I think it's a good and legitimate use of the question system to ask people to help you locate posts you can't quite remember where it is, or request posts relevant to a topic you're interested in. If there are ever "too many" such questions, I'm sure we can find a suitable way to "filter" them to be seen only in suitable places.

The posts is something about a particle moving at the speed of light and that you should continue to believe in your models even though you can't observe it any more: moving at the speed of light + expanding universe (?).