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How would THE observer explain another observer, such as humans or amoeba, which have free will and the ability to create endless entropy through thought and interaction with/unexpected manipulation of its known universe? Does an observer only have vision, hearing, smell, feeling(physical), taste?
These kinds of question essentially boil down to Ontology and even Epistemology, which are very broad and complex subjects. People have been contemplating them for thousands of years, so I don't think you'll get a quick and easy answer. I would say however that gathering knowledge does not have to be restricted to the physical senses, otherwise how would we know that atoms exist. Vespine (talk) 03:08, 3 March 2011 (UTC)[reply]
B/C we use our senses to interpret the output of the apparatus that was made by us (with our hands).
In which case you again come back to epistemology. It was a rhetorical question. Vespine (talk) 22:05, 3 March 2011 (UTC)[reply]
Actually you misinterpreted the question. Like if the observer were observing 4-d space with some matter and some energy in it, and he was doing this for a period of time, when a pteradactyl flies by the matter and interacts with the energy, how would the observer explain this and his opinion of the matter and energy from that point on.
Using the laws of physics, only of course. wouldnt he have to include that event mathmatically for every subsequent observation?
In which case sorry but I don't really understand what you are trying to ask.. What do you mean by how would they explain it? Do you mean how would they model the interaction? Or how would they explain the forces involved? Or how would they predict the outcome? Or something else? The initial question was something about using your senses, while ultimately anything you can perceive or conceive is mediated by the senses, no matter what instruments or techniques you use, that doesn't mean nothing is real and nothing can be known or explained. Vespine (talk) 03:24, 4 March 2011 (UTC)[reply]
Yes. yes. no. no. I meant in the article "observer" it talks about the observer being the reference frame -four dimensions of spacetime. 'Note that these uses differ significantly from the ordinary English meaning of "observer". Reference frames are inherently nonlocal constructs, covering all of space and time or a nontrivial part of it; thus it does not make sense to speak of an observer (in the special relativistic sense) having a location. Also, an inertial observer cannot accelerate at a later time, nor can an accelerating observer stop accelerating.' But that alone does not ensure the ability to percieve the universe, just part of it (empty space). it gives matter a place to be, but not matter or energy itself.
Personally, I think the whole concept of observation is a pointless fudge of a concept - everything in the universe is observing everything else, albeit indirectly or otherwise. There is no yes or no answer to whether or not some process is being observed or have been observed. It's all about "stage fright", is the audience big enough. In double slit electron experiment, the apparatus is observing the electron's double path, even if the exprimentor is not. I think it's related to the Butterfly effect, the further the effects of a proccess become magnified, the less stable the super position becomes. (the bigger the "stage fright"). Plasmic Physics (talk) 04:49, 4 March 2011 (UTC)[reply]
That will make it easy for me to disregard your observation.
How is that? I think you're confusing observation with deduction. Plasmic Physics (talk) 21:25, 4 March 2011 (UTC)[reply]
Kind of like how you confuse have with has.
You are missing the point I am not talking about AN observer, I am talking about the objective frame of reference like you are talking about, du, the apparatus - the observer "'Note that these uses differ significantly from the ordinary English meaning of "observer". Reference frames are inherently nonlocal constructs, covering all of space and time or a nontrivial part of it; thus it does not make sense to speak of an observer (in the special relativistic sense) having a location. Also, an inertial observer cannot accelerate at a later time, nor can an accelerating observer stop accelerating.'
I know, I was just making a side note. Not sure about your logic though. A reference frame is completely arbitrary, with an assigned coordinate relative to an observer and event. Plasmic Physics (talk) 02:04, 5 March 2011 (UTC)[reply]
OK in my example above, wouldn't the "laws" of physics all have to contain the effect of the flyby forever? Every measurement would discover the anomaly and have to explain it or on the contrary incorporate it as part of the laws. If you didn't observe the flyby you would have no idea that it was a pteradactyl. We know that the flyby has is happened(ing) at least once because we are the ones flying by. Why couldnt it have happened any number of times before.
