Wikipedia:Reference desk/Archives/Science/2011 February 2
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February 2
[edit]How do microorganisms cause mutations?
[edit]I do not understand how the different microorganisms can cause mutations. I know that viruses attach to a cell and insert their dna in, but how do fungi, protists and bacteria infect cells and cause mutations. —Preceding unsigned comment added by 206.116.124.140 (talk) 03:06, 2 February 2011 (UTC)
- The simplest answer is that microorganisms usually do not "cause" mutations. Perhaps you could explain where you got that notion from? Yes, there are some examples of retroviruses whose replication cycle involves insertion of copies of their genetic material into the host's genome (which can sometimes interrupt a gene thus causing a "mutation" of sorts), but this is not generally the infective strategy of other viruses, fungi, protists, and bacteria. Some microorganisms are intracellular pathogens, which means that they enter the cell, hijack its replication machinery to make copies, and then destroy the cell in the process -- others are extracellular pathogens that cause problems through production of toxins. Unfortunately, our microbiology article isn't particularly great. The pathogen article and the separate articles on viruses, bacteria, protists and fungi are probably a good place to start. --- Medical geneticist (talk) 03:27, 2 February 2011 (UTC)
- (ec)It's not guaranteed that they do cause mutations. There are specific cases such as aflatoxin where microbial products are mutagenic or carcinogenic. Persistent infections might also increase the rate of cell division and tissue regeneration, potentially leading to cancer, as in Helicobacter pylori infection in stomach ulcers. I'm sure I'm neglecting other examples. Wnt (talk) 03:29, 2 February 2011 (UTC)
- Prions can also cause mutations. See bovine spongiform encephalopathy and NDM-1. ~AH1(TCU) 21:41, 2 February 2011 (UTC)
- No, they don't. Dauto (talk) 00:26, 3 February 2011 (UTC)
- Prions can also cause mutations. See bovine spongiform encephalopathy and NDM-1. ~AH1(TCU) 21:41, 2 February 2011 (UTC)
Snowstorm
[edit]We are currently having a snowstorm here in WIsconsin (grr.... shoveling ): WHy is it that it is very rare for snowstorms to have thunderr and lightneing? Thanks. 24.92.70.160 (talk) 05:32, 2 February 2011 (UTC)
- Thunderstorms usually form in the warm summer months where there is a very steep temperature gradient between the ground and the atmosphere above the ground. This sharp temperature gradient coupled with a strong area of low pressure generates rapid lift of warm, moist air (known as Vertical draft) into a much colder area just above it. This causes the air to rapidly recondense, generating fast, heavy rains and the necessary electric charge seperation between the clouds and the ground necessary to form lightning. In the winter, it is rare that these conditions will exist because there just isn't the same temperature profile of warm, moist air near the surface and colder air just above it (i.e. its cold everywhere, so the lack of a steep gradient in temperature inhibits thunderstorm formation). The article Thundersnow does describe the necessary conditions for this rare (but not unheard of) event to occur. --Jayron32 05:41, 2 February 2011 (UTC)
- It happened in (old) England this winter on several occasions. Dbfirs 19:01, 2 February 2011 (UTC)
Opaque universe
[edit]At the beginning, the universe was too opaque to let light through, but as density decreased, light was able to start shining through. What is the cutoff density point at which the universe loses its opacity?--Leptictidium (mt) 07:05, 2 February 2011 (UTC)
- As far as I understand it, the critical parameter was not as much density as temperature. The early universe was a plasma of charged particles, which interacts strongly with electromagnetic radiation. Once the temperature dropped enough, most of the matter condensed into neutral atoms which are much more transparent. See, Recombination (cosmology). –Henning Makholm (talk) 11:19, 2 February 2011 (UTC)
- Is there any way of knowing the density of the universe towards that period? Leptictidium (mt) 14:08, 2 February 2011 (UTC)
- Recombination happened at redshift z=1100. The densities of ordinary (and dark) matter scale as (1+z)3, so the density was a factor of a billion (109) higher than today. This applies to the mean density in the Universe, which is a few times 10-27 g/cm3 today. The (energy) density of radiation scales as (1+z)4, so it was a factor 1012 higher than today. (the density of dark energy is constant, it was the same then as it is now). --Wrongfilter (talk) 17:50, 2 February 2011 (UTC)
- Do we also know the volume of the universe back then? Leptictidium (mt) 21:01, 2 February 2011 (UTC)
- No. We don't even know the size of the entire universe now, only the size of the visible universe. We don't even know the shape of the universe, which includes consideration of the universe's size (like finite vs. infinite). The infinite flat model is currently the most popular model among cosmologists, but there are other models that also fit the available data. Red Act (talk) 21:47, 2 February 2011 (UTC)
