4 ms·
A broader question that puzzles me, not specific to this phenomenon. Pulse length is often used to bound the size of a source in space (it cannot be smaller th
by cheerlessbog 6y ago
A broader question that puzzles me, not specific to this phenomenon. Pulse length is often used to bound the size of a source in space (it cannot be smaller than light takes to traverse the object). But it’s possible that two phenomena can be correlated without being close, if there is a delayed action (akin to setting two alarm clocks and separating them in space). How can we confidently use this as evidence of size?
- throwaway4220 6y ago> Pulse length is often used to bound the size of a source in space (it cannot be smaller than light takes to traverse the object). Sorry for the possibly noob question, but why is this? I can't think of an intuitive explanation
- cheerlessbog 6y agoI guess the assumption is that the phenomenon starts at a point, spreads across the object sized l at c, and lasts for only a period of time t at any location. Therefore the pulse ends after l/c + t = T. By measuring T you can put an upper bound on l. Example of this inference, from the Wikipedia on Fast Radio Bursts (but I have seen in many contexts): > The sources are thought to be a few hundred kilometers or less in size, as the bursts last for only a few milliseconds Does that make sense?
- cheerlessbog 6y agoI just realized what I described is not giving a lower bound.