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Tnad

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Posts posted by Tnad

  1. No, this has nothing really to do with the brain. This happens at the level of the receptors in the retina of the eye (which get slightly fatigued from over-firing), and the effect is known as an afterimage.

     

    http://faculty.washington.edu/chudler/after.html

     

    Thanks for your reply. However, I failed to relate my example to the link you provided since your link shows a colored image that is reproduced hence the after-image. Although my pic shows a Non-colored pic that after staring at it for a long time it is reproduced and this time with Colors. Reason why I was thinking that there might be some kind of editing that is done since the final results produces something that's far different from the initial data.Though I agree with your information that this happens mainly at the eye/retina level, I'd like to know if there isn't any extension of the process that takes place at the brain level. Thanks again.

     

    I hope this doesn’t take this thread too far off topic, but as a biker I have been made very aware, from experience, that we are sometimes blind to what we’re not expecting.

     

     

    http://www.theinvisiblegorilla.com/gorilla_experiment.html

     

    http://www.simplypsychology.org/perception-theories.html

     

    Thanks for yr reply. I guess you are talking about cognitive bias as shown in yr link abt selective attention-invisible gorrilla(actually I tried the experiments but I saw the gorilla bcoz i expected to see one from the title however I tried it with a friend of mine who said which gorilla?' then I said you didn't see a gorilla and the friend exclaimed 'Oh yeah I saw a gorilla!' by which I concluded that my friend actually saw the gorilla but didn't percieve the gorilla. And I guess dimreepr was also refering to a similar kind of selective/biased perception which happens to all of us almost everytime. I even doubt if one can ever be absolutely irrational since we always have some sort of bias that we sometimes don't have control over. ENOUGH SAID, LET'S GET BACK TO THE INITIAL THREAD, I appreciate yr links that arised some interesting facts (although the yahoo link is dead-can't access it) but still HOW DID YOUR EXAMPLES ABOUT DISTORTED PERCEPTION RELATE TO MY INITIAL POST? DID YOU MEAN THAT ONE PERCEIVES THE SECOND IMAGE DUE TO ONE'S EXPECTATIONS? In any case, I'm still trying to understand the implications.

     

    Thanks for all the replies. Keep them coming please!!!!!!

  2. 1.LOOK AT THE YELLOW DOT FOR 10sec. 2.THEN LOOK AT THE BLANK AREA

     

    538249_126184787520529_9038537_n.jpg

     

    I was amazed by this pic but most importantly by the final result. How by focusing for ten seconds on the yellow dot(which I call the center of gravity of the image), and then turning one's sight to the white/blank area, the image is reproduced in its actual/positive form. Does it have to do with the photographic ability of the human brain via the visual senses? does it imply that that the human brain has the ability of processing digital image data from negative(AS IN BLACK/WHITE) to positive (as in COLORED)? I can only make guesses but can't surely explain the implication of this wonderful realization.

  3.  

     

    I have refered to insane_alien as IA, but that one really isn't official.

    trust me this got me confused the first time i saw it. In my mind, IA referred to Internal Assement -back then when i was stuffed with IB IAs:] but when am on sfn .....

  4. you then run the test in an experiment by limiting the other factors

    I didn't mean in case of experiments but Research.

     

    the point of a hypothesis is to have a testable prediction
    .

    exactly, you start your investigation when you have already predicted the outcome! don't u think this is a key factor that will influence yr confirmation bias.

  5. 1.given that it is common knowledge that one needs to formulate a hypothesis before carrying out a research ( this applies mostly to scholars writting their theses). Then, isn't true that these hypotheses acts as misleaders since they fuel the confirmation bias of the researcher?

     

    2.again, if confirmation bias exists, disconfirmation bias must exist as well(seems like they are interdependent in a way!), but how can one give evidence of its existence without making proof that he is also influenced by confirmation bias?--(i mean how to argue neutrally about one of these biases)

     

    3.i think a 'fair' researcher should navigate btn confirmation and disconfirmation biases. what do you think about it?

     

    Thank you.

  6. Do you honestly think human beings will be around 5 billion years from now?

    Honestly, why not?!

    I would venture to guess that in a million years, humans will be extinct
    .

    Can you explain on which basis do you make such a guess?

     

    Will we be replaced by another species of human? Who knows.

    Exactly! we are still in evolution.Humans are still undergoing some slow transformations which may result into something different from what we call 'human' today but still called "another species of HUMAN"

  7. However,

    'The European Mars Express mission detected hints of methane in Mars's atmosphere last year, and some astrobiologists have speculated that the methane could be a by-product of extremophilic methanogens or some other form of microbial life.' Note also that they have been some bacteria found in the edge of our planet's atmosphere( are said to be far to have come from earth thus are from outer spaces). Hope they really are!why not.

