Hello, my friends, It is very close to the date of GPB data release. Everyone can say something as a prediction. After April 14, any word is no longer prediction! My prediction is here which was successfully added to my arxiv deposit: astro-ph/0605213. I wrote it within one hour. Sorry for the hurry. Your correction and suggestion are greatly appreciated. I had planned to add some words to the prediction for my sincere thanks to physorg forums fellows. But I missed them. Declaration of Flat Spacetime and Prediction on Gravity Probe B Data Article 1. Space and time are perceived and measured only by means of physical processes. The processes are usually (light) waves. Furthermore, different reference frames give different measurement of spatial distances and timing (relativity). The measuring equipment which corresponds to a reference frame is static with respect to the frame. Article 2. Measured by a reference frame, the speed of light is the highest one than the ones of all material particles. The two articles would be the principles of special relativity (SR) if we changed the word on light speed, `highest`, into `constant and highest`. However, SR does not deal with gravity. SR would be globally true if the distribution of mass in the universe were homogeneous and invariant with time. In that case, light speed were constant and the reference frames were called inertial ones. The coordinate transformations between the frames were Lorenz ones which were linear transformations of coordinates. In the real world, mass distribution is inhomogeneous and changes with time. That is, test particles no longer move in straight lines at constant speeds and we say that they suffer gravity. However, I declare that the above two articles provide the sufficient principles which describe particle motion in gravity. The declaration is called the HE declaration of flat spacetime. Its further explanation is given as follows. Article 3. Because real-world mass distribution is inhomogeneous and changes with time, global inertial reference frames do not exist. Instead we have local free-fall reference frames which are the single-body frames (moon, earth, sun, stellar frames, etc.) or the composite ones (Milky Way reference frame, etc.). Because any finite mass or inhomogeneous mass distribution presents gravitational interaction in its neighborhood and affects any measurement (physical process, e.g., light wave), such real free-fall frame (RFF) does not measure the local result given by special-relativity. That is, light speed is not constant. Instead light speed varies with time or position. But it is still maximum one. However, a man-made satellite has approximately zero mass compared to the earth one and can be considered to be zero-mass. Measured by a zero-mass free-fall frame, light speed is constant and special relativity is true with respect to the frame. Therefore, zero-mass free-fall frame (denoted by ZFF) defines rectangular Cartesian coordinates. Fortunately, any real free-fall frame of any mass or mass distribution can be imagined to be a ZFF which is the original frame but all its mass content is imagined to be removed. Because the motion of a frame in its parent gravitational field does not depend on the mass of the child frame, RFF has little difference from ZFF with respect to parent gravity. However, only ZFF provides the correct coordinate description of the self-gravity of the child frame. This is explained by my prediction on Gravity Probe B data as follows. Article 4. Gravity Probe B involves two reference frames. One is earth and the other is the satellite. In the coordinate description of earth ZFF, the earth gravitational field is Schwarzschild metric form (Lagrangian functional form). Therefore, the geodesic effect and frame-dragging effect concern the angles between the directions of the gyroscopes and the direction of earth ZFF frame. Not the one of guide star. We heard the complaint from GPB theoretical staff that the proper motion of guide star can not be accurately determined. In fact, general relativity never has a correct definition of measurement and people should ask the question, with respect to which reference frame was the Gravity Probe B data measured? My declaration of flat spacetime has no such confusion. For example, the satellite ZFF measures no variance with time of angles between the four gyroscopes inside the free-fall staellite. According to earth ZFF, however, the measured angles do vary with time. I hope future Gravity Probe C will be designed to measure the effect! Article 5. The difference between HE declaration and general relativity is easy to be seen: the former involves no definition of spacetime. Instead, it has the spatial and temporal measurement based on real mass distributions and physical processes. ZFF is important concept. Fish scales (ZFFs) are flat and form the flat fish. We have hierarchical gravitational structure but still flat. The latter (GR), however, requires all scales connect each other at some angles to form a multilateral surface (curved surface, i.e., curved spacetime). Black holes and big Bang are the results of curved spacetime assumption.