Science desk | ||
---|---|---|
< February 7 | << Jan | February | Mar >> | February 9 > |
Welcome to the Wikipedia Science Reference Desk Archives |
---|
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
Especially about using NLP to make me invisible! I heard there's a British guy who perfected this. TinyTonyyy ( talk) 01:35, 8 February 2009 (UTC)
hey. can anyone help me out with this one?
recently according to some research in india it has come to light that because of pulse polio pragramme people from villages are not taking their kids for getting the scheduled vaccines! i wanted to do a project on this topic. can anyone give me any information about this topic? i would be really grateful to anyone who helps! thanks. —Preceding unsigned comment added by 59.92.242.169 ( talk) 16:05, 8 February 2009 (UTC)
Having done an Astronomy qualification, one thing still puzzles me - why the Sun appears yellow. It seems several sources diagree slightly on this: whether it is because the scattering of blue light in Earth's atmosphere leaves yellow (i.e. white minus blue = yellow) or whether it was because the atmosphere of the Sun - white light came directly from the Sun, but yellow could also be emitted in other directions, absorbed by Hydrogen (or Helium) and re-emitted in the direction of Earth. Are they both factors, and, if so, which is more important? - Jarry1250 ( t, c) 16:08, 8 February 2009 (UTC)
Spinningpsark alluded to this, but it bears saying by itself: We perceive the Sun as yellow because, when we can look at it, it's low in the sky and the higher frequencies are scattered away. When the Sun is directly overhead, it's white. In fact that's probably pretty much the definition of white. -- Trovatore ( talk) 21:47, 9 February 2009 (UTC)
Our eyes and brains have evolved to treat sunlight as "white" - regardless of what energies are emitted at what frequencies - the totality of sunlight MUST be "white" because it is the very definition of the word. Since the sky is blue - we know that some of the blue that comes directly from the sun must be being scattered across the sky - ergo the direct path of light from the sun must be white minus blue - which is yellow. SteveBaker ( talk) 03:10, 10 February 2009 (UTC)
The sun looks white when it falls on a surface on a clear day. But when you look (briefly!) at it it is surrounded by a blue sky, and color contrast may make it look yellow. Edison ( talk) 21:03, 10 February 2009 (UTC)
Whether this is or isn't a request for medical advice is being discussed here: [1]. StuRat ( talk) 22:28, 9 February 2009 (UTC)
so, to give you an idea of why I'm asking, I'm thinking about what notes are a physical impossibility to play in immediate succession on the piano (where "immediate sucession" would be a 64th note, or 128th or 256th, 512th, 1024th or whatever), even for someone who was playing the piano since birth + was the world's record fastest piano player + did this particular test on performance enhancing drugs... so I'm really asking about physics possibility!
what might be a good way to come up with a time in which it is CERTAIN no one can move their hand by, say, 1 meter, even once. I have some ideas for upper bounds: you can figure out the "jerk" that would be required (change in accelleration) and figure out what the time interval would be for which such a jerk would be sufficient to sever a hand. I mean, if you think about it, there MUST be a certain jerk that would sever a person's hand completely! But this is a way way way way way too high upper bounds! I'm looking for a more reasonable one... Any ideas?
One approach could be like, taking the power required for the displacement in the given amount of time, and making it larger than the maximum power human muscles can produce for any lenght of time. But it's hard because there are SO many muscles, the maximum instantaneous power oculd be huge -- I don't see why it coulnd't a gigawatt, if we're only talking about a SINGLE microsecond.
So any way to estimate physical impossibility?
I have to encourage a group of moderately disaffected youngsters to take seriously the need to express themselves clearly in written English. If all goes well, they will be accepted into Year One of university computer science programs. Their maths and CS abilities are in need of a little attention, hence this Year Zero program. Their English is in need of a lot of attention, hence this remedial class. As a generalisation, the group as a whole was "never good at English" at school, which is why they have opted for CS degrees. Some of them see little point in attempting to improve their written English, as they do not expect to have to use it in the careers they hope for.
