[wyager]

He’s referring to the fact that if you sweep a laser pointer across the moon, the dot can easily move faster than light. This is not proscribed by physics, nor are similar phenomena like the phase velocity of a wave exceeding the speed of light. None of these things allow you to transmit information faster than light.

[cb321]

Another fun example besides projections like laser pointers or the spot of a searchlight on the clouds is the junction between blades of scissors. Almost all the examples one sees of this relate to synchronization defined entities not being physical objects. In my experience explaining this, the larger scale of the searchlight on the clouds seems to help people "get it".

[lupire]

To really kill the illusion, imagine a long line of people, doing "The Wave". The wave can move arbitrarily fast as the delay between people decreases, and even infine speed! (everyone does their part at the same time, assuming they have synced clocks and aren't dependent on their neighbor for the trigger, which is the key feature of the faster-than-light illusion.)

[cb321]

That's also a good one! ..Basically a sub-example of "phase velocity" mentioned in the greatgrandparent. Imagining oneself as an active participant in The Wave seems like it would boost saliency a lot. I'll try that one next time. :)