Recent content by DrToby

Does anybody have experience with using a electronic screen projector to simulate the (sunlight illuminated) outside world to image it through a small pinhole? The basic experimental setup would consist of i) a blank screen, ii) a vertical cardboard with a small hole and iii) a screen projector...

Thank you for confirmation. Nice to find people to discuss stuff with.

The Sun is orbited by another mass. The origin of a coordinate system is placed at the center of the Sun. The Sun pulls on the mass with a given force. According to Newtons third law the Sun is pulled towards the mass with an equal force. Hence the coordinate system is accelerated and hence it...

The two-body Kepler problem where the Sun is at rest in a coordinate system orbited by another body: is the coordinate system an inertial reference system or not? Please no yes/no answers. A bit of elaboration is appreciated towards why and which principles apply.

I am wondering how the eccentricity of a circumbinary (binary star system) planet is defined? To my knowledge Kepler elements, including e, are non-inertial elements. So, how is the planets eccentricity measured?