Wikipedia:Reference desk/Archives/Miscellaneous/2007 December 6

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December 6

Eyesight affect photos

Suppose if one is nearsighted and takes photos using a DSLR, or any camera for instance, would the focus of the camera be different than if the person had correct vision? As a result, will the resulting photo be not properly focused? Acceptable (talk) 00:15, 6 December 2007 (UTC)

Most camera viewfinders have a mechanism to adjust for people who are nearsighted so they can see the image clearly without their glasses. If a nearsighted person uses the LCD screen rather than the viewfinder, and their vision is corrected (either by contact lenses or eyeglasses) then the image will be in focus and therefore the photographer will be able to adjust the camera focus just as well as someone with normal vision. In actual practice, many cameras have a system to automatically focus the lens in most situations, so they don't require the photographer to judge focus at all before taking the picture.Thomprod (talk) 02:30, 6 December 2007 (UTC)

Do expect some trouble shooting while wearing glasses though. --antilived^{T | C | G} 09:15, 6 December 2007 (UTC)

With an SLR camera, whether analog or digital, when you look in the viewfinder you're not looking directly at the scene you're shooting; you're looking at a focusing screen inside the camera. See the diagram at that link. It's only a short distance from your eye, but the viewfinder includes its own lens to enable you to focus that close while your eye muscles are set to focus on infinity. The camera is in focus when the image on the focusing screen is in focus; your vision only affects how well your eye can focus on the focusing screen, and that's completely independent.

In other words, with good vision or proper glasses, and the camera correctly set, you see a focused image of a focused image. If the camera is set wrong, you see a focused image of an unfocused image. If your vision is poor but the camera is set correctly, you see an unfocused image of a focused image.

Since I wear fairly strong glasses for myopia, I was able to verify this by taking my glasses off, then setting my SLR for manual focus and pointing it at an object a few feet away. I adjusted the focus control until the fuzziness of the image I saw was minimized -- I was then seeing an unfocused image (no glasses) of a focused image (camera correctly set), and sure enough, when I put my glasses back on, the image was almost perfectly sharp. (The reason it was "almost" was without being able to reduce the fuzziness to zero, it was hard to tell the degree of it with sufficient accuracy.)

Similar considerations apply if the camera uses an LCD screen viewfinder display. The image on the LCD screen will be in focus if the camera is, and your vision only affects how well you can tell if it is.

For the older type of camera with a separate viewfinder, I'm not sure how your vision affects it.

--Anonymous, 02:15 UTC, December 7, 2007.

So, to summarize, I have perfect vision up close, should I be concerned with the focus of my DSLR (without live preview)? Acceptable (talk) 00:57, 8 December 2007 (UTC)

My Nikon D50 allows adjustment from +3.0 (far sighted) to -1.0 (near sighted), so if you're not that myopic you can see the image in crystal clear quality, without the need for glasses. You shouldn't be worried about focus per se, as it will autofocus whether or not you see it clearly, it's just that if you're too myopic for the correction and don't have glasses, you can't see the image and the data below it (shutter speed, aperture etc.) clearly. It would have no effect on your photos, unless you've autofocused on a wrong part of the frame and couldn't check because you can't really see it. --antilived^{T | C | G} 22:36, 8 December 2007 (UTC)

Roland Micro Cube or Line 6 Spider III 15?

Which is an all around better amp? MalwareSmarts (talk) 01:53, 6 December 2007 (UTC)

It's not really a question the ref desk can do much to answer. Presumably you've read about the features they offer, right? You could try reading product reviews, too. Or better yet, play around with them both at your local music store and figure out which you prefer. They've probably both got more bells and whistles than you'll ever use. Does one or the other have particular bells and whistles that appeal to you? Friday (talk) 01:59, 6 December 2007 (UTC)

Roland is better, as line 6 can be hard to use, what with all its added extra effects. But better still is marshall, but the untimate, mmm, is a Mesa Boogie. Excuse me while I drool. —Preceding unsigned comment added by 12.191.136.3 (talk) 13:24, 6 December 2007 (UTC)

Plate

I have a plate with three compartments, I think it's pewter. Stamped on the back is the word's MAYFLOWER GOMHAM, then an anchor and a boat like a clipper ship, then it says E P silver soldered, then the number 012591. I'd like to know what it is and if it's worth anything. Any help will be greatly appreciated.. Thank You CGreenberg001 (talk) 02:38, 6 December 2007 (UTC)CGreenberg001

