Those quack homeopathy treatments operate on the assumption that water has a "memory", and it's somehow enough that it's been in contact with some molecule in the past. The astronomy version would be that space has a memory, and you can observe anything if you know there was a relevant photon out there at some point.
Those quack homeopathy treatments operate on the assumption that water has a "memory", and it's somehow enough that it's been in contact with some molecule in the past. The astronomy version would be that space has a memory, and you can observe anything if you know there was a relevant photon out there at some point.