My question to you: many of you, I take it, have or have had jobs to do with computers. Many of you enjoy the art of written expression (attested to by your voluntary participation here). How would you suggest I awaken the interest of these students? Or, if that is too blatantly an opinion question, what sources can you point me towards that demonstrate the value of clear written expression in the obtaining of desirable CS jobs? How does good English help in a good career? Many thanks! BusinessAsUnusual ( talk) 21:56, 8 February 2009 (UTC)
I've been a computer programmer for 35 years - and I'm very certain that I've written more English than C++ code (or any other kind of code) in the course of my job in all of those years. Documentation, comments inside code, messages to users from within your code...all of those things require good English skills. It's certainly a fact that you need good English skills. It's also a fact that many programmers are just like your kids and hate being made to write documentation and copious code comments...sadly. It's going to be hard to convince them that this is true though. I have a hard enough time making people write decent documentation who have the requisite skills. Math skills MAY be less important - it depends on what you're doing. You can write accountancy software knowing nothing but how to add and subtract...but if you want to write video games - your math skills had better be razor sharp or you won't even make it to interview. When the companies I have worked for are thinking of interviewing a job candidate, we first subject them to a half hour to an hour of 'phone interview' which probes math skills in great detail. Fail that and you'll never get as far as the front door. One of the things beginning programmers don't understand is that programming is a team activity. It's very rare indeed for someone to be able to write something by themselves. Yet schools and colleges (and people playing around with computers at home) pretty much treat it as a solo activity. When you have 10, 20, 50 people writing a piece of software containing several MILLION lines of software - the ability to communicate effectively is paramount. A lot of that is in email - Wiki's and (rarely) paper documentation...but it's English. If you think you can write emails in 'leet-speak'...you've got to be kidding! You'd be laughed off the team in the game programming teams I've worked on.
Sadly - I can't think of any way to enthuse them. I suppose you could get a real, live game programmer to come and talk to them (most companies are receptive to the idea of having their staff take a couple of hours out to go talk to local school/college kids once in a while). Unfortunately, your kids will cynically see this as another "Stay In School! Study Hard!" lecture and they'll likely just tune it out.
I applaud your efforts though. SteveBaker ( talk) 16:20, 9 February 2009 (UTC)
My girlfriend hears a high pitched noise when the tv set is on. She can tell when it's on even if she's not in the room.
what is she hearing? 192.136.22.5 ( talk) 23:51, 8 February 2009 (UTC)
I hear high pitched noise from a great many common electronic devices like TVs (including a new flat screen one), ethernet hubs (wireless or not), palm pilot type devices, digital clocks, etc. Often the noise is very quiet. Certainly these sounds are generally overwhelmed by the relentless household noise of the furnace, refrigerator, misc computers, etc. Sometimes I try to turn it all off. Inevitably I end up still hearing some electronic noise after turning the obvious things off and search around until I discover that there is a little hiss coming from the egg timer, or something. But it is always very striking how quiet it is when all the electrical things are off, making me realize how a myriad of ordinary household noises add up to a constant din. I guess most people are just used to it, or don't hear it as well? Anyway, it makes me wonder what is it about electronics that makes so much noise--hisses and hums and such... usually fairly quiet for a given device. Sometimes I've noticed solid state devices, like musical synths, get noisers over the years. Could it have to do with power supplies? Do Operational amplifiers tend to produce a bit of noise? Curious. Pfly ( talk) 08:50, 9 February 2009 (UTC)
Many people could hear the 15 khz TV noise when young. Audiograms taken over the decades may show that 15000 Hz is clearly audible in the young, but exposure to noise can cause severe hearing loss above 4000 Hz, Then when they are old, they may hear similar high pitched noise all the time, in the form of Tinnitus, although that is likely to be pulsating rather than steady. Exposure to loud noise like music, aircraft, traffic noise, shooting, mechanical or construction equipment, screaming babies over the years can eliminate the ability to hear high frequencies by causing Hearing impairment. This has led to Noise regulation laws. Edison ( talk) 20:54, 10 February 2009 (UTC)
Science desk | ||
---|---|---|
< February 7 | << Jan | February | Mar >> | February 9 > |
Welcome to the Wikipedia Science Reference Desk Archives |
---|
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
Especially about using NLP to make me invisible! I heard there's a British guy who perfected this. TinyTonyyy ( talk) 01:35, 8 February 2009 (UTC)
hey. can anyone help me out with this one?