- Do we also know the volume of the universe back then? Leptictidium (mt) 21:01, 2 February 2011 (UTC)
- Recombination happened at redshift z=1100. The densities of ordinary (and dark) matter scale as (1+z)3, so the density was a factor of a billion (109) higher than today. This applies to the mean density in the Universe, which is a few times 10-27 g/cm3 today. The (energy) density of radiation scales as (1+z)4, so it was a factor 1012 higher than today. (the density of dark energy is constant, it was the same then as it is now). --Wrongfilter (talk) 17:50, 2 February 2011 (UTC)
- Is there any way of knowing the density of the universe towards that period? Leptictidium (mt) 14:08, 2 February 2011 (UTC)
How can one know the density of something without knowing the volume????? —Preceding unsigned comment added by 165.212.189.187 (talk) 14:32, 3 February 2011 (UTC)
- That's easy, as long as the "something" is homogeneous, which at least the observable universe appears to be remarkably close to being on the largest of scales. The volume and mass (and energy) of the observable universe can be determined, so the density of the observable universe can be calculated. And then it's reasonable to assume that the density of the unobservable portion of the universe is about the same as the density of the observable portion, if you assume that the observed homogeneity of the observable universe extends to the rest of the universe. It's sort of like how you can measure the density of seawater to within a few percent by taking measurements on just a small sample of seawater, even if you don't know the volume of the world's oceans. Red Act (talk) 15:36, 3 February 2011 (UTC)
That is a pretty big ASSumption! Its funny that we dare assume what happens beyond the event horizon of a black hole, but it epidemically OK to assume that the entire universe, the extent of which we don't know since it's also beyond a so-called "event horizon", is homogeneous! —Preceding unsigned comment added by 165.212.189.187 (talk) 19:26, 3 February 2011 (UTC)
- I don't think there's a whole lot of science that relies on an assumption of homogeneity outside of the observable universe. I think calculations pertaining to the expansion rate, composition, age, local geometry etc. of the universe all basically really just care about the observable universe. So you could just mentally insert the word "observable" before every occurrence of the word "universe" in any discussion of the density of the universe, if that makes you feel more comfortable. That being said, I don't think there's any evidence that would suggest that some parts of the universe outside of the observable universe might not be homogeneous, so it's simplest to just figure that the rest of the universe is probably a lot like the observable portion, unless and until there's some evidence that would suggest otherwise. Red Act (talk) 20:56, 3 February 2011 (UTC)
Ever hear of a black hole?? Look it up. —Preceding unsigned comment added by 165.212.189.187 (talk) 21:12, 3 February 2011 (UTC) Then lets make similar assumptions about black hole event horizons, while we're at it, right? I thought an event horizon is an event horizon, now I realize its just a green curtain. —Preceding unsigned comment added by 165.212.189.187 (talk) 21:10, 3 February 2011 (UTC)
- Black holes are a bit different. The universe being homogeneous is something that's only approximately true anyway, and significant inhomogeneity outside of the observable universe would just involve some unexpected characteristics of the universe's initial conditions. Black hole event horizons not behaving the way they are thought to, on the other hand, would require one of the most fundamental laws of physics to be wrong. But if you have an alternative complete, testable theory of gravity that fits all existing experimental evidence but would result in different behavior pertaining to black holes (or perhaps the lack thereof), by all means go publish it somewhere (but not here). Red Act (talk) 21:48, 3 February 2011 (UTC)
That would be easy if I could use your fuzzy math and language: "which at least the observable universe APPEARS TO BE remarkably CLOSE TO BEING on the largest of scales. The volume and mass (and energy) of the observable universe can be determined, so the density of the observable universe can be calculated. And then it's reasonable to ASSUME that the density of the unobservable portion of the universe is ABOUT THE SAME as the density of the observable portion, IF YOU ASSUME that the observed homogeneity of the observable universe extends to the rest of the universe. One assumption based on another assumption based on a few more assumptions. —Preceding unsigned comment added by 165.212.189.187 (talk) 13:45, 4 February 2011 (UTC)
- I'm only making one assumption not based on experimental evidence, that the homogeneity observed in the observable universe presumably extends to the unobservable portion of the universe. Uniformity in density is a logical consequence of the homogeneity.
