Recent content by AleksanderPhy

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    B Quantum field theory VS Quantum mechanics

    Thanks for such great awnser!
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    B Quantum field theory VS Quantum mechanics

    Hello I am little bit confused about one topic on theoretical Physics and that is If we want to describe our Quantum world (example atoms in metal) then should I use Quantum field theory or Quantum mechanics?
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    I Quasars: What Metric Should You Use?

    Hello I just got interested into quasars and I have a question:What metric do you use for quasars?
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    I Geodesic Equation: Lagrange Approximation Solution for Schwarzschild Metric

    Hello so if we have geodesic equation lagrange approximation solution: d/ds(mgμνdxν/ds)=m∂gμν∂xλdxμ/ds dxν/ds. So if we have schwarzschild metric (wich could be used to describe example sun) which is:ds2=(1-rs/r)dt2-(1-rs/r)-1dr2-r2[/SUP]-sin22. But that means that ∂gμν/∂xλ=0. So that means that...
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    B How Does Time Dilation Influence Perceived Velocity?

    Hello I have a question about how time effects velocity:So we have a car on Earth traveling 200m with 5 seconds we get that car moves 40m/s and 40x3600=144000 and 144000:1000=144km/h so car on Earth travels 144km/h now let's consider a that there is observer on spacecraft traveling 0.5c...
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    B Euler-Lagrange equation for calculating geodesics

    But why do you take s instead of τ?
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    B Euler-Lagrange equation for calculating geodesics

    Hello I am little bit confused about lagrange approximation to geodesic equation: So we have lagrange equal to L=gμνd/dxμd/dxν And we have Euler-Lagrange equation:∂L/∂xμ-d/dt ∂/∂x(dot)μ=0 And x(dot)μ=dxμ/dτ. How do I find the value of x(dot)μ?
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    I Ricci tensor for Schwarzschild metric

    Hello I am little bit confused about calculating Ricci tensor for schwarzschild metric: So we have Ricci flow equation,∂tgμν=-2Rμν. And we have metric tensor for schwarzschild metric: Diag((1-rs/r),(1-rs]/r)-1,(r2),(sin2Θ) and ∂tgμν=0 so 0=-2Rμν and we get that Rμν=0.But Rμν should not equal to...
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    I Solving Geodesic Equations with Killing Vectors: Is There a General Solution?

    Hello I am concered about way of solving geodesic equation. Is there a general solution to geodesic equation? How to calculate the Cristoffel symbol at the right side of the equation? Thanks for helping me out!
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    I What is the Meaning of δ in δΓ?

    Many thanks I thought so that it was Kronecker delta
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    I What is the Meaning of δ in δΓ?

    Hello I have seen this symbol in many equations it looks like this:δΓ. I know that Γ means (that is Cristoffel symbol) but I don't know what δ means. Does anybody know?
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    Other Writing lectures about physics (equation editing software)

    Hello I don't know is it right place to ask this question but does anyone know a writing program that allows to write Equations?
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    B Schwarzschild Metric: Non-Rotating Black Holes & Examples

    Is it too much to ask but can somebody give me link about calculating the trajectory of object falling into a black hole or give me an example how to calculate a trajectory of a object that falls into a black hole?
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