EP probably means 'electroplated'. The word "Gomham" doesn't occur anywhere in Wikipedias' 2.1 million articles and gets almost zero Google hits (just a few people's surnames and misspellings of "Gotham") - are you 100% sure that's how it's spelled? SteveBaker (talk) 05:04, 6 December 2007 (UTC)

OK - I searched for just 'Mayflower Pewter' - it seems that there is or was a company that made Pewter called "MAYFLOWER". This sounds EXACTLY like your piece: [1] If so, you can buy one new for $45. Here is an example of some of their work on eBay [2] and here [3] is some Mayflower pewter on sale at a British antique store. This stuff doesn't seem to be too valuable - Mayflower pewter items on eBay are selling for just a few bucks - and even in the fancy-schmancy antique store, you can pick up a three-piece collection for 40 pounds. SteveBaker (talk) 05:37, 6 December 2007 (UTC)

I am reasonably certain that Gomham is actually Gorham Manufacturing Company. Take a look at the marks found here [4]. The clipper ship may represent the year 1926. See Gorham date codes here [5]. The 012591 is probably and individual item number. --Seuss (talk) 06:35, 6 December 2007 (UTC)

"EP" = English pewter. DuncanHill (talk) 13:30, 6 December 2007 (UTC)

The Pewter Society offer a free identification service at their website here [6]. As they seem to know more about pewter than might reasonably be expected, I suggest trying that. DuncanHill (talk) 00:24, 7 December 2007 (UTC)

counter intuitive

may you please give the definition for counter intuitive?202.88.234.90 (talk) 08:11, 6 December 2007 (UTC)

Counter-intuitive Rockpocket 08:22, 6 December 2007 (UTC)

work and leisure

will you please give the definition for work and leisure?202.88.234.90 (talk) 08:12, 6 December 2007 (UTC)

Work and leisure. Rockpocket 08:23, 6 December 2007 (UTC)

lol Acceptable (talk) 00:56, 8 December 2007 (UTC)

change

what are the driving forces of change?why are they useful if that is the case?202.88.234.90 (talk) 08:18, 6 December 2007 (UTC)

In what context? Depending on what you are interested in changing, the forces driving it could be very different. See here for some sources for the forces driving change in nature. Rockpocket 08:26, 6 December 2007 (UTC)

Changes are often made just for the sake of change; certainly true of governments or managers just wanting to justify their existence.--88.111.25.42 (talk) 08:40, 6 December 2007 (UTC)

The use of change is that it shakes things up. People have to consider the reasons for things instead of simply accepting their existence. Change is usually accompanied by entropy and chaos. Steewi (talk) 10:45, 6 December 2007 (UTC)

Of course, another driving force of change is large denominations of currency. Steewi (talk) 10:46, 6 December 2007 (UTC)

Necessity is the mother of invention? Dismas|^(talk) 11:26, 6 December 2007 (UTC)

I thought that was Frank Zappa. -- JackofOz (talk) 07:37, 7 December 2007 (UTC)

Human beings have an almost unique relationship to the phenomenon of change. All species have the potential to adapt to changing environmental factors (such as a change in climate or a change in pH levels in the water, etc.) - some to a greater degree than others. But human beings seem to specialize in not only adapting to changing environmental factors, but to actually be the initiators of change themselves. This was theoretically first done when early hominids picked up a rock to use as a tool to break into a large bone to get at the marrow inside, or to pick up a branch to scare away a threatening enemy, or to use a gourd to transport potable water, etc. Once we humans started using tools in a large way, we embarked on a long road that has brought us to where we are today - the most successful large mammal species currently in existence. Because of our use of tools and technology, we actually introduce change in our lives through the use of these tools.

I'm using the term "tools" in as broad a sense as possible, too, so to include the idea that human speech, mathematics, and idealization of theoretical knowledge are included as being "tools" we use to accomplish something. Please don't criticize my use of this term to cover these aspects, I'm merely temporarily using it to accomplish the point of indicating how we are tool users. One may actually go further with this to the point of possibly including the individual conscious mind as a tool that each person creates from birth to help us solve problems in our lives.