recently according to some research in india it has come to light that because of pulse polio pragramme people from villages are not taking their kids for getting the scheduled vaccines! i wanted to do a project on this topic. can anyone give me any information about this topic? i would be really grateful to anyone who helps! thanks. —Preceding unsigned comment added by 59.92.242.169 ( talk) 16:05, 8 February 2009 (UTC)
Having done an Astronomy qualification, one thing still puzzles me - why the Sun appears yellow. It seems several sources diagree slightly on this: whether it is because the scattering of blue light in Earth's atmosphere leaves yellow (i.e. white minus blue = yellow) or whether it was because the atmosphere of the Sun - white light came directly from the Sun, but yellow could also be emitted in other directions, absorbed by Hydrogen (or Helium) and re-emitted in the direction of Earth. Are they both factors, and, if so, which is more important? - Jarry1250 ( t, c) 16:08, 8 February 2009 (UTC)
Spinningpsark alluded to this, but it bears saying by itself: We perceive the Sun as yellow because, when we can look at it, it's low in the sky and the higher frequencies are scattered away. When the Sun is directly overhead, it's white. In fact that's probably pretty much the definition of white. -- Trovatore ( talk) 21:47, 9 February 2009 (UTC)
Our eyes and brains have evolved to treat sunlight as "white" - regardless of what energies are emitted at what frequencies - the totality of sunlight MUST be "white" because it is the very definition of the word. Since the sky is blue - we know that some of the blue that comes directly from the sun must be being scattered across the sky - ergo the direct path of light from the sun must be white minus blue - which is yellow. SteveBaker ( talk) 03:10, 10 February 2009 (UTC)
The sun looks white when it falls on a surface on a clear day. But when you look (briefly!) at it it is surrounded by a blue sky, and color contrast may make it look yellow. Edison ( talk) 21:03, 10 February 2009 (UTC)
Whether this is or isn't a request for medical advice is being discussed here: [1]. StuRat ( talk) 22:28, 9 February 2009 (UTC)
so, to give you an idea of why I'm asking, I'm thinking about what notes are a physical impossibility to play in immediate succession on the piano (where "immediate sucession" would be a 64th note, or 128th or 256th, 512th, 1024th or whatever), even for someone who was playing the piano since birth + was the world's record fastest piano player + did this particular test on performance enhancing drugs... so I'm really asking about physics possibility!
what might be a good way to come up with a time in which it is CERTAIN no one can move their hand by, say, 1 meter, even once. I have some ideas for upper bounds: you can figure out the "jerk" that would be required (change in accelleration) and figure out what the time interval would be for which such a jerk would be sufficient to sever a hand. I mean, if you think about it, there MUST be a certain jerk that would sever a person's hand completely! But this is a way way way way way too high upper bounds! I'm looking for a more reasonable one... Any ideas?
One approach could be like, taking the power required for the displacement in the given amount of time, and making it larger than the maximum power human muscles can produce for any lenght of time. But it's hard because there are SO many muscles, the maximum instantaneous power oculd be huge -- I don't see why it coulnd't a gigawatt, if we're only talking about a SINGLE microsecond.
So any way to estimate physical impossibility?
I have to encourage a group of moderately disaffected youngsters to take seriously the need to express themselves clearly in written English. If all goes well, they will be accepted into Year One of university computer science programs. Their maths and CS abilities are in need of a little attention, hence this Year Zero program. Their English is in need of a lot of attention, hence this remedial class. As a generalisation, the group as a whole was "never good at English" at school, which is why they have opted for CS degrees. Some of them see little point in attempting to improve their written English, as they do not expect to have to use it in the careers they hope for.
