Can an observer really catch up with light?

ar X iv : g r - qc / 0 21 10 10 v 1 3 N ov 2 00 2 Can an observer really catch up with light ? ∗

Given a null geodesic γ0(λ) with a point r in (p, q) conjugate to p along γ0(λ) , there will be a variation of γ0(λ) which will give a time-like curve from p to q. This is a well-known theory proved in the famous book[3]. In the paper we prove that the timelike curves coming from the above-mentioned variation have a proper acceleration which approaches infinity as the time-like curve approaches...

How can reporting catch up with an accelerating world?

Runaway TB epidemic--can we catch up?

Can we ever catch up with the Web?

The Semantic Web is about to grow up. By efforts such as the Linking Open Data initiative, we finally find ourselves at the edge of a Web of Data becoming reality. Standards such as OWL 2, RIF and SPARQL 1.1 shall allow us to reason with and ask complex structured queries on this data, but still they do not play together smoothly and robustly enough to cope with huge amounts of noisy Web data. ...

Playing Catch-up with Iterated Exponentials

Suppose that we have two animals that make the same number of strides per minute, but one of them makes larger strides than the other. If the strides of the smaller animal (the prey) have length a, and those of the larger animal (the predator) have length b, it is easy to see that a persistent predator will always be able to catch up with its prey. Let us assume that the prey starts one step ah...