3 ms·
It's when you (for example) sweep a beam across a field. The spot of light can move really quickly, even crossing the field faster than light itself could, but
by andrewaylett 12y ago
It's when you (for example) sweep a beam across a field. The spot of light can move really quickly, even crossing the field faster than light itself could, but it's not conveying information from where it's been to where it's going. Nothing physical is moving at anything even approaching the speed of light.
- mrec 12y agoI hadn't seen "non-information" used as a way to describe that sort of thing before, but it makes a lot of sense. Avoids a whole bunch of unproductive arguments about whether something's "real" or not.
- maaaats 12y agoWow, I've never considered such a thing before. Can this be used for anything?
- Semiapies 12y agoSadly, no. Imagine an immense wall light-years wide and a light-year or so away from you. If you have a (really!) bright laser pointing at it, you can wiggle around the dot so that the dot moves at FTL speeds. But, there'll be at least a year's lag from your wiggle to the dot moving (and another year before you can see the dot move), so you can't use it for signaling faster-than-light or anything like that.
- ezpuzzle 12y agounless there's an alien with another laser pointer on the other side ;)