Albert Einstein Autographed Signed Equation.

Albert Einstein signature with a hand-written equation, double matted and framed, with a photograph of Einstein. The equation was first published in the Annus mirabilis papers (from Latin annus mīrābilis, "extraordinary year" or "miracle year"), which are the papers of Albert Einstein published in the Annalen der Physik scientific journal in 1905. These four articles contributed substantially to the foundation of modern physics and changed views on space, time, mass, and energy. The first of these papers was titled "On a Heuristic Viewpoint Concerning the Production and Transformation of Light" and proposed the idea of energy quanta. The second, "On the Motion of Small Particles Suspended in a Stationary Liquid, as Required by the Molecular Kinetic Theory of Heat," delineated a stochastic model of Brownian Motion.  The third was "On the Electrodynamics of Moving Bodies" (later known as Einstein's special theory of relativity), and the fourth, which this particular equation comes from, was entitled "Does the Inertia of a Body Depend Upon its Energy-Content", in which it is said that Einstein also deduced the most famous of all equations: E = mc². Interestingly, Einstein never actually wrote this actual equation in any of his papers. What he wrote is “If a body gives off the energy L in the form of radiation, its mass diminishes by L/c2… the mass of a body is a measure of its energy-content”, which is  just another way to say the same thing. The following is an excerpt from the paper with regard to the equation shown here: Let there be a stationary body in the system (x, y, z), and let its energy— referred to the system (x, y, z) be E0. Let the energy of the body relative to the system (ξ, η, ζ) moving as above with the velocity v, be H0. Let this body send out, in a direction making an angle φ with the axis of x, plane waves of light, of energy 1/2 L measured relatively to (x, y, z), and simultaneously an equal quantity of light in the opposite direction. Meanwhile the body remains at rest with respect to the system (x, y, z). The principle of energy must apply to this process, and in fact (by the principle of relativity) with respect to both systems of co-ordinates. If we call the energy of the body after the emission of light E1 or H1 respectively, measured relatively to the system (x, y, z) or (ξ, η, ζ) respectively, then by employing the relation given above we obtain (the equation pictured). The entire piece measures 14 inches by 18.5 inches. A wonderful and unique piece of history, particularly in regards to this very famous paper.