Many derivations of mercury precession angle per orbit [tex]\Delta[/tex][tex]\Phi[/tex], equate this to extra angle per orbit [tex]\delta[/tex] in excess of [tex]2\pi[/tex](adsbygoogle = window.adsbygoogle || []).push({});

that is [tex]\delta[/tex] = [tex]\Delta[/tex][tex]\Phi[/tex]

But I am getting this relation

[tex]\sqrt{4\pi\delta}[/tex]= [tex]\Delta[/tex][tex]\Phi[/tex]

from arc length of helix and circular orbit.

What am I doing wrong?

What is the intution for above approximation? Shouldn't the total angle be less than [tex]2\pi[/tex] + [tex]\Delta[/tex][tex]\Phi[/tex]

because planet takes short cut [analagous to hypotenuse length being less than sum of other two sides]

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# Precession angle per orbit of perhelion precession mercury

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