Using tools is a double edged sword - it not only helps us to do something easier, but it also carries with it a cost for its use. This cost can be something like (for example) how by using speech, we actually change our perception of the world around us - speech actually changes how we think about something, which creates change when we then act in a way that would perhaps be different than might have been otherwise had we not the capability of speech. Another example (more concrete) is how when we use the tool of the gasoline-powered automobile in large numbers, we are putting more carbon in the atmosphere than the environment can get rid of, which seems to be raising global temperatures.

One of the best examinations of this subject of change is the Indian philosophical concept of Karma, which is basically boiled down to the study of "cause and effect", (also known in philosophical terms as Causality). As humans we cannot help but create (or cause) change (or effects). Usually this is done through action, but even were it possible for a person to completely be free of any action, this itself would be something that would create a change. Therefore, we cause change whether we choose to act or not act. This is part of our mortal existence to which we are inexorably caught. So, by focusing one's attention as much as possible on what kind of change one is instigating by one's actions, it is possible to try to live one's life to produce the most desirable changes as possible. An interesting philosophy that takes this into account is called Consequentialism. Hope all that helps... Saukkomies 15:02, 8 December 2007 (UTC)

Post-script note: By saying that humans can be the initiators of change themselves, I do not imply that humans are the only species that is capable of this. Saukkomies 15:14, 8 December 2007 (UTC)

non future journels

wiki please give the names of some non future journels which are useful to learn about the future?202.88.234.90 (talk) 08:20, 6 December 2007 (UTC)

The Journal of Future Studies [7], The Futurist, Futures Research Quarterly, Futures: The Journal of Forecasting and Planning, Futurics: A Quarterly Journal of Alternative Futures & Futures Research, Technological Forecasting & Social Change: An International Journal Rockpocket 08:31, 6 December 2007 (UTC)

Hey, that's pretty good - not one of those journals hasn't been invented yet! --Psud (talk) 13:20, 7 December 2007 (UTC)

You might also be interested in reading Futurology. SteveBaker (talk) 15:10, 7 December 2007 (UTC)

Generation(s)

What number of years define a generation please--88.111.25.42 (talk) 08:38, 6 December 2007 (UTC)

See Generation. MrRedact (talk) 09:00, 6 December 2007 (UTC)

Splendid, just what I needed, Thanks--88.111.25.42 (talk) 09:04, 6 December 2007 (UTC)

How do they keep highway signs free of snow?

I live in the baltimore area, and I noticed when driving this morning that, while the exit signs, speed limit signs, and other signs at the side of the road were covered in frost/snow, the big green signs that hang over the road and list the exits, distances, etc were completely clear. I can't imagine that the snow didn't blow on to them, since it covered pretty much everything else, and every sign above the road was perfectly clear. I googled it, searched wiki for information about highway signs and searched the annotated code of maryland to see if they said anything about that sort of maintenance, but couldn't find anything. There are little lamp units under the signs, but surely that wouldn't generate enough heat spread around the entire sign to keep the sign completely clear, would it?

Tigger89 (talk) 13:28, 6 December 2007 (UTC)

Well lights do produce a lot of heat and if it is close to the metal of the sign the whole sign would heat as a whole, just a small difference in temperature would cause any built up snow to slide off as opposed to melting all the snow and keep it clear. The lightbulb article does has some figures on efficiency. Heat rising from automobiles and exhausts would also contribute. Lanfear's Bane | t 13:51, 6 December 2007 (UTC)

Ok thank you, I hadn't thought of the heat from the exhaust.

Tigger89 (talk) 14:42, 6 December 2007 (UTC)

While exhaust is a factor, I would expect that radiant heat from the lights is far and away the primary source of heat. If there's even a slight bit of wind, that exhaust is going to be dispersed before it can do much good. Similarly, that dispersal is going to mean that signs beside the road (at least on the downwind side) get about as much exhaust benefit as those above, and as you've noted, those signs don't stay clear. — Lomn 16:18, 6 December 2007 (UTC)

Part of the answer (and I am not a physicist, and I don't comprehend the answer completely) is probably that the metal conducts heat much more readily than most other materials. You experience this first hand when you touch metal outside in the cold; it feels much colder than (for instance) wood, because it conducts the heat more quickly away from your fingers, although the wood is really the same temperature as the metal. So, if there are hot lights burning on the bottom of the metal signs (as the green highway signs), they will conduct that heat throughout the sign and melt off the ice that's formed more easily than if the signs were, say, plastic. What I wonder about is the Stop signs, that don't have lights on them. They clearly gather condensation quickly, and the cold wind should freeze the snow on the front of the sign pretty easily, but I rarely see a sign that is encased in snow (although they often have icicles). Any physics geniuses want to make sense of it all? Faithfully, Deltopia (talk) 16:39, 6 December 2007 (UTC)

