- #1

DaTario

- 1,039

- 35

Hi All,

I was just watching the video on the Veritassium channel about scientific dissemination of general relativity. And I could see once again that when you try to use animations and/or computer graphics to show the transition from free space geodesics to geodesics around a planet, what you do is simply fade out the free space geodesics (based on square cells) and apply a fade in effect to a typical geodesic system around a mass uniformly distributed in a spherical region.

My question is: Let's consider that initially we have a mass-free space geodesic system (with square or cubic cells) and we choose a point in space (let's be the origin of our coordinate system) such that at this point a small sphere will appear whose mass will grow in time smoothly from zero according to a function something like ##m(t) = (t^2)/\alpha##, where ##\alpha## is a positive real parameter. How does the transition occurs from this system of geodesics to the one which is usually shown in didactic expositions, namely, a system of geodesics that is formed by closed curves (typically circles) centered on the location of the mass?

Best wishes,

DaTario

I was just watching the video on the Veritassium channel about scientific dissemination of general relativity. And I could see once again that when you try to use animations and/or computer graphics to show the transition from free space geodesics to geodesics around a planet, what you do is simply fade out the free space geodesics (based on square cells) and apply a fade in effect to a typical geodesic system around a mass uniformly distributed in a spherical region.

My question is: Let's consider that initially we have a mass-free space geodesic system (with square or cubic cells) and we choose a point in space (let's be the origin of our coordinate system) such that at this point a small sphere will appear whose mass will grow in time smoothly from zero according to a function something like ##m(t) = (t^2)/\alpha##, where ##\alpha## is a positive real parameter. How does the transition occurs from this system of geodesics to the one which is usually shown in didactic expositions, namely, a system of geodesics that is formed by closed curves (typically circles) centered on the location of the mass?

Best wishes,

DaTario

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