- By "appears to be", I mean "experimental evidence is that". Consistent with the cosmological principle, experimental evidence shows that the observable universe is very homogeneous at the largest of scales. The observable universe has no discernible structure at scales larger than the End of Greatness, which is about 280 times smaller than the diameter of the observable universe.
- And by "close to being", I mean remarkably close indeed. The cosmic microwave background radiation, with which we can "see" all the way to the edge of the observable universe, is uniform from all directions, to within 1 part in 100,000. Red Act (talk) 16:56, 4 February 2011 (UTC)
Fast cold
[edit]Wanting to see whether the rapid cooling feat in this video works, I tried it and it works like a charm: fill a bowl with icewater, pour salt in, dunk a warm soda in it, stir, and you get an ice cold soda in about two minutes. I understand that salt lowers the freezing point, but I don't understand why it makes the soda cool so rapidly. Can you explain this to me?--141.155.143.65 (talk) 07:09, 2 February 2011 (UTC) P.S. Some of the other stuff they show in the video is rather neat, but I should add that the particular phenomenon I am here about is shown at 4:36 minutes in.--141.155.143.65 (talk) 07:14, 2 February 2011 (UTC)
- Salt makes ice melt faster by lowering its melting point. That also allows the water in the bowl to get colder than it would normally, which I'm going to assume is at least partly why salty icewater works better than plain old icewater; most of the heat transfer is going to be between the can and water, rather than directly between the can and the ice. Someguy1221 (talk) 07:26, 2 February 2011 (UTC)
- From Freezing-point depression "This phenomenon is effective in quickly lowering the temperature of a beverage placed in an ice bath containing salt; it is commonly used to make ice cream or cool beers rapidly." Try the same thing but using something besides salt like sugar. CambridgeBayWeather (talk) 07:42, 2 February 2011 (UTC)
- It's not just a matter of "allowing" the water to get cold; adding salt actively lowers the temperature by forcing the ice to melt (you could look at this as a kind of osmotic pressure gradient across the saltwater/ice boundary that sucks water out of the ice). The melting ice still has to pay the heat of fusion cost, and the only place to take that energy from is the heat energy. –Henning Makholm (talk) 11:26, 2 February 2011 (UTC)
- For reference, here's a plot of freezing point versus salt concentration (for an aqueous solution of sodium chloride). For a fairly concentrated brine solution (about 20% salt by weight) the freezing point can be reduced by about 20 degrees Celsius. To a passable approximation, the rate of heat transfer out of the can of soda is proportional to the difference in temperature between the can and its surroundings. Consider a can at 10°C (cool, but not quite refrigerator 'cold'). Immersed in a plain icewater bath at 0°C, you get one-third the temperature difference and therefore one-third the rate of cooling that you'd see with a -20°C brine bath. (I'll note that either method will still cool your beverage faster than just sticking in the fridge; the air in the refrigerator is going to be even warmer – around 4°C – and the air's lower heat capacity means a much less efficient transfer of heat than you'd see with liquid immersion.) TenOfAllTrades(talk) 14:31, 2 February 2011 (UTC)
You're roughly correct, but I think your math is wrong. Maybe I am mistaken here, but the difference in cooling rates between the ice bath at 0C and the salt-ice bath at -20C is 273/253 or about an 8% increase in cooling rate. I think you need to use an absolute temperature scale like Kelvin, not celsius, which is an arbitrary scale and has no connection to the physical behavior of the matter involved. Assuming two cans at the same temperature are placed into those baths, the two cans will reach arbitrary identical temperatures at a rate difference of about 8%; that is the can in the cooler bath may take 100 seconds to drop 1 degree, the can in the warmer bath should then take about about 108 seconds to also drop 1 degree. This is, of course, a different question than asking how long each can takes to achieve equilibrium with the bath. It also ignores the fact that the specific heat of the salt water bath will be different