarkets and buy a cheap frozen  bulk bags of  coley  and beef mince (and don't forget kitchen scraps). The cat will appreciate it more and it will keep him healthier. Cat don't like very cold food though. So, deforest to room temperature and pussy will come back for more. At nine month old it will naturally start to forage due to instincts. It may soon be bring home the odd rat, half as big as himself and dump it on the kitchen door step. Praise such an instance. It is his way of showing that he is now able to contribute to the family that feeds him. As I said, cat domesticated man. So for a happy symbiotic relationship – don't use brain- allow the cat to guide you as to how to satisfy its needs and desires. It really is that simple when it comes to caring for cats.--Aspro (talk) 14:11, 19 May 2016 (UTC)


 * Re: "deforest to room temperature", won't this deforestation deny them the trees they need for emergency escapes ? :-) StuRat (talk) 15:56, 19 May 2016 (UTC)


 * Nice to no, that that you have tooken the bother two reed wot eye have rote :¬)--Aspro (talk) 12:57, 20 May 2016 (UTC)


 * It's very rare for urban foxes to kill cats - they mostly ignore each other and, although they do occasionally fight, the fox often comes off worst. Cats do not have any other predators in the UK (and no, there are no coyotes).  Richerman    (talk) 17:01, 19 May 2016 (UTC)


 * True, but I have witnessed cats spooked by the presence of foxes and they avoid confrontation. That is probable why the statistics show  that “fox attacks on cats are exceptionally rare”. I would also agree with your source written by Dr Pete Wedderburn BVM&S CertVR MRCVS that “Foxes are generally shy creatures that do their best to avoid contact with humans” but  round my way they aren’t. This File:The_thirsty_fox.jpg is a photo of one of the  foxes  that drinks at my local pub. Give him a few years and I wouldn’t be surprised to find him  standing beside me at the bar winking at all the barmaids.  Just because someone has letters after his name  doesn’t mean his utterances are to be taken as dependable guidance (after all he is a vet) – as it is promoting the fallacy argumentum ad verecundiam . One's cat 'needs'  some where to take refuge and avoid confrontation.--Aspro (talk) 12:57, 20 May 2016 (UTC)
 * @Aspro, why is the fox anonomised in your photo - did he refuse to sign the model's waiver rights release form? ;-) DrChrissy (talk) 16:47, 20 May 2016 (UTC)
 * As I am using the photo for editorial purposes only, I didn't think I needed the fox to sign  a model release form. I might run the idea past him next time we meet, as I am sure he'll except a fee of yesterdays left-over Kentucky fried chicken wings. Here's hoping.--Aspro (talk) 20:10, 20 May 2016 (UTC)


 * There are cars, which run over animals all the time. Also, outdoors cats are more likely to be attacked by fleas and diseases. If the OP doesn't care what happens to his cat, then so be it. ←Baseball Bugs What's up, Doc? carrots→ 19:04, 19 May 2016 (UTC)


 * Don't forget dogs, and other cats, as in the case of intact males fighting. StuRat (talk) 03:43, 20 May 2016 (UTC)


 * Bugs, you do your reputation and argument no good by continually bickering from a point of obvious ignorance and lack of experience. Many (if not almost all) cats in the UK wear 'flea collars' to avoid infestation and cats are more likely to get fleas from other cats and not the outdoors per se. It is very rare to see or hear of a cat killed by a vehicle in the UK, other animals, predominantly in rural areas, are killed more frequently but that is irrelevant to this argument. I am unclear what you mean by "other diseases". Your final sentence with its inflammatory emotional claim is crude and unhelpful. Richard Avery (talk) 06:41, 20 May 2016 (UTC)

I have worked in the veterinary profession for 20+ years, I lecture vet students on animal behaviour, and I am a cat owner living in rural UK (North Somerset, so plenty of dangerous foxes and badgers and drop bears). I believe the main concern about moving a cat to a new area and letting it out, is injuries caused by other cats. Cats have a great way of time-sharing their territories. They can determine how long it is since a previous cat was in the territory by sniffing the pheromones in each others urine. They avoid visiting the place too soon after another cat has been there, and so generally do not meet. However, if they do meet, they may fight. Cats are extremely dangerous when riled (they have 5 sets of weapons whereas dogs have only 1). The most likely wound that your cat might experience is a cat bite abscess. These usually occur on the cat's cheeks or the flank. Inspecting your cat or noting any tenderness when stroked will reveal an abscess early in development and you must seek veterinary advice immediately for antibiotics, otherwise this can become deeply infected and very expensive! Regarding the time taken to let the cat outdoors, this will depend a lot on his experience. If the cat is used to change and stimulation, he will be rather plastic (flexible) in his behaviour and will quickly adapt to his new environment; if he has had a less stimulating history it may be more fearful and unwilling to go out. In your favour is that he is still young and therefore naturally more inquisitive. Get a cat flap -- and give the cat the choice about inddors or outdoors. Don't let him out for the first 2 weeks, but establish where he gets his food. Then, take the plunge and open the cat flap. By the way, I have a male neutered cat who eats only dry food and is now so fat he can't get out the cat flap! - Very handy! Best of luck. DrChrissy (talk) 16:41, 20 May 2016 (UTC)


