Entries by Dale

PF’s policy on Lorentz Ether Theory and Block Universe

What is the PF’s policy on Lorentz Ether Theory and Block Universe? Debates about the superiority or “truth” of modern Lorentz Ether Theory (LET) and the Block Universe (BU) concept are outside the scope of PF because: There is little or no debate among professional physicists about these issues (as opposed to e.g. interpretations of […]

Understanding the General Relativity View of Gravity on Earth

Often students have difficulty reconciling the General Relativity (GR) view of gravity versus their own experience with gravity on the surface of Earth. This article covers some of the basic concepts and explains how they work with “everyday” gravity. Important Concepts Spacetime: the combination of 3 dimensions of space and 1 dimension of time into a unified 4D […]

What is Energy?

What is energy? For some reason, this perfectly legitimate question seems to spawn far more than its share of bad threads. So what is energy and how do conversations about what it is go wrong? Energy in Newtonian mechanics The first definition of energy that is usually encountered is “energy is the capacity of a system […]