than that of pure water, and of course that to be scrupulously correct specific heat itself is temperature dependent, and so some calculus will need to be done to find the exact comparison. But I think that as a back-of-the-envelope sort of calculation, it should come out to a roughly 8% difference. --Jayron32 16:48, 2 February 2011 (UTC)- No, you're mistaken. The rate of heat transfer depends on the magnitude of the temperature difference between the source and the sink, not on their absolute values: Newton's law of cooling. (Consider the implications of your math. If a -20°C bath will always draw off heat 8% faster than a 0°C bath, does this still make sense when the can is at 1°C? What if we start with a can at -5°C?) Yes, I agree that differences in heat capacity between water and brine will modify the answer somewhat – not to mention differences in viscosity, which I suspect may be more important for convective heat transfer here – but that's why I described my response as an approximation. TenOfAllTrades(talk) 17:30, 2 February 2011 (UTC)
- Thanks for the link. Once again, my physics knowledge is just good enough to be dangerously wrong. Sorry for drawing the wrong conclusions. It makes much more sense now; of course the ΔT which matters, not the absolute temperature, and ΔT works the same in any temperature scale. Thanks again for clarifying and providing an article link. --Jayron32 17:45, 2 February 2011 (UTC)
- See Mpemba effect. ~AH1(TCU) 21:22, 2 February 2011 (UTC)
- No, the Mpemba effect is completely irrelevent in this case. The Mpemba effect is mainly an effect that occurs during the interaction between fluid dynamics and thermodynamics, and has absolutely no bearing on the current discussion, which is more about the effect of adding salt to ice. --Jayron32 21:28, 2 February 2011 (UTC)
- No, you're mistaken. The rate of heat transfer depends on the magnitude of the temperature difference between the source and the sink, not on their absolute values: Newton's law of cooling. (Consider the implications of your math. If a -20°C bath will always draw off heat 8% faster than a 0°C bath, does this still make sense when the can is at 1°C? What if we start with a can at -5°C?) Yes, I agree that differences in heat capacity between water and brine will modify the answer somewhat – not to mention differences in viscosity, which I suspect may be more important for convective heat transfer here – but that's why I described my response as an approximation. TenOfAllTrades(talk) 17:30, 2 February 2011 (UTC)
- The problem with all your explanations is that you're stating that the ice-salt-water bath has a lower temperature than a plain ice-water bath. That's definitely not true. What I think happens is that the melting of ice is an endothermic reaction, thus pulling heat out of its environment (similar to how the evaporation of sweat cools you down). The salt lowers the melting point, causing ice to melt easier, causing more heat to be sucked in from the environment, i.e. whatever is conducting heat outside of the ice-salt-bath system, i.e. the soda can or ice cream bag. SamuelRiv (talk) 03:24, 3 February 2011 (UTC)
- No. The ice-salt-water bath definitely has a lower temperature than a plain ice-water bath. It's a standard experiment for kids to do. Also see cooling bath. --Stephan Schulz (talk) 03:38, 3 February 2011 (UTC)
- Listen, I'm the guy asking the question so obviously I'm not the one who knows the science here, but I can tell you that those saying it's just colder--that makes no sense to me and appears clearly wrong. The whole point is that if you take a soda and stir it in ice water for a minute or so, it will still be warm, just marginally cooler, so if the salt makes it s few degrees colder (not enough to even tel a difference with your hand) that will have an effect but not nearly enough to take a warm soda and make it ice cold in a short amount of time. There is some effect going on that accelerates the cooling down by a lot, so even though I don't know much about the science, I am listening to those talking about osmotic pressure and endothermic reactions and so on and ignoring those who are just talking about a temperature lowering.--141.155.143.65 (talk) 00:27, 6 February 2011 (UTC)
- Um, I was the one who mentioned osmotic pressure, but I also think lowered temperature must be the mechanism, so are you listening to me or not?
