Wikipedia:Reference desk/Archives/Miscellaneous/2011 November 26

Welcome to the Wikipedia Miscellaneous Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

November 26

Ice maker

So my wife really likes the kind of ice "balls" you get at restaurants like Sonic. It is basically little, round, pebble-sized ice balls. It there a home version of this. All I can find is "restaurant grade" equipment and they are all very expensive (like, thousands of dollars). I'm thinking of a Christmas present version of this. Quinn ^{✩ STARRY NIGHT} 03:34, 26 November 2011 (UTC)

This is the only thing I could find after 10 minutes of google searches for under $1000. It offers multiple sized ice cubes; but I have no idea if their smallest setting would work for you. Nothing else I find is of the "christmas present" price range (assuming you belong to the 99% and not the 1%). --Jayron32 03:43, 26 November 2011 (UTC)

this list has 3-4 in the sub thousand dollar price range. No idea if any meet your needs. --Jayron32 03:47, 26 November 2011 (UTC)

Thanks, most of that is what I have seen, but some not. I can't justify an Xmas present at more that $1k for an item like this, so your info was very helpful! Quinn ^{✩ STARRY NIGHT} 04:01, 26 November 2011 (UTC)

I have a cheaper idea: Use an egg tray instead of an ice-cube tray in the freezer, to form hemispheres, then add a bit of water on top of half and place the other half on top, and freeze the two halves together. Here's a tray: [1]. To make them a bit smaller and freeze the two halves together even better, melt them down a bit after in cups of cold water (don't put more than one sphere in a cup, or they may freeze together). This will fill in any gaps between the pieces with ice. (Any water which gets between the ice chunks will freeze due to the ice being below freezing temp.) StuRat (talk) 16:17, 26 November 2011 (UTC)

I'm inclined to think that any ice chunks that get water between them will melt, due to water being above freezing temp - but I don't really know.  Card Zero  (talk) 19:36, 26 November 2011 (UTC)

Nope. Ice straight out of the freezer is well below freezing, and the cold water I specified should be only a few degrees above freezing. It also takes lots of energy to melt ice even if it was right at freezing. Combine this with only a thin film of water between the two ice hemispheres, and it would quickly freeze. Haven't you ever had ice cubes freeze together in your drink ? StuRat (talk) 03:37, 27 November 2011 (UTC)

In any event, eggs are the wrong size. Sonic ice looks like this. --Mr.98 (talk) 19:43, 26 November 2011 (UTC)

What about just getting a mold, like this or this or this or this? (The latter seems pretty nice to me — the reviews say they are really small, so small that the reviewers rated them negatively!) They're not all perfectly round but they're pretty close to the same size. The relevant search term seems to be "mini cube" if you want things that make very tiny ice cubes, I have now learned. I think the technical term for the Sonic ice is "nugget ice", but true nugget ice machines seem to only be produced for thousands of dollars, apparently because they use a fairly complicated process to make the ice. --Mr.98 (talk) 19:43, 26 November 2011 (UTC)

I don't know if the product is available in the US, or even under what name to google it, but in Germany we have foil bags for making (semi-round) ice balls. You fill them with water, and put them in the freezer. See [2]. --Stephan Schulz (talk) 20:17, 26 November 2011 (UTC)

If hundreds of little ice pebbles are needed per drink, like in your picture, then moulds can't be the solution. When you're in need of a cocktail, removing just two or three ice cubes from a mould is arduous enough, I find.  Card Zero  (talk) 21:57, 26 November 2011 (UTC)

The image seems to show crushed ice. You can make that with an ice crusher (*surprise* ;-), or with a double plastic bag and a hammer. But that won't give you nice balls. --Stephan Schulz (talk) 22:19, 26 November 2011 (UTC)

Apparently most Sonics will sell bags of ice. That's probably the best solution for getting the ice. But it doesn't really work as a Christmas present. --JGGardiner (talk) 19:59, 26 November 2011 (UTC)

Sustainable Cannibalism

Could a species sustain itself indefinitely through being cannibals? E.g. say there were 100 rabbits and (ignoring other factors like nutrition etc) all they had to eat was themselves, could they sustain themselves long enough to have offspring and then that offspring to cannibalise their former generation/some of themselves? I assume that basically it's a non-starter as the total energy levels start with whatever the energy of 100 rabbits is and reduce each time (and that each new rabbit costs more energy to raise than it gives back in food/gets back in food). Terrible question I know but was watching a documentary with Polar Bears apparently sometimes eating the little ones if they get hungry enough. ny156uk (talk) 09:48, 26 November 2011 (UTC)