 * Wholeheartedly agree. The OP's garden may already be the territory of another cat. Yet,  as the OP lives in a fairly quiet part of the countryside- the pressure to defend  territorial rights  may  not be that great. The other cat will sense that this new guy in town has a domicile and it owners will soon appear  if they  start hissing at the new kid on the block and will  slowly back off – alothough perhaps, only after spraying urine over the poor little feller first (I make that six sets of offensive weapons).--Aspro (talk) 20:16, 20 May 2016 (UTC)


 * In that case, why don't you restrict his food supply and/or use diet food ? StuRat (talk) 16:48, 20 May 2016 (UTC)


 * Believe me, I have tried the food restriction. It is my own poor behaviour as a pet owner, I accept this, but having a cat which meows constantly for food and scratches at the kitchen door to get to his bowl quickly becomes totally intolerable.  I have weighed up the ethics and consequences of having an overweight cat and my own mental health, and in this case, my life comes first.  I could try diet food, but these are expensive.  I also have a second cat who eats normally, and I suspect my male would simply steal hers if he felt unsated. DrChrissy (talk) 17:05, 20 May 2016 (UTC)
 * By the way, I think I should explain that I think of animal welfare in terms of "feelings". It is the feelings of the animal that matter.  My overweight cat does not know that his life is shortened by being overweight or that there is a higher risk of him becoming diabetic, so there is no animal welfare problem (although his "well-being" is sub-optimal).  This can also be applied to the OP's question, some of the responses, and my suggestion to have a cat flap.  If the OP's cat decides never to go out, I would argue that there is no welfare problem whatsoever, irrespective of the cat's domestication, breeding, hunting tendencies.  Animals show us what they want and what they do not want.  Allowing them to do this is (usually) the best way to maximise their welfare (again distinct from "well-being"). DrChrissy (talk) 17:39, 20 May 2016 (UTC)


 * The modern phenomena of morbid cat obesity is down to modern cat foods (got no references off -hand but just telling you in the nicest possible way) which contain cheap vegetable protein and often sugars . In other words, it is the waste from the food processing industry that is not fit for human consumption. I have no objection to the animal protein that is derived from waste which is not fit for human consumption because it is good for cats but I do object to vegetable and sugary stuff. Association is no proof of causation but the life expectancy of cats is decreasing and their health problems are  increasing following the increasing popularity of modern cat foods. As you may well know and appreciate, cats thrive best on live caught prey complete with 'animal derived roughage' fur, bone, feathers and guts etc.  Grant you, those  little plastic tags around the leg of a racing pigeon and so on, may not have any nutritional value but we don't live in a perfect world.   Second best,  is to hunt around on supermarkets bargain shelves for out-of-date mince, fish fingers,  etc. If one has a large chest freezer, get a friend with a wholesalers-card (they may run a restaurant or café or something) to take you along there. Feed this  to him raw. Never even thought of doing  a proper double blind test but try offering two bowls. One with cooked meat and one with raw. See which he goes for first – you can guess what I wager on the outcome. And don't forget kitchen scraps. Cats like bones, grizzle and all other sorts of things that their instincts tell them to chew upon. But they will only eat as much vegetable as takes their fancy and leave the rest. With modern pet food they have no choice but to eat the whole unhealthy  homogeneous offering which costs more that providing a proper diet. The cat ends up having to eat more to satisfy its biological (meta-biological?) need  for animal protein; and so becomes obese due to the vegetable and sugar content... Mind you, one might not want to mussel too up close to moggie during the weight loss processes do to ketosis which will give him very bad breath. --Aspro (talk) 20:21, 20 May 2016 (UTC)


 * If you put a pill in the cat's wet food, he will eat all the food except the pill, licked clean of gravy. :-) StuRat (talk) 02:00, 21 May 2016 (UTC)