(On the Relativity Principle and the Conclusions Drawn from It), Elektromagnetische Grundgleichungen für bewegte Körper
(On the Fundamental Electromagnetic Equations for Moving Bodies), Principe de relativité et ses conséquences dans la physique moderne
(The Principle of Relativity and Its Consequences in Modern Physics), Einfluss der Schwerkraft auf die Ausbreitung des LichtesÂ
(On the Influence of Gravitation on the Propagation of Light), Entwurf einer verallgemeinerten Relativitätstheorie und eine Theorie der Gravitation. I. Physikalischer Teil von A. Einstein II. Mathematischer Teil von M. Grossmann
(Outline of a Generalized Theory of Relativity and of a Theory of Gravitation. I. Physical Part by A. Einstein II. Mathematical Part by M. Grossmann), Kovarianzeigenschaften der Feldgleichungen der auf die verallgemeinerte Relativitätstheorie gegründeten Gravitationstheorie
(Covariance Properties of the Field Equations of the Theory of Gravitation Based on the Generalized Theory of Relativity), Zur allgemeinen Relativitätstheorie (On the General Theory of Relativity), Erklärung der Perihelbewegung des Merkur aus der allgemeinen Relativitätstheorie
(Explanation of the Perihelion Motion of Mercury from the General Theory of Relativity) and Feldgleichungen der Gravitation
(The Field Equations of Gravitation).
Isaac Newton proposed the the famous theory of ” attractive force emanating from object (masses) with a given radius exudes a pull/force towards surrounding objects”. This principle governs the earth’s orbits around the sun, the moon orbit around the earth. The famous science tale  of an apple falling to the ground; is explained as the earth’s attractive pull towards the apple. In a Newtonian world, heavenly bodies are supposed to move uniformly at a straight lines at constant speed or uniform acceleration  (two dimensional flat geometry in an inertial reference frame). Newton postulated that the force of gravity explains the departure  from the law of inertia in all reference frames; where the deviations from the straight line path into a curved path of accelerated motion of planets are due to the gravitational influence form the Sun. Newton’s gravity skeptics has raised issues on this theory that includes the source power of gravity, the speed of gravity (assumed to be greater than the speed of light from Newton’s equations), the world exists in a four dimensional geometry rather two dimensional geometry, and the diminishing/increasing strength of gravity . I don’t want to get into the specific on the issues with “gravity” but this are lingering problems that arises from the the theory. Irregardless, the scientific society has acknowledge that the ” newton theory” as the only explicable and acceptable explanation to planetary motion at his time until………
    Einstein in actuality also contributed a different reasoning towards the “incomplete physical explanation of gravity”. Einstein was perplexed with Newton’s theory because of this unexplained source of gravity. Einstein in his “General theory of Relativity” proposed that space is malleable and that time and space were part of a four-dimensional system. The Sun (largest matter in our planetary system) distort the fabric of space-time continuum or fabric causing what physicists call space-time curvature forming a tunnel/funnel shaped center of the solar system . This curvature affects the motion and cosmic distribution of other masses: in other words, it is what Newton thought was “force of gravity” and we perceive as “gravity “. This curvature solves the disparity between inertial reference frame and accelerated frame. Therefore in a uniform inertia of flat geometry is no different from a curved path in an accelerated reference frame. In essence the law of inertia  is conserved in all reference frames and depends in the geometry of the reference frame at which the motion is observed.  Planets follow the contours of the space-time curvature (created by the sun’s influence on the space time fabric) and it depends on the observer who might see it as a straight line inertial reference frame or accelerated reference frame of a curved path.  This curvature creates the foundation of a four dimensional geometry wherein we can observe the difference between flatness and curvature of space using Riemann (non-Euclidean) geometrical properties of a sphere.  Einstein theory also states “speed of gravity” is equal to speed of light because gravity’s speed is not instantaneous; so any changes to the gravitational field at the sun will take a little time before the earth experiences it. This speed of light governs the essence of special relativity and on a larger scale, General relativity. Although the space-time continuum has not be observed and measured but the consequences of space-time curvature has been confirmed including gravitational lensing, Mercury gradual orbital change,  gravitational redshifitng, gravitational waves and localized space-time distortion by the rotating Earth.
Einstein therefore trounces Issac Newton………..
Comment-Einstein view is kind of hard to wrap your head around, very abstract but also very accurate .
The problem with measuring undetectable gravity is that the instrumentation, methodology, principles used are based on previous ideologies (Newton and Kepler) that constricts the results to an agreeable conclusion with existing theories therefore lacking a “new perspective of gravity and ingenuity”. Simply the experiments are redundant and not ground-breaking.
P.s. -“Don’t blame gravity for falling in love”-Albert Einstein
💡Cosmic Frame>>>∞ and beyond💡 