If I wasn't confused before, I am now. I leave it to someone else to interpret. Plasmic Physics (talk) 12:35, 5 March 2011 (UTC)[reply]
What happens when I divide two random physical units? To me, it is clear that km/h is speed. But, what about height/temperature of a body? May I name the resulting unit towards me? 212.169.189.17 (talk) 03:05, 3 March 2011 (UTC)[reply]
It's adoption not discovery which gives units their names. You haven't really "discovered" anything new or novel. Celsius is named after a person, but he didn't "discover" temperature, he invented a good and reliable way to measure it, so people used it, he didn't "force" people to use it or impose some sort of patent to measuring temperature that everyone had to use, even now lots of people prefer Fahrenheit. It's not enough to simply stick 2 existing units together, you have to "offer" something new that people will want to adopt. Vespine (talk) 03:27, 3 March 2011 (UTC)[reply]
You're welcome to name a derived unit after yourself, but as Vespine notes, no one is likely to follow your lead without compelling reason to do so. The General Conference on Weights and Measures (CGPM) is responsible for officially adopting names and prefixes for the units which form the International System of Units (SI, or the 'metric system'). If you can sell the CGPM on your new unit, you'll be set—otherwise, this is an unlikely route for you to achieve immortality. TenOfAllTrades(talk) 03:35, 3 March 2011 (UTC)[reply]
Dimensional analysis shows what happens. You need to use absolute temperature to get anything physically meaningful. Dmcq (talk) 04:11, 3 March 2011 (UTC)[reply]
If I divide my absolute temperature (310 K) by my height in cm (181) I don't believe I get anything meaningful. What does 1,71270718 K/cm mean? The calculation are, at the first sight, right. Quest09 (talk) 15:32, 3 March 2011 (UTC)[reply]
How compound units like that become useful is through data correlation. For this example, assume I had tons of patient data and I'm looking at some outcome. I find that the outcome is positively correlated to the patient's temperature and negatively correlated to the patients height. I would then derive a formula that multiplies some constant by the temperature and divides by the height. Then, I'd have a result in temp/height units that would have meaning for that particular outcome. So, trying to make a compound unit without reason simply isn't reasonable. Deriving it as part of an observation is reasonable. -- kainaw™ 15:43, 3 March 2011 (UTC)[reply]
The PDF by Vignaux, G.A. (1991). "Dimensional analysis in data modelling", linked to in the Buckingham π theorem article, discusses that point. 92.15.15.174 (talk) 21:25, 3 March 2011 (UTC)[reply]
At one time it amused me to rank colleges by "books per acre," as opposed to more commonly cited stats like "student-teacher ratio." A large midwestern (US) university needed a humongous library to equal a compact downtown college in my index. Thus Purdue University (2.5 million books, 15,000 acres) has a ratio of 166, slightly higher than Shimer College, ratio 120 (20,000 books, 166 acres. Michigan State University ranks higher with a ratio of 490 (4.9 million books, 10,000 acres. This ratio addresses the issue of whether one would prefer to read or wander around. Edison (talk) 05:11, 4 March 2011 (UTC)[reply]
Thats funny, that is not the information I used before I would wander around my campus, even if I has such info. —Preceding unsigned comment added by 165.212.189.187 (talk) 13:46, 4 March 2011 (UTC)[reply]
One of my instructors once mentioned how you can get in trouble with blind dimensional analysis. Consider a sailboat of length L moving at speed V. Then the age of the captain is T=L/V. Short Brigade Harvester Boris (talk) 08:16, 5 March 2011 (UTC)[reply]
This is just the wrong way to think about it. You divide physical units to get a new unit to reflect that you divide physical quantities to get a new, meaningful quantity. By starting out thinking about dividing units, you're doing something that has no meaning at all. You have to think why you are dividing height by temperature, and what the result might mean.--Srleffler (talk) 17:49, 5 March 2011 (UTC)[reply]