- Where do you get the information that the salt is going to make the icewater only "a few degrees colder"? If there's too little salt to make the solution appreciably colder, then it shouldn't have any appreciable influence on how fast the soda is cooled either. If you have experiments that say otherwise, how sure are you that the addition of salt is the only difference between the two situations? One factor that must be controlled for is the amount of stirring. If you stir more vigorously (such as in an attempt to get the salt to dissolve) you get much more efficient heat transfer from the soda, quite independently of whether there's any salt in the water. If you're stirring by hand, I wouldn't put any scientific trust in the results unless you make at least a dozen trials to smooth out statistical variations, and set it up as a randomized blind experiment where you don't know whether there's salt or not while you stir. –Henning Makholm (talk) 00:54, 6 February 2011 (UTC)
Legend of the frogurt's curse
[edit]I recently acquired six large tubs of plain soy yogurt. Or "soygurt", as the package insists on calling it. It will take me a year to finish it. In the meantime, I worry that it might spoil, but I hesitate to freeze it. I'm afraid that freezing it might kill the bacteria. I've been getting conflicting advice on the matter. On the one hand, I've been told that freezing the yogurt will indeed obliterate its probiotic properties. I've also been told that my fears are groundless, and that the bacteria are merely rendered dormant by freezing. My own knowledge of bacteria is too scanty to be of any use. Intuitively, I would be surprised to discover that frozen yogurt retains the same probiotic properties as unfrozen yogurt, but I really don't know. LANTZYTALK 08:16, 2 February 2011 (UTC)
- There's actually an amazing amount of research on this (see here). Most of those are paywalled, but I gather the jist of it is that 50-90% of the bacteria may die during the freezing process, and this may depend on what is being frozen, what bacteria are in it, and how it is frozen. Papers from over fifteen years ago seem to say that there was no evidence that the naturally occuring bacteria in milk are sensitive to cold, so this may be a somewhat recent finding, although repeated several times. Someguy1221 (talk) 09:21, 2 February 2011 (UTC)
- Although anyway, it stands to reason you shouldn't care about the bacteria. No significant metabolic activity is going to happen while it's frozen; a more significant concern is how the texture of the yogurt might be affected by freezing. Someguy1221 (talk) 09:23, 2 February 2011 (UTC)
- ... but killing 90% might affect the "probiotic" properties, though the stomach does a pretty good job of killing most bacteria anyway. Dbfirs 09:31, 2 February 2011 (UTC)
- Cynics like me would say that a) "soygurt" is spoiled at the concept level, and b) that the evidence for benefits from probiotics in general is fairly scant, and what benefit there is is most likely not due to the living microorganisms (as the stomach kills them anyways), but doe to the presence of their metabolic products. --Stephan Schulz (talk) 09:40, 2 February 2011 (UTC)
- That sounds reasonable. But why the automatic scorn for soy yogurt? It has a longer shelf life, and it tastes especially good with lemon juice. Maybe you're confusing being a cynic with being a puke. LANTZYTALK 15:25, 2 February 2011 (UTC)
- Cynics like me would say that a) "soygurt" is spoiled at the concept level, and b) that the evidence for benefits from probiotics in general is fairly scant, and what benefit there is is most likely not due to the living microorganisms (as the stomach kills them anyways), but doe to the presence of their metabolic products. --Stephan Schulz (talk) 09:40, 2 February 2011 (UTC)
- ... but killing 90% might affect the "probiotic" properties, though the stomach does a pretty good job of killing most bacteria anyway. Dbfirs 09:31, 2 February 2011 (UTC)
- The problem I have with "soy milk" products like soygurt is that soybeans don't have teats. They are clearly soy juice products, and calling something milk when it clearly has never been inside of a mammal is misleading... --Jayron32 13:26, 2 February 2011 (UTC)
- It's not even soya juice. As our article soya milk says "Soy milk can be made from whole soybeans or full-fat soy flour. The dry beans are soaked in water overnight or for a minimum of 3 hours or more depending on the temperature of the water. The rehydrated beans then undergo wet grinding with enough added water to give the desired solids content to the final product. The ratio of water to beans on a weight basis should be about 10:1. The resulting slurry or purée is brought to a boil in order to improve its nutritional value by heat inactivating soybean trypsin inhibitor, improve its flavor and to sterilize the product. Heating at or near the boiling point is continued for a period of time, 15–20 minutes, followed by the removal of an insoluble residue (soy pulp fiber or okara) by filtration." It's an industrial slurry. DuncanHill (talk) 13:42, 2 February 2011 (UTC)