You are correct, the lack of energy input into the ecosystem would cause it to fail. Plenty of animals have been known to eat their young in difficult times, though. If there isn't enough food, the young aren't going to survive anyway so the parents eat them to maximise their chances of surviving until better times when they can have more young. --Tango (talk) 14:57, 26 November 2011 (UTC)

We have a sections of articles on the subject: Infanticide (zoology)#Infanticide by parents and caregivers and Cannibalism (zoology)#Filial Cannibalism. --Tango (talk) 15:05, 26 November 2011 (UTC)

Agreed that it's not sustainable, but a species could survive an amazingly long time period through cannibalism. Let's take humans as an example. If we each ate another person, that ought to provide food for around 6 months. This assumes that each body can be frozen, or each body shared among many people so they don't rot, and there would be nutritional deficiencies from an all meat diet, so you'd have to assume vitamin pills are available. But, at the end of 6 months, you'd have half as many people. If you continued this practice you'd have 1/4 as many people at the end of one year, 1/16th as many after 2 years, etc. After 16 years you'd have 1/4294967296 of the original population, or about 2 people left. Then it's time to decide if you want to repopulate the planet or get out the butcher block one last time. :-) StuRat (talk) 15:54, 26 November 2011 (UTC)

That decision rests on whether there's a she and she's a pretty she. Cuddlyable3 (talk) 23:23, 26 November 2011 (UTC)

I wouldn't call 16 years an amazingly long time - that's less than one generation. I also think you would be lucky to get 6 months of food from one person. You could probably do it by rationing yourself and only eating, say, 1500kcal a day (which is low, but probably survivable). However, if you did that then after a couple of years the people you are eating have been on a very calorie poor diet for a couple of years, so they're going to be very underweight and you won't get 6 months of food out of them however well you ration it. --Tango (talk) 19:14, 26 November 2011 (UTC)

You could stretch it much further if you decide on your target population, and butcher and freeze the remainder in advance. If you only need one breeding pair, you could probably keep them alive until the sun became a red giant. Of course, some of the remainder might object. --Stephan Schulz (talk) 20:42, 26 November 2011 (UTC)

Something that no one has mentioned yet, is that high rates of cannibalism could also promote the development and spread of a prion disease similar to Kuru.--Aspro (talk) 19:27, 26 November 2011 (UTC)

The OP began with rabbits eating themselves. Given that rabbits are herbivores, we are already in hypothetical territory. If we had a carnivore (say, these already odd rabbits) which could also photosynthesise like plants, they could use sunshine as an extra energy source. Maybe cannibalism would work then. HiLo48 (talk) 20:51, 26 November 2011 (UTC)

Oh, but rabbits do sometimes eat their own (usually stillborn) young. I probably ought to cite something ... the information is probably somewhere in rabbit it's in Infanticide_(zoology).  Card Zero  (talk) 21:31, 26 November 2011 (UTC)

When you run out of food, you always start by eating a person - that is, yourself. You start metabolizing your own fat and muscle cells (with the balance normally skewed heavily in favor of burning fat). Assuming that you're moderately overweight (as most Westerners are) and you have enough drinking water, you can last about 6 months without any food whatsoever before you die. --Itinerant1 (talk) 01:24, 27 November 2011 (UTC)

This would have been better placed at the Science Refdesk. In general, warm-blooded animals need much more food than cold-blooded animals (I've heard the figure ten times as much, though I'm not sure how meaningful such a general number can be). As a result, sustainable cannibalism is far more plausible in cold-blooded animals. Frogs are especially well known for this - adults can feed on tadpoles, or larger tadpoles can feed on the smaller, with various arrangements ([3]) I remember that The Legacy of Heorot cited some example of a species whose adults actually relied on larvae as their food source, but I don't think I ever tracked down whether it was true or not. Wnt (talk) 01:35, 27 November 2011 (UTC)

Spiders are arguably the most notorious for this. Sexual cannibalism (killing of males by females after fertilization) and matricide (the killing and eating of the mother by her offspring).-- Obsidi♠n Soul 02:20, 27 November 2011 (UTC)

Digestive processes are fairly efficient in all. But cold-blooded animals waste less energy on basal metabolism (as a human, you need to consume 0.5% of your body mass in carbohydrates per day just lying in bed, without gaining mass or engaging in any activities, a lot of that energy spent effectively on heating the room). In addition, in adult animals, the efficiency of conversion of plant matter into body mass is near zero, because they only eat as much as needed to sustain themselves.

Therefore, an ideal target for sustainable cannibalism is a cold-blooded, young, rapidly growing animal. Such as a young fish or a tadpole.