how can i make firefox or ie save my address when i make a order. it wont do it — Preceding unsigned comment added by Wdk789 (talk • contribs) 05:51, 3 March 2011 (UTC)[reply]
Do you want Firefox/Internet Explorer to automatically fill out your address in web forms? Firefox stores the username/password fields if enabled ( Tools / Options / Security ). It can also guess what to put in the form, for example, if a form has a field called "username", then firefox will examine the value of all the "username" fields that you've previously filled out, and use this for the auto-completion values. As WNT said, you'd be far better of asking at the computing desk for more details. CS Miller (talk) 12:53, 3 March 2011 (UTC)[reply]
IT IS ENABLED BUT ITS not working sry caps — Preceding unsigned comment added by Wdk789 (talk • contribs) 11:15, 4 March 2011 (UTC)[reply]
Why is Sydney Basin called Sydney Basin? 220.233.83.26 (talk) 06:25, 3 March 2011 (UTC)[reply]
Have you tried reading Sydney Basin? Lots of information there. Dolphin(t) 06:33, 3 March 2011 (UTC)[reply]
yer i have now thanks! but just quickly how was the basin formed in like a dead easy way that even i can understand. i anyone could help me with this i would be really appreciative. 220.233.83.26 (talk) 06:48, 3 March 2011 (UTC)[reply]
alright thanks guys for answering me... :/ ^^ 220.233.83.26 (talk) 09:18, 3 March 2011 (UTC)[reply]
The Sydney Basin is an example of a foreland basin. Foreland basins area created by the loading of the leading edge of a tectonic plate by a thrust belt. This loading cause downflexing and the accommodation space is then filled with sediment. The loading also causes a flexural forebulge to develop, which migrates with time into the foreland as does the foreland basin. A typical sequence would be - continental to shallow water sediments derived from the forebulge followed by progressively deeper water marine sediments (often called a flysch sequence) finally filled in by coarse material (conglomerates and sands derived from the mountain belt) deposited into progressively shallower water before becoming continental again (often referred to as a molasse sequence). The sequence described for the Sydney Basin matches this pretty well. Mikenorton (talk) 10:07, 3 March 2011 (UTC)[reply]
A statement issued by the Second World Social Forum on Health condemned the "World Health Organisation's lack of transparency in acknowledging the failure of the Global Polio Eradication Initiative strategy and instead...using monovalent OPV, an untested vaccine, without informed consent." According to this document, mOPV1 is not a new vaccine. "Except that it does not contain types 2 and 3, mOPV1 is in all other respects similar to tOPV...monovalent oral polio vaccines for all the 3 types of polioviruses were used extensively in the early days of polio vaccination in the late 1950s and early 1960s". Is there any merit in the statement of World Social Forum on Health? Did they withdraw it later? There have been condemnations about the trials of bivalent polio vaccines in India as well. Is the situation same? A WHO document mentions "In 2009, a clinical trial was conducted in India to compare the rates of seroconversion to WPV1 and WPV3 generated by a bOPV with that of the respective monovalent OPVs (mOPV) and trivalent OPV (tOPV)". But the Government of India, while introducing the vaccine in 2009, claims that "The vaccine will be new for India but it is an established vaccine with many developed countries already using it".14.139.128.15 (talk) 07:13, 3 March 2011 (UTC)[reply]
The “negative aspects” mentioned in the Second World Social Forum on Health highlight the fact that when wild polio is 'almost' eliminated from a geographic area, then most cases of acute flaccid paralysis arises from the live attenuated polio vaccine viruses reverting back to their 'wild' and dangerous form. As different companies often come out with their own version of existing vaccines, I assume that the untested OPV mentioned, is new product and thus still untested an OPV(as of 2007) rather than one of the older ones. Ideally, prophylactic measures employing killed injectable polio virus (which can't revert back) would be therefore more advantageous to mope up the last remnants of polio in a nearly polio free area but unfortunately these countries are denied these more expensive injectable vaccines due to cost augments. Thus the local people start to resist getting any more of their children vaccinated for this disease and the local health providers get the blame for poor vaccine coverage and the inevitable return of circulating polio. India is now facing the same situation where it would make more health sense to switch over to injectable killed viruses. It all come down to money. That's it I think -in a nut shell.--Aspro (talk) 16:34, 3 March 2011 (UTC)[reply]
