Recent content by alkmini

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    Undergrad Example to make clear the difference between specific intensity and fl

    thank you
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    Undergrad Example to make clear the difference between specific intensity and fl

    hello I amm trying to understand the difference between flux and specific intensity of radiation. I understand that one is dependent on distance the other is not, but can you make it more tangible with an example?
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    Graduate Measurment that proves that the universe is flat

    well, maby it is not a proof, but this in not what i am looking for. I am just trying to understand the thought, the logic, behind what may , or may not be a proof. the insight is interesting
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    Graduate Measurment that proves that the universe is flat

    http://scienceblogs.com/startswithabang/2012/07/18/how-big-is-the-entire-universe/
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    Graduate Measurment that proves that the universe is flat

    i don't understand why the angular size of temperature fluctuations should be 1 degree to prove that it is flat
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    Graduate Measurment that proves that the universe is flat

    the foolowing are 2 other links that say the same thing . http://www.einstein-online.info/spotlights/cosmic_sound/?searchterm=angular%20size i don't understand why it is a proof and i don't understand why it is not a proof either
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    Graduate Measurment that proves that the universe is flat

    thank you for your reply mathman when we measure the apparent size of temperature fluctuations, in order to determine the curvature of the universe, is the measurement local or global ?
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    Graduate Are rays from opposite sides of a hot spot of CMB parallel or not?

    thank you both Noel and Torquil for your explanations. they helped
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    Graduate Are rays from opposite sides of a hot spot of CMB parallel or not?

    do you can consider the ENTIRE space between the spot and the eye as a mirror?
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    Graduate Are rays from opposite sides of a hot spot of CMB parallel or not?

    thank you so much Noel I understand the similarity with the mirrors but isn't it true that rays coming from a distant object are parallel?
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    Graduate Measurment that proves that the universe is flat

    hello I have a question: i am trying to understand how we find out that the curvature of the universe is zero using the angular size of the hot spots of the d microwave background radiation. http://scienceblogs.com/startswithab...tire-universe/ there is a picture in this blog showing the...
    • alkmini
    • Thread
    • Flat Measurment Universe
    • Replies: 8
    • Forum: Cosmology
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    Graduate Are rays from opposite sides of a hot spot of CMB parallel or not?

    hello I have a question: i am trying to understand how we find out that the curvature of the universe is zero using the angular size of the hot spots of the d microwave background radiation. http://scienceblogs.com/startswithabang/2012/07/18/how-big-is-the-entire-universe/ there is a...
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    Relationship between potential and induced emf?

    i know the thread is old but i have a question what shall we take as a length to calculate E, the length πr of the arc or the length 2r of the line segment and why? thanks a lot
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    Free fall of straight wire in a homogeneous magnetic field

    thanks a lot
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    Free fall of straight wire in a homogeneous magnetic field

    hello every body. I have a high school problem a straight horizontal wire is falling freely in a homogeneous horizontal magnetic field, perpendicular to the wire and i want to find the inductive voltage. I said E= Blv=Blgt But I can also say E=ΔΦ/Δt=BΔΑ/Δt=Βl1/2gt [t][2]/Δt=1/2Blgt why...