3 ms·

"...QFT...does not work when space-time curvature is important". Forgive the probable confusion of an ignoramus, but is there significant space-time curvature

by thyrsus 10y ago

"...QFT...does not work when space-time curvature is important". Forgive the probable confusion of an ignoramus, but is there significant space-time curvature in the vicinity of a gold atom nucleus? I ask because I remember these claims about special relativity and the gold atom: https://www.fourmilab.ch/documents/golden_glow/ https://www.fourmilab.ch/documents/golden_glow/ - of course, I could be dreadfully confusing special relativity effects with general relativity effects.

btilly 10y ago
You are indeed confusing special relativity with general relativity. Special relativity says that when things begin moving fast, they weigh more. Gold's properties are due in part to the fact that the electrons move so fast that relativistic effects alter the shape and energy of the orbitals that they stay in. That's special relativity. In order to get significant curvature you would need the amount of gravity to be created to be significant. But electromagnetism is about 10^39 times as powerful as gravity. We only notice gravity on a macro scale because positive and negative charges almost perfectly balance. However on an atomic scale, the theoretical effects of Newtonian gravity are many orders of magnitude smaller than any possible measurement error. Let alone the size of general relativistic corrections to that theory!
sampo 10y ago
You can use the Schrödinger equation in a classical, non-relativistic, space-time, do calculations and get a lot of the chemistry explained more or less correctly. There is no speed of light, and electric fields have immediate effects over long distances. But to explain the electron transitions that make gold yellow, you need to use the Schrödinger equation in a relativistic space-time. (But just special relativity suffices here, no need to go to general relativity.)

by thyrsus 10y ago

btilly 10y ago

You are indeed confusing special relativity with general relativity. Special relativity says that when things begin moving fast, they weigh more. Gold's properties are due in part to the fact that the electrons move so fast that relativistic effects alter the shape and energy of the orbitals that they stay in. That's special relativity. In order to get significant curvature you would need the amount of gravity to be created to be significant. But electromagnetism is about 10^39 times as powerful as gravity. We only notice gravity on a macro scale because positive and negative charges almost perfectly balance. However on an atomic scale, the theoretical effects of Newtonian gravity are many orders of magnitude smaller than any possible measurement error. Let alone the size of general relativistic corrections to that theory!

sampo 10y ago

You can use the Schrödinger equation in a classical, non-relativistic, space-time, do calculations and get a lot of the chemistry explained more or less correctly. There is no speed of light, and electric fields have immediate effects over long distances. But to explain the electron transitions that make gold yellow, you need to use the Schrödinger equation in a relativistic space-time. (But just special relativity suffices here, no need to go to general relativity.)