  8. I've started reading "confessions of a philosopher" by Bryan Magee. I find it a nice introduction to philosophy.you don't need to hav some background in the field to read it.I am on the chapt.about Problem of perception.(seems like my skepticism is put on test,after all !!)

  9. Surprising!I thought i was the only one who makes up my ideas giving things colours, sometimes gender. I tend to imagine days,hours,letters& numbers each associated with a certain colour. However, i can't tell the criteria i use.for example Tuesday seems pink.Although I like pink, tuesday is not my favourite day of the week. A looks white,C is gray and Z is blue!

  10. if you think you know a country that no one else kow

     

    Can any one find one? ok maybe not on this limited earth surface, otherwise even the fact that it has a name,occupy some place on earth, then more than one person knows it.(internet makes it easy).

  11. There is no doubt that life could adapt fast enough to adjust to this change.

     

    Me too I believe that despite the moon receeding from us and earth slowing.

    however the catastrophic problem will be when the sun dies off. otherwise, we can still learn how to deal with the rest as long as we have energy.

  12. Do you mean to die in the sens of stopping to exist or stopping to live?

    coz things cease to live but still exist.althaugh in a different form.i consider the universe as a closed system where nothing is created any more or lost But where things keep on changing their forms of existing. so why not to think that maybe human won't stay the way they are now but will still exist?!

  13. Me too I have to say that i sometimes have that problem.But it is mostly in subjects/topics in which i have less interest.To deal with it I try to relate such names,events with something more interesting sometimes even funny as long as it enables me to remember.For your case I don't know your interest but for example, in recalling the uses of bronze I can call the elt Bronze for Bell( used to make bells) or B^2 or assemble its uses (let's say the first letter of each)in a way they make a sentence that i will easly remember. For theories try to internalise it relating to your daily life and mark an attention on their differences it will enable you to know this is the first bcoz xyz... thus this is next.For me I sometimes create some links between theory and the person(althaugh mostly not logical, i forge it as long as it helps me remembering both!)but keep the real explanation! nice that u're good remembering basic principles,u can make it easly!

  14. ttemp-sunspot-co2_svg.png

    the sun is the main controller of earth climate. NASA funded study has been carried out to check its influence on actual temperature changes. an increase of 0.05% per decade is observed in solar radiations emitted.Thaugh small,the number can cause significant changes in earth temp per decade.Another experiment by NASA found a sun-climate connection by refering to old nile records and actual situations.Variations in sun's uv cause adjustement in climate pattern called northern annular mode affecting climate in north hemisphere.Which is the actual conditions.It was observed that when solar activity is high condition are drier and wetter when solar activity is low. C02 is a greenhouse gas,C02 is increasing; temp. is increasing; does it necessarly follow that c02 is increasing temp.! In 1940,despite high c02 emissions, temp, decreased. Even now, the temp, keeps increasing and decreasing.The above graph shows relationship between temperature,c02 and solar activity.The c02 curve is ever increasing which is not the case for temperature.However the temp curve has changes not far corresponded to sunspots curve changes.

     

    http://www.scienceforums.net/forum/attachment.php?attachmentid=2485&stc=1&d=1272487244

    Below is another graph

     

    CO2 increases well below the projected path. The blue region shows the IPCC’s currently-projected range of increases in CO2 concentration; the blue curve beneath this region is NOAA’s deseasonalized global trend; the cyan line is the least-squares linear regression on that trend, equivalent to ~200 ppmv/century.

     

    Careful examination of Figure shows that the IPCC’s CO2 projections are exponential curves, so that the IPCC imagines the concentration will reach its projected interval [730, 1040] ppmv by 2100, central projection 836 ppmv. However, the observed trend is entirely below the IPCC’s predicted path. Furthermore, the residuals of the NOAA’s CO2-concentration trend are so close to the fit that the trend may itself be near-linear, in which event, even if humankind takes no action at all to curb CO2 emissions, the concentration by 2100 will be little more than 580 ppmv. Note that the IPCC does not even include its estimates of the CO2 concentration by 2100 in its 2007 Summary for Policymakers.