If what you're seeing is observed after a snow that's heavy enough to plow, perhaps the roadside signs have had the snow plowed onto them? Light, drifting snow won't stick to a cold metal sign, regardless of lighting, but a concentrated stream of half-melted snow, slush, and sand, directed at the sign at a significant horizontal speed, certainly could. jeffjon (talk) 17:00, 6 December 2007 (UTC)

Signs mounted above highways aren't mounted dead vertically; they're mounted with the visible side tilted downwards towards the road surface. Besides making for better visibility (because they're more-perpendicular to your line of sight looking upwards at them), this also tends to keep them clear of snow, at least non-wind-driven snow. This is not so true of signs at the sides of the road, though. Solar heating of the signs and their relatively slick surface (allowing gravity to work) seems to be the other big factor in keeping signs clear. The angle of repose of melty snow is far, far lower than the steep surface of the signs.

One of the biggest problems I've seen is dew on the signs as it tends to cancel most of the reflective characteristics of the sign material (for example, Scotchlite). But dew tends to only last a very few hours.

Atlant (talk) 17:35, 6 December 2007 (UTC)

On vertical surfaces, another factor may be vibration. Those large signs are vibrating as traffic rumbles by underneath them. Small signs are stiffer and vibrate less - so perhaps the snow is also being shaken off of these huge signs before it can really build up. I doubt there is any one single reason here. Large signs are also (usually) the dark-green or blue ones - roadside signs are generally white with black lettering. This might allow the dark coloured ones to absorb more sunlight during the day than the white ones. Being retro-reflective, they are very efficient at reflecting light in the wavelengths corresponding to their colour - but since they are designed not to glare out to white under car headlamps, the green ones ought to absorb the red wavelengths pretty well - and perhaps the infra-red very strongly. SteveBaker (talk) 19:31, 6 December 2007 (UTC)

what kind of plant

what kind of plants would be able to survive well in a dorm room? It would get watered regularily, so that wouldnt be a problem, but there just wouldnt be very much sunlight, unless you count flourescent lights as sunlight... —Preceding unsigned comment added by 128.101.53.177 (talk) 20:27, 6 December 2007 (UTC)

One is the snake plant. The jade plant is pretty tolerant. You can't kill an aloe vera no matter what you do, and you can squeeze the juice on hangnails and burns. --Milkbreath (talk) 20:47, 6 December 2007 (UTC)

Things I have found hard to kill in a dorm are spider plant, busy Lizzie and Tradescantia. SaundersW (talk) 20:58, 6 December 2007 (UTC)

I've had a wandering jew for years that has gone to the brink of death on more than one occasion since I'm not really a plant guy. Whenever it gets really bad, I just break off the dead stuff, replant the living stuff, and it takes off growing like a weed again. Dismas|^(talk) 22:51, 6 December 2007 (UTC)

Spider plants and Tradescantias are ideal for this situation. Both thrive on neglect, and seem not to care too much about light levels. DuncanHill (talk) 22:57, 6 December 2007 (UTC)

I"ve had amazing success with the Dracaena fragrans plant (also known as the Corn Plant). Here's a link that talks about it: [[8]]. This plant will grow ANYWHERE. It grows as tall as a low tree, but when it gets too tall I just cut it and place the top in a jar of water for a while till it puts out roots from the bottom where it was cut, and then I plant it in the pot along with its bottom. The bottom part where it was cut will then put out new branches from near the top and keep growing. One plant can therefore be cut and repotted in the same (largish) pot, thus making it quite bushy over time. The leaves naturally grow a bit brownish over long time, which can then be trimmed off to show the attractive trunk. I've grown this plant in a totally dark room, but it does better when there's even a little bit of indirect outdoor light that suffuses into the 15:57, 8 December 2007 (UTC)

Will the poor always be with us?

