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Showing content with the highest reputation on 09/02/20 in Posts

  1. 1 point
    Hi everyone! I am currently getting myself started in Physics. But for some reason I can't understand what vectors and scalers actually are.
  2. 1 point
    A scalar is something that can be represented by a number (and usually units) Mass, for example. A rock with a mass of 2 kg. A vector has a direction. It has a value, but also tells which way. Velocity, for example. “moving 10 m/s in the x-direction” The magnitude of a vector is a scalar “I am 100m north of you” represents a vector. “I am 100m away” represents a scalar.
  3. 1 point
    Good question. Maybe when you tickle yourself, you already know exactly the location and the kind tickle you intend. When somebody else tickles you, you cannot anticipate location and kind of tickling? After my answer I googled "why can't i tickle myself" and I got this: "...basically comes down to your cerebellum having the ability to predict the tickle, therefore cancelling it out before the sensation takes over. "Our studies at University College London have shown that the cerebellum can predict sensations when your own movement causes them but not when someone else does," Blakemore explained to Scientific American. "When you try to tickle yourself, the cerebellum predicts the sensation and this prediction is used to cancel the response of other brain areas to the tickle." https://www.sciencealert.com/the-scientific-reason-you-can-t-tickle-yourself
  4. 1 point
    Would that be because it's a hard drive ? That about describes the original T - Model, currently posing as President.
  5. 1 point
    1) Ants can’t die from falling Because of their body proportions and tough exoskeleton, an ant’s terminal velocity isn’t enough to kill or hurt it on impact. They can survive being dropped from the Empire State Building and walk away unharmed. 2) You can't kill yourself by holding your breath At the very worst, voluntary breath-holding will only lead to unconsciousness. 3) You can't tickle yourself ---------- 1) and 2) make a lot of sense. Why 3)?
  6. 1 point
    Everything we can detect is within the observable universe. Beyond the last scattering surface, the universe is opaque to radiation and we can't see anything, except maybe with gravitational waves; and beyond that, not even with gravitational waves. I agree that local objects bend space, but on average the universe looks very (spatially) flat. Around black holes and very massive objects you can detect local curvature, like e.g. Einstein rings, but the sphere of the sky looks pretty flat overall. What the paper that @iNow has linked to seems to imply is that within the observable universe the telescopes have detected large-scale lensing that must have to do with curvature within the horizon. That's what's very surprising to me. I'd like to follow up on that.
  7. 1 point
    What happens of you import numpy?
  8. 1 point
    Hi. Welcome. Very old question, but very difficult to answer nonetheless. So I'm going to get hold of some visual aids found on the web. Nothingness is quite easy to picture in your mind. Maybe we get that picture from our hours of sleeping without dreams. I don't know. But, The picture of the closest thing to nothingness that we can build from physics is not a featureless scenario. It's more like this: Or, more diagramatically, like this: A perpetual struggle of opposites annihilating each other. It just isn't just nothing. What it suggests is that what we call "nothing" is more like this ephemeral tug of war between ephemeral somethingnesses (virtual particle-antiparticle pairs). Nothing (in a poetic picture derived from serious physics) is a struggle between opposites in which nobody wins. At some point in the past, somebody won (why that was so is still an enigma; I don't like the word "mystery".) The status of the theory so far is that something like this sea of opposites annihilating each other must have fell downhill some kind of modulating field (inflaton field) 13 point something billion years ago, generating real particles and filling the universe with structure. That's called inflationary model of the universe. I hope that helps, but it's been a long time since Leibniz set that question to nowadays. So the story has become more involved.
  9. 1 point
    AFAIK it's diffraction from something that can be approximated as a point source (as opposed to a plane diffractor, e.g. a grating)
  10. 1 point
    In the context of distortion, phase shift ( of 45o ) can be interpreted as a time delay. The distorting component is delayed by a time equivalent to one eigth of a cycle. More information might be available if you can expand on the context.
  11. 1 point
    You can think of complex numbers as points on a plane where the real numbers form the X axis and the “imaginary” numbers (multiplied by i) form the Y axis. Values multiplied by sqrt(i) would form a line at 45º. To put it another way, multiplying by i is equivalent to rotating by 90º and rotating by sqrt(i) is equivalent to rotating by 45º. Note that rotating by 45º and then by 45º (i.e. rotating by 90º) is equivalent to multiplying by sqrt(i) then by sqrt(i) again; in other words multiplying by i (i.e. rotating by 90º). (Because they can encode angles and magnitude in one (complex) number, they are very useful in things like signal processing and circuit design)
  12. 1 point
    The square root of a complex number is more easily obtained in terms of absolute value and argument. Because number i (the imaginary unit) is 190º, and the square root of a complex number is: z=rtheta z1/2=r1/2theta/2 You would have i1/2=145º I hope that helps.
  13. 1 point
    The longest known word in Finnish is ( take a deep breath) Lentokonesuihkuturbiinimoottoriapumekaanikkoaliupseerioppilas Though to be fair, this is a compound word. One of the possible reasons Finnish has so many words is the penchant for forming compound words. "black and White" is Mustavalkoinen, which is Musta(black) and valkoinen(white) pushed together into one word. Now there might be more of a reason behind this than originally appears. Remember how I said above how adjectives had to be in the same case as the Noun? If you translate "it belongs to the black cat" you get "se kuuluu mustalle kissalle" (kissa = cat) the lle denoting a change of case However, "it belongs to the white cat" translates as "se kuuluu valkoiseen kissaan", which has different case endings. So if you try to translate "it belongs to the black and white cat" using Musta ja valkoinen for "black and white", which case ending do you use? But if you use mustavalkionen as a single word, you only need to consider how it ends and "it belongs to the black and white cat" - se kuuluu mustavalkoiseen kissaan. So making a single compound word can simplify things when dealing with cases. Thus with Lentokonesuihkuturbiinimoottoriapumekaanikkoaliupseerioppilas , which translates to "airplane jet turbine engine auxiliary mechanic non-commissioned officer student" If you kept it as separate words, changing the case, As in " it belongs to the airplane jet turbine engine auxiliary mechanic non-commissioned officer student", would involve case changes for every word, rather than just making a change to the end of one word.
  14. 1 point
    Fewest. (Well, it's a discussion about words..)
  15. 1 point
    If you just want to count words should you bother with all the variations? If I know the verb "walk", I can deduce some of the variations "walks" "walked" "walker" etc I'd need to learn the use of "walk" as a noun, separately. But from that, I can deduce a plural- "walks" If I was counting the words in a language with a view to choosing one to learn, I might not need to count the words like "wugs" which I'll never need to remember because I can "create" them when needed. But do I count walk(v) separately from walk(n)? Perhaps I should. To the extent that there's a rule in English for making verbs into nouns, I should go to a walking, in the same way that I go to a meeting. It looks very much like the answer to the question "Which language has most words" is "it depends" BTW, since the title of the thread lacks a question mark, it is a statement. So what's "which language"?
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