Thank you very for for your reply and also for showing me the NEJM article. In response to a mail of mine, the author, John F. Modlin, said that "The statement by the World Social Forum on Health is frankly disingenuous and misleading. The monovalent vaccines used in India today are derived from the same strains used 50 years ago to control polio in many (at the time) industrialized countries. I would not give this statement any credence." 14.139.128.15 (talk) 13:45, 5 March 2011 (UTC)[reply]
Whoa whoa whoa! If that's the case, then why do countries like the UK still use oral polio vaccine? Last I checked, polio was pretty much eliminated here except for unvaccinated people changing recently-vaccinated babies' nappies. I know there was something about new mothers being vaccinated to avoid that, but why not switch to injectable killed virus? 82.24.248.137 (talk) 21:45, 4 March 2011 (UTC)[reply]
I have checked on the BNF just to make sure of the situation now, as these things often change. A live oral vaccine is still licensed and available to control an outbreak, should there be one and can thus can be supplied in one and ten dose containers. So NOT used but can be. Routine immunisation still uses as of 2004 (as the two above references state) inactivated forms and usually administered as one of the polyvalent vaccines which includes diphtheria and/or tetanus. I wouldn't give undue wait to any criticism any doctor levels at an organisation or forum without knowing just how deeply they are involved in creating the vaccination policy being criticised or promoting the pharmaceutical company that manufactures the product being used or both. If, instead of answering the criticisms, they come back with flat out contradictions (a new vaccine might be derived from the same strain isolated 50 years ago but how does that make the new product proven - it's a non sequitur ), ect... Well! I leave you to judge.--Aspro (talk) 15:34, 5 March 2011 (UTC)[reply]
A patient with history of immbolization also suffers from chest pain. How closely does the patient's past history of immbolization affect the patient, who also has recurrent chest pains?
aniketnik (talk) 08:07, 3 March 2011 (UTC)[reply]
Whoa, sorry I misread the question!!! Ignore response below. I assume you mean embolisation
What caused the immobilisation? was it muscular? neurological? trauma? Does the term "past history" mean that the patient is no longer immobile? What is the character of the chest pain? I think a more focussed question would be helpful - assuming this is not seeking medical advice. Richard Avery (talk) 08:29, 3 March 2011 (UTC)[reply]
Is this a homework question? Ariel. (talk) 09:58, 3 March 2011 (UTC)[reply]
The patient has a past medical history of immobilisation because of a motor vehicle accident that happened many years ago. Following the accident the patient was in a knee immobilizer for a short span of time. The musculoskeletal system of the patient is now functioning properly. So the patient is now no longer immobile. The patient is an obese male and being obese the patient has recurrent sharp chest pain, which occurs at regular intervals. So does the past history of immobilization followed by obesity, is it going to one of the major contributing factor to the patient's physical condition? Is the past medical history of immobilization affecting the patient's health and also in one way or other responsible for the frequent and recurrent chest pains? — Preceding unsigned comment added by Aniketnik (talk • contribs) 04:31, 4 March 2011 (UTC)[reply]
This reference desk can not answer these types of medical questions, sorry. Does the patient have a doctor? Ariel. (talk) 07:08, 4 March 2011 (UTC)[reply]
The patient has an allergy to Meperidine drug. What effect does Meperidine have on a patient who has an allergy to Meperidine?