And where does this quote come from anyway? BrainyBabe (talk) 21:55, 6 December 2007 (UTC)

From Jesus. Matthew 26:11. 207.148.157.228 (talk) 22:19, 6 December 2007 (UTC)

Well unless everyone had exactly the same of everything (life, love, health, money, opportunities etc.) then 'poor' will always exist because it is such a broad-word. Will 'absolute poverty' always exist? Depends on whether we change the definition. The wealth and life of people has increased unbelievably the world over in the past 100 years according to people such as Hans Rosling, who has some interesting presentations on nation wealth across time. I have no idea where the quote comes from, but in some definition poverty will always exist. We're already starting to move from people living on under a dollar a day to considering replacing it with living on under 2 dollars a day - it might sound like small progress but it isn't. ny156uk (talk) 22:25, 6 December 2007 (UTC)

To put it in context, the Gospel of Matthew in the Bible has Jesus say it not long before he dies. A woman uses expensive perfumed oils to anoint Jesus while he is eating, and his disciples berate her for wasting it in this manner, since it could have been sold and the money given to the poor. Jesus uses 'The poor will always be with you' as a way of telling his disciples off for being mean to someone who was trying to do something good. Also, to say that while the poor would always be with them, they would not always have him. I always read it as an injunction not to get picky with other people, pointing out how they could have done something even better. Essentially, not to get 'holier than thou'. Also, that while helping the poor is a good thing, it's a bit vague and will never be finished. Sometimes more immediate concerns take priority. Skittle (talk) 00:16, 7 December 2007 (UTC)

It actually predates the NT. Deuteronomy 15:11 says, "The poor will never cease to exist in the land." -- Mwalcoff (talk) 00:49, 7 December 2007 (UTC)

It's the same sentiment, and no doubt the NT is referencing it, but the actual quote comes from the NT. 130.88.140.39 (talk) 13:08, 7 December 2007 (UTC)

We answered a question similar to this a few days ago. Someone wanted to know what would happen if everyone was rich. The problem is that keeping everyone at the same income level is virtually impossible - and because it removes the incentive to excel, it ends up being a bad thing for society. What is needed is some way to limit the spread of incomes. Nobody really needs more than maybe a quarter of a million dollars a year to be extremely happy and well off and to be able to do the things they want to do in life. At the other end of the scale, nobody deserves to be so poor that they can't eat, have adequate basic health care and plain, simple housing. We need poorer and richer people - but not insanely rich and ridiculously poor. At one time it was calculated that Bill Gates was earning so much money that if he saw a $100 bill lying in the street, it would not be cost-effective for him to bend down and pick it up (he was earning over $100 per SECOND at that time). That is definitely more money than anyone needs. The trick is to limit the extremes without resorting to the failed ideas of full-up communism. —Preceding unsigned comment added by SteveBaker (talk • contribs) 15:03, 7 December 2007 (UTC)

An interesting idea. I would suggest the trick is to limit the lower extreme without creating a ceiling of accruable wealth. The money Bill Gates has is unfathomable (even, i'm sure, to himself) but it circulates through society. It's in banks being used as capital for loans, it's in investments, it's in stock, it's buying X-million pound boats that keep boat-manufacturers/etc. etc. in business. I personally think focussing on how we get the poor richer is much much much more important than making the rich slightly poorer. Remember it isn't a zero sum game, the insanely rich don't have to get poorer for the poor to get richer. The US and Western Europe is home to most of the world's richest people...List of countries by the number of billionaires (some reason Asia isn't on there), and they also are the nations where the respective poor in society are likely to be the richest 'poor' people too (yes some of the rich are rich from exploiting poor around the world, but the poor are also raising in wealth virtually the world over). ny156uk (talk) 01:37, 8 December 2007 (UTC)

What do you mean 'Asia isn't on there'? :-? Skittle (talk) 15:04, 8 December 2007 (UTC) Ah, I see there was vandalism that hung around for weeks and wasn't caught until an hour after you posted... Skittle (talk) 15:08, 8 December 2007 (UTC)

Yes, my question was partly in response to the previous query about what would happen if everyone were rich. It is not quite the same thing to say, what would happen if no one was poor. I guess I am conceptualising a tripartite division: rich, poor, and middling (which most of us reading this are). Perhaps others were thinking of a binary rich/poor division. I have a thought experiment to propose, but will do that as a separate question another day, once I think of a clear wording. And "will the poor always be with us?" , posed as a non-rhetorical question, cries out for an explanation, not just a yes/no assertion. Why does poverty persist? (absolute or relative poverty.) BrainyBabe (talk) 08:54, 9 December 2007 (UTC)