Is this a realistic possibility then I'm still confused. How do trapped surfaces differ from event horizons? Is there some intuitive way of defining the two?
Ok thank you for that. What about Tipler's claim then. Does it make sense?
Can an event horizon be thought of as a weak form of a trapped surface which disappears if the universe ends in a c-boundary which is a single point?
Can anyone please explain to me in simple terms what the difference is between a trapped surface and an event horizon. I'm not familiar with global general relativity so cannot understand any of the results I've looked up by googling. I think that Tipler has said that when the future C-boundary...
The entropy of sub systems is additive so the overall entropy of the universe must be greater than zero. This must be equal to T dS hence dS of the whole universe must be positive not zero?
Ok Ryden has for section 4.2 THE FLUID AND ACCELERATION EQUATIONS she derives the fluid equation first then uses the ist F'man equation to get the 2nd accn eqn. I call the fluid equation the continuity equation.