The mass of a body depends on its change in velocity." The author of this quote was most likely Albert Einstein. Although this statement is based off of one of Isaac newton’s laws, this statement is more like the general theory of gravity an in depth look at modern physics and newton’s law of universal gravity written by Albert Einstein. Einstein ( March 1879 – 18 April 1955) is considered one of the founding fathers of today’s modern physics because of his ground breaking research. Einstein treated matter and energy as exchangeable. This radical idea of thinking laid the ground work for atomic energy and is why Einstein is considered one of the brightest men ever to walk the earth. Lavoisier, Newton and Einstein relative to the study of mass "The mass of a body is its resistance to a change in motion." Sir Isaac Newton would most likely be the father of this quote because this statement is describing inertia which was discovered by Newton and is one of his three laws of motion. Sir Isaac Newton ( January 1643 – 31 March 1727) was many things; Philosopher, writer, mathematician , and even alchemist but he is most known for his three laws of motion that have become one of the most important and accepted facts about gravity and the reaction of forces on objects. Newton laid the ground work to understanding the way forces affect us, why there is weight and what causes objects to fall back to earth. Even though his laws s are around 300 years old they are still the principal for scientists around the world and without a understanding of his laws it would have been impossible for so many of today’s modern achievements such as flight and spacecraft. by nick kennedy "The mass of a body is a measure of the quantity of matter in it." This was Most likely said by Antoine Lavoisier because of its relevance and agreement with the research Lavoisier conducted. Lavoisier (August 1743 – 8 May 1794) is considered the father of modern chemistry. He discovered: matter can exists in three states (water, solid, gas), the combustion theory, and the conservation of matter along with many other things . Lavoisier was also very interested in the atom and his work with the atom and matter is why I believe he was likely to say something of this manor.