- Coconuts, pigeons, and magnesium hydroxide all produce milk, so why shouldn't soy? Do you lack the milk of human kindness? --Colapeninsula (talk) 14:15, 2 February 2011 (UTC)
- The word "milk" is never used by soy milk manufacturers in my part of the world. They call it "soy drink". I don't really understand such superstitions about etymology. Who's afraid of a little semantic drift? LANTZYTALK 15:25, 2 February 2011 (UTC)
- A web search turned up this research draft, Is Soy Milk? The Economics of the Soy Milk Market. Apparently, economists, agronomists, marketers, and government regulators are all a bit afraid of semantic drift: "Many of the major US dairy producer organizations have lobbied to have soy beverages banned from using the moniker “milk”. Much of the relevance of this debate hinges on whether soy milk competes against cow’s milk or serves a separate consumer market." ... "Understanding the interactions between these milk types will improve our ability to determine of whether trade in both milk markets exhibits the hallmarks of anti-competitive behavior." The paper goes on to analyze marketability of "soy drink" and the impact of the phrase "milk" on price-economics. Nimur (talk) 19:20, 2 February 2011 (UTC)
- The free frogurt is cursed... but it comes with choice of topping! Note the toppings contain potassium benzoate. That's bad. SamuelRiv (talk) 03:27, 3 February 2011 (UTC)
- @ Stephan Schultz - The benefits of "probiotic" yoghurt are financially hugely successful, nutritionally I agree with you! Richard Avery (talk) 13:48, 3 February 2011 (UTC)
- The word "milk" is never used by soy milk manufacturers in my part of the world. They call it "soy drink". I don't really understand such superstitions about etymology. Who's afraid of a little semantic drift? LANTZYTALK 15:25, 2 February 2011 (UTC)
- Coconuts, pigeons, and magnesium hydroxide all produce milk, so why shouldn't soy? Do you lack the milk of human kindness? --Colapeninsula (talk) 14:15, 2 February 2011 (UTC)
- It's not even soya juice. As our article soya milk says "Soy milk can be made from whole soybeans or full-fat soy flour. The dry beans are soaked in water overnight or for a minimum of 3 hours or more depending on the temperature of the water. The rehydrated beans then undergo wet grinding with enough added water to give the desired solids content to the final product. The ratio of water to beans on a weight basis should be about 10:1. The resulting slurry or purée is brought to a boil in order to improve its nutritional value by heat inactivating soybean trypsin inhibitor, improve its flavor and to sterilize the product. Heating at or near the boiling point is continued for a period of time, 15–20 minutes, followed by the removal of an insoluble residue (soy pulp fiber or okara) by filtration." It's an industrial slurry. DuncanHill (talk) 13:42, 2 February 2011 (UTC)
Schizophrenia with catatonia
[edit]Are people suffering from Schizophrenia with catatonic excitement capable of living normal lives at least in some situations...i.e while continuing to suffer from such bouts occasionally? —Preceding unsigned comment added by 1.23.10.106 (talk) 18:10, 2 February 2011 (UTC)
- Yes, many treatments can be very effective, but of course depends on the individual case. Management of schizophrenia explains some of the widely-recognized treatments, including medication, that can ease the burden and minimize the symptoms. Schizophrenia can be a very serious psychiatric condition, so any patient should be under the care of a psychiatrist to make sure that they are receiving the treatment they need and obtaining the results that make their life most comfortable and normal. Nimur (talk) 19:03, 2 February 2011 (UTC)
Actually I wanted to ask that whether a person still suffering from catatonia can behave as a normal person while erupting once in a while? Sorry for wrong questioning. —Preceding unsigned comment added by 1.23.10.106 (talk) 01:05, 3 February 2011 (UTC)
- Catatonia is simply an observed behaviour. If such a person in this state, suddenly gets up and goes off to do some shopping, they are no longer in that state. However, it depends on why they entered this state. Neuroleptic malignant syndrome and a few other causes might mean that it is persistent. They may not even eat. Or, they might slip in and out of it. When out of it, they may appear and act -like you or I.--Aspro (talk) 01:26, 3 February 2011 (UTC)
Scientist Qualifications
[edit]What is the scientific attitude and what attitudes and characteristics define a good scientist? -GlennRichardAllison Mr. 900 Jr. bowling —Preceding undated comment added 19:02, 2 February 2011 (UTC).
