Recent content by hawkdron496

Yep, I suppose I will. Thank you for the help.

So, that strange notation occurs again, later in the paper: which makes it feel less likely that it's a typo.

From what I've been able to find online, the symbol ##\tilde{D}(S)## is the same as the usual symbol for domain of dependence, but only for timelike curves rather than any causal curve, according to this stack overflow post...

Will do: the relevant paragraph is here: The questionable notation is in the Proof section of the proposition.

I'm not clear on what it means when he takes ##\mathfrak{I}^+(q)##. Is it just the set of null rays going off to infinity that pass through q?

I'm reading Tipler's 1976 paper, "Causality Violation in Asymptotically Flat Spacetimes" and he keeps using a symbol which seems to resemble the symbol for Future Null Infinity in a strange font, but it's usage doesn't make sense with what I would expect if that's what the symbol meant. He...

I believe this clarifies things a lot, thank you for the help, I appreciate it.

Surely though if in one frame the endpoint of the worldline is ##(\tau, 0,0,0)##, in the frame transformed according to ##t' = 2t## the worldlike would end at ##(2\tau, 0,0,0)##, meaning someone using the second set of coordinates wouldn't measure proper time along the path? I think the root of...

Is what you're saying that the proper time quantity won't be equal to the coordinate time quantity in the ##t'## frame, because in the ##t'## frame you're essentially measuring time in half-units, and once you do the unit conversion it will stop being an issue? Surely though you could construct...

I understand that much. My question is more about *coordinate* time, in the sense that I can imagine constructing a coordinate system in which the observer is spacially at rest, and coordinate time = proper time. I can also imagine constructing a coordinate system in which the observer is...

In texts on General Relativity, the proper time ##d\tau^2 = -ds^2## (with an appropriate choice of metric signature) is commonly said that the time measured by a timelike observer traveling along a path is given by the integral of ##d\tau## along this path. Of course it's possible to construct a...

On pages 106-107 of Spacetime & Geometry, Carroll derives the geodesic equation by extremizing the proper time functional. He writes: What I am unclear on is the step in 3.47. I understand that the four velocity is normalized to -1 for timelike paths, but if the value of f is fixed, how can we...

i have a friend and i am trying to explain to him that until it interacts with something it is evrywhere and no where but has more of a probability in being in place a than place b or c but until it interacts we don't know so there for it is evrywhere. that is the concept as i understand it. he...