> This theory has it that all types of energy—including matter, radiation, and pressure—curve space, and the curvature in return influences how the energy-types move. The authors of the new paper, led by Antonia Seifert, don’t question this. They question instead how we use Einstein’s math.<p>This is so fascinating. I think the principle applies to so much of the natural sciences. GR describes a set of rules (differential equations using tensors) that describe how matter moves in spacetime, and how it curves it. But outside of certain specific conditions (Schwarzschild etc), we can't (yet) use it to build useful models! We can use it to an extent to validate parts of models, but it leaves so much to the <i>imagination</i>. We are still using Newtonian models in cosmology, then applying <i>GR effects</i> like GEM piecemeal, and the time dilation effects in the article, where complexity and understanding allow.<p>We have these rules, but don't know how to use them to model! See also: Quantum mechanics and ab-initio chemistry. It's as if the universe is written in differential equations, but we are novices at how to use them.