aniketnik (talk) 08:10, 3 March 2011 (UTC)[reply]
This question is borderline on if we can answer it. On one hand it's a request for information, not diagnoses. But on the other it sounds like you would make a medical decision based on what we would say, and that would be a problem. I can point you to Meperidine which has some information on this drug (although nothing about allergy). And also suggest that since this is a painkilling drug, perhaps pick a different one. Ariel. (talk) 09:56, 3 March 2011 (UTC)[reply]
Also: Is this a homework question? Ariel. (talk) 09:58, 3 March 2011 (UTC)[reply]
Why is the shannon diversity denoted H'? Our article Entropy_(information_theory) uses H for the same quantity. Enthalpy is also denoted by H, but physical entropy uses S. So, is there some rationale or historical reason for using H' to denote the Shannon-wiener index? Thanks, SemanticMantis (talk) 15:57, 3 March 2011 (UTC)[reply]
The rationale is that it is calculated using the same formula. The only difference is that the values that get plugged into the formula are population fractions rather than probabilities. Looie496 (talk) 17:50, 3 March 2011 (UTC)[reply]
The question is since, as you pointed out, this index uses the same formula used for entropy, why don't they use the letter S to represent it? Dauto (talk) 19:15, 3 March 2011 (UTC)[reply]
Ok, I just dug into Shannon (1948). He uses H, and says it is the same as Boltzmann's H from "Boltzmann's famous H theorem." Am I correct to assume this must have been Boltzmann's entropy? That is, perhaps Boltzmann originally used H, but later changed to S. In any case the H' notation seems spurious, I may change our article to H unless I find any good reason not to. As it stands, using H' in some cases and H in others makes a distinction without a difference. SemanticMantis (talk) 19:31, 3 March 2011 (UTC)[reply]
Mathematicians in general don't have much patience with worries about what letters are used to represent things. In fact, one of the greatest challenges in teaching mathematics is getting students to see through the letters and symbols to the conceptual entities they are supposed to represent. Looie496 (talk) 01:23, 4 March 2011 (UTC)[reply]
Indeed. However, compact, efficient notation is still useful and desirable. Also, I'm specifically talking about the use and notation of the shannon index in biology, not as a topic in pure math. "Seeing through letters and symbols" is not something an undergrad bio major is accustomed to, so why make it more difficult than we have to? SemanticMantis (talk) 15:19, 4 March 2011 (UTC)[reply]
what is magnetic polarity in a electric currentedit
sorry for the strange wording but what is magnetic polarity in a electric current — Preceding unsigned comment added by Lufc88 (talk • contribs) 19:13, 3 March 2011 (UTC)[reply]
See Right-hand rule. Prediction of direction of field (B), given that the current I flows in the direction of the thumb.. If your right hand were encircling a wire carrying current, with the thumb pointing in the direction conventional current (positive to negative) flows, then the fingers point in the direction of the magnetic B field. The arrow on the B field corresponds to the North pole of a magnet. The magnetic field corresponds to a series of concentric circles, and the field is stronger near the conductor. The arrangement of the conductor (one wire, a solenoid, a solenoid around a ferromagneticmaterial) strongly affects the shape and strength of the magnetic field. (Do not actually put your hand around a bare wire carrying current, since you might get electrocuted! It is just a "thought experiment.") Edison (talk)
Just chiming in to link the pictures at solenoid. Loosely, when the wire is straight, the magnetic field lines are circular, but wrapping the wire in a coil produces a magnetic field with straight lines inside the solenoid. SemanticMantis (talk) 21:17, 3 March 2011 (UTC)[reply]
Hi. The Sun is currently in an active phase, and some sunspots as well as coronal holes are present and capable of producing both solar wind and strong solar flares. My question is, do the potential X-class solar flares pose a risk to astronauts currently in space? Also, are the SDO and other instruments capable of monitoring sunspots behind or to the side of the Sun? Thanks. ~AH1(TCU) 19:46, 3 March 2011 (UTC)[reply]
This isn't a complete answer at all, but this link discusses the Forbush decrease, in which a coronal mass ejection results in less radiation absorbed by astronauts who happen to be up there at the time. Comet Tuttle (talk) 21:04, 3 March 2011 (UTC)[reply]
In Earth orbit the Magnetosphere attenuates the particle flux down. This NASA article explains the potential X class danger to the station. Sickening Solar Flares . As the article mentions, the aluminium hull further reduces the danger. The impact though, produces a shower of secondary particles and so a plastic shield (because it is made of lots of light atoms) has been added to reduce these secondaries.--Aspro (talk) 22:04, 3 March 2011 (UTC)[reply]
The Big Bang (the event) is better classified, per the article lede, as "the event which led to the formation of the universe, according to the prevailing cosmological theory of the universe's early development (known as the Big Bang theory)" than as a "fact". We also note that the Big Bang theory incorporates some of the best-ever matches between theoretical predictions and observed values in all of science (the Cosmic Microwave Background).