    Climate sensitivity: the effect of CO2 on temperature: At its simplest, the IPCC’s guess is that the effect of changes in CO2 concentration on temperature is logarithmic: i.e. a multiple of the natural logarithm of the proportionate increase in CO2 concentration:

    ?Ts = c ln(C/C0),

     

    where the bracketed term is the proportionate increase. From the fact that the IPCC’s projected temperature change in response to a doubling of CO2 concentration is [2, 4.5] °C, central projection 3.26 °C, we may calculate that the coefficient c in the CO2-change-to-temperature-change equation falls on the interval [2.9, 6.5], central projection 4.7.

     

    If, ad argumentum, the IPCC’s central projection of the influence of CO2 on global temperature were correct, and taking today’s CO2 concentration as 385 ppmv, then at our projected 580 ppmv in 2100, we might instantly derive the corresponding increase in mean global surface temperature compared with today, thus –

    ?Ts = c ln(C/C0) ˜ 4.7 ln(580/385) ˜ 1.9 °C.

     

    This value is little more than half the 3.6 °C that would result by 2100 if CO2 concentration were to increase at the IPCC’s central rate, giving 836 ppmv rather than 570 ppmv by 2100.

     

    Thanx.

    temperature_co2_change_scientific_briefing.png

  15. Allow me to make some clarifications

    1.

    timo;561392]I find it hard to believe that you are asked about the politics of global warming in a science exam

    Of course no! actually the second post was directed to IA; I wanted you to consider the first.thanx.

    2.@ VedekPako

    True that it is not false because it is used by politician.and I didn't say so. I said it is exaggerated(by some scientist or wrongly explained) in order to gain support from goverments.Thus a propaganda.

    3.@IA

    I think I either misunderstood your qn or you misunderstood me. You asked why I think it is a propaganda thus I looked at the qn in a political angle and that is how I answered (in politics,quotes are not crap). However even If you re-read my first post, I first said that i do not believe that it is a result of man activities there follows that I believe it is a result of other activities not controlled by man. actually,the political side of the fact doesn't matter when comes to my exams. If you did google the people I mentionned, you should have realised that they are scientists not politicians.their research is Scientific and that is why I referred you to them. They explain it better "scientifically" unless you wanted me to reproduce their works to show why I desagree "scientifically".

     

    4. Pliz, consider my first post , that is the problem for which I need the answer. not the explanation of my political views which has nothing to do with my exams.

    Thank you!

  16. just out of curiosity(and to give you some practice) why DO you think its propaganda?

     

    Well,of course I dont have one answer to that but many or a long one.

     

    It's a propaganda bcoz 'it is an idea that is false or exaggerated ,used to gain support from a political leader'; do you thing GW is not fit within that definition? What was the aim of the copenhaguen and all these other meetings about global warming? do you think any leader can maybe say that he is not interested in GW business and still be considered 'normal'( I can't find the right term). any world leader MUST support the idea.Is it the case for other sientific issues? I think of let say leader X decides there will be no more space exploration projects funded by the gov't, no matter the importance, it won't be such an issue except in the scientific community but politically, who cares? It's not a 'MUST support' issue!

     

    '"the essence of the Greens’ theory of global warming—has about as much basis in science as Marxism and Freudianism. Global warming, like Marxism, is a political theory of actions, demanding compliance with its rules.

     

    Marxism, Freudianism, global warming. These are proof—of which history offers so many examples—that people can be suckers on a grand scale. To their fanatical followers they are a substitute for religion. Global warming, in particular, is a creed, a faith, a dogma that has little to do with science. If people are in need of religion, why don’t they just turn to the genuine article?

     

    —Paul Johnson

    do you think Paul is absolutely wrong! I don't think so.

     

    "Global warming is a topic that sprawls in a thousand directions. There is no such thing as an ‘expert’ on global warming, because no one can master all the relevant subjects. On the subject of climate change everyone is an amateur on many if not most of the relevant topics.”

     

    True or not?

    I can't tell all the facts WHY, but here are some people, who,in their respective areas and with their respective abilities, have done some studies and researches about the 'untold' side of the issue.

    Prof Bob carter(Reaserch prof ,Australia),Willie soon(astrophysicist,harvard). Google them, there are related articles about their assertions. Then u can compare and make your conclusion.(some articles will be against them of course but it's suprising to observe how some people don't want to look at the other side of the issue!why?!!)

     

    Again thanx for all the advices .They are welcome.

  17. Great!You mean magnetism is affected by temperatures!

    By the way, why do the magnetic field lines have to cross from pole to pole if they originate from the center?(case of the sun)

    and the creation of sunspots is linked( thaugh maybe indirectly) to the twisting of magnetic flux tubes at the sun equator(due to faster rotation) which slows the convection currents ....etc right? so the rotation also affects the magnetic field ? how is it linked to the electric conductors which had generated the magnetic force?

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