The same also applies to meat-eating in general. For human consumption, there's an additional requirement that the victim should be reasonably large (larger than, say, 1 kg), so that rules out all insects, and most reptiles. But we've learned to do quite well with certain warm-blooded animals. Broiler chickens weigh less than 50 g when they are born, they go from 50 g to 5 kg in about ten weeks, and then, while they are still growing, they are slaughtered for meat. Newborn pigs weigh 500 g, they rapidly and steadily gain weight, and, by the time they are slaughtered (six to ten months from birth, which would be, I think, somewhere between 8 and 14 in human years), they top 100 kg. Both chickens and pigs have feed conversion rates less than 4:1 (more than 1 kg of weight gain per 4 kg of feed). One other common animal below 4:1 is a domestic rabbit.--Itinerant1 (talk) 03:20, 27 November 2011 (UTC)

Note that a small segment of a species (say 1%) could survive exclusively by cannibalism, provided they feed on other members of the species, which have other food sources. This would possibly result in the species evolving into two. StuRat (talk) 14:13, 27 November 2011 (UTC)

Morlock and Eloi. Collect (talk) 15:09, 27 November 2011 (UTC)

According to our article Cannibalism in pre-Columbian America, some scholars believe (controversially) that for premodern Mesoamerican elites cannibalism was an important dietary element. Marco polo (talk) 17:10, 27 November 2011 (UTC)

I seem to recall this being an element in New Guinea as well. Jared Diamond tosses out a suggestion in GGS about the paucity of protein sources in New Guinea correlating with cannibalism as a regular practice, I believe. --Mr.98 (talk) 00:20, 28 November 2011 (UTC)

In my 1960s childhood, it was confidently predicted that the Earth's population would soon outgrow its food supply. One result of all that angst was a 1973 sci-fi film called Soylent Green; set in 2022 (not long to go!), people are killed off and turned into a protein supplement to feed the masses. Alansplodge (talk) 09:13, 28 November 2011 (UTC)

facebook related question

So, I have been reccomended getting an account on facebook, but the problem is that my social life at the moment is a little complicated and awkward, I am wondering, would I be right in thinking that if I had an account everyone that I knew could find it, and then find each other through that? Also, I would not be allowed two, would I, to keep different aspects of my private life separate from each other?

148.197.80.214 (talk) 21:40, 26 November 2011 (UTC)

According to the Facebook rules, you're not supposed to have two accounts (section 4.2 of their TOS). Though I know at least 5 people who do. Dismas|^(talk) 21:46, 26 November 2011 (UTC)

(after e/c) :I don't know what FB's rules say, except that you are supposed to be at least 13 to have an account. I do know of individuals who have accounts not in their real names and who have more than one account (each in a different name, though I think none of this is actually permitted). Your name can be found, perhaps: I have certainly searched for names I knew were being used, but to no avail. If it is found, others can only read what parts you make public. (Note that "public" is the default, though.) You don't have to permit anyone access, and you can remove people from your friends' list at will. You can also create groups of people that only receive (or see) certain messages. Bielle (talk) 21:51, 26 November 2011 (UTC)

So, if I didn't want for example one group of friends/colleagues to know about another group, I could keep them apart and up to date on two different sets of information without them knowing I was doing so? What about this rumour I have heard that the site randomly sends people information about friends of friends in case they are interested in each other? 148.197.80.214 (talk) 22:12, 26 November 2011 (UTC)

If the two personas you are using have friends, or friends of friends, in common, then you will get suggestions that you might like to add these common friends to your list of friends. These common friends will likely also get suggestions about adding you. You don't have to do anything about this, and you can ignore requests from them to be added to your list. What you can't do is keep one account entirely secret from the other if they have anyone in common. They will know the other account exists, but not whose it is (unless you are using your own name on one of them). I wouldn't count on them remaining secret, though Bielle (talk) 22:22, 26 November 2011 (UTC)

(edit conflict with Bielle) For the first question, there is a way to prevent a list of your friends from being displayed on your profile [4]. However, there may still be ways for inquisitive people to discover who your friends are - according to that blog post, Facebook considers friend lists "public information". So if you're friends with boyfriend A, boyfriend B may be able to see that somehow, even if you hide your friend list.

An additional problem is your wall. You can set who can see your wall (basically either "everyone" or "my friends", or "only me"), but you can't set it so only selective sets of your friends can see a given post. So you could set it so only you can see stuff posted on your wall, which would work fine, but most people don't really use Facebook that way (they prefer to be able to snoop at what other people are having posted). But if you set your wall to "friends only" (or worse, "everyone"), then when boyfriend A posts saying "I love you", boyfriend B (and all of your other friends) can see that.