Alternately, what do you mean by "fact"? — Lomn 00:01, 4 March 2011 (UTC)[reply]
I'm just debating with an annoying religious guy, and I want to make sure I'm correct if I say the Big Bang is a fact. ScienceApe (talk) 00:03, 4 March 2011 (UTC)[reply]
The big bang is a theory supported by an overwhelming amount of evidence and almost univerally accepted by mainstream science. Some people choose to describe such things as "fact". Personally, I prefer to avoid the word. --Tango (talk) 00:25, 4 March 2011 (UTC)[reply]
But if I were to call it a fact, I wouldn't be wrong would I? ScienceApe (talk) 01:32, 4 March 2011 (UTC)[reply]
You might be, though so would the majority of cosmologists. Scientists prefer to use more cautious language when describing the current understanding of the universe. Theories are always being evaluated and refined. While I doubt that the Big Bang theory will be shown incorrect the way, say Phlogiston theory was, it's certain that the currently accepted cosmology will continue to undergo revision. Buddy431 (talk) 01:45, 4 March 2011 (UTC)[reply]
The Big Bang is the model that best explains a lot of evidence that we've seen (the evidence itself is definitely fact). Scientific theories aren't definite, final, and certain; they're all open to revision and replacement, and a lot of people don't understand or just don't like that, even though it's Science's greatest strength. In other words: good luck. -- Consumed Crustacean (talk) 01:52, 4 March 2011 (UTC)[reply]
(edit conflict with SA) The article History of the Big Bang theory is interesting as well, if a bit rough. Since the late 1960s, with the measurement of the Cosmic microwave background radiation, the Big Bang theory has become the overwhelmingly accepted model for the early history of the universe. In recent years, the CMB has been measured with greater and greater accuracy, with spacecraft such as the WMAP. While proponents of Non-standard cosmologies are not necessarily cranks, it is becoming increasingly difficult (both scientifically and socially) to entertain serious alternatives to the standard cosmology. Buddy431 (talk) 01:41, 4 March 2011 (UTC)[reply]
Well, there is a difference between a fact and a theory, but again it boils down to an argument of epistemology.. Take evolution for example, there is the FACT of evolution (that at its core) allele frequency varies over time in populations of animals; The THEORY of evolution proposes natural selection as the primary method by which this occurs. We have a Big Bang THEORY, but what is the "facts"? The facts are we have MBR and cosmic expansion and all those other things which perfectly fit the model of the big bang theory and no one has been able to come up with a better explanation, but will that ever lead to Big Bang being a "absolute fact"? I don't think it will, even if it is justified true belief. The problem as I see it is, generally "religious minded" people can't get it into their skulls that their doctrines which "claim" to be infallible and absolute are actually LESS reliable then science which makes no such claims and humbly accepts it doesn't know the absolute truth of much at all. Vespine (talk)
How about to get him to agree its a fact you say that his god was the one who made the big bang, because it was the only way to make other beings or whatever reason he is arguing. —Preceding unsigned comment added by 98.221.254.154 (talk) 03:18, 4 March 2011 (UTC)[reply]
You state that you'r debating with an "annoying religious guy". Such guys are not really after fact, or having their opinions up for reconsideration. It's a distinction between dialogue and rhetorics that's been debated since Gorgias. EverGreg (talk) 08:43, 4 March 2011 (UTC)[reply]