- First, "scientists" is a very large and vastly diverse group of people. There is no way to answer with one attitude. Second, you must define "good". How you define good is purely up to you and will drastically change what the question means. For example: A good scientist is one who gets published often. ...or... A good scientist is one who never makes mistakes during calculations. ...or... A good scientist is one who gets a lot of research funding. etc. etc. etc. -- kainaw™ 19:05, 2 February 2011 (UTC)
- There are a lot of different ways to answer this, and people have put forward many different opinions over the years. I suspect the ones that most scientists today would self-identify with (even if it doesn't quite cover the gamut in terms of actual practices) are the Mertonian norms put forward by the sociologist Robert K. Merton in 1942. But it's a big question and a big topic, depending on, as Kainaw notes, different measures of "good". You could contrast this with, say, the model put forward by Thomas Kuhn in The Structure of Scientific Revolutions, where "good" scientists (working under "normal science") are actually not pushing the envelope every day, but producing dogmatic "stability" of theories, and only once in awhile get swept up into a "revolutionary" confusion that leads to creating new theories. Or you could contrast both of these with the views of a radical like Paul Feyerabend, who essentially said there was no scientific method whatsoever, and no "good" scientists whatsoever — just different people using totally different methods to come up with knowledge. --Mr.98 (talk) 19:14, 2 February 2011 (UTC)
- It is perhaps easier to say what is good science than who is a good scientist. That is, a certain work can be critiqued and assessed for scientific quality, this is the goal of peer review. As for characteristics that define a 'good scientist', this is tantamount to asking for characteristics that define a 'good person'. Scientists are people; it's easier to objectively judge the quality of their work than the quality of their personhood. SemanticMantis (talk) 19:26, 2 February 2011 (UTC)
- I'm not sure they're judging personhood. I can say somebody is "good scientist" but a "lousy person," the same way I could say someone is a "good cop" or a "good fireman" without passing judgment on whether they are "good people" or not. I think most scientists would identify "good scientists" are being those who adhere to or embody Mertonian norms — they are "disinterested" and share their data and participate in "organized skepticism" and measure worth by objective terms and so on. A "good cop" would be one who caught the bad guys without accidentally harming the good guys and so on, whether he was a good person or not. A "good fireman" saves lives and puts out fires and retrieves cats from trees and so on, even if he's actually a jerk in all other respects. --Mr.98 (talk) 20:56, 2 February 2011 (UTC)
- I think a main primary attribute of "good scientists" is critical thinker. Not all scientists are good critical thinkers, but I'd argue all good scientists are. Vespine (talk) 22:02, 2 February 2011 (UTC)
- I wholly agree, Vespine. A good scientist is one who thinks scientifically, and makes no compromises. Science is a way of thought. Mac Davis (talk) 23:24, 2 February 2011 (UTC)
- Saying: "a good scientist thinks scientifically" is a circular definition. Ariel. (talk) 01:27, 3 February 2011 (UTC)
- Maybe Mac meant to write a good scientist is one who thinks critically? While critical and scientific thinking aren't too far off being synonyms, I think critical thinking is a subset of scientific thinking. Critical thinking can, in a fairly well defined way, be applied by people who are not scientists, however it takes more then 'just' critical thinking to successfully apply the scientific method, but critical thinking would play a part all along the way. Vespine (talk) 02:29, 3 February 2011 (UTC)
- Saying: "a good scientist thinks scientifically" is a circular definition. Ariel. (talk) 01:27, 3 February 2011 (UTC)
- I wholly agree, Vespine. A good scientist is one who thinks scientifically, and makes no compromises. Science is a way of thought. Mac Davis (talk) 23:24, 2 February 2011 (UTC)
- I like your example Mr. 98. A "good cop" might not be a "good person", but it is certainly a person who does cop stuff well. Thus, we can say a "good scientist" is a person who performs good scientific work. This is not circular, because we have (relatively) objective ways of assessing the latter. Not to diminish the Mertonion norms; they are great guidelines, and I profess them. But one can certainly be a great scientist and not follow any of the norms. We just promote them because we think good science is more likely to occur under these practices. I'm sure we can find famous scientists of the past who did not believe in openness, were not detached, but still produced amazing work that qualifies them as "good scientists". SemanticMantis (talk) 16:48, 3 February 2011 (UTC)
- I just want to add that I don't think the Mertonian norms actually are accurate, either, but that they are often what are invoked to answer this kind of question. I am more of a Feyerabendian myself — there are lots of different ways to do science, lots of different methods, lots of different types of people. I would be wary about making a blanket determination that is supposed to cover all scientists. There is certainly no model that covers all of the good ones, historically. They run the gamut from the entirely boring John Bardeen to the nearly-nutty Isaac Newton. --Mr.98 (talk) 02:39, 4 February 2011 (UTC)
- I think a main primary attribute of "good scientists" is critical thinker. Not all scientists are good critical thinkers, but I'd argue all good scientists are. Vespine (talk) 22:02, 2 February 2011 (UTC)
- I'm not sure they're judging personhood. I can say somebody is "good scientist" but a "lousy person," the same way I could say someone is a "good cop" or a "good fireman" without passing judgment on whether they are "good people" or not. I think most scientists would identify "good scientists" are being those who adhere to or embody Mertonian norms — they are "disinterested" and share their data and participate in "organized skepticism" and measure worth by objective terms and so on. A "good cop" would be one who caught the bad guys without accidentally harming the good guys and so on, whether he was a good person or not. A "good fireman" saves lives and puts out fires and retrieves cats from trees and so on, even if he's actually a jerk in all other respects. --Mr.98 (talk) 20:56, 2 February 2011 (UTC)
SS United States
[edit]It is generally accepted that the SS United States was subsidized in large part by the US because it could be converted to a troop ship.
