Deriving GR from maximum power

bcrowell
Staff Emeritus
Science Advisor
Insights Author
Messages
6,723
Reaction score
431
MTW has a cute argument on p. 980 that the maximum power radiated from any system is a fixed number, about 10^53 W. I came across this and filed it away as a piece of cool trivia. But it turns out that apparently you can derive the GR field equations from nothing more than the assumption that there is a maximum power across any surface:

Jacobson, "Thermodynamics of spacetime: the Einstein equation of state," PRL 75 (1995) 1260, http://arxiv.org/abs/gr-qc/9504004

C. Schiller has made an attempt to present this at a lower mathematical level in Motion Mountain, v. II, ch. 4: http://motionmountain.net/

Schiller's treatment, unforunately, seems to veer wildly between different levels of sophistication, and I wasn't able to make much of it.
 
Physics news on Phys.org
That's really cool.
 
Related: Padmanabhan, Gravity: The Inside Story, http://www.gravityresearchfoundation.org/pdf/awarded/2008/Padmanabhan_2008.pdf
 
Last edited by a moderator:
Thread 'Can this experiment break Lorentz symmetry?'

Thread 'Can this experiment break Lorentz symmetry?'

1. The Big Idea: According to Einstein’s relativity, all motion is relative. You can’t tell if you’re moving at a constant velocity without looking outside. But what if there is a universal “rest frame” (like the old idea of the “ether”)? This experiment tries to find out by looking for tiny, directional differences in how objects move inside a sealed box. 2. How It Works: The Two-Stage Process Imagine a perfectly isolated spacecraft (our lab) moving through space at some unknown speed V...
View full post »

Thread 'Relativator (Circular Slide-Rule): Simulated with Desmos - Insight'

Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. The Relativator was sold by (as printed) Atomic Laboratories, Inc. 3086 Claremont Ave, Berkeley 5, California , which seems to be a division of Cenco Instruments (Central Scientific Company)... Source: https://www.physicsforums.com/insights/relativator-circular-slide-rule-simulated-with-desmos/ by @robphy
View full post »

Thread 'A sufficient condition for integrability of equation ##\nabla g=0##'

In Philippe G. Ciarlet's book 'An introduction to differential geometry', He gives the integrability conditions of the differential equations like this: $$ \partial_{i} F_{lj}=L^p_{ij} F_{lp},\,\,\,F_{ij}(x_0)=F^0_{ij}. $$ The integrability conditions for the existence of a global solution ##F_{lj}## is: $$ R^i_{jkl}\equiv\partial_k L^i_{jl}-\partial_l L^i_{jk}+L^h_{jl} L^i_{hk}-L^h_{jk} L^i_{hl}=0 $$ Then from the equation: $$\nabla_b e_a= \Gamma^c_{ab} e_c$$ Using cartesian basis ## e_I...
View full post »

Similar threads

CHR&R answer 20year Jacobson question (GR foundations+Thermo)
Replies
18
Views
9K
Einstein Equation of State vs Gravity from Entanglement
Replies
6
Views
4K

Hot Threads

Recent Insights

Back
Top