My question to you: many of you, I take it, have or have had jobs to do with computers. Many of you enjoy the art of written expression (attested to by your voluntary participation here). How would you suggest I awaken the interest of these students? Or, if that is too blatantly an opinion question, what sources can you point me towards that demonstrate the value of clear written expression in the obtaining of desirable CS jobs? How does good English help in a good career? Many thanks! BusinessAsUnusual ( talk) 21:56, 8 February 2009 (UTC)
I've been a computer programmer for 35 years - and I'm very certain that I've written more English than C++ code (or any other kind of code) in the course of my job in all of those years. Documentation, comments inside code, messages to users from within your code...all of those things require good English skills. It's certainly a fact that you need good English skills. It's also a fact that many programmers are just like your kids and hate being made to write documentation and copious code comments...sadly. It's going to be hard to convince them that this is true though. I have a hard enough time making people write decent documentation who have the requisite skills. Math skills MAY be less important - it depends on what you're doing. You can write accountancy software knowing nothing but how to add and subtract...but if you want to write video games - your math skills had better be razor sharp or you won't even make it to interview. When the companies I have worked for are thinking of interviewing a job candidate, we first subject them to a half hour to an hour of 'phone interview' which probes math skills in great detail. Fail that and you'll never get as far as the front door. One of the things beginning programmers don't understand is that programming is a team activity. It's very rare indeed for someone to be able to write something by themselves. Yet schools and colleges (and people playing around with computers at home) pretty much treat it as a solo activity. When you have 10, 20, 50 people writing a piece of software containing several MILLION lines of software - the ability to communicate effectively is paramount. A lot of that is in email - Wiki's and (rarely) paper documentation...but it's English. If you think you can write emails in 'leet-speak'...you've got to be kidding! You'd be laughed off the team in the game programming teams I've worked on.
Sadly - I can't think of any way to enthuse them. I suppose you could get a real, live game programmer to come and talk to them (most companies are receptive to the idea of having their staff take a couple of hours out to go talk to local school/college kids once in a while). Unfortunately, your kids will cynically see this as another "Stay In School! Study Hard!" lecture and they'll likely just tune it out.
I applaud your efforts though. SteveBaker ( talk) 16:20, 9 February 2009 (UTC)
My girlfriend hears a high pitched noise when the tv set is on. She can tell when it's on even if she's not in the room.
what is she hearing? 192.136.22.5 ( talk) 23:51, 8 February 2009 (UTC)
I hear high pitched noise from a great many common electronic devices like TVs (including a new flat screen one), ethernet hubs (wireless or not), palm pilot type devices, digital clocks, etc. Often the noise is very quiet. Certainly these sounds are generally overwhelmed by the relentless household noise of the furnace, refrigerator, misc computers, etc. Sometimes I try to turn it all off. Inevitably I end up still hearing some electronic noise after turning the obvious things off and search around until I discover that there is a little hiss coming from the egg timer, or something. But it is always very striking how quiet it is when all the electrical things are off, making me realize how a myriad of ordinary household noises add up to a constant din. I guess most people are just used to it, or don't hear it as well? Anyway, it makes me wonder what is it about electronics that makes so much noise--hisses and hums and such... usually fairly quiet for a given device. Sometimes I've noticed solid state devices, like musical synths, get noisers over the years. Could it have to do with power supplies? Do Operational amplifiers tend to produce a bit of noise? Curious. Pfly ( talk) 08:50, 9 February 2009 (UTC)
Many people could hear the 15 khz TV noise when young. Audiograms taken over the decades may show that 15000 Hz is clearly audible in the young, but exposure to noise can cause severe hearing loss above 4000 Hz, Then when they are old, they may hear similar high pitched noise all the time, in the form of Tinnitus, although that is likely to be pulsating rather than steady. Exposure to loud noise like music, aircraft, traffic noise, shooting, mechanical or construction equipment, screaming babies over the years can eliminate the ability to hear high frequencies by causing Hearing impairment. This has led to Noise regulation laws. Edison ( talk) 20:54, 10 February 2009 (UTC)