As a teenager, my neighbor who was Chief Stewart, hosted my family while the ship was berthed in NYC. He confided that the ship was not designed to be converted to a troop carrier but an aircraft carrier. He explained to me that the elevators were designed so that multiple elevators could be yoked together to move airplanes to the flight deck.
Is there any evidence or suggestion that indeed the SS United States was secretly designed to be converted to an aircraft carrier (not a troop ship) and that the government and builders were dealing in disinformation? —Preceding unsigned comment added by 70.125.52.217 (talk) 20:13, 2 February 2011 (UTC)
- It was designed as a troop carrier in the sense that it has a design specifically to quickly load and unload troops. By "converted" in this sense, it merely means that it will be used for a different purpose. To "convert" into an aircraft carrier, it would have to be lengthened by about 100 feet, have the entire bridge removed and replaced, and then have numerous other alterations made for the actual service requirements of an aircraft carrier. So, it could be converted into an aircraft carrier by changing the ship itself, but no changes are necessary to use it as a troop carrier. -- kainaw™ 20:24, 2 February 2011 (UTC)
- A secret aircraft carrier design seems highly unlikely, but note that the cancelled USS United States (CVA-58) was under construction at approximately the same time, which could lead to confusion. A cruise ship is not built with the vast open spaces needed to support a hangar deck, nor the vast fuel stores to support an aviation wing, nor any of the armor or other protective measures needed for a ship intended to sail in harm's way. Note that a troop ship needs none of those things, but does need vast spaces for holding, feeding, and (dis)embarking personnel -- right up a cruise ship's alley. Note also the case of the Lexington class battlecruisers, successful conversions to aircraft carriers. Those conversions were performed early in construction (a case of fitting carrier equipment into a given hull's dimensions), not post-completion as the supposed SS United States conversion would entail. Note also that the budgeted cost of the conversion was higher than that of keel-up new construction, and was undertaken only because (a) some money had already been sunk into the project and (b) naval treaty limits applied, which wouldn't have been the case in the SS US timeframe. — Lomn 21:27, 2 February 2011 (UTC)
- I will point out that civilian service ships are regularly under contract to the United States Government, including the Department of Defense, with very little need for secrecy or covertness. We have an article on the United States Merchant Marine, which is the total set of civilian-owned ships that can be called upon as part of the Navy Auxiliary if needed. Here in the United States, we also have Military Sealift Command and the National Defense Reserve Fleet, not to mention the prepositioned strategic fleet. There seems to be zero reason to "hide" the fact that one extra ship might have a role for military service if the time and need arises. So it's very unlikely that the ship would have such a "hidden" purpose. Nimur (talk) 21:31, 2 February 2011 (UTC)
- Concur with Lomn: it's a confusion between SS United States and the quite real, but ultimately canceled aircraft carrier USS United States (CVA-58). The name is something of a jinx in the Navy - there have been three projects since the original USS United States (1797), none of which have been launched except for CVN-75, which was renamed USS Harry S. Truman (CVN-75). Acroterion (talk) 04:46, 3 February 2011 (UTC)
- HMS Argus (I49) was a converted liner - not a very good job, but not bad when you consider that no-one had ever built an aircraft carrier before. Alansplodge (talk) 21:46, 3 February 2011 (UTC)