It is indeed against the rules to have multiple accounts, but if you aren't using them maliciously, you are unlikely to get caught. If some people know about both of your accounts, though, it may be hard to keep the existence of one secret from people. If you do want to get on Facebook, this is probably the best way to go.

Finally, remember that no matter how hard you try to keep things private, Facebook is ultimately geared towards getting your information out there. Facebook is not your friend. Facebook is trying to make money off of you. They do this by offering a free service that encourages you to give them, and others, your information. Privacy settings seem to change every year or so when Facebook rolls out a new design, and default settings are often changed towards less privacy. Facebook makes money by advertising, and they can make more money if advertisers know more about you. user:Nimur has made a number of good posts on the subject. Take a look at some of the articles he linked to on his talk page last August. Buddy431 (talk) 22:26, 26 November 2011 (UTC)

That isn't really true, you can, on a post by post basis, select which of your friends can see your wall post when posting. Facebook has had this feature since a while (I think 2008 or 2009 from something I read recently, I was using it in late 2010 when I briefly started using FB regularly for a while) but they've recently changed so it's even clearer, generally suggested to be partially in response to Google+. More significantly, they've now enabled you to modify the privacy settings after posting (before once you posted it was stuck at that setting which you could view but not modify) although this may not help you if the person has already seen the post or set something up to record your posts automatically. Also it isn't true you can only set those 3 options. For starters there is a 'friends of friends' option. Also, you can select specific friends or you can make lists of friends and then choose a whole list. In addition, you can hide posts from people, so you can do all my friends; except these people (or this list of people).

There are still risks of course. You could screw up. And there's obviously nothing stopping someone else allowing others to see your post either directly or by reposting or mentioning it. (However if they simply comment on it, people should not see any sign they've done so unless they can see the post.)

In the same vein, remember you have no control over the privacy settings of others. If you post 'I love you' to boyfriend B's wall and boyfriend B allows everyone to see their wall, obviously this means your girlfriend G will be able to see that you did so. And this will appear as an update on your wall, although you can delete that. It's true you can't hide updates except by hiding your wall to that person, if you really wanted to you could temporarily change the privacy settings of your wall, make the post, and delete the update on your wall and change back. But this seems a false sense of security to me, since the problem remains your post on the other person's wall depends on their privacy settings not yours. And even if it's currently not visible to the person you don't want to see it, remember this could change e.g. girlfriend G could become friends with boyfriend B, boyfriend B may relax the privacy settings accidentally or on purpose etc. Note that one thing you can do is type @ and then type and choose the person from the friends list that appears. This means the post will show up on the person's wall but isn't actually a post to their wall, so the privacy settings remain dependent on your privacy settings for that post (although again bear in mind the risk of the person sharing etc).

Nil Einne (talk) 06:32, 27 November 2011 (UTC)

I just saw a commercial for Google+, Google's new social networking service, which seemed to promote the idea that you can divide your contacts into multiple groups and share different types of information with each of them. Maybe that's up your alley. -- Mwalcoff (talk) 00:23, 27 November 2011 (UTC)

If you create a FB account, people you add as friends will see any messages you post, names of your other friends, and any public comments from your other friends. You can configure your account to prevent the rest of the world from seeing anything except your name and your profile photo.--Itinerant1 (talk) 01:18, 27 November 2011 (UTC)

Not Logged In - Along with everything that Nil Einne said above, make sure you never add anyone to both groups, and set all your sharing settings never broader than "Friends". Do not allow any Facebook App to access your account, do not allow Facebook access to your email(find friends quickly or some such honeypot). Set your browser to clear all cookies at the end of each session, do not switch between Facebook accounts without clearing your cookies. — Preceding unsigned comment added by 71.212.96.247 (talk) 03:59, 28 November 2011 (UTC)

One thing I forgot to make clear, the ability to select by friends and list of friends, and exclude friends applies to most Facebook privacy settings. Perhaps not so relevant to the OP but if you want to add friends you don't really trust, you may want to consider making a private list and adding all of them to it, then excluding the list from the parts of your profile you wish to keep private, and probably from your wall posts by default. BTW, one of the big privacy concerns from Facebook tends to be with apps. Nil Einne (talk) 20:15, 28 November 2011 (UTC)

Or as I do with my emails, have the two accounts on separate computers. I think, though, I will just stick with the one main account, the other stuff I didn't want to be too public doesn't really need to be linked to that particular site, when there are plenty others around. 148.197.81.179 (talk) 09:15, 28 November 2011 (UTC)