To: Dan Ceppa 13-Aug-93 12:44am Subject: finding patterns DC+gt;No, it only equals that in

Master Index Current Directory Index Go to SkepticTank Go to Human Rights activist Keith Henson Go to Scientology cult

Skeptic Tank!

From: Kelsey Bjarnason To: Dan Ceppa 13-Aug-93 12:44am Subject: finding patterns DC>No, it only equals that in Newtownian physics. Relativity and DC>Quantum physics uses other theory, and changes the mass, based on DC>the basic formula, E=MC^2. No, they use another theory and keep mass the same: As stated above, massless particles all travel at c. As to other attributes of particles, the presence of charge requires that there be mass, because of the potential energy of the field (this being energy of the system, independent of the motion - thus it contributes to the total mass of the system as m = E/c^2). Early in this century some thought that _all_ of the mass of the electron might be electromagnetic in origin - and they had formulas (based on different assumptions as to the shape and structure of the electron), such as E= 3/4 * mc^2 (which is my favorite). But Henri Poincare was able to show that these were not sufficient, for you would also need an additional force to hold this semi-mechanical model together. When Einstein derived E=mc^2 it became clear that mass is more of a relationship between the energy and momentum of a (closed) system. The complete Einstein equation is E^2/c^2 = p^2 + m^2 * c^2, which I think I mentioned in the other post. And yes, p (momentum) is a vector; it is a three-dimensional vector, which forms part of the four vector: (E/c, px, py, pz). It is the _length_ of this so-called 4-momentum which gives the mass (and the rest energy). As a good vector, it has the same length for all inertial observers, and hence is a "Lorentz invariant". Stolen freely from Peter Diehr to Mark Lambert on the Science echo.


E-Mail Fredric L